Annotation of gcc/emit-rtl.c, revision 1.1.1.4

1.1       root        1: /* Emit RTL for the GNU C-Compiler expander.
                      2:    Copyright (C) 1987, 1988, 1992 Free Software Foundation, Inc.
                      3: 
                      4: This file is part of GNU CC.
                      5: 
                      6: GNU CC is free software; you can redistribute it and/or modify
                      7: it under the terms of the GNU General Public License as published by
                      8: the Free Software Foundation; either version 2, or (at your option)
                      9: any later version.
                     10: 
                     11: GNU CC is distributed in the hope that it will be useful,
                     12: but WITHOUT ANY WARRANTY; without even the implied warranty of
                     13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     14: GNU General Public License for more details.
                     15: 
                     16: You should have received a copy of the GNU General Public License
                     17: along with GNU CC; see the file COPYING.  If not, write to
                     18: the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
                     19: 
                     20: 
                     21: /* Middle-to-low level generation of rtx code and insns.
                     22: 
                     23:    This file contains the functions `gen_rtx', `gen_reg_rtx'
                     24:    and `gen_label_rtx' that are the usual ways of creating rtl
                     25:    expressions for most purposes.
                     26: 
                     27:    It also has the functions for creating insns and linking
                     28:    them in the doubly-linked chain.
                     29: 
                     30:    The patterns of the insns are created by machine-dependent
                     31:    routines in insn-emit.c, which is generated automatically from
                     32:    the machine description.  These routines use `gen_rtx' to make
                     33:    the individual rtx's of the pattern; what is machine dependent
                     34:    is the kind of rtx's they make and what arguments they use.  */
                     35: 
                     36: #include "config.h"
                     37: #include "gvarargs.h"
                     38: #include "rtl.h"
                     39: #include "flags.h"
                     40: #include "function.h"
                     41: #include "expr.h"
                     42: #include "regs.h"
                     43: #include "insn-config.h"
                     44: #include "real.h"
1.1.1.4 ! root       45: #include <stdio.h>
1.1       root       46: 
                     47: /* This is reset to LAST_VIRTUAL_REGISTER + 1 at the start of each function.
                     48:    After rtl generation, it is 1 plus the largest register number used.  */
                     49: 
                     50: int reg_rtx_no = LAST_VIRTUAL_REGISTER + 1;
                     51: 
                     52: /* This is *not* reset after each function.  It gives each CODE_LABEL
                     53:    in the entire compilation a unique label number.  */
                     54: 
                     55: static int label_num = 1;
                     56: 
                     57: /* Lowest label number in current function.  */
                     58: 
                     59: static int first_label_num;
                     60: 
                     61: /* Highest label number in current function.
                     62:    Zero means use the value of label_num instead.
                     63:    This is nonzero only when belatedly compiling an inline function.  */
                     64: 
                     65: static int last_label_num;
                     66: 
                     67: /* Value label_num had when set_new_first_and_last_label_number was called.
                     68:    If label_num has not changed since then, last_label_num is valid.  */
                     69: 
                     70: static int base_label_num;
                     71: 
                     72: /* Nonzero means do not generate NOTEs for source line numbers.  */
                     73: 
                     74: static int no_line_numbers;
                     75: 
                     76: /* Commonly used rtx's, so that we only need space for one copy.
                     77:    These are initialized once for the entire compilation.
                     78:    All of these except perhaps the floating-point CONST_DOUBLEs
                     79:    are unique; no other rtx-object will be equal to any of these.  */
                     80: 
                     81: rtx pc_rtx;                    /* (PC) */
                     82: rtx cc0_rtx;                   /* (CC0) */
                     83: rtx cc1_rtx;                   /* (CC1) (not actually used nowadays) */
                     84: rtx const0_rtx;                        /* (CONST_INT 0) */
                     85: rtx const1_rtx;                        /* (CONST_INT 1) */
                     86: rtx const2_rtx;                        /* (CONST_INT 2) */
                     87: rtx constm1_rtx;               /* (CONST_INT -1) */
                     88: rtx const_true_rtx;            /* (CONST_INT STORE_FLAG_VALUE) */
                     89: 
                     90: /* We record floating-point CONST_DOUBLEs in each floating-point mode for
                     91:    the values of 0, 1, and 2.  For the integer entries and VOIDmode, we
                     92:    record a copy of const[012]_rtx.  */
                     93: 
                     94: rtx const_tiny_rtx[3][(int) MAX_MACHINE_MODE];
                     95: 
                     96: REAL_VALUE_TYPE dconst0;
                     97: REAL_VALUE_TYPE dconst1;
                     98: REAL_VALUE_TYPE dconst2;
                     99: REAL_VALUE_TYPE dconstm1;
                    100: 
                    101: /* All references to the following fixed hard registers go through
                    102:    these unique rtl objects.  On machines where the frame-pointer and
                    103:    arg-pointer are the same register, they use the same unique object.
                    104: 
                    105:    After register allocation, other rtl objects which used to be pseudo-regs
                    106:    may be clobbered to refer to the frame-pointer register.
                    107:    But references that were originally to the frame-pointer can be
                    108:    distinguished from the others because they contain frame_pointer_rtx.
                    109: 
                    110:    In an inline procedure, the stack and frame pointer rtxs may not be
                    111:    used for anything else.  */
                    112: rtx stack_pointer_rtx;         /* (REG:Pmode STACK_POINTER_REGNUM) */
                    113: rtx frame_pointer_rtx;         /* (REG:Pmode FRAME_POINTER_REGNUM) */
                    114: rtx arg_pointer_rtx;           /* (REG:Pmode ARG_POINTER_REGNUM) */
                    115: rtx struct_value_rtx;          /* (REG:Pmode STRUCT_VALUE_REGNUM) */
                    116: rtx struct_value_incoming_rtx; /* (REG:Pmode STRUCT_VALUE_INCOMING_REGNUM) */
                    117: rtx static_chain_rtx;          /* (REG:Pmode STATIC_CHAIN_REGNUM) */
                    118: rtx static_chain_incoming_rtx; /* (REG:Pmode STATIC_CHAIN_INCOMING_REGNUM) */
                    119: rtx pic_offset_table_rtx;      /* (REG:Pmode PIC_OFFSET_TABLE_REGNUM) */
                    120: 
                    121: rtx virtual_incoming_args_rtx; /* (REG:Pmode VIRTUAL_INCOMING_ARGS_REGNUM) */
                    122: rtx virtual_stack_vars_rtx;    /* (REG:Pmode VIRTUAL_STACK_VARS_REGNUM) */
                    123: rtx virtual_stack_dynamic_rtx; /* (REG:Pmode VIRTUAL_STACK_DYNAMIC_REGNUM) */
                    124: rtx virtual_outgoing_args_rtx; /* (REG:Pmode VIRTUAL_OUTGOING_ARGS_REGNUM) */
                    125: 
                    126: /* We make one copy of (const_int C) where C is in
                    127:    [- MAX_SAVED_CONST_INT, MAX_SAVED_CONST_INT]
                    128:    to save space during the compilation and simplify comparisons of
                    129:    integers.  */
                    130: 
                    131: #define MAX_SAVED_CONST_INT 64
                    132: 
                    133: static rtx const_int_rtx[MAX_SAVED_CONST_INT * 2 + 1];
                    134: 
                    135: /* The ends of the doubly-linked chain of rtl for the current function.
                    136:    Both are reset to null at the start of rtl generation for the function.
                    137:    
                    138:    start_sequence saves both of these on `sequence_stack' and then
                    139:    starts a new, nested sequence of insns.  */
                    140: 
                    141: static rtx first_insn = NULL;
                    142: static rtx last_insn = NULL;
                    143: 
                    144: /* INSN_UID for next insn emitted.
                    145:    Reset to 1 for each function compiled.  */
                    146: 
                    147: static int cur_insn_uid = 1;
                    148: 
                    149: /* Line number and source file of the last line-number NOTE emitted.
                    150:    This is used to avoid generating duplicates.  */
                    151: 
                    152: static int last_linenum = 0;
                    153: static char *last_filename = 0;
                    154: 
                    155: /* A vector indexed by pseudo reg number.  The allocated length
                    156:    of this vector is regno_pointer_flag_length.  Since this
                    157:    vector is needed during the expansion phase when the total
                    158:    number of registers in the function is not yet known,
                    159:    it is copied and made bigger when necessary.  */
                    160: 
                    161: char *regno_pointer_flag;
                    162: int regno_pointer_flag_length;
                    163: 
                    164: /* Indexed by pseudo register number, gives the rtx for that pseudo.
                    165:    Allocated in parallel with regno_pointer_flag.  */
                    166: 
                    167: rtx *regno_reg_rtx;
                    168: 
                    169: /* Stack of pending (incomplete) sequences saved by `start_sequence'.
                    170:    Each element describes one pending sequence.
                    171:    The main insn-chain is saved in the last element of the chain,
                    172:    unless the chain is empty.  */
                    173: 
                    174: struct sequence_stack *sequence_stack;
                    175: 
                    176: /* start_sequence and gen_sequence can make a lot of rtx expressions which are
                    177:    shortly thrown away.  We use two mechanisms to prevent this waste:
                    178: 
                    179:    First, we keep a list of the expressions used to represent the sequence
                    180:    stack in sequence_element_free_list.
                    181: 
                    182:    Second, for sizes up to 5 elements, we keep a SEQUENCE and its associated
                    183:    rtvec for use by gen_sequence.  One entry for each size is sufficient
                    184:    because most cases are calls to gen_sequence followed by immediately
                    185:    emitting the SEQUENCE.  Reuse is safe since emitting a sequence is
                    186:    destructive on the insn in it anyway and hence can't be redone.
                    187: 
                    188:    We do not bother to save this cached data over nested function calls.
                    189:    Instead, we just reinitialize them.  */
                    190: 
                    191: #define SEQUENCE_RESULT_SIZE 5
                    192: 
                    193: static struct sequence_stack *sequence_element_free_list;
                    194: static rtx sequence_result[SEQUENCE_RESULT_SIZE];
                    195: 
                    196: extern int rtx_equal_function_value_matters;
                    197: 
                    198: /* Filename and line number of last line-number note,
                    199:    whether we actually emitted it or not.  */
                    200: extern char *emit_filename;
                    201: extern int emit_lineno;
                    202: 
                    203: rtx change_address ();
                    204: void init_emit ();
                    205: 
                    206: /* rtx gen_rtx (code, mode, [element1, ..., elementn])
                    207: **
                    208: **         This routine generates an RTX of the size specified by
                    209: **     <code>, which is an RTX code.   The RTX structure is initialized
                    210: **     from the arguments <element1> through <elementn>, which are
                    211: **     interpreted according to the specific RTX type's format.   The
                    212: **     special machine mode associated with the rtx (if any) is specified
                    213: **     in <mode>.
                    214: **
                    215: **         gen_rtx() can be invoked in a way which resembles the lisp-like
                    216: **     rtx it will generate.   For example, the following rtx structure:
                    217: **
                    218: **           (plus:QI (mem:QI (reg:SI 1))
                    219: **                    (mem:QI (plusw:SI (reg:SI 2) (reg:SI 3))))
                    220: **
                    221: **             ...would be generated by the following C code:
                    222: **
                    223: **             gen_rtx (PLUS, QImode,
                    224: **                 gen_rtx (MEM, QImode,
                    225: **                     gen_rtx (REG, SImode, 1)),
                    226: **                 gen_rtx (MEM, QImode,
                    227: **                     gen_rtx (PLUS, SImode,
                    228: **                         gen_rtx (REG, SImode, 2),
                    229: **                         gen_rtx (REG, SImode, 3)))),
                    230: */
                    231: 
                    232: /*VARARGS2*/
                    233: rtx
                    234: gen_rtx (va_alist)
                    235:      va_dcl
                    236: {
                    237:   va_list p;
                    238:   enum rtx_code code;
                    239:   enum machine_mode mode;
                    240:   register int i;              /* Array indices...                     */
                    241:   register char *fmt;          /* Current rtx's format...              */
                    242:   register rtx rt_val;         /* RTX to return to caller...           */
                    243: 
                    244:   va_start (p);
                    245:   code = va_arg (p, enum rtx_code);
                    246:   mode = va_arg (p, enum machine_mode);
                    247: 
                    248:   if (code == CONST_INT)
                    249:     {
1.1.1.4 ! root      250:       HOST_WIDE_INT arg = va_arg (p, HOST_WIDE_INT);
1.1       root      251: 
                    252:       if (arg >= - MAX_SAVED_CONST_INT && arg <= MAX_SAVED_CONST_INT)
                    253:        return const_int_rtx[arg + MAX_SAVED_CONST_INT];
                    254: 
                    255:       if (const_true_rtx && arg == STORE_FLAG_VALUE)
                    256:        return const_true_rtx;
                    257: 
                    258:       rt_val = rtx_alloc (code);
                    259:       INTVAL (rt_val) = arg;
                    260:     }
                    261:   else if (code == REG)
                    262:     {
                    263:       int regno = va_arg (p, int);
                    264: 
                    265:       /* In case the MD file explicitly references the frame pointer, have
                    266:         all such references point to the same frame pointer.  This is used
                    267:         during frame pointer elimination to distinguish the explicit
1.1.1.2   root      268:         references to these registers from pseudos that happened to be
1.1       root      269:         assigned to them.
                    270: 
                    271:         If we have eliminated the frame pointer or arg pointer, we will
                    272:         be using it as a normal register, for example as a spill register.
                    273:         In such cases, we might be accessing it in a mode that is not
1.1.1.4 ! root      274:         Pmode and therefore cannot use the pre-allocated rtx.
1.1       root      275: 
1.1.1.4 ! root      276:         Also don't do this when we are making new REGs in reload,
        !           277:         since we don't want to get confused with the real pointers.  */
        !           278: 
        !           279:       if (frame_pointer_rtx && regno == FRAME_POINTER_REGNUM && mode == Pmode
        !           280:          && ! reload_in_progress)
1.1       root      281:        return frame_pointer_rtx;
                    282: #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
1.1.1.4 ! root      283:       if (arg_pointer_rtx && regno == ARG_POINTER_REGNUM && mode == Pmode
        !           284:          && ! reload_in_progress)
1.1       root      285:        return arg_pointer_rtx;
                    286: #endif
1.1.1.4 ! root      287:       if (stack_pointer_rtx && regno == STACK_POINTER_REGNUM && mode == Pmode
        !           288:          && ! reload_in_progress)
1.1       root      289:        return stack_pointer_rtx;
                    290:       else
                    291:        {
                    292:          rt_val = rtx_alloc (code);
                    293:          rt_val->mode = mode;
                    294:          REGNO (rt_val) = regno;
                    295:          return rt_val;
                    296:        }
                    297:     }
                    298:   else
                    299:     {
                    300:       rt_val = rtx_alloc (code);       /* Allocate the storage space.  */
                    301:       rt_val->mode = mode;             /* Store the machine mode...  */
                    302: 
                    303:       fmt = GET_RTX_FORMAT (code);     /* Find the right format...  */
                    304:       for (i = 0; i < GET_RTX_LENGTH (code); i++)
                    305:        {
                    306:          switch (*fmt++)
                    307:            {
                    308:            case '0':           /* Unused field.  */
                    309:              break;
                    310: 
                    311:            case 'i':           /* An integer?  */
                    312:              XINT (rt_val, i) = va_arg (p, int);
                    313:              break;
                    314: 
1.1.1.4 ! root      315:            case 'w':           /* A wide integer? */
        !           316:              XWINT (rt_val, i) = va_arg (p, HOST_WIDE_INT);
        !           317:              break;
        !           318: 
1.1       root      319:            case 's':           /* A string?  */
                    320:              XSTR (rt_val, i) = va_arg (p, char *);
                    321:              break;
                    322: 
                    323:            case 'e':           /* An expression?  */
                    324:            case 'u':           /* An insn?  Same except when printing.  */
                    325:              XEXP (rt_val, i) = va_arg (p, rtx);
                    326:              break;
                    327: 
                    328:            case 'E':           /* An RTX vector?  */
                    329:              XVEC (rt_val, i) = va_arg (p, rtvec);
                    330:              break;
                    331: 
                    332:            default:
                    333:              abort();
                    334:            }
                    335:        }
                    336:     }
                    337:   va_end (p);
                    338:   return rt_val;               /* Return the new RTX...                */
                    339: }
                    340: 
                    341: /* gen_rtvec (n, [rt1, ..., rtn])
                    342: **
                    343: **         This routine creates an rtvec and stores within it the
                    344: **     pointers to rtx's which are its arguments.
