Return to alloca.s CVS log

Up to [CSRG BSD Unix] / 43BSD / contrib / emacs / src

Annotation of 43BSD/contrib/emacs/src/alloca.s, revision 1.1

1.1     ! root        1: /* `alloca' standard 4.2 subroutine for 68000's and 16000's and pyramids.
        !             2:    Also has _setjmp and _longjmp for pyramids.
        !             3:    Also has hack_sky for sun 2.
        !             4:    Copyright (C) 1985 Richard M. Stallman.
        !             5: 
        !             6: This file is part of GNU Emacs.
        !             7: 
        !             8: GNU Emacs is distributed in the hope that it will be useful,
        !             9: but WITHOUT ANY WARRANTY.  No author or distributor
        !            10: accepts responsibility to anyone for the consequences of using it
        !            11: or for whether it serves any particular purpose or works at all,
        !            12: unless he says so in writing.  Refer to the GNU Emacs General Public
        !            13: License for full details.
        !            14: 
        !            15: Everyone is granted permission to copy, modify and redistribute
        !            16: GNU Emacs, but only under the conditions described in the
        !            17: GNU Emacs General Public License.   A copy of this license is
        !            18: supposed to have been given to you along with GNU Emacs so you
        !            19: can know your rights and responsibilities.  It should be in a
        !            20: file named COPYING.  Among other things, the copyright notice
        !            21: and this notice must be preserved on all copies.  */
        !            22: 
        !            23: 
        !            24: /* Both 68000 systems I have run this on have had broken versions of alloca.
        !            25:    Also, I am told that non-berkeley systems do not have it at all.
        !            26:    So replace whatever system-provided alloca there may be
        !            27:    on all 68000 systems.  */
        !            28: 
        !            29: #include "config.h"
        !            30: 
        !            31: #ifndef HAVE_ALLOCA  /* define this to use system's alloca */
        !            32: 
        !            33: #ifdef hp9000s200
        !            34:        data
        !            35:        text
        !            36:        globl   _alloca
        !            37: _alloca        
        !            38:        move.l  (sp)+,a0        ; pop return addr from top of stack
        !            39:        move.l  (sp)+,d0        ; pop size in bytes from top of stack
        !            40:        add.l   #ROUND,d0       ; round size up to long word
        !            41:        and.l   #MASK,d0        ; mask out lower two bits of size
        !            42:        sub.l   d0,sp           ; allocate by moving stack pointer
        !            43:        tst.b   PROBE(sp)       ; stack probe to allocate pages
        !            44:        move.l  sp,d0           ; return pointer
        !            45:        add.l   #-4,sp          ; new top of stack
        !            46:        jmp     (a0)            ; not a normal return
        !            47: MASK   equ     -4              ; Longword alignment
        !            48: ROUND  equ     3               ; ditto
        !            49: PROBE  equ     -128            ; safety buffer for C compiler scratch
        !            50:        data
        !            51: 
        !            52: #else
        !            53: #ifdef m68k                    /* SGS assembler totally different */
        !            54:        file    "alloca.s"
        !            55:        global  alloca
        !            56: alloca:
        !            57:        mov.l   (%sp)+,%a1      # pop return addr from top of stack
        !            58:        mov.l   (%sp)+,%d0      # pop size in bytes from top of stack
        !            59:        add.l   &R%1,%d0        # round size up to long word
        !            60:        and.l   &-4,%d0         # mask out lower two bits of size
        !            61:        sub.l   %d0,%sp         # allocate by moving stack pointer
        !            62:        tst.b   P%1(%sp)        # stack probe to allocate pages
        !            63:        mov.l   %sp,%a0         # return pointer as pointer
        !            64:        mov.l   %sp,%d0         # return pointer as int to avoid disaster
        !            65:        add.l   &-4,%sp         # new top of stack
        !            66:        jmp     (%a1)           # not a normal return
        !            67:        set     S%1,64          # safety factor for C compiler scratch
        !            68:        set     R%1,3+S%1       # add to size for rounding
        !            69:        set     P%1,-132        # probe this far below current top of stack
        !            70: 
        !            71: #else /* not m68k */
        !            72: 
        !            73: #ifdef m68000
        !            74: 
        !            75: /* Some systems want the _, some do not.  Win with both kinds.  */
        !            76: .globl _alloca