                    345: */
                    346: 
                    347: /*VARARGS1*/
                    348: rtvec
                    349: gen_rtvec (va_alist)
                    350:      va_dcl
                    351: {
                    352:   int n, i;
                    353:   va_list p;
                    354:   rtx *vector;
                    355: 
                    356:   va_start (p);
                    357:   n = va_arg (p, int);
                    358: 
                    359:   if (n == 0)
                    360:     return NULL_RTVEC;         /* Don't allocate an empty rtvec...     */
                    361: 
                    362:   vector = (rtx *) alloca (n * sizeof (rtx));
                    363:   for (i = 0; i < n; i++)
                    364:     vector[i] = va_arg (p, rtx);
                    365:   va_end (p);
                    366: 
                    367:   return gen_rtvec_v (n, vector);
                    368: }
                    369: 
                    370: rtvec
                    371: gen_rtvec_v (n, argp)
                    372:      int n;
                    373:      rtx *argp;
                    374: {
                    375:   register int i;
                    376:   register rtvec rt_val;
                    377: 
                    378:   if (n == 0)
                    379:     return NULL_RTVEC;         /* Don't allocate an empty rtvec...     */
                    380: 
                    381:   rt_val = rtvec_alloc (n);    /* Allocate an rtvec...                 */
                    382: 
                    383:   for (i = 0; i < n; i++)
                    384:     rt_val->elem[i].rtx = *argp++;
                    385: 
                    386:   return rt_val;
                    387: }
                    388: 
                    389: /* Generate a REG rtx for a new pseudo register of mode MODE.
                    390:    This pseudo is assigned the next sequential register number.  */
                    391: 
                    392: rtx
                    393: gen_reg_rtx (mode)
                    394:      enum machine_mode mode;
                    395: {
                    396:   register rtx val;
                    397: 
                    398:   /* Don't let anything called by or after reload create new registers
                    399:      (actually, registers can't be created after flow, but this is a good
                    400:      approximation).  */
                    401: 
                    402:   if (reload_in_progress || reload_completed)
                    403:     abort ();
                    404: 
                    405:   /* Make sure regno_pointer_flag and regno_reg_rtx are large
                    406:      enough to have an element for this pseudo reg number.  */
                    407: 
                    408:   if (reg_rtx_no == regno_pointer_flag_length)
                    409:     {
                    410:       rtx *new1;
                    411:       char *new =
                    412:        (char *) oballoc (regno_pointer_flag_length * 2);
                    413:       bzero (new, regno_pointer_flag_length * 2);
                    414:       bcopy (regno_pointer_flag, new, regno_pointer_flag_length);
                    415:       regno_pointer_flag = new;
                    416: 
                    417:       new1 = (rtx *) oballoc (regno_pointer_flag_length * 2 * sizeof (rtx));
                    418:       bzero (new1, regno_pointer_flag_length * 2 * sizeof (rtx));
                    419:       bcopy (regno_reg_rtx, new1, regno_pointer_flag_length * sizeof (rtx));
                    420:       regno_reg_rtx = new1;
                    421: 
                    422:       regno_pointer_flag_length *= 2;
                    423:     }
                    424: 
                    425:   val = gen_rtx (REG, mode, reg_rtx_no);
                    426:   regno_reg_rtx[reg_rtx_no++] = val;
                    427:   return val;
                    428: }
                    429: 
                    430: /* Identify REG as a probable pointer register.  */
                    431: 
                    432: void
                    433: mark_reg_pointer (reg)
                    434:      rtx reg;
                    435: {
                    436:   REGNO_POINTER_FLAG (REGNO (reg)) = 1;
                    437: }
                    438: 
                    439: /* Return 1 plus largest pseudo reg number used in the current function.  */
                    440: 
                    441: int
                    442: max_reg_num ()
                    443: {
                    444:   return reg_rtx_no;
                    445: }
                    446: 
                    447: /* Return 1 + the largest label number used so far in the current function.  */
                    448: 
                    449: int
                    450: max_label_num ()
                    451: {
                    452:   if (last_label_num && label_num == base_label_num)
                    453:     return last_label_num;
                    454:   return label_num;
                    455: }
                    456: 
                    457: /* Return first label number used in this function (if any were used).  */
                    458: 
                    459: int
                    460: get_first_label_num ()
                    461: {
                    462:   return first_label_num;
                    463: }
                    464: 
                    465: /* Return a value representing some low-order bits of X, where the number
                    466:    of low-order bits is given by MODE.  Note that no conversion is done
                    467:    between floating-point and fixed-point values, rather, the bit 
                    468:    representation is returned.
                    469: 
                    470:    This function handles the cases in common between gen_lowpart, below,
                    471:    and two variants in cse.c and combine.c.  These are the cases that can
                    472:    be safely handled at all points in the compilation.
                    473: 
                    474:    If this is not a case we can handle, return 0.  */
                    475: 
                    476: rtx
                    477: gen_lowpart_common (mode, x)
                    478:      enum machine_mode mode;
                    479:      register rtx x;
                    480: {
                    481:   int word = 0;
                    482: 
                    483:   if (GET_MODE (x) == mode)
                    484:     return x;
                    485: 
                    486:   /* MODE must occupy no more words than the mode of X.  */
                    487:   if (GET_MODE (x) != VOIDmode
                    488:       && ((GET_MODE_SIZE (mode) + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD
                    489:          > ((GET_MODE_SIZE (GET_MODE (x)) + (UNITS_PER_WORD - 1))
                    490:             / UNITS_PER_WORD)))
                    491:     return 0;
                    492: 
                    493:   if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD)
                    494:     word = ((GET_MODE_SIZE (GET_MODE (x))
                    495:             - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD))
                    496:            / UNITS_PER_WORD);
                    497: 
                    498:   if ((GET_CODE (x) == ZERO_EXTEND || GET_CODE (x) == SIGN_EXTEND)
1.1.1.4 ! root      499:       && (GET_MODE_CLASS (mode) == MODE_INT
        !           500:          || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT))
1.1       root      501:     {
                    502:       /* If we are getting the low-order part of something that has been
                    503:         sign- or zero-extended, we can either just use the object being
                    504:         extended or make a narrower extension.  If we want an even smaller
                    505:         piece than the size of the object being extended, call ourselves
                    506:         recursively.
                    507: 
                    508:         This case is used mostly by combine and cse.  */
                    509: 
                    510:       if (GET_MODE (XEXP (x, 0)) == mode)
                    511:        return XEXP (x, 0);
                    512:       else if (GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (XEXP (x, 0))))
                    513:        return gen_lowpart_common (mode, XEXP (x, 0));
                    514:       else if (GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (x)))
                    515:        return gen_rtx (GET_CODE (x), mode, XEXP (x, 0));
                    516:     }
                    517:   else if (GET_CODE (x) == SUBREG
                    518:           && (GET_MODE_SIZE (mode) <= UNITS_PER_WORD
                    519:               || GET_MODE_SIZE (mode) == GET_MODE_UNIT_SIZE (GET_MODE (x))))
                    520:     return (GET_MODE (SUBREG_REG (x)) == mode && SUBREG_WORD (x) == 0
                    521:            ? SUBREG_REG (x)
                    522:            : gen_rtx (SUBREG, mode, SUBREG_REG (x), SUBREG_WORD (x)));
                    523:   else if (GET_CODE (x) == REG)
                    524:     {
                    525:       /* If the register is not valid for MODE, return 0.  If we don't
                    526:         do this, there is no way to fix up the resulting REG later.  */
                    527:       if (REGNO (x) < FIRST_PSEUDO_REGISTER
                    528:          && ! HARD_REGNO_MODE_OK (REGNO (x) + word, mode))
                    529:        return 0;
                    530:       else if (REGNO (x) < FIRST_PSEUDO_REGISTER
                    531:               /* integrate.c can't handle parts of a return value register. */
                    532:               && (! REG_FUNCTION_VALUE_P (x)
1.1.1.4 ! root      533:                   || ! rtx_equal_function_value_matters)
        !           534:               /* We want to keep the stack, frame, and arg pointers
        !           535:                  special.  */
        !           536:               && REGNO (x) != FRAME_POINTER_REGNUM
        !           537: #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
        !           538:               && REGNO (x) != ARG_POINTER_REGNUM
        !           539: #endif
        !           540:               && REGNO (x) != STACK_POINTER_REGNUM)
1.1       root      541:        return gen_rtx (REG, mode, REGNO (x) + word);
                    542:       else
                    543:        return gen_rtx (SUBREG, mode, x, word);
                    544:     }
                    545: 
                    546:   /* If X is a CONST_INT or a CONST_DOUBLE, extract the appropriate bits
                    547:      from the low-order part of the constant.  */
1.1.1.4 ! root      548:   else if ((GET_MODE_CLASS (mode) == MODE_INT
        !           549:            || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT)
        !           550:           && GET_MODE (x) == VOIDmode
1.1       root      551:           && (GET_CODE (x) == CONST_INT || GET_CODE (x) == CONST_DOUBLE))
1.1.1.3   root      552:     {
                    553:       /* If MODE is twice the host word size, X is already the desired
                    554:         representation.  Otherwise, if MODE is wider than a word, we can't
                    555:         do this.  If MODE is exactly a word, return just one CONST_INT.
                    556:         If MODE is smaller than a word, clear the bits that don't belong
                    557:         in our mode, unless they and our sign bit are all one.  So we get
                    558:         either a reasonable negative value or a reasonable unsigned value
                    559:         for this mode.  */
                    560: 
1.1.1.4 ! root      561:       if (GET_MODE_BITSIZE (mode) == 2 * HOST_BITS_PER_WIDE_INT)
1.1.1.3   root      562:        return x;
1.1.1.4 ! root      563:       else if (GET_MODE_BITSIZE (mode) > HOST_BITS_PER_WIDE_INT)
1.1.1.3   root      564:        return 0;
1.1.1.4 ! root      565:       else if (GET_MODE_BITSIZE (mode) == HOST_BITS_PER_WIDE_INT)
1.1.1.3   root      566:        return (GET_CODE (x) == CONST_INT ? x
1.1.1.4 ! root      567:                : GEN_INT (CONST_DOUBLE_LOW (x)));
1.1.1.3   root      568:       else
                    569:        {
                    570:          /* MODE must be narrower than HOST_BITS_PER_INT.  */
                    571:          int width = GET_MODE_BITSIZE (mode);
1.1.1.4 ! root      572:          HOST_WIDE_INT val = (GET_CODE (x) == CONST_INT ? INTVAL (x)
        !           573:                               : CONST_DOUBLE_LOW (x));
1.1.1.3   root      574: 
1.1.1.4 ! root      575:          if (((val & ((HOST_WIDE_INT) (-1) << (width - 1)))
        !           576:               != ((HOST_WIDE_INT) (-1) << (width - 1))))
        !           577:            val &= ((HOST_WIDE_INT) 1 << width) - 1;
1.1.1.3   root      578: 
                    579:          return (GET_CODE (x) == CONST_INT && INTVAL (x) == val ? x
1.1.1.4 ! root      580:                  : GEN_INT (val));
1.1.1.3   root      581:        }
                    582:     }
                    583: 
                    584:   /* If X is an integral constant but we want it in floating-point, it
                    585:      must be the case that we have a union of an integer and a floating-point
                    586:      value.  If the machine-parameters allow it, simulate that union here
                    587:      and return the result.  The two-word and single-word cases are 
                    588:      different.  */
                    589: 
                    590:   else if (((HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT
1.1.1.4 ! root      591:             && HOST_BITS_PER_WIDE_INT == BITS_PER_WORD)
1.1.1.3   root      592:            || flag_pretend_float)
                    593:           && GET_MODE_CLASS (mode) == MODE_FLOAT
                    594:           && GET_MODE_SIZE (mode) == UNITS_PER_WORD
                    595:           && GET_CODE (x) == CONST_INT
1.1.1.4 ! root      596:           && sizeof (float) * HOST_BITS_PER_CHAR == HOST_BITS_PER_WIDE_INT)
1.1.1.3   root      597:     {
1.1.1.4 ! root      598:       union {HOST_WIDE_INT i; float d; } u;
1.1.1.3   root      599: 
                    600:       u.i = INTVAL (x);
                    601:       return immed_real_const_1 (u.d, mode);
                    602:     }
                    603: 
                    604:   else if (((HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT
1.1.1.4 ! root      605:             && HOST_BITS_PER_WIDE_INT == BITS_PER_WORD)
1.1.1.3   root      606:            || flag_pretend_float)
                    607:           && GET_MODE_CLASS (mode) == MODE_FLOAT
                    608:           && GET_MODE_SIZE (mode) == 2 * UNITS_PER_WORD
                    609:           && (GET_CODE (x) == CONST_INT || GET_CODE (x) == CONST_DOUBLE)
                    610:           && GET_MODE (x) == VOIDmode
1.1.1.4 ! root      611:           && (sizeof (double) * HOST_BITS_PER_CHAR
        !           612:               == 2 * HOST_BITS_PER_WIDE_INT))
1.1.1.3   root      613:     {
1.1.1.4 ! root      614:       union {HOST_WIDE_INT i[2]; double d; } u;
        !           615:       HOST_WIDE_INT low, high;
1.1.1.3   root      616: 
                    617:       if (GET_CODE (x) == CONST_INT)
1.1.1.4 ! root      618:        low = INTVAL (x), high = low >> (HOST_BITS_PER_WIDE_INT -1);
1.1.1.3   root      619:       else
                    620:        low = CONST_DOUBLE_LOW (x), high = CONST_DOUBLE_HIGH (x);
                    621: 
                    622: #ifdef HOST_WORDS_BIG_ENDIAN
                    623:       u.i[0] = high, u.i[1] = low;
                    624: #else
                    625:       u.i[0] = low, u.i[1] = high;
                    626: #endif
                    627: 
                    628:       return immed_real_const_1 (u.d, mode);
                    629:     }
                    630: 
                    631:   /* Similarly, if this is converting a floating-point value into a
                    632:      single-word integer.  Only do this is the host and target parameters are
                    633:      compatible.  */
                    634: 
                    635:   else if (((HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT
1.1.1.4 ! root      636:             && HOST_BITS_PER_WIDE_INT == BITS_PER_WORD)
1.1.1.3   root      637:            || flag_pretend_float)
1.1.1.4 ! root      638:           && (GET_MODE_CLASS (mode) == MODE_INT
        !           639:               || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT)
1.1.1.3   root      640:           && GET_CODE (x) == CONST_DOUBLE
                    641:           && GET_MODE_CLASS (GET_MODE (x)) == MODE_FLOAT
                    642:           && GET_MODE_BITSIZE (mode) == BITS_PER_WORD)
                    643:     return operand_subword (x, 0, 0, GET_MODE (x));
                    644: 
                    645:   /* Similarly, if this is converting a floating-point value into a
                    646:      two-word integer, we can do this one word at a time and make an
                    647:      integer.  Only do this is the host and target parameters are
                    648:      compatible.  */
                    649: 
                    650:   else if (((HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT
1.1.1.4 ! root      651:             && HOST_BITS_PER_WIDE_INT == BITS_PER_WORD)
1.1.1.3   root      652:            || flag_pretend_float)
1.1.1.4 ! root      653:           && (GET_MODE_CLASS (mode) == MODE_INT
        !           654:               || GET_MODE_CLASS (mode) == MODE_PARTIAL_INT)
1.1.1.3   root      655:           && GET_CODE (x) == CONST_DOUBLE
                    656:           && GET_MODE_CLASS (GET_MODE (x)) == MODE_FLOAT
                    657:           && GET_MODE_BITSIZE (mode) == 2 * BITS_PER_WORD)
                    658:     {
                    659:       rtx lowpart = operand_subword (x, WORDS_BIG_ENDIAN, 0, GET_MODE (x));
                    660:       rtx highpart = operand_subword (x, ! WORDS_BIG_ENDIAN, 0, GET_MODE (x));
                    661: 
                    662:       if (lowpart && GET_CODE (lowpart) == CONST_INT
                    663:          && highpart && GET_CODE (highpart) == CONST_INT)
                    664:        return immed_double_const (INTVAL (lowpart), INTVAL (highpart), mode);
                    665:     }
1.1       root      666: 
                    667:   /* Otherwise, we can't do this.  */
                    668:   return 0;
                    669: }
                    670: 
1.1.1.4 ! root      671: /* Return the real part (which has mode MODE) of a complex value X.
        !           672:    This always comes at the low address in memory.  */
        !           673: 
        !           674: rtx
        !           675: gen_realpart (mode, x)
        !           676:      enum machine_mode mode;
        !           677:      register rtx x;
        !           678: {
        !           679:   if (WORDS_BIG_ENDIAN)
        !           680:     return gen_highpart (mode, x);
        !           681:   else
        !           682:     return gen_lowpart (mode, x);
        !           683: }
        !           684: 
        !           685: /* Return the imaginary part (which has mode MODE) of a complex value X.
        !           686:    This always comes at the high address in memory.  */
        !           687: 
        !           688: rtx
        !           689: gen_imagpart (mode, x)
        !           690:      enum machine_mode mode;
        !           691:      register rtx x;
        !           692: {
        !           693:   if (WORDS_BIG_ENDIAN)
        !           694:     return gen_lowpart (mode, x);
        !           695:   else
        !           696:     return gen_highpart (mode, x);
        !           697: }
        !           698: 
1.1       root      699: /* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a value,
                    700:    return an rtx (MEM, SUBREG, or CONST_INT) that refers to the
                    701:    least-significant part of X.
                    702:    MODE specifies how big a part of X to return;
                    703:    it usually should not be larger than a word.
                    704:    If X is a MEM whose address is a QUEUED, the value may be so also.  */
                    705: 
                    706: rtx
                    707: gen_lowpart (mode, x)
                    708:      enum machine_mode mode;
                    709:      register rtx x;
                    710: {
                    711:   rtx result = gen_lowpart_common (mode, x);
                    712: 
                    713:   if (result)
                    714:     return result;
                    715:   else if (GET_CODE (x) == MEM)
                    716:     {
                    717:       /* The only additional case we can do is MEM.  */
                    718:       register int offset = 0;
                    719:       if (WORDS_BIG_ENDIAN)
                    720:        offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD)
                    721:                  - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD));
                    722: 
                    723:       if (BYTES_BIG_ENDIAN)
                    724:        /* Adjust the address so that the address-after-the-data
                    725:           is unchanged.  */
                    726:        offset -= (MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode))
                    727:                   - MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (x))));
                    728: 
                    729:       return change_address (x, mode, plus_constant (XEXP (x, 0), offset));
                    730:     }
                    731:   else
                    732:     abort ();
                    733: }
                    734: 
1.1.1.4 ! root      735: /* Like `gen_lowpart', but refer to the most significant part. 
        !           736:    This is used to access the imaginary part of a complex number.  */
        !           737: 
        !           738: rtx
        !           739: gen_highpart (mode, x)
        !           740:      enum machine_mode mode;
        !           741:      register rtx x;
        !           742: {
        !           743:   /* This case loses if X is a subreg.  To catch bugs early,
        !           744:      complain if an invalid MODE is used even in other cases.  */
        !           745:   if (GET_MODE_SIZE (mode) > UNITS_PER_WORD
        !           746:       && GET_MODE_SIZE (mode) != GET_MODE_UNIT_SIZE (GET_MODE (x)))
        !           747:     abort ();
        !           748:   if (GET_CODE (x) == CONST_DOUBLE
        !           749: #if !(TARGET_FLOAT_FORMAT != HOST_FLOAT_FORMAT || defined(REAL_IS_NOT_DOUBLE))
        !           750:       && GET_MODE_CLASS (GET_MODE (x)) != MODE_FLOAT
        !           751: #endif
        !           752:       )
        !           753:     return gen_rtx (CONST_INT, VOIDmode,
        !           754:                    CONST_DOUBLE_HIGH (x) & GET_MODE_MASK (mode));
        !           755:   else if (GET_CODE (x) == CONST_INT)
        !           756:     return const0_rtx;
        !           757:   else if (GET_CODE (x) == MEM)
        !           758:     {
        !           759:       register int offset = 0;
        !           760: #if !WORDS_BIG_ENDIAN
        !           761:       offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD)
        !           762:                - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD));
        !           763: #endif
        !           764: #if !BYTES_BIG_ENDIAN
        !           765:       if (GET_MODE_SIZE (mode) < UNITS_PER_WORD)
        !           766:        offset -= (GET_MODE_SIZE (mode)
        !           767:                   - MIN (UNITS_PER_WORD,
        !           768:                          GET_MODE_SIZE (GET_MODE (x))));
        !           769: #endif
        !           770:       return change_address (x, mode, plus_constant (XEXP (x, 0), offset));
        !           771:     }
        !           772:   else if (GET_CODE (x) == SUBREG)
        !           773:     {
        !           774:       /* The only time this should occur is when we are looking at a
        !           775:         multi-word item with a SUBREG whose mode is the same as that of the
        !           776:         item.  It isn't clear what we would do if it wasn't.  */
        !           777:       if (SUBREG_WORD (x) != 0)
        !           778:        abort ();
        !           779:       return gen_highpart (mode, SUBREG_REG (x));
        !           780:     }
        !           781:   else if (GET_CODE (x) == REG)
        !           782:     {
        !           783:       int word = 0;
        !           784: 
        !           785: #if !WORDS_BIG_ENDIAN
        !           786:       if (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD)
        !           787:        word = ((GET_MODE_SIZE (GET_MODE (x))
        !           788:                 - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD))
        !           789:                / UNITS_PER_WORD);
        !           790: #endif
        !           791:       if (REGNO (x) < FIRST_PSEUDO_REGISTER
        !           792:          /* We want to keep the stack, frame, and arg pointers special.  */
        !           793:          && REGNO (x) != FRAME_POINTER_REGNUM
        !           794: #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
        !           795:          && REGNO (x) != ARG_POINTER_REGNUM
        !           796: #endif
        !           797:          && REGNO (x) != STACK_POINTER_REGNUM)
        !           798:        return gen_rtx (REG, mode, REGNO (x) + word);
        !           799:       else
        !           800:        return gen_rtx (SUBREG, mode, x, word);
        !           801:     }
        !           802:   else
        !           803:     abort ();
        !           804: }
        !           805: 
1.1       root      806: /* Return 1 iff X, assumed to be a SUBREG,
                    807:    refers to the least significant part of its containing reg.
                    808:    If X is not a SUBREG, always return 1 (it is its own low part!).  */
                    809: 
                    810: int
                    811: subreg_lowpart_p (x)
                    812:      rtx x;
                    813: {
                    814:   if (GET_CODE (x) != SUBREG)
                    815:     return 1;
                    816: 
                    817:   if (WORDS_BIG_ENDIAN
                    818:       && GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))) > UNITS_PER_WORD)
                    819:     return (SUBREG_WORD (x)
                    820:            == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
                    821:                 - MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD))
                    822:                / UNITS_PER_WORD));
                    823: 
                    824:   return SUBREG_WORD (x) == 0;
                    825: }
                    826: 
                    827: /* Return subword I of operand OP.
                    828:    The word number, I, is interpreted as the word number starting at the
                    829:    low-order address.  Word 0 is the low-order word if not WORDS_BIG_ENDIAN,
                    830:    otherwise it is the high-order word.
                    831: 
                    832:    If we cannot extract the required word, we return zero.  Otherwise, an
                    833:    rtx corresponding to the requested word will be returned.
                    834: 
                    835:    VALIDATE_ADDRESS is nonzero if the address should be validated.  Before
                    836:    reload has completed, a valid address will always be returned.  After
                    837:    reload, if a valid address cannot be returned, we return zero.
                    838: 
                    839:    If VALIDATE_ADDRESS is zero, we simply form the required address; validating
                    840:    it is the responsibility of the caller.
                    841: 
                    842:    MODE is the mode of OP in case it is a CONST_INT.  */
                    843: 
                    844: rtx
                    845: operand_subword (op, i, validate_address, mode)
                    846:      rtx op;
                    847:      int i;
                    848:      int validate_address;
                    849:      enum machine_mode mode;
                    850: {
1.1.1.4 ! root      851:   HOST_WIDE_INT val;
        !           852:   int size_ratio = HOST_BITS_PER_WIDE_INT / BITS_PER_WORD;
1.1       root      853: 
                    854:   if (mode == VOIDmode)
                    855:     mode = GET_MODE (op);
                    856: 
                    857:   if (mode == VOIDmode)
                    858:     abort ();
                    859: 
                    860:   /* If OP is narrower than a word or if we want a word outside OP, fail.  */
                    861:   if (mode != BLKmode
                    862:       && (GET_MODE_SIZE (mode) < UNITS_PER_WORD
                    863:          || (i + 1) * UNITS_PER_WORD > GET_MODE_SIZE (mode)))
                    864:     return 0;
                    865: 
                    866:   /* If OP is already an integer word, return it.  */
                    867:   if (GET_MODE_CLASS (mode) == MODE_INT
                    868:       && GET_MODE_SIZE (mode) == UNITS_PER_WORD)
                    869:     return op;
                    870: 
                    871:   /* If OP is a REG or SUBREG, we can handle it very simply.  */
                    872:   if (GET_CODE (op) == REG)
                    873:     {
                    874:       /* If the register is not valid for MODE, return 0.  If we don't
                    875:         do this, there is no way to fix up the resulting REG later.  */
                    876:       if (REGNO (op) < FIRST_PSEUDO_REGISTER
                    877:          && ! HARD_REGNO_MODE_OK (REGNO (op) + i, word_mode))
                    878:        return 0;
                    879:       else if (REGNO (op) >= FIRST_PSEUDO_REGISTER
                    880:               || (REG_FUNCTION_VALUE_P (op)
1.1.1.4 ! root      881:                   && rtx_equal_function_value_matters)
        !           882:               /* We want to keep the stack, frame, and arg pointers
        !           883:                  special.  */
        !           884:               || REGNO (op) == FRAME_POINTER_REGNUM
        !           885: #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
        !           886:               || REGNO (op) == ARG_POINTER_REGNUM
        !           887: #endif
        !           888:               || REGNO (op) == STACK_POINTER_REGNUM)
1.1       root      889:        return gen_rtx (SUBREG, word_mode, op, i);
                    890:       else
                    891:        return gen_rtx (REG, word_mode, REGNO (op) + i);
                    892:     }
                    893:   else if (GET_CODE (op) == SUBREG)
                    894:     return gen_rtx (SUBREG, word_mode, SUBREG_REG (op), i + SUBREG_WORD (op));
                    895: 
                    896:   /* Form a new MEM at the requested address.  */
                    897:   if (GET_CODE (op) == MEM)
                    898:     {
                    899:       rtx addr = plus_constant (XEXP (op, 0), i * UNITS_PER_WORD);
                    900:       rtx new;
                    901: 
                    902:       if (validate_address)
                    903:        {
                    904:          if (reload_completed)
                    905:            {
                    906:              if (! strict_memory_address_p (word_mode, addr))
                    907:                return 0;
                    908:            }
                    909:          else
                    910:            addr = memory_address (word_mode, addr);
                    911:        }
                    912: 
                    913:       new = gen_rtx (MEM, word_mode, addr);
                    914: 
                    915:       MEM_VOLATILE_P (new) = MEM_VOLATILE_P (op);
                    916:       MEM_IN_STRUCT_P (new) = MEM_IN_STRUCT_P (op);
                    917:       RTX_UNCHANGING_P (new) = RTX_UNCHANGING_P (op);
                    918: 
                    919:       return new;
                    920:     }
                    921: 
                    922:   /* The only remaining cases are when OP is a constant.  If the host and
                    923:      target floating formats are the same, handling two-word floating
                    924:      constants are easy.  */
                    925:   if (((HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT
1.1.1.4 ! root      926:        && HOST_BITS_PER_WIDE_INT == BITS_PER_WORD)
1.1       root      927:        || flag_pretend_float)
                    928:       && GET_MODE_CLASS (mode) == MODE_FLOAT
                    929:       && GET_MODE_SIZE (mode) == 2 * UNITS_PER_WORD
                    930:       && GET_CODE (op) == CONST_DOUBLE)
1.1.1.4 ! root      931:     {
        !           932:       /* The constant is stored in the host's word-ordering,
        !           933:         but we want to access it in the target's word-ordering.  Some
        !           934:         compilers don't like a conditional inside macro args, so we have two
        !           935:         copies of the return.  */
1.1.1.3   root      936: #ifdef HOST_WORDS_BIG_ENDIAN
1.1.1.4 ! root      937:       return GEN_INT (i == WORDS_BIG_ENDIAN
        !           938:                      ? CONST_DOUBLE_HIGH (op) : CONST_DOUBLE_LOW (op));
1.1.1.3   root      939: #else
1.1.1.4 ! root      940:       return GEN_INT (i != WORDS_BIG_ENDIAN
        !           941:                      ? CONST_DOUBLE_HIGH (op) : CONST_DOUBLE_LOW (op));
1.1.1.3   root      942: #endif
1.1.1.4 ! root      943:     }
1.1       root      944: 
                    945:   /* Single word float is a little harder, since single- and double-word
                    946:      values often do not have the same high-order bits.  We have already
                    947:      verified that we want the only defined word of the single-word value.  */
                    948:   if (((HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT
1.1.1.4 ! root      949:        && HOST_BITS_PER_WIDE_INT == BITS_PER_WORD)
1.1       root      950:        || flag_pretend_float)
                    951:       && GET_MODE_CLASS (mode) == MODE_FLOAT
                    952:       && GET_MODE_SIZE (mode) == UNITS_PER_WORD
                    953:       && GET_CODE (op) == CONST_DOUBLE)
                    954:     {
                    955:       double d;
1.1.1.4 ! root      956:       union {float f; HOST_WIDE_INT i; } u;
1.1       root      957: 
                    958:       REAL_VALUE_FROM_CONST_DOUBLE (d, op);
                    959: 
                    960:       u.f = d;
1.1.1.4 ! root      961:       return GEN_INT (u.i);
1.1       root      962:     }
                    963:       
                    964:   /* The only remaining cases that we can handle are integers.
                    965:      Convert to proper endianness now since these cases need it.
                    966:      At this point, i == 0 means the low-order word.  
                    967: 
                    968:      Note that it must be that BITS_PER_WORD <= HOST_BITS_PER_INT.
                    969:      This is because if it were greater, it could only have been two
                    970:      times greater since we do not support making wider constants.  In
                    971:      that case, it MODE would have already been the proper size and
                    972:      it would have been handled above.  This means we do not have to
                    973:      worry about the case where we would be returning a CONST_DOUBLE.  */
                    974: 
                    975:   if (GET_MODE_CLASS (mode) != MODE_INT
                    976:       || (GET_CODE (op) != CONST_INT && GET_CODE (op) != CONST_DOUBLE))
                    977:     return 0;
                    978: 
                    979:   if (WORDS_BIG_ENDIAN)
                    980:     i = GET_MODE_SIZE (mode) / UNITS_PER_WORD - 1 - i;
                    981: 
                    982:   /* Find out which word on the host machine this value is in and get
                    983:      it from the constant.  */
                    984:   val = (i / size_ratio == 0
                    985:         ? (GET_CODE (op) == CONST_INT ? INTVAL (op) : CONST_DOUBLE_LOW (op))
                    986:         : (GET_CODE (op) == CONST_INT
                    987:            ? (INTVAL (op) < 0 ? ~0 : 0) : CONST_DOUBLE_HIGH (op)));
                    988: 
                    989:   /* If BITS_PER_WORD is smaller than an int, get the appropriate bits.  */
1.1.1.4 ! root      990:   if (BITS_PER_WORD < HOST_BITS_PER_WIDE_INT)
1.1       root      991:     val = ((val >> ((i % size_ratio) * BITS_PER_WORD))
1.1.1.4 ! root      992:           & (((HOST_WIDE_INT) 1
        !           993:               << (BITS_PER_WORD % HOST_BITS_PER_WIDE_INT)) - 1));
1.1       root      994: 
1.1.1.4 ! root      995:   return GEN_INT (val);
1.1       root      996: }
                    997: 
                    998: /* Similar to `operand_subword', but never return 0.  If we can't extract
                    999:    the required subword, put OP into a register and try again.  If that fails,
                   1000:    abort.  We always validate the address in this case.  It is not valid
                   1001:    to call this function after reload; it is mostly meant for RTL
                   1002:    generation. 
                   1003: 
                   1004:    MODE is the mode of OP, in case it is CONST_INT.  */
                   1005: 
                   1006: rtx
                   1007: operand_subword_force (op, i, mode)
                   1008:      rtx op;
                   1009:      int i;
                   1010:      enum machine_mode mode;
                   1011: {
                   1012:   rtx result = operand_subword (op, i, 1, mode);
                   1013: 
                   1014:   if (result)
                   1015:     return result;
                   1016: 
                   1017:   if (mode != BLKmode && mode != VOIDmode)
                   1018:     op = force_reg (mode, op);
                   1019: 
                   1020:   result = operand_subword (op, i, 1, mode);
                   1021:   if (result == 0)
                   1022:     abort ();
                   1023: 
                   1024:   return result;
                   1025: }
                   1026: 
                   1027: /* Given a compare instruction, swap the operands.