        !            77: _alloca:
        !            78: .globl alloca
        !            79: alloca:
        !            80:        movl    sp@+,a0
        !            81:        movl    a7,d0
        !            82:        subl    sp@,d0
        !            83:        andl    #~3,d0
        !            84:        movl    d0,sp
        !            85:        tstb    sp@(0)          /* Make stack pages exist  */
        !            86:                                /* Needed on certain systems
        !            87:                                   that lack true demand paging */
        !            88:        addql   #4,d0
        !            89:        jmp     a0@
        !            90: 
        !            91: #endif /* m68000 */
        !            92: #endif /* not m68k */
        !            93: #endif /* not hp9000s200 */
        !            94: 
        !            95: #ifdef ns16000
        !            96: 
        !            97:        .text
        !            98:        .align  2
        !            99: /* Some systems want the _, some do not.  Win with both kinds.  */
        !           100: .globl _alloca
        !           101: _alloca:
        !           102: .globl alloca
        !           103: alloca:
        !           104: 
        !           105: /* Two different assembler syntaxes are used for the same code
        !           106:        on different systems.  */
        !           107: 
        !           108: #ifdef sequent
        !           109: #define IM
        !           110: #define REGISTER(x) x
        !           111: #else
        !           112: #define IM $
        !           113: #define REGISTER(x) 0(x)
        !           114: #endif
        !           115: 
        !           116: /*
        !           117:  * The ns16000 is a little more difficult, need to copy regs.
        !           118:  * Also the code assumes direct linkage call sequence (no mod table crap).
        !           119:  * We have to copy registers, and therefore waste 32 bytes.
        !           120:  *
        !           121:  * Stack layout:
        !           122:  * new sp ->   junk    
        !           123:  *             registers (copy)
        !           124:  *     r0 ->   new data                
        !           125:  *              |        (orig retval)
        !           126:  *              |        (orig arg)
        !           127:  * old  sp ->  regs      (orig)
        !           128:  *             local data
        !           129:  *     fp ->   old fp
        !           130:  */
        !           131: 
        !           132:        movd    tos,r1          /*  pop return addr */
        !           133:        negd    tos,r0          /*  pop amount to allocate */
        !           134:        sprd    sp,r2
        !           135:        addd    r2,r0
        !           136:        bicb    IM/**/3,r0      /*  4-byte align */
        !           137:        lprd    sp,r0
        !           138:        adjspb  IM/**/36        /*  space for regs, +4 for caller to pop */
        !           139:        movmd   0(r2),4(sp),IM/**/4     /*  copy regs */
        !           140:        movmd   0x10(r2),0x14(sp),IM/**/4
        !           141:        jump    REGISTER(r1)    /* funky return */
        !           142: #endif /* ns16000 */
        !           143: 
        !           144: #ifdef pyramid
        !           145: 
        !           146: .globl _alloca
        !           147: 
        !           148: _alloca: addw $3,pr0   # add 3 (dec) to first argument
        !           149:        bicw $3,pr0     # then clear its last 2 bits
        !           150:        subw pr0,sp     # subtract from SP the val in PR0
        !           151:        movw sp,pr0     # ret. current SP
        !           152:        ret
        !           153: 
        !           154: .globl __longjmp
        !           155: .globl _longjmp
        !           156: .globl __setjmp
        !           157: .globl _setjmp
        !           158: 
        !           159: __longjmp: jump _longjmp
        !           160: __setjmp:  jump _setjmp
        !           161: 
        !           162: #endif /* pyramid */
        !           163: 
        !           164: #ifdef ATT3B5
        !           165: 
        !           166:        .align 4
        !           167:        .globl alloca
        !           168: 
        !           169: alloca:
        !           170:        movw %ap, %r8
        !           171:        subw2 $9*4, %r8
        !           172:        movw 0(%r8), %r1    /* pc */
        !           173:        movw 4(%r8), %fp
        !           174:        movw 8(%r8), %sp
        !           175:        addw2 %r0, %sp /* make room */
        !           176:        movw %sp, %r0 /* return value */
        !           177:        jmp (%r1) /* continue... */
        !           178: 
        !           179: #endif /* ATT3B5 */
        !           180: 
        !           181: /*
        !           182:   A Hack to reinitialize the floating point table in C or Fortran
        !           183:   