                   1028:    A test instruction is changed into a compare of 0 against the operand.  */
                   1029: 
                   1030: void
                   1031: reverse_comparison (insn)
                   1032:      rtx insn;
                   1033: {
                   1034:   rtx body = PATTERN (insn);
                   1035:   rtx comp;
                   1036: 
                   1037:   if (GET_CODE (body) == SET)
                   1038:     comp = SET_SRC (body);
                   1039:   else
                   1040:     comp = SET_SRC (XVECEXP (body, 0, 0));
                   1041: 
                   1042:   if (GET_CODE (comp) == COMPARE)
                   1043:     {
                   1044:       rtx op0 = XEXP (comp, 0);
                   1045:       rtx op1 = XEXP (comp, 1);
                   1046:       XEXP (comp, 0) = op1;
                   1047:       XEXP (comp, 1) = op0;
                   1048:     }
                   1049:   else
                   1050:     {
                   1051:       rtx new = gen_rtx (COMPARE, VOIDmode,
                   1052:                         CONST0_RTX (GET_MODE (comp)), comp);
                   1053:       if (GET_CODE (body) == SET)
                   1054:        SET_SRC (body) = new;
                   1055:       else
                   1056:        SET_SRC (XVECEXP (body, 0, 0)) = new;
                   1057:     }
                   1058: }
                   1059: 
                   1060: /* Return a memory reference like MEMREF, but with its mode changed
                   1061:    to MODE and its address changed to ADDR.
                   1062:    (VOIDmode means don't change the mode.
                   1063:    NULL for ADDR means don't change the address.)  */
                   1064: 
                   1065: rtx
                   1066: change_address (memref, mode, addr)
                   1067:      rtx memref;
                   1068:      enum machine_mode mode;
                   1069:      rtx addr;
                   1070: {
                   1071:   rtx new;
                   1072: 
                   1073:   if (GET_CODE (memref) != MEM)
                   1074:     abort ();
                   1075:   if (mode == VOIDmode)
                   1076:     mode = GET_MODE (memref);
                   1077:   if (addr == 0)
                   1078:     addr = XEXP (memref, 0);
                   1079: 
                   1080:   /* If reload is in progress or has completed, ADDR must be valid.
                   1081:      Otherwise, we can call memory_address to make it valid.  */
                   1082:   if (reload_completed || reload_in_progress)
                   1083:     {
                   1084:       if (! memory_address_p (mode, addr))
                   1085:        abort ();
                   1086:     }
                   1087:   else
                   1088:     addr = memory_address (mode, addr);
                   1089:        
                   1090:   new = gen_rtx (MEM, mode, addr);
                   1091:   MEM_VOLATILE_P (new) = MEM_VOLATILE_P (memref);
                   1092:   RTX_UNCHANGING_P (new) = RTX_UNCHANGING_P (memref);
                   1093:   MEM_IN_STRUCT_P (new) = MEM_IN_STRUCT_P (memref);
                   1094:   return new;
                   1095: }
                   1096: 
                   1097: /* Return a newly created CODE_LABEL rtx with a unique label number.  */
                   1098: 
                   1099: rtx
                   1100: gen_label_rtx ()
                   1101: {
1.1.1.4 ! root     1102:   register rtx label = gen_rtx (CODE_LABEL, VOIDmode, 0, 0, 0,
        !          1103:                                label_num++, NULL_PTR);
1.1       root     1104:   LABEL_NUSES (label) = 0;
                   1105:   return label;
                   1106: }
                   1107: 
                   1108: /* For procedure integration.  */
                   1109: 
                   1110: /* Return a newly created INLINE_HEADER rtx.  Should allocate this
                   1111:    from a permanent obstack when the opportunity arises.  */
                   1112: 
                   1113: rtx
                   1114: gen_inline_header_rtx (first_insn, first_parm_insn, first_labelno,
                   1115:                       last_labelno, max_parm_regnum, max_regnum, args_size,
                   1116:                       pops_args, stack_slots, function_flags,
                   1117:                       outgoing_args_size, original_arg_vector,
                   1118:                       original_decl_initial)
                   1119:      rtx first_insn, first_parm_insn;
                   1120:      int first_labelno, last_labelno, max_parm_regnum, max_regnum, args_size;
                   1121:      int pops_args;
                   1122:      rtx stack_slots;
                   1123:      int function_flags;
                   1124:      int outgoing_args_size;
                   1125:      rtvec original_arg_vector;
                   1126:      rtx original_decl_initial;
                   1127: {
                   1128:   rtx header = gen_rtx (INLINE_HEADER, VOIDmode,
1.1.1.4 ! root     1129:                        cur_insn_uid++, NULL_RTX,
1.1       root     1130:                        first_insn, first_parm_insn,
                   1131:                        first_labelno, last_labelno,
                   1132:                        max_parm_regnum, max_regnum, args_size, pops_args,
                   1133:                        stack_slots, function_flags, outgoing_args_size,
                   1134:                        original_arg_vector, original_decl_initial);
                   1135:   return header;
                   1136: }
                   1137: 
                   1138: /* Install new pointers to the first and last insns in the chain.
                   1139:    Used for an inline-procedure after copying the insn chain.  */
                   1140: 
                   1141: void
                   1142: set_new_first_and_last_insn (first, last)
                   1143:      rtx first, last;
                   1144: {
                   1145:   first_insn = first;
                   1146:   last_insn = last;
                   1147: }
                   1148: 
                   1149: /* Set the range of label numbers found in the current function.
                   1150:    This is used when belatedly compiling an inline function.  */
                   1151: 
                   1152: void
                   1153: set_new_first_and_last_label_num (first, last)
                   1154:      int first, last;
                   1155: {
                   1156:   base_label_num = label_num;
                   1157:   first_label_num = first;
                   1158:   last_label_num = last;
                   1159: }
                   1160: 
                   1161: /* Save all variables describing the current status into the structure *P.
                   1162:    This is used before starting a nested function.  */
                   1163: 
                   1164: void
                   1165: save_emit_status (p)
                   1166:      struct function *p;
                   1167: {
                   1168:   p->reg_rtx_no = reg_rtx_no;
                   1169:   p->first_label_num = first_label_num;
                   1170:   p->first_insn = first_insn;
                   1171:   p->last_insn = last_insn;
                   1172:   p->sequence_stack = sequence_stack;
                   1173:   p->cur_insn_uid = cur_insn_uid;
                   1174:   p->last_linenum = last_linenum;
                   1175:   p->last_filename = last_filename;
                   1176:   p->regno_pointer_flag = regno_pointer_flag;
                   1177:   p->regno_pointer_flag_length = regno_pointer_flag_length;
                   1178:   p->regno_reg_rtx = regno_reg_rtx;
                   1179: }
                   1180: 
                   1181: /* Restore all variables describing the current status from the structure *P.
                   1182:    This is used after a nested function.  */
                   1183: 
                   1184: void
                   1185: restore_emit_status (p)
                   1186:      struct function *p;
                   1187: {
                   1188:   int i;
                   1189: 
                   1190:   reg_rtx_no = p->reg_rtx_no;
                   1191:   first_label_num = p->first_label_num;
                   1192:   first_insn = p->first_insn;
                   1193:   last_insn = p->last_insn;
                   1194:   sequence_stack = p->sequence_stack;
                   1195:   cur_insn_uid = p->cur_insn_uid;
                   1196:   last_linenum = p->last_linenum;
                   1197:   last_filename = p->last_filename;
                   1198:   regno_pointer_flag = p->regno_pointer_flag;
                   1199:   regno_pointer_flag_length = p->regno_pointer_flag_length;
                   1200:   regno_reg_rtx = p->regno_reg_rtx;
                   1201: 
                   1202:   /* Clear our cache of rtx expressions for start_sequence and gen_sequence. */
                   1203:   sequence_element_free_list = 0;
                   1204:   for (i = 0; i < SEQUENCE_RESULT_SIZE; i++)
                   1205:     sequence_result[i] = 0;
                   1206: }
                   1207: 
                   1208: /* Go through all the RTL insn bodies and copy any invalid shared structure.
                   1209:    It does not work to do this twice, because the mark bits set here
                   1210:    are not cleared afterwards.  */
                   1211: 
                   1212: void
                   1213: unshare_all_rtl (insn)
                   1214:      register rtx insn;
                   1215: {
                   1216:   for (; insn; insn = NEXT_INSN (insn))
                   1217:     if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
                   1218:        || GET_CODE (insn) == CALL_INSN)
                   1219:       {
                   1220:        PATTERN (insn) = copy_rtx_if_shared (PATTERN (insn));
                   1221:        REG_NOTES (insn) = copy_rtx_if_shared (REG_NOTES (insn));
                   1222:        LOG_LINKS (insn) = copy_rtx_if_shared (LOG_LINKS (insn));
                   1223:       }
                   1224: 
                   1225:   /* Make sure the addresses of stack slots found outside the insn chain
                   1226:      (such as, in DECL_RTL of a variable) are not shared
                   1227:      with the insn chain.
                   1228: 
                   1229:      This special care is necessary when the stack slot MEM does not
                   1230:      actually appear in the insn chain.  If it does appear, its address
                   1231:      is unshared from all else at that point.  */
                   1232: 
                   1233:   copy_rtx_if_shared (stack_slot_list);
                   1234: }
                   1235: 
                   1236: /* Mark ORIG as in use, and return a copy of it if it was already in use.
                   1237:    Recursively does the same for subexpressions.  */
                   1238: 
                   1239: rtx
                   1240: copy_rtx_if_shared (orig)
                   1241:      rtx orig;
                   1242: {
                   1243:   register rtx x = orig;
                   1244:   register int i;
                   1245:   register enum rtx_code code;
                   1246:   register char *format_ptr;
                   1247:   int copied = 0;
                   1248: 
                   1249:   if (x == 0)
                   1250:     return 0;
                   1251: 
                   1252:   code = GET_CODE (x);
                   1253: 
                   1254:   /* These types may be freely shared.  */
                   1255: 
                   1256:   switch (code)
                   1257:     {
                   1258:     case REG:
                   1259:     case QUEUED:
                   1260:     case CONST_INT:
                   1261:     case CONST_DOUBLE:
                   1262:     case SYMBOL_REF:
                   1263:     case CODE_LABEL:
                   1264:     case PC:
                   1265:     case CC0:
                   1266:     case SCRATCH:
                   1267:       /* SCRATCH must be shared because they represent distinct values. */
                   1268:       return x;
                   1269: 
                   1270:     case INSN:
                   1271:     case JUMP_INSN:
                   1272:     case CALL_INSN:
                   1273:     case NOTE:
                   1274:     case LABEL_REF:
                   1275:     case BARRIER:
                   1276:       /* The chain of insns is not being copied.  */
                   1277:       return x;
                   1278: 
                   1279:     case MEM:
                   1280:       /* A MEM is allowed to be shared if its address is constant
                   1281:         or is a constant plus one of the special registers.  */
                   1282:       if (CONSTANT_ADDRESS_P (XEXP (x, 0))
                   1283:          || XEXP (x, 0) == virtual_stack_vars_rtx
                   1284:          || XEXP (x, 0) == virtual_incoming_args_rtx)
                   1285:        return x;
                   1286: 
                   1287:       if (GET_CODE (XEXP (x, 0)) == PLUS
                   1288:          && (XEXP (XEXP (x, 0), 0) == virtual_stack_vars_rtx
                   1289:              || XEXP (XEXP (x, 0), 0) == virtual_incoming_args_rtx)
                   1290:          && CONSTANT_ADDRESS_P (XEXP (XEXP (x, 0), 1)))
                   1291:        {
                   1292:          /* This MEM can appear in more than one place,
                   1293:             but its address better not be shared with anything else.  */
                   1294:          if (! x->used)
                   1295:            XEXP (x, 0) = copy_rtx_if_shared (XEXP (x, 0));
                   1296:          x->used = 1;
                   1297:          return x;
                   1298:        }
                   1299:     }
                   1300: 
                   1301:   /* This rtx may not be shared.  If it has already been seen,
                   1302:      replace it with a copy of itself.  */
                   1303: 
                   1304:   if (x->used)
                   1305:     {
                   1306:       register rtx copy;
                   1307: 
                   1308:       copy = rtx_alloc (code);
                   1309:       bcopy (x, copy, (sizeof (*copy) - sizeof (copy->fld)
                   1310:                       + sizeof (copy->fld[0]) * GET_RTX_LENGTH (code)));
                   1311:       x = copy;
                   1312:       copied = 1;
                   1313:     }
                   1314:   x->used = 1;
                   1315: 
                   1316:   /* Now scan the subexpressions recursively.
                   1317:      We can store any replaced subexpressions directly into X
                   1318:      since we know X is not shared!  Any vectors in X
                   1319:      must be copied if X was copied.  */
                   1320: 
                   1321:   format_ptr = GET_RTX_FORMAT (code);
                   1322: 
                   1323:   for (i = 0; i < GET_RTX_LENGTH (code); i++)
                   1324:     {
                   1325:       switch (*format_ptr++)
                   1326:        {
                   1327:        case 'e':
                   1328:          XEXP (x, i) = copy_rtx_if_shared (XEXP (x, i));
                   1329:          break;
                   1330: 
                   1331:        case 'E':
                   1332:          if (XVEC (x, i) != NULL)
                   1333:            {
                   1334:              register int j;
                   1335: 
                   1336:              if (copied)
                   1337:                XVEC (x, i) = gen_rtvec_v (XVECLEN (x, i), &XVECEXP (x, i, 0));
                   1338:              for (j = 0; j < XVECLEN (x, i); j++)
                   1339:                XVECEXP (x, i, j)
                   1340:                  = copy_rtx_if_shared (XVECEXP (x, i, j));
                   1341:            }
                   1342:          break;
                   1343:        }
                   1344:     }
                   1345:   return x;
                   1346: }
                   1347: 
                   1348: /* Clear all the USED bits in X to allow copy_rtx_if_shared to be used
                   1349:    to look for shared sub-parts.  */
                   1350: 
                   1351: void
                   1352: reset_used_flags (x)
                   1353:      rtx x;
                   1354: {
                   1355:   register int i, j;
                   1356:   register enum rtx_code code;
                   1357:   register char *format_ptr;
                   1358:   int copied = 0;
                   1359: 
                   1360:   if (x == 0)
                   1361:     return;
                   1362: 
                   1363:   code = GET_CODE (x);
                   1364: 
                   1365:   /* These types may be freely shared so we needn't do any reseting
                   1366:      for them.  */
                   1367: 
                   1368:   switch (code)
                   1369:     {
                   1370:     case REG:
                   1371:     case QUEUED:
                   1372:     case CONST_INT:
                   1373:     case CONST_DOUBLE:
                   1374:     case SYMBOL_REF:
                   1375:     case CODE_LABEL:
                   1376:     case PC:
                   1377:     case CC0:
                   1378:       return;
                   1379: 
                   1380:     case INSN:
                   1381:     case JUMP_INSN:
                   1382:     case CALL_INSN:
                   1383:     case NOTE:
                   1384:     case LABEL_REF:
                   1385:     case BARRIER:
                   1386:       /* The chain of insns is not being copied.  */
                   1387:       return;
                   1388:     }
                   1389: 
                   1390:   x->used = 0;
                   1391: 
                   1392:   format_ptr = GET_RTX_FORMAT (code);
                   1393:   for (i = 0; i < GET_RTX_LENGTH (code); i++)
                   1394:     {
                   1395:       switch (*format_ptr++)
                   1396:        {
                   1397:        case 'e':
                   1398:          reset_used_flags (XEXP (x, i));
                   1399:          break;
                   1400: 
                   1401:        case 'E':
                   1402:          for (j = 0; j < XVECLEN (x, i); j++)
                   1403:            reset_used_flags (XVECEXP (x, i, j));
                   1404:          break;
                   1405:        }
                   1406:     }
                   1407: }
                   1408: 
                   1409: /* Copy X if necessary so that it won't be altered by changes in OTHER.
                   1410:    Return X or the rtx for the pseudo reg the value of X was copied into.
                   1411:    OTHER must be valid as a SET_DEST.  */
                   1412: 
                   1413: rtx
                   1414: make_safe_from (x, other)
                   1415:      rtx x, other;
                   1416: {
                   1417:   while (1)
                   1418:     switch (GET_CODE (other))
                   1419:       {
                   1420:       case SUBREG:
                   1421:        other = SUBREG_REG (other);
                   1422:        break;
                   1423:       case STRICT_LOW_PART:
                   1424:       case SIGN_EXTEND:
                   1425:       case ZERO_EXTEND:
                   1426:        other = XEXP (other, 0);
                   1427:        break;
                   1428:       default:
                   1429:        goto done;
                   1430:       }
                   1431:  done:
                   1432:   if ((GET_CODE (other) == MEM
                   1433:        && ! CONSTANT_P (x)
                   1434:        && GET_CODE (x) != REG
                   1435:        && GET_CODE (x) != SUBREG)
                   1436:       || (GET_CODE (other) == REG
                   1437:          && (REGNO (other) < FIRST_PSEUDO_REGISTER
                   1438:              || reg_mentioned_p (other, x))))
                   1439:     {
                   1440:       rtx temp = gen_reg_rtx (GET_MODE (x));
                   1441:       emit_move_insn (temp, x);
                   1442:       return temp;
                   1443:     }
                   1444:   return x;
                   1445: }
                   1446: 
                   1447: /* Emission of insns (adding them to the doubly-linked list).  */
                   1448: 
                   1449: /* Return the first insn of the current sequence or current function.  */
                   1450: 
                   1451: rtx
                   1452: get_insns ()
                   1453: {
                   1454:   return first_insn;
                   1455: }
                   1456: 
                   1457: /* Return the last insn emitted in current sequence or current function.  */
                   1458: 
                   1459: rtx
                   1460: get_last_insn ()
                   1461: {
                   1462:   return last_insn;
                   1463: }
                   1464: 
                   1465: /* Specify a new insn as the last in the chain.  */
                   1466: 
                   1467: void
                   1468: set_last_insn (insn)
                   1469:      rtx insn;
                   1470: {
                   1471:   if (NEXT_INSN (insn) != 0)
                   1472:     abort ();
                   1473:   last_insn = insn;
                   1474: }
                   1475: 
                   1476: /* Return the last insn emitted, even if it is in a sequence now pushed.  */
                   1477: 
                   1478: rtx
                   1479: get_last_insn_anywhere ()
                   1480: {
                   1481:   struct sequence_stack *stack;
                   1482:   if (last_insn)
                   1483:     return last_insn;
                   1484:   for (stack = sequence_stack; stack; stack = stack->next)
                   1485:     if (stack->last != 0)
                   1486:       return stack->last;
                   1487:   return 0;
                   1488: }
                   1489: 
                   1490: /* Return a number larger than any instruction's uid in this function.  */
                   1491: 
                   1492: int
                   1493: get_max_uid ()
                   1494: {
                   1495:   return cur_insn_uid;
                   1496: }
                   1497: 
                   1498: /* Return the next insn.  If it is a SEQUENCE, return the first insn
                   1499:    of the sequence.  */
                   1500: 
                   1501: rtx
                   1502: next_insn (insn)
                   1503:      rtx insn;
                   1504: {
                   1505:   if (insn)
                   1506:     {
                   1507:       insn = NEXT_INSN (insn);
                   1508:       if (insn && GET_CODE (insn) == INSN
                   1509:          && GET_CODE (PATTERN (insn)) == SEQUENCE)
                   1510:        insn = XVECEXP (PATTERN (insn), 0, 0);
                   1511:     }
                   1512: 
                   1513:   return insn;
                   1514: }
                   1515: 
                   1516: /* Return the previous insn.  If it is a SEQUENCE, return the last insn
                   1517:    of the sequence.  */
                   1518: 
                   1519: rtx
                   1520: previous_insn (insn)
                   1521:      rtx insn;
                   1522: {
                   1523:   if (insn)
                   1524:     {
                   1525:       insn = PREV_INSN (insn);
                   1526:       if (insn && GET_CODE (insn) == INSN
                   1527:          && GET_CODE (PATTERN (insn)) == SEQUENCE)
                   1528:        insn = XVECEXP (PATTERN (insn), 0, XVECLEN (PATTERN (insn), 0) - 1);
                   1529:     }
                   1530: 
                   1531:   return insn;
                   1532: }
                   1533: 
                   1534: /* Return the next insn after INSN that is not a NOTE.  This routine does not
                   1535:    look inside SEQUENCEs.  */
                   1536: 
                   1537: rtx
                   1538: next_nonnote_insn (insn)
                   1539:      rtx insn;
                   1540: {
                   1541:   while (insn)
                   1542:     {
                   1543:       insn = NEXT_INSN (insn);
                   1544:       if (insn == 0 || GET_CODE (insn) != NOTE)
                   1545:        break;
                   1546:     }
                   1547: 
                   1548:   return insn;
                   1549: }
                   1550: 
                   1551: /* Return the previous insn before INSN that is not a NOTE.  This routine does
                   1552:    not look inside SEQUENCEs.  */
                   1553: 
                   1554: rtx
                   1555: prev_nonnote_insn (insn)
                   1556:      rtx insn;
                   1557: {
                   1558:   while (insn)
                   1559:     {
                   1560:       insn = PREV_INSN (insn);
                   1561:       if (insn == 0 || GET_CODE (insn) != NOTE)
                   1562:        break;
                   1563:     }
                   1564: 
                   1565:   return insn;
                   1566: }
                   1567: 
                   1568: /* Return the next INSN, CALL_INSN or JUMP_INSN after INSN;
                   1569:    or 0, if there is none.  This routine does not look inside
                   1570:    SEQUENCEs. */
                   1571: 
                   1572: rtx
                   1573: next_real_insn (insn)
                   1574:      rtx insn;
                   1575: {
                   1576:   while (insn)
                   1577:     {
                   1578:       insn = NEXT_INSN (insn);
                   1579:       if (insn == 0 || GET_CODE (insn) == INSN
                   1580:          || GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == JUMP_INSN)
                   1581:        break;
                   1582:     }
                   1583: 
                   1584:   return insn;
                   1585: }
                   1586: 
                   1587: /* Return the last INSN, CALL_INSN or JUMP_INSN before INSN;
                   1588:    or 0, if there is none.  This routine does not look inside
                   1589:    SEQUENCEs.  */
                   1590: 
                   1591: rtx
                   1592: prev_real_insn (insn)
                   1593:      rtx insn;
                   1594: {
                   1595:   while (insn)
                   1596:     {
                   1597:       insn = PREV_INSN (insn);
                   1598:       if (insn == 0 || GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN
                   1599:          || GET_CODE (insn) == JUMP_INSN)
                   1600:        break;
                   1601:     }
                   1602: 
                   1603:   return insn;
                   1604: }
                   1605: 
                   1606: /* Find the next insn after INSN that really does something.  This routine
                   1607:    does not look inside SEQUENCEs.  Until reload has completed, this is the
                   1608:    same as next_real_insn.  */
                   1609: 
                   1610: rtx
                   1611: next_active_insn (insn)
                   1612:      rtx insn;
                   1613: {
                   1614:   while (insn)
                   1615:     {
                   1616:       insn = NEXT_INSN (insn);
                   1617:       if (insn == 0
                   1618:          || GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == JUMP_INSN
                   1619:          || (GET_CODE (insn) == INSN
                   1620:              && (! reload_completed
                   1621:                  || (GET_CODE (PATTERN (insn)) != USE
                   1622:                      && GET_CODE (PATTERN (insn)) != CLOBBER))))
                   1623:        break;
                   1624:     }
                   1625: 
                   1626:   return insn;
                   1627: }
                   1628: 
                   1629: /* Find the last insn before INSN that really does something.  This routine
                   1630:    does not look inside SEQUENCEs.  Until reload has completed, this is the
                   1631:    same as prev_real_insn.  */
                   1632: 
                   1633: rtx
                   1634: prev_active_insn (insn)
                   1635:      rtx insn;
                   1636: {
                   1637:   while (insn)
                   1638:     {
                   1639:       insn = PREV_INSN (insn);
                   1640:       if (insn == 0
                   1641:          || GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == JUMP_INSN
                   1642:          || (GET_CODE (insn) == INSN
                   1643:              && (! reload_completed
                   1644:                  || (GET_CODE (PATTERN (insn)) != USE
                   1645:                      && GET_CODE (PATTERN (insn)) != CLOBBER))))
                   1646:        break;
                   1647:     }
                   1648: 
                   1649:   return insn;
                   1650: }
                   1651: 
                   1652: /* Return the next CODE_LABEL after the insn INSN, or 0 if there is none.  */
                   1653: 
                   1654: rtx
                   1655: next_label (insn)
                   1656:      rtx insn;
                   1657: {
                   1658:   while (insn)
                   1659:     {
                   1660:       insn = NEXT_INSN (insn);
                   1661:       if (insn == 0 || GET_CODE (insn) == CODE_LABEL)
                   1662:        break;
                   1663:     }
                   1664: 
                   1665:   return insn;
                   1666: }
                   1667: 
                   1668: /* Return the last CODE_LABEL before the insn INSN, or 0 if there is none.  */
                   1669: 
                   1670: rtx
                   1671: prev_label (insn)
                   1672:      rtx insn;
                   1673: {
                   1674:   while (insn)
                   1675:     {
                   1676:       insn = PREV_INSN (insn);
                   1677:       if (insn == 0 || GET_CODE (insn) == CODE_LABEL)
                   1678:        break;
                   1679:     }
                   1680: 
                   1681:   return insn;
                   1682: }
                   1683: 
                   1684: #ifdef HAVE_cc0
1.1.1.3   root     1685: /* INSN uses CC0 and is being moved into a delay slot.  Set up REG_CC_SETTER
                   1686:    and REG_CC_USER notes so we can find it.  */
                   1687: 
                   1688: void
                   1689: link_cc0_insns (insn)
                   1690:      rtx insn;
                   1691: {
                   1692:   rtx user = next_nonnote_insn (insn);
                   1693: 
                   1694:   if (GET_CODE (user) == INSN && GET_CODE (PATTERN (user)) == SEQUENCE)
                   1695:     user = XVECEXP (PATTERN (user), 0, 0);
                   1696: 
                   1697:   REG_NOTES (user) = gen_rtx (INSN_LIST, REG_CC_SETTER, insn,
                   1698:                              REG_NOTES (user));
                   1699:   REG_NOTES (insn) = gen_rtx (INSN_LIST, REG_CC_USER, user, REG_NOTES (insn));
                   1700: }
                   1701: 
1.1       root     1702: /* Return the next insn that uses CC0 after INSN, which is assumed to
                   1703:    set it.  This is the inverse of prev_cc0_setter (i.e., prev_cc0_setter
                   1704:    applied to the result of this function should yield INSN).
                   1705: 
                   1706:    Normally, this is simply the next insn.  However, if a REG_CC_USER note
                   1707:    is present, it contains the insn that uses CC0.
                   1708: 
                   1709:    Return 0 if we can't find the insn.  */
                   1710: 
                   1711: rtx
                   1712: next_cc0_user (insn)
                   1713:      rtx insn;
                   1714: {
1.1.1.4 ! root     1715:   rtx note = find_reg_note (insn, REG_CC_USER, NULL_RTX);
1.1       root     1716: 
                   1717:   if (note)
                   1718:     return XEXP (note, 0);
                   1719: 
                   1720:   insn = next_nonnote_insn (insn);
                   1721:   if (insn && GET_CODE (insn) == INSN && GET_CODE (PATTERN (insn)) == SEQUENCE)
                   1722:     insn = XVECEXP (PATTERN (insn), 0, 0);
                   1723: 
                   1724:   if (insn && GET_RTX_CLASS (GET_CODE (insn)) == 'i'
                   1725:       && reg_mentioned_p (cc0_rtx, PATTERN (insn)))
                   1726:     return insn;
                   1727: 
                   1728:   return 0;
                   1729: }
                   1730: 
                   1731: /* Find the insn that set CC0 for INSN.  Unless INSN has a REG_CC_SETTER
                   1732:    note, it is the previous insn.  */
                   1733: 
                   1734: rtx
                   1735: prev_cc0_setter (insn)
                   1736:      rtx insn;
                   1737: {
1.1.1.4 ! root     1738:   rtx note = find_reg_note (insn, REG_CC_SETTER, NULL_RTX);
1.1       root     1739:   rtx link;
                   1740: 
                   1741:   if (note)
                   1742:     return XEXP (note, 0);
                   1743: 
                   1744:   insn = prev_nonnote_insn (insn);
                   1745:   if (! sets_cc0_p (PATTERN (insn)))
                   1746:     abort ();
                   1747: 
                   1748:   return insn;
                   1749: }
                   1750: #endif
                   1751: 
                   1752: /* Try splitting insns that can be split for better scheduling.
                   1753:    PAT is the pattern which might split.
                   1754:    TRIAL is the insn providing PAT.
                   1755:    BACKWARDS is non-zero if we are scanning insns from last to first.
                   1756: 
                   1757:    If this routine succeeds in splitting, it returns the first or last
                   1758:    replacement insn depending on the value of BACKWARDS.  Otherwise, it
                   1759:    returns TRIAL.  If the insn to be returned can be split, it will be.  */
                   1760: 
                   1761: rtx
                   1762: try_split (pat, trial, backwards)
                   1763:      rtx pat, trial;
                   1764:      int backwards;
                   1765: {
                   1766:   rtx before = PREV_INSN (trial);
                   1767:   rtx after = NEXT_INSN (trial);
                   1768:   rtx seq = split_insns (pat, trial);
                   1769:   int has_barrier = 0;
                   1770:   rtx tem;
                   1771: 
                   1772:   /* If we are splitting a JUMP_INSN, it might be followed by a BARRIER.
                   1773:      We may need to handle this specially.  */
                   1774:   if (after && GET_CODE (after) == BARRIER)
                   1775:     {
                   1776:       has_barrier = 1;
                   1777:       after = NEXT_INSN (after);
                   1778:     }
                   1779: 
                   1780:   if (seq)
                   1781:     {
                   1782:       /* SEQ can either be a SEQUENCE or the pattern of a single insn.
                   1783:         The latter case will normally arise only when being done so that
                   1784:         it, in turn, will be split (SFmode on the 29k is an example).  */
                   1785:       if (GET_CODE (seq) == SEQUENCE)
                   1786:        {
                   1787:          /* If we are splitting a JUMP_INSN, look for the JUMP_INSN in
                   1788:             SEQ and copy our JUMP_LABEL to it.  If JUMP_LABEL is non-zero,
                   1789:             increment the usage count so we don't delete the label.  */
                   1790:          int i;
                   1791: 
                   1792:          if (GET_CODE (trial) == JUMP_INSN)
                   1793:            for (i = XVECLEN (seq, 0) - 1; i >= 0; i--)
                   1794:              if (GET_CODE (XVECEXP (seq, 0, i)) == JUMP_INSN)
                   1795:                {
                   1796:                  JUMP_LABEL (XVECEXP (seq, 0, i)) = JUMP_LABEL (trial);
                   1797: 
                   1798:                  if (JUMP_LABEL (trial))
                   1799:                    LABEL_NUSES (JUMP_LABEL (trial))++;
                   1800:                }
                   1801: 
                   1802:          tem = emit_insn_after (seq, before);
                   1803: 
                   1804:          delete_insn (trial);
                   1805:          if (has_barrier)
                   1806:            emit_barrier_after (tem);
                   1807:        }
                   1808:       /* Avoid infinite loop if the result matches the original pattern.  */
                   1809:       else if (rtx_equal_p (seq, pat))
                   1810:        return trial;
                   1811:       else
                   1812:        {
                   1813:          PATTERN (trial) = seq;
                   1814:          INSN_CODE (trial) = -1;
                   1815:        }
                   1816: 
                   1817:       /* Set TEM to the insn we should return.  */
                   1818:       tem = backwards ? prev_active_insn (after) : next_active_insn (before);
                   1819:       return try_split (PATTERN (tem), tem, backwards);
                   1820:     }
                   1821: 
                   1822:   return trial;
                   1823: }
                   1824: 
                   1825: /* Make and return an INSN rtx, initializing all its slots.
1.1.1.4 ! root     1826:    Store PATTERN in the pattern slots.  */
1.1       root     1827: 
                   1828: rtx
1.1.1.4 ! root     1829: make_insn_raw (pattern)
1.1       root     1830:      rtx pattern;
                   1831: {
                   1832:   register rtx insn;
                   1833: 
                   1834:   insn = rtx_alloc(INSN);
                   1835:   INSN_UID(insn) = cur_insn_uid++;
                   1836: 
                   1837:   PATTERN (insn) = pattern;
                   1838:   INSN_CODE (insn) = -1;
                   1839:   LOG_LINKS(insn) = NULL;
                   1840:   REG_NOTES(insn) = NULL;
                   1841: 
                   1842:   return insn;
                   1843: }
                   1844: 
                   1845: /* Like `make_insn' but make a JUMP_INSN instead of an insn.  */
                   1846: 
                   1847: static rtx
1.1.1.4 ! root     1848: make_jump_insn_raw (pattern)
1.1       root     1849:      rtx pattern;
                   1850: {
                   1851:   register rtx insn;
                   1852: 
1.1.1.4 ! root     1853:   insn = rtx_alloc (JUMP_INSN);
1.1       root     1854:   INSN_UID(insn) = cur_insn_uid++;
                   1855: 
                   1856:   PATTERN (insn) = pattern;
                   1857:   INSN_CODE (insn) = -1;
                   1858:   LOG_LINKS(insn) = NULL;
                   1859:   REG_NOTES(insn) = NULL;
                   1860:   JUMP_LABEL(insn) = NULL;
                   1861: 
                   1862:   return insn;
                   1863: }
                   1864: 
                   1865: /* Add INSN to the end of the doubly-linked list.
                   1866:    INSN may be an INSN, JUMP_INSN, CALL_INSN, CODE_LABEL, BARRIER or NOTE.  */
                   1867: 
                   1868: void
                   1869: add_insn (insn)
                   1870:      register rtx insn;
                   1871: {
                   1872:   PREV_INSN (insn) = last_insn;
                   1873:   NEXT_INSN (insn) = 0;
                   1874: 
                   1875:   if (NULL != last_insn)
                   1876:     NEXT_INSN (last_insn) = insn;
                   1877: 
                   1878:   if (NULL == first_insn)
                   1879:     first_insn = insn;
                   1880: 
                   1881:   last_insn = insn;
                   1882: }
                   1883: 
                   1884: /* Add INSN into the doubly-linked list after insn AFTER.  This should be the
                   1885:    only function called to insert an insn once delay slots have been filled
                   1886:    since only it knows how to update a SEQUENCE.  */
                   1887: 
                   1888: void
                   1889: add_insn_after (insn, after)
                   1890:      rtx insn, after;
                   1891: {
                   1892:   rtx next = NEXT_INSN (after);
                   1893: 
                   1894:   NEXT_INSN (insn) = next;
                   1895:   PREV_INSN (insn) = after;
                   1896: 
                   1897:   if (next)
                   1898:     {
                   1899:       PREV_INSN (next) = insn;
                   1900:       if (GET_CODE (next) == INSN && GET_CODE (PATTERN (next)) == SEQUENCE)
                   1901:        PREV_INSN (XVECEXP (PATTERN (next), 0, 0)) = insn;
                   1902:     }
                   1903:   else if (last_insn == after)
                   1904:     last_insn = insn;
                   1905:   else
                   1906:     {
                   1907:       struct sequence_stack *stack = sequence_stack;
                   1908:       /* Scan all pending sequences too.  */
                   1909:       for (; stack; stack = stack->next)
                   1910:        if (after == stack->last)
                   1911:          stack->last = insn;
                   1912:     }
                   1913: 
                   1914:   NEXT_INSN (after) = insn;
                   1915:   if (GET_CODE (after) == INSN && GET_CODE (PATTERN (after)) == SEQUENCE)
                   1916:     {
                   1917:       rtx sequence = PATTERN (after);
                   1918:       NEXT_INSN (XVECEXP (sequence, 0, XVECLEN (sequence, 0) - 1)) = insn;
                   1919:     }
                   1920: }
                   1921: 
                   1922: /* Delete all insns made since FROM.
                   1923:    FROM becomes the new last instruction.  */
                   1924: 
                   1925: void
                   1926: delete_insns_since (from)
                   1927:      rtx from;
                   1928: {
                   1929:   if (from == 0)
                   1930:     first_insn = 0;
                   1931:   else
                   1932:     NEXT_INSN (from) = 0;
                   1933:   last_insn = from;
                   1934: }
                   1935: 
                   1936: /* Move a consecutive bunch of insns to a different place in the chain.
                   1937:    The insns to be moved are those between FROM and TO.
                   1938:    They are moved to a new position after the insn AFTER.
                   1939:    AFTER must not be FROM or TO or any insn in between.
                   1940: 
                   1941:    This function does not know about SEQUENCEs and hence should not be
                   1942:    called after delay-slot filling has been done.  */
                   1943: 
                   1944: void
                   1945: reorder_insns (from, to, after)
                   1946:      rtx from, to, after;
                   1947: {
                   1948:   /* Splice this bunch out of where it is now.  */
                   1949:   if (PREV_INSN (from))
                   1950:     NEXT_INSN (PREV_INSN (from)) = NEXT_INSN (to);
                   1951:   if (NEXT_INSN (to))
                   1952:     PREV_INSN (NEXT_INSN (to)) = PREV_INSN (from);
                   1953:   if (last_insn == to)
                   1954:     last_insn = PREV_INSN (from);
                   1955:   if (first_insn == from)
                   1956:     first_insn = NEXT_INSN (to);
                   1957: 
                   1958:   /* Make the new neighbors point to it and it to them.  */
                   1959:   if (NEXT_INSN (after))
                   1960:     PREV_INSN (NEXT_INSN (after)) = to;
                   1961: 
                   1962:   NEXT_INSN (to) = NEXT_INSN (after);
                   1963:   PREV_INSN (from) = after;
                   1964:   NEXT_INSN (after) = from;
                   1965:   if (after == last_insn)
                   1966:     last_insn = to;
                   1967: }
                   1968: 
                   1969: /* Return the line note insn preceding INSN.  */
                   1970: 
                   1971: static rtx
                   1972: find_line_note (insn)
                   1973:      rtx insn;
                   1974: {
                   1975:   if (no_line_numbers)
                   1976:     return 0;
                   1977: 
                   1978:   for (; insn; insn = PREV_INSN (insn))
                   1979:     if (GET_CODE (insn) == NOTE
                   1980:         && NOTE_LINE_NUMBER (insn) >= 0)
                   1981:       break;
                   1982: 
                   1983:   return insn;
                   1984: }
                   1985: 
                   1986: /* Like reorder_insns, but inserts line notes to preserve the line numbers
                   1987:    of the moved insns when debugging.  This may insert a note between AFTER
                   1988:    and FROM, and another one after TO.  */
                   1989: 
                   1990: void
                   1991: reorder_insns_with_line_notes (from, to, after)
                   1992:      rtx from, to, after;
                   1993: {
                   1994:   rtx from_line = find_line_note (from);
                   1995:   rtx after_line = find_line_note (after);
                   1996: 
                   1997:   reorder_insns (from, to, after);
                   1998: 
                   1999:   if (from_line == after_line)
                   2000:     return;
                   2001: 
                   2002:   if (from_line)
                   2003:     emit_line_note_after (NOTE_SOURCE_FILE (from_line),
                   2004:                          NOTE_LINE_NUMBER (from_line),
                   2005:                          after);
                   2006:   if (after_line)
                   2007:     emit_line_note_after (NOTE_SOURCE_FILE (after_line),
                   2008:                          NOTE_LINE_NUMBER (after_line),
                   2009:                          to);
                   2010: }
                   2011: 
                   2012: /* Emit an insn of given code and pattern
                   2013:    at a specified place within the doubly-linked list.  */
                   2014: 
                   2015: /* Make an instruction with body PATTERN
                   2016:    and output it before the instruction BEFORE.  */
                   2017: 
                   2018: rtx
                   2019: emit_insn_before (pattern, before)
                   2020:      register rtx pattern, before;
                   2021: {
                   2022:   register rtx insn = before;
                   2023: 
                   2024:   if (GET_CODE (pattern) == SEQUENCE)
                   2025:     {
                   2026:       register int i;
                   2027: 
                   2028:       for (i = 0; i < XVECLEN (pattern, 0); i++)
                   2029:        {
                   2030:          insn = XVECEXP (pattern, 0, i);
                   2031:          add_insn_after (insn, PREV_INSN (before));
                   2032:        }
                   2033:       if (XVECLEN (pattern, 0) < SEQUENCE_RESULT_SIZE)
                   2034:        sequence_result[XVECLEN (pattern, 0)] = pattern;
                   2035:     }
                   2036:   else
                   2037:     {
1.1.1.4 ! root     2038:       insn = make_insn_raw (pattern);
1.1       root     2039:       add_insn_after (insn, PREV_INSN (before));
                   2040:     }
                   2041: 
                   2042:   return insn;
                   2043: }
                   2044: 
                   2045: /* Make an instruction with body PATTERN and code JUMP_INSN
                   2046:    and output it before the instruction BEFORE.  */
                   2047: 
                   2048: rtx
                   2049: emit_jump_insn_before (pattern, before)
                   2050:      register rtx pattern, before;
                   2051: {
                   2052:   register rtx insn;
                   2053: 
                   2054:   if (GET_CODE (pattern) == SEQUENCE)
                   2055:     insn = emit_insn_before (pattern, before);
                   2056:   else
                   2057:     {
1.1.1.4 ! root     2058:       insn = make_jump_insn_raw (pattern, NULL_RTVEC);
1.1       root     2059:       add_insn_after (insn, PREV_INSN (before));
                   2060:     }
                   2061: 
                   2062:   return insn;
                   2063: }
                   2064: 
                   2065: /* Make an instruction with body PATTERN and code CALL_INSN
                   2066:    and output it before the instruction BEFORE.  */
                   2067: 
                   2068: rtx
                   2069: emit_call_insn_before (pattern, before)
                   2070:      register rtx pattern, before;
                   2071: {
                   2072:   rtx insn = emit_insn_before (pattern, before);
                   2073:   PUT_CODE (insn, CALL_INSN);
                   2074:   return insn;
                   2075: }
                   2076: 
                   2077: /* Make an insn of code BARRIER
                   2078:    and output it before the insn AFTER.  */
                   2079: 
                   2080: rtx
                   2081: emit_barrier_before (before)
                   2082:      register rtx before;
                   2083: {
                   2084:   register rtx insn = rtx_alloc (BARRIER);
                   2085: 
                   2086:   INSN_UID (insn) = cur_insn_uid++;
                   2087: 
                   2088:   add_insn_after (insn, PREV_INSN (before));
                   2089:   return insn;
                   2090: }
                   2091: 
                   2092: /* Emit a note of subtype SUBTYPE before the insn BEFORE.  */
                   2093: 
                   2094: rtx
                   2095: emit_note_before (subtype, before)
                   2096:      int subtype;
                   2097:      rtx before;
                   2098: {
                   2099:   register rtx note = rtx_alloc (NOTE);
                   2100:   INSN_UID (note) = cur_insn_uid++;
                   2101:   NOTE_SOURCE_FILE (note) = 0;
                   2102:   NOTE_LINE_NUMBER (note) = subtype;
                   2103: 
                   2104:   add_insn_after (note, PREV_INSN (before));
                   2105:   return note;
                   2106: }
                   2107: 
                   2108: /* Make an insn of code INSN with body PATTERN
                   2109:    and output it after the insn AFTER.  */
                   2110: 
                   2111: rtx
                   2112: emit_insn_after (pattern, after)
                   2113:      register rtx pattern, after;
                   2114: {
                   2115:   register rtx insn = after;
                   2116: 
                   2117:   if (GET_CODE (pattern) == SEQUENCE)
                   2118:     {
                   2119:       register int i;
                   2120: 
                   2121:       for (i = 0; i < XVECLEN (pattern, 0); i++)
                   2122:        {
                   2123:          insn = XVECEXP (pattern, 0, i);
                   2124:          add_insn_after (insn, after);
                   2125:          after = insn;
                   2126:        }
                   2127:       if (XVECLEN (pattern, 0) < SEQUENCE_RESULT_SIZE)
                   2128:        sequence_result[XVECLEN (pattern, 0)] = pattern;
                   2129:     }
                   2130:   else
                   2131:     {
1.1.1.4 ! root     2132:       insn = make_insn_raw (pattern);
1.1       root     2133:       add_insn_after (insn, after);
                   2134:     }
                   2135: 
                   2136:   return insn;
                   2137: }
                   2138: 
1.1.1.4 ! root     2139: /* Similar to emit_insn_after, except that line notes are to be inserted so
        !          2140:    as to act as if this insn were at FROM.  */
        !          2141: 
        !          2142: void
        !          2143: emit_insn_after_with_line_notes (pattern, after, from)
        !          2144:      rtx pattern, after, from;
        !          2145: {
        !          2146:   rtx from_line = find_line_note (from);
        !          2147:   rtx after_line = find_line_note (after);
        !          2148:   rtx insn = emit_insn_after (pattern, after);
        !          2149: 
        !          2150:   if (from_line)
        !          2151:     emit_line_note_after (NOTE_SOURCE_FILE (from_line),
        !          2152:                          NOTE_LINE_NUMBER (from_line),
        !          2153:                          after);
        !          2154: 
        !          2155:   if (after_line)
        !          2156:     emit_line_note_after (NOTE_SOURCE_FILE (after_line),
        !          2157:                          NOTE_LINE_NUMBER (after_line),
        !          2158:                          insn);
        !          2159: }
        !          2160: 
1.1       root     2161: /* Make an insn of code JUMP_INSN with body PATTERN
                   2162:    and output it after the insn AFTER.  */
                   2163: 
                   2164: rtx
                   2165: emit_jump_insn_after (pattern, after)
                   2166:      register rtx pattern, after;
                   2167: {
                   2168:   register rtx insn;
                   2169: 
                   2170:   if (GET_CODE (pattern) == SEQUENCE)
                   2171:     insn = emit_insn_after (pattern, after);
                   2172:   else
                   2173:     {
1.1.1.4 ! root     2174:       insn = make_jump_insn_raw (pattern, NULL_RTVEC);
1.1       root     2175:       add_insn_after (insn, after);
                   2176:     }
                   2177: 
                   2178:   return insn;
                   2179: }
                   2180: 
                   2181: /* Make an insn of code BARRIER
                   2182:    and output it after the insn AFTER.  */
                   2183: 
                   2184: rtx
                   2185: emit_barrier_after (after)
                   2186:      register rtx after;
                   2187: {
                   2188:   register rtx insn = rtx_alloc (BARRIER);
                   2189: 
                   2190:   INSN_UID (insn) = cur_insn_uid++;
                   2191: 
                   2192:   add_insn_after (insn, after);
                   2193:   return insn;
                   2194: }
                   2195: 
                   2196: /* Emit the label LABEL after the insn AFTER.  */
                   2197: 
                   2198: rtx
                   2199: emit_label_after (label, after)
                   2200:      rtx label, after;
                   2201: {
                   2202:   /* This can be called twice for the same label
                   2203:      as a result of the confusion that follows a syntax error!
                   2204:      So make it harmless.  */
                   2205:   if (INSN_UID (label) == 0)
                   2206:     {
                   2207:       INSN_UID (label) = cur_insn_uid++;
                   2208:       add_insn_after (label, after);
                   2209:     }
                   2210: 
                   2211:   return label;
                   2212: }
                   2213: 
                   2214: /* Emit a note of subtype SUBTYPE after the insn AFTER.  */
                   2215: 
                   2216: rtx
                   2217: emit_note_after (subtype, after)
                   2218:      int subtype;
                   2219:      rtx after;
                   2220: {
                   2221:   register rtx note = rtx_alloc (NOTE);
                   2222:   INSN_UID (note) = cur_insn_uid++;
                   2223:   NOTE_SOURCE_FILE (note) = 0;
                   2224:   NOTE_LINE_NUMBER (note) = subtype;
                   2225:   add_insn_after (note, after);
                   2226:   return note;
                   2227: }
                   2228: 
                   2229: /* Emit a line note for FILE and LINE after the insn AFTER.  */
                   2230: 
                   2231: rtx
                   2232: emit_line_note_after (file, line, after)
                   2233:      char *file;
                   2234:      int line;
                   2235:      rtx after;
                   2236: {
                   2237:   register rtx note;
                   2238: 
                   2239:   if (no_line_numbers && line > 0)
                   2240:     {
                   2241:       cur_insn_uid++;
                   2242:       return 0;
                   2243:     }
                   2244: 
                   2245:   note  = rtx_alloc (NOTE);
                   2246:   INSN_UID (note) = cur_insn_uid++;
                   2247:   NOTE_SOURCE_FILE (note) = file;
                   2248:   NOTE_LINE_NUMBER (note) = line;
                   2249:   add_insn_after (note, after);
                   2250:   return note;
                   2251: }
                   2252: 
                   2253: /* Make an insn of code INSN with pattern PATTERN
                   2254:    and add it to the end of the doubly-linked list.
                   2255:    If PATTERN is a SEQUENCE, take the elements of it
                   2256:    and emit an insn for each element.
                   2257: 
                   2258:    Returns the last insn emitted.  */
                   2259: 
                   2260: rtx
                   2261: emit_insn (pattern)
                   2262:      rtx pattern;
                   2263: {
                   2264:   rtx insn = last_insn;
                   2265: 
                   2266:   if (GET_CODE (pattern) == SEQUENCE)
                   2267:     {
                   2268:       register int i;
                   2269: 
                   2270:       for (i = 0; i < XVECLEN (pattern, 0); i++)
                   2271:        {
                   2272:          insn = XVECEXP (pattern, 0, i);
                   2273:          add_insn (insn);
                   2274:        }
                   2275:       if (XVECLEN (pattern, 0) < SEQUENCE_RESULT_SIZE)
                   2276:        sequence_result[XVECLEN (pattern, 0)] = pattern;
                   2277:     }
                   2278:   else
                   2279:     {
1.1.1.4 ! root     2280:       insn = make_insn_raw (pattern);
1.1       root     2281:       add_insn (insn);
                   2282:     }
                   2283: 
                   2284:   return insn;
                   2285: }
                   2286: 
                   2287: /* Emit the insns in a chain starting with INSN.
                   2288:    Return the last insn emitted.  */
                   2289: 
                   2290: rtx
                   2291: emit_insns (insn)
                   2292:      rtx insn;
                   2293: {
                   2294:   rtx last = 0;
                   2295: 
                   2296:   while (insn)
                   2297:     {
                   2298:       rtx next = NEXT_INSN (insn);
                   2299:       add_insn (insn);
                   2300:       last = insn;
                   2301:       insn = next;
                   2302:     }
                   2303: 
                   2304:   return last;
                   2305: }
                   2306: 
                   2307: /* Emit the insns in a chain starting with INSN and place them in front of
                   2308:    the insn BEFORE.  Return the last insn emitted.  */
                   2309: 
                   2310: rtx
                   2311: emit_insns_before (insn, before)
                   2312:      rtx insn;
                   2313:      rtx before;
                   2314: {
                   2315:   rtx last = 0;
                   2316: 
                   2317:   while (insn)
                   2318:     {
                   2319:       rtx next = NEXT_INSN (insn);
                   2320:       add_insn_after (insn, PREV_INSN (before));
                   2321:       last = insn;
                   2322:       insn = next;
                   2323:     }
                   2324: 
                   2325:   return last;
                   2326: }
                   2327: 
1.1.1.4 ! root     2328: /* Emit the insns in a chain starting with FIRST and place them in back of
        !          2329:    the insn AFTER.  Return the last insn emitted.  */
        !          2330: 
        !          2331: rtx
        !          2332: emit_insns_after (first, after)
        !          2333:      register rtx first;
        !          2334:      register rtx after;
        !          2335: {
        !          2336:   register rtx last;
        !          2337:   register rtx after_after;
        !          2338: 
        !          2339:   if (!after)
        !          2340:     abort ();
        !          2341: 
        !          2342:   if (!first)
        !          2343:     return first;
        !          2344: 
        !          2345:   for (last = first; NEXT_INSN (last); last = NEXT_INSN (last))
        !          2346:     continue;
        !          2347: 
        !          2348:   after_after = NEXT_INSN (after);
        !          2349: 
        !          2350:   NEXT_INSN (after) = first;
        !          2351:   PREV_INSN (first) = after;
        !          2352:   NEXT_INSN (last) = after_after;
        !          2353:   if (after_after)
        !          2354:     PREV_INSN (after_after) = last;
        !          2355: 
        !          2356:   if (after == last_insn)
        !          2357:     last_insn = last;
        !          2358:   return last;
        !          2359: }
        !          2360: 
1.1       root     2361: /* Make an insn of code JUMP_INSN with pattern PATTERN
                   2362:    and add it to the end of the doubly-linked list.  */
                   2363: 
                   2364: rtx
                   2365: emit_jump_insn (pattern)
                   2366:      rtx pattern;
                   2367: {
                   2368:   if (GET_CODE (pattern) == SEQUENCE)
                   2369:     return emit_insn (pattern);
                   2370:   else
                   2371:     {
1.1.1.4 ! root     2372:       register rtx insn = make_jump_insn_raw (pattern, NULL_RTVEC);
1.1       root     2373:       add_insn (insn);
                   2374:       return insn;
                   2375:     }
                   2376: }
                   2377: 
                   2378: /* Make an insn of code CALL_INSN with pattern PATTERN
                   2379:    and add it to the end of the doubly-linked list.  */
                   2380: 
                   2381: rtx
                   2382: emit_call_insn (pattern)
                   2383:      rtx pattern;
                   2384: {
                   2385:   if (GET_CODE (pattern) == SEQUENCE)
                   2386:     return emit_insn (pattern);
                   2387:   else
                   2388:     {
1.1.1.4 ! root     2389:       register rtx insn = make_insn_raw (pattern);
1.1       root     2390:       add_insn (insn);
                   2391:       PUT_CODE (insn, CALL_INSN);
                   2392:       return insn;
                   2393:     }
                   2394: }
                   2395: 
                   2396: /* Add the label LABEL to the end of the doubly-linked list.  */
                   2397: 
                   2398: rtx
                   2399: emit_label (label)
                   2400:      rtx label;
                   2401: {
                   2402:   /* This can be called twice for the same label
                   2403:      as a result of the confusion that follows a syntax error!
                   2404:      So make it harmless.  */
                   2405:   if (INSN_UID (label) == 0)
                   2406:     {
                   2407:       INSN_UID (label) = cur_insn_uid++;
                   2408:       add_insn (label);
                   2409:     }
                   2410:   return label;
                   2411: }
                   2412: 
                   2413: /* Make an insn of code BARRIER
                   2414:    and add it to the end of the doubly-linked list.  */
                   2415: 
                   2416: rtx
                   2417: emit_barrier ()
                   2418: {
                   2419:   register rtx barrier = rtx_alloc (BARRIER);
                   2420:   INSN_UID (barrier) = cur_insn_uid++;
                   2421:   add_insn (barrier);
                   2422:   return barrier;
                   2423: }
                   2424: 
                   2425: /* Make an insn of code NOTE
                   2426:    with data-fields specified by FILE and LINE
                   2427:    and add it to the end of the doubly-linked list,
                   2428:    but only if line-numbers are desired for debugging info.  */
                   2429: 
                   2430: rtx
                   2431: emit_line_note (file, line)
                   2432:      char *file;
                   2433:      int line;
                   2434: {
                   2435:   emit_filename = file;
                   2436:   emit_lineno = line;
                   2437: 
                   2438: #if 0
                   2439:   if (no_line_numbers)
                   2440:     return 0;
                   2441: #endif
                   2442: 
                   2443:   return emit_note (file, line);
                   2444: }
                   2445: 
                   2446: /* Make an insn of code NOTE
                   2447:    with data-fields specified by FILE and LINE
                   2448:    and add it to the end of the doubly-linked list.
                   2449:    If it is a line-number NOTE, omit it if it matches the previous one.  */
                   2450: 
                   2451: rtx
                   2452: emit_note (file, line)
                   2453:      char *file;
                   2454:      int line;
                   2455: {
                   2456:   register rtx note;
                   2457: 
                   2458:   if (line > 0)
                   2459:     {
                   2460:       if (file && last_filename && !strcmp (file, last_filename)
                   2461:          && line == last_linenum)
                   2462:        return 0;
                   2463:       last_filename = file;
                   2464:       last_linenum = line;
                   2465:     }
                   2466: 
                   2467:   if (no_line_numbers && line > 0)
                   2468:     {
                   2469:       cur_insn_uid++;
                   2470:       return 0;
                   2471:     }
                   2472: 
                   2473:   note = rtx_alloc (NOTE);
                   2474:   INSN_UID (note) = cur_insn_uid++;
                   2475:   NOTE_SOURCE_FILE (note) = file;
                   2476:   NOTE_LINE_NUMBER (note) = line;
                   2477:   add_insn (note);
                   2478:   return note;
                   2479: }
                   2480: 
                   2481: /* Emit a NOTE, and don't omit it even if LINE it the previous note.  */
                   2482: 
                   2483: rtx
                   2484: emit_line_note_force (file, line)
                   2485:      char *file;
                   2486:      int line;
                   2487: {
                   2488:   last_linenum = -1;
                   2489:   return emit_line_note (file, line);
                   2490: }
                   2491: 
                   2492: /* Cause next statement to emit a line note even if the line number
                   2493:    has not changed.  This is used at the beginning of a function.  */
                   2494: 
                   2495: void
                   2496: force_next_line_note ()
                   2497: {
                   2498:   last_linenum = -1;
                   2499: }
                   2500: 
                   2501: /* Return an indication of which type of insn should have X as a body.
                   2502:    The value is CODE_LABEL, INSN, CALL_INSN or JUMP_INSN.  */
                   2503: 
                   2504: enum rtx_code
                   2505: classify_insn (x)
                   2506:      rtx x;
                   2507: {
                   2508:   if (GET_CODE (x) == CODE_LABEL)
                   2509:     return CODE_LABEL;
                   2510:   if (GET_CODE (x) == CALL)
                   2511:     return CALL_INSN;
                   2512:   if (GET_CODE (x) == RETURN)
                   2513:     return JUMP_INSN;
                   2514:   if (GET_CODE (x) == SET)
                   2515:     {
                   2516:       if (SET_DEST (x) == pc_rtx)
                   2517:        return JUMP_INSN;
                   2518:       else if (GET_CODE (SET_SRC (x)) == CALL)
                   2519:        return CALL_INSN;
                   2520:       else
                   2521:        return INSN;
                   2522:     }
                   2523:   if (GET_CODE (x) == PARALLEL)
                   2524:     {
                   2525:       register int j;
                   2526:       for (j = XVECLEN (x, 0) - 1; j >= 0; j--)
                   2527:        if (GET_CODE (XVECEXP (x, 0, j)) == CALL)
                   2528:          return CALL_INSN;
                   2529:        else if (GET_CODE (XVECEXP (x, 0, j)) == SET
                   2530:                 && SET_DEST (XVECEXP (x, 0, j)) == pc_rtx)
                   2531:          return JUMP_INSN;
                   2532:        else if (GET_CODE (XVECEXP (x, 0, j)) == SET
                   2533:                 && GET_CODE (SET_SRC (XVECEXP (x, 0, j))) == CALL)
                   2534:          return CALL_INSN;
                   2535:     }
                   2536:   return INSN;
                   2537: }
                   2538: 
                   2539: /* Emit the rtl pattern X as an appropriate kind of insn.
                   2540:    If X is a label, it is simply added into the insn chain.  */
                   2541: 
                   2542: rtx
                   2543: emit (x)
                   2544:      rtx x;
                   2545: {
                   2546:   enum rtx_code code = classify_insn (x);
                   2547: 
                   2548:   if (code == CODE_LABEL)
                   2549:     return emit_label (x);
                   2550:   else if (code == INSN)
                   2551:     return emit_insn (x);
                   2552:   else if (code == JUMP_INSN)
                   2553:     {
                   2554:       register rtx insn = emit_jump_insn (x);
                   2555:       if (simplejump_p (insn) || GET_CODE (x) == RETURN)
                   2556:        return emit_barrier ();
                   2557:       return insn;
                   2558:     }
                   2559:   else if (code == CALL_INSN)
                   2560:     return emit_call_insn (x);
                   2561:   else
                   2562:     abort ();
                   2563: }
                   2564: 
                   2565: /* Begin emitting insns to a sequence which can be packaged in an RTL_EXPR.  */
                   2566: 
                   2567: void
                   2568: start_sequence ()
                   2569: {
                   2570:   struct sequence_stack *tem;
                   2571: 
                   2572:   if (sequence_element_free_list)
                   2573:     {
                   2574:       /* Reuse a previously-saved struct sequence_stack.  */
                   2575:       tem = sequence_element_free_list;
                   2576:       sequence_element_free_list = tem->next;
                   2577:     }
                   2578:   else
                   2579:     tem = (struct sequence_stack *) permalloc (sizeof (struct sequence_stack));
                   2580: 
                   2581:   tem->next = sequence_stack;
                   2582:   tem->first = first_insn;
                   2583:   tem->last = last_insn;
                   2584: 
                   2585:   sequence_stack = tem;
                   2586: 
                   2587:   first_insn = 0;
                   2588:   last_insn = 0;
                   2589: }
                   2590: 
                   2591: /* Set up the insn chain starting with FIRST
                   2592:    as the current sequence, saving the previously current one.  */
                   2593: 
                   2594: void
                   2595: push_to_sequence (first)
                   2596:      rtx first;
                   2597: {
                   2598:   rtx last;
                   2599: 
                   2600:   start_sequence ();
                   2601: 
                   2602:   for (last = first; last && NEXT_INSN (last); last = NEXT_INSN (last));
                   2603: 
                   2604:   first_insn = first;
                   2605:   last_insn = last;
                   2606: }
                   2607: 
                   2608: /* After emitting to a sequence, restore previous saved state.
                   2609: 
                   2610:    To get the contents of the sequence just made,
                   2611:    you must call `gen_sequence' *before* calling here.  */
                   2612: 
                   2613: void
                   2614: end_sequence ()
                   2615: {
                   2616:   struct sequence_stack *tem = sequence_stack;
                   2617: 
                   2618:   first_insn = tem->first;
                   2619:   last_insn = tem->last;
                   2620:   sequence_stack = tem->next;
                   2621: 
                   2622:   tem->next = sequence_element_free_list;
                   2623:   sequence_element_free_list = tem;
                   2624: }
                   2625: 
                   2626: /* Return 1 if currently emitting into a sequence.  */
                   2627: 
                   2628: int
                   2629: in_sequence_p ()
                   2630: {
                   2631:   return sequence_stack != 0;
                   2632: }
                   2633: 
                   2634: /* Generate a SEQUENCE rtx containing the insns already emitted
                   2635:    to the current sequence.
                   2636: 
                   2637:    This is how the gen_... function from a DEFINE_EXPAND
                   2638:    constructs the SEQUENCE that it returns.  */
                   2639: 
                   2640: rtx
                   2641: gen_sequence ()
                   2642: {
                   2643:   rtx result;
                   2644:   rtx tem;
                   2645:   rtvec newvec;
                   2646:   int i;
                   2647:   int len;
                   2648: 
                   2649:   /* Count the insns in the chain.  */
                   2650:   len = 0;
                   2651:   for (tem = first_insn; tem; tem = NEXT_INSN (tem))
                   2652:     len++;
                   2653: 
                   2654:   /* If only one insn, return its pattern rather than a SEQUENCE.
                   2655:      (Now that we cache SEQUENCE expressions, it isn't worth special-casing
                   2656:      the case of an empty list.)  */
                   2657:   if (len == 1
                   2658:       && (GET_CODE (first_insn) == INSN
                   2659:          || GET_CODE (first_insn) == JUMP_INSN
                   2660:          || GET_CODE (first_insn) == CALL_INSN))
                   2661:     return PATTERN (first_insn);
                   2662: 
                   2663:   /* Put them in a vector.  See if we already have a SEQUENCE of the
                   2664:      appropriate length around.  */
                   2665:   if (len < SEQUENCE_RESULT_SIZE && (result = sequence_result[len]) != 0)
                   2666:     sequence_result[len] = 0;
                   2667:   else
                   2668:     {
                   2669:       /* Ensure that this rtl goes in saveable_obstack, since we may be
                   2670:         caching it.  */
                   2671:       int in_current_obstack = rtl_in_saveable_obstack ();
                   2672:       result = gen_rtx (SEQUENCE, VOIDmode, rtvec_alloc (len));
                   2673:       if (in_current_obstack)
                   2674:        rtl_in_current_obstack ();
                   2675:     }
                   2676: 
                   2677:   for (i = 0, tem = first_insn; tem; tem = NEXT_INSN (tem), i++)
                   2678:     XVECEXP (result, 0, i) = tem;
                   2679: 
                   2680:   return result;
                   2681: }
                   2682: 
                   2683: /* Set up regno_reg_rtx, reg_rtx_no and regno_pointer_flag
                   2684:    according to the chain of insns starting with FIRST.
                   2685: 
                   2686:    Also set cur_insn_uid to exceed the largest uid in that chain.
                   2687: 
                   2688:    This is used when an inline function's rtl is saved
                   2689:    and passed to rest_of_compilation later.  */
                   2690: 
                   2691: static void restore_reg_data_1 ();
                   2692: 
                   2693: void
                   2694: restore_reg_data (first)
                   2695:      rtx first;
                   2696: {
                   2697:   register rtx insn;
                   2698:   int i;
                   2699:   register int max_uid = 0;
                   2700: 
                   2701:   for (insn = first; insn; insn = NEXT_INSN (insn))
                   2702:     {
                   2703:       if (INSN_UID (insn) >= max_uid)
                   2704:        max_uid = INSN_UID (insn);
                   2705: 
                   2706:       switch (GET_CODE (insn))
                   2707:        {
                   2708:        case NOTE:
                   2709:        case CODE_LABEL:
                   2710:        case BARRIER:
                   2711:          break;
                   2712: 
                   2713:        case JUMP_INSN:
                   2714:        case CALL_INSN:
                   2715:        case INSN:
                   2716:          restore_reg_data_1 (PATTERN (insn));
                   2717:          break;
                   2718:        }
                   2719:     }
                   2720: 
                   2721:   /* Don't duplicate the uids already in use.  */
                   2722:   cur_insn_uid = max_uid + 1;
                   2723: 
                   2724:   /* If any regs are missing, make them up.  
                   2725: 
                   2726:      ??? word_mode is not necessarily the right mode.  Most likely these REGs
                   2727:      are never used.  At some point this should be checked.  */
                   2728: 
                   2729:   for (i = FIRST_PSEUDO_REGISTER; i < reg_rtx_no; i++)
                   2730:     if (regno_reg_rtx[i] == 0)
                   2731:       regno_reg_rtx[i] = gen_rtx (REG, word_mode, i);
                   2732: }
                   2733: 
                   2734: static void
                   2735: restore_reg_data_1 (orig)
                   2736:      rtx orig;
                   2737: {
                   2738:   register rtx x = orig;
                   2739:   register int i;
                   2740:   register enum rtx_code code;
                   2741:   register char *format_ptr;
                   2742: 
                   2743:   code = GET_CODE (x);
                   2744: 
                   2745:   switch (code)
                   2746:     {
                   2747:     case QUEUED:
                   2748:     case CONST_INT:
                   2749:     case CONST_DOUBLE:
                   2750:     case SYMBOL_REF:
                   2751:     case CODE_LABEL:
                   2752:     case PC:
                   2753:     case CC0:
                   2754:     case LABEL_REF:
                   2755:       return;
                   2756: 
                   2757:     case REG:
                   2758:       if (REGNO (x) >= FIRST_PSEUDO_REGISTER)
                   2759:        {
                   2760:          /* Make sure regno_pointer_flag and regno_reg_rtx are large
                   2761:             enough to have an element for this pseudo reg number.  */
                   2762:          if (REGNO (x) >= reg_rtx_no)
                   2763:            {
                   2764:              reg_rtx_no = REGNO (x);
                   2765: 
                   2766:              if (reg_rtx_no >= regno_pointer_flag_length)
                   2767:                {
                   2768:                  int newlen = MAX (regno_pointer_flag_length * 2,
                   2769:                                    reg_rtx_no + 30);
                   2770:                  rtx *new1;
                   2771:                  char *new = (char *) oballoc (newlen);
                   2772:                  bzero (new, newlen);
                   2773:                  bcopy (regno_pointer_flag, new, regno_pointer_flag_length);
                   2774: 
                   2775:                  new1 = (rtx *) oballoc (newlen * sizeof (rtx));
                   2776:                  bzero (new1, newlen * sizeof (rtx));
                   2777:                  bcopy (regno_reg_rtx, new1, regno_pointer_flag_length * sizeof (rtx));
                   2778: 
                   2779:                  regno_pointer_flag = new;
                   2780:                  regno_reg_rtx = new1;
                   2781:                  regno_pointer_flag_length = newlen;
                   2782:                }
                   2783:              reg_rtx_no ++;
                   2784:            }
                   2785:          regno_reg_rtx[REGNO (x)] = x;
                   2786:        }
                   2787:       return;
                   2788: 
                   2789:     case MEM:
                   2790:       if (GET_CODE (XEXP (x, 0)) == REG)
                   2791:        mark_reg_pointer (XEXP (x, 0));
                   2792:       restore_reg_data_1 (XEXP (x, 0));
                   2793:       return;
                   2794:     }
                   2795: 
                   2796:   /* Now scan the subexpressions recursively.  */
                   2797: 
                   2798:   format_ptr = GET_RTX_FORMAT (code);
                   2799: 
                   2800:   for (i = 0; i < GET_RTX_LENGTH (code); i++)
                   2801:     {
                   2802:       switch (*format_ptr++)
                   2803:        {
                   2804:        case 'e':
                   2805:          restore_reg_data_1 (XEXP (x, i));
                   2806:          break;
                   2807: 
                   2808:        case 'E':
                   2809:          if (XVEC (x, i) != NULL)
                   2810:            {
                   2811:              register int j;
                   2812: 
                   2813:              for (j = 0; j < XVECLEN (x, i); j++)
                   2814:                restore_reg_data_1 (XVECEXP (x, i, j));
                   2815:            }
                   2816:          break;
                   2817:        }
                   2818:     }
                   2819: }
                   2820: 
                   2821: /* Initialize data structures and variables in this file
                   2822:    before generating rtl for each function.  */
                   2823: 
                   2824: void
                   2825: init_emit ()
                   2826: {
                   2827:   int i;
                   2828: 
                   2829:   first_insn = NULL;
                   2830:   last_insn = NULL;
                   2831:   cur_insn_uid = 1;
                   2832:   reg_rtx_no = LAST_VIRTUAL_REGISTER + 1;
                   2833:   last_linenum = 0;
                   2834:   last_filename = 0;
                   2835:   first_label_num = label_num;
                   2836:   last_label_num = 0;
                   2837: 
                   2838:   /* Clear the start_sequence/gen_sequence cache.  */
                   2839:   sequence_element_free_list = 0;
                   2840:   for (i = 0; i < SEQUENCE_RESULT_SIZE; i++)
                   2841:     sequence_result[i] = 0;
                   2842: 
                   2843:   /* Init the tables that describe all the pseudo regs.  */
                   2844: 
                   2845:   regno_pointer_flag_length = LAST_VIRTUAL_REGISTER + 101;
                   2846: 
                   2847:   regno_pointer_flag 
                   2848:     = (char *) oballoc (regno_pointer_flag_length);
                   2849:   bzero (regno_pointer_flag, regno_pointer_flag_length);
                   2850: 
                   2851:   regno_reg_rtx 
                   2852:     = (rtx *) oballoc (regno_pointer_flag_length * sizeof (rtx));
                   2853:   bzero (regno_reg_rtx, regno_pointer_flag_length * sizeof (rtx));
                   2854: 
                   2855:   /* Put copies of all the virtual register rtx into regno_reg_rtx.  */
                   2856:   regno_reg_rtx[VIRTUAL_INCOMING_ARGS_REGNUM] = virtual_incoming_args_rtx;
                   2857:   regno_reg_rtx[VIRTUAL_STACK_VARS_REGNUM] = virtual_stack_vars_rtx;
                   2858:   regno_reg_rtx[VIRTUAL_STACK_DYNAMIC_REGNUM] = virtual_stack_dynamic_rtx;
                   2859:   regno_reg_rtx[VIRTUAL_OUTGOING_ARGS_REGNUM] = virtual_outgoing_args_rtx;
1.1.1.4 ! root     2860: 
        !          2861:   /* Indicate that the virtual registers and stack locations are
        !          2862:      all pointers.  */
        !          2863:   REGNO_POINTER_FLAG (STACK_POINTER_REGNUM) = 1;
        !          2864:   REGNO_POINTER_FLAG (FRAME_POINTER_REGNUM) = 1;
        !          2865:   REGNO_POINTER_FLAG (ARG_POINTER_REGNUM) = 1;
        !          2866: 
        !          2867:   REGNO_POINTER_FLAG (VIRTUAL_INCOMING_ARGS_REGNUM) = 1;
        !          2868:   REGNO_POINTER_FLAG (VIRTUAL_STACK_VARS_REGNUM) = 1;
        !          2869:   REGNO_POINTER_FLAG (VIRTUAL_STACK_DYNAMIC_REGNUM) = 1;
        !          2870:   REGNO_POINTER_FLAG (VIRTUAL_OUTGOING_ARGS_REGNUM) = 1;
1.1       root     2871: }
                   2872: 
                   2873: /* Create some permanent unique rtl objects shared between all functions.
                   2874:    LINE_NUMBERS is nonzero if line numbers are to be generated.  */
                   2875: 
                   2876: void
                   2877: init_emit_once (line_numbers)
                   2878:      int line_numbers;
                   2879: {
                   2880:   int i;
                   2881:   enum machine_mode mode;
                   2882: 
                   2883:   no_line_numbers = ! line_numbers;
                   2884: 
                   2885:   sequence_stack = NULL;
                   2886: 
                   2887:   /* Create the unique rtx's for certain rtx codes and operand values.  */
                   2888: 
                   2889:   pc_rtx = gen_rtx (PC, VOIDmode);
                   2890:   cc0_rtx = gen_rtx (CC0, VOIDmode);
                   2891: 
                   2892:   /* Don't use gen_rtx here since gen_rtx in this case
                   2893:      tries to use these variables.  */
                   2894:   for (i = - MAX_SAVED_CONST_INT; i <= MAX_SAVED_CONST_INT; i++)
                   2895:     {
                   2896:       const_int_rtx[i + MAX_SAVED_CONST_INT] = rtx_alloc (CONST_INT);
                   2897:       PUT_MODE (const_int_rtx[i + MAX_SAVED_CONST_INT], VOIDmode);
                   2898:       INTVAL (const_int_rtx[i + MAX_SAVED_CONST_INT]) = i;
                   2899:     }
                   2900: 
                   2901:   /* These four calls obtain some of the rtx expressions made above.  */
1.1.1.4 ! root     2902:   const0_rtx = GEN_INT (0);
        !          2903:   const1_rtx = GEN_INT (1);
        !          2904:   const2_rtx = GEN_INT (2);
        !          2905:   constm1_rtx = GEN_INT (-1);
1.1       root     2906: 
                   2907:   /* This will usually be one of the above constants, but may be a new rtx.  */
1.1.1.4 ! root     2908:   const_true_rtx = GEN_INT (STORE_FLAG_VALUE);
1.1       root     2909: 
                   2910:   dconst0 = REAL_VALUE_ATOF ("0");
                   2911:   dconst1 = REAL_VALUE_ATOF ("1");
                   2912:   dconst2 = REAL_VALUE_ATOF ("2");
                   2913:   dconstm1 = REAL_VALUE_ATOF ("-1");
                   2914: 
                   2915:   for (i = 0; i <= 2; i++)
                   2916:     {
                   2917:       for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT); mode != VOIDmode;
                   2918:           mode = GET_MODE_WIDER_MODE (mode))
                   2919:        {
                   2920:          rtx tem = rtx_alloc (CONST_DOUBLE);
                   2921:          union real_extract u;
                   2922: 
                   2923:          bzero (&u, sizeof u);  /* Zero any holes in a structure.  */
                   2924:          u.d = i == 0 ? dconst0 : i == 1 ? dconst1 : dconst2;
                   2925: 
                   2926:          bcopy (&u, &CONST_DOUBLE_LOW (tem), sizeof u);
                   2927:          CONST_DOUBLE_MEM (tem) = cc0_rtx;
                   2928:          PUT_MODE (tem, mode);
                   2929: 
                   2930:          const_tiny_rtx[i][(int) mode] = tem;
                   2931:        }
                   2932: 
1.1.1.4 ! root     2933:       const_tiny_rtx[i][(int) VOIDmode] = GEN_INT (i);
1.1       root     2934: 
                   2935:       for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode;
                   2936:           mode = GET_MODE_WIDER_MODE (mode))
1.1.1.4 ! root     2937:        const_tiny_rtx[i][(int) mode] = GEN_INT (i);
1.1       root     2938:     }
                   2939: 
1.1.1.4 ! root     2940:   for (mode = GET_CLASS_NARROWEST_MODE (MODE_CC); mode != VOIDmode;
        !          2941:        mode = GET_MODE_WIDER_MODE (mode))
        !          2942:     const_tiny_rtx[0][(int) mode] = const0_rtx;
        !          2943: 
1.1       root     2944:   stack_pointer_rtx = gen_rtx (REG, Pmode, STACK_POINTER_REGNUM);
                   2945:   frame_pointer_rtx = gen_rtx (REG, Pmode, FRAME_POINTER_REGNUM);
                   2946: 
                   2947:   if (FRAME_POINTER_REGNUM == ARG_POINTER_REGNUM)
                   2948:     arg_pointer_rtx = frame_pointer_rtx;
                   2949:   else if (STACK_POINTER_REGNUM == ARG_POINTER_REGNUM)
                   2950:     arg_pointer_rtx = stack_pointer_rtx;
                   2951:   else
                   2952:     arg_pointer_rtx = gen_rtx (REG, Pmode, ARG_POINTER_REGNUM);
                   2953: 
                   2954:   /* Create the virtual registers.  Do so here since the following objects
                   2955:      might reference them.  */
                   2956: 
                   2957:   virtual_incoming_args_rtx = gen_rtx (REG, Pmode,
                   2958:                                       VIRTUAL_INCOMING_ARGS_REGNUM);
                   2959:   virtual_stack_vars_rtx = gen_rtx (REG, Pmode,
                   2960:                                    VIRTUAL_STACK_VARS_REGNUM);
                   2961:   virtual_stack_dynamic_rtx = gen_rtx (REG, Pmode,
                   2962:                                       VIRTUAL_STACK_DYNAMIC_REGNUM);
                   2963:   virtual_outgoing_args_rtx = gen_rtx (REG, Pmode,
                   2964:                                       VIRTUAL_OUTGOING_ARGS_REGNUM);
                   2965: 
                   2966: #ifdef STRUCT_VALUE
                   2967:   struct_value_rtx = STRUCT_VALUE;
                   2968: #else
                   2969:   struct_value_rtx = gen_rtx (REG, Pmode, STRUCT_VALUE_REGNUM);
                   2970: #endif
                   2971: 
                   2972: #ifdef STRUCT_VALUE_INCOMING
                   2973:   struct_value_incoming_rtx = STRUCT_VALUE_INCOMING;
                   2974: #else
                   2975: #ifdef STRUCT_VALUE_INCOMING_REGNUM
                   2976:   struct_value_incoming_rtx
                   2977:     = gen_rtx (REG, Pmode, STRUCT_VALUE_INCOMING_REGNUM);
                   2978: #else
                   2979:   struct_value_incoming_rtx = struct_value_rtx;
                   2980: #endif
                   2981: #endif
                   2982: 
                   2983: #ifdef STATIC_CHAIN_REGNUM
                   2984:   static_chain_rtx = gen_rtx (REG, Pmode, STATIC_CHAIN_REGNUM);
                   2985: 
                   2986: #ifdef STATIC_CHAIN_INCOMING_REGNUM
                   2987:   if (STATIC_CHAIN_INCOMING_REGNUM != STATIC_CHAIN_REGNUM)
                   2988:     static_chain_incoming_rtx = gen_rtx (REG, Pmode, STATIC_CHAIN_INCOMING_REGNUM);
                   2989:   else
                   2990: #endif
                   2991:     static_chain_incoming_rtx = static_chain_rtx;
                   2992: #endif
                   2993: 
                   2994: #ifdef STATIC_CHAIN
                   2995:   static_chain_rtx = STATIC_CHAIN;
                   2996: 
                   2997: #ifdef STATIC_CHAIN_INCOMING
                   2998:   static_chain_incoming_rtx = STATIC_CHAIN_INCOMING;
                   2999: #else
                   3000:   static_chain_incoming_rtx = static_chain_rtx;
                   3001: #endif
                   3002: #endif
                   3003: 
                   3004: #ifdef PIC_OFFSET_TABLE_REGNUM
                   3005:   pic_offset_table_rtx = gen_rtx (REG, Pmode, PIC_OFFSET_TABLE_REGNUM);
                   3006: #endif
                   3007: }

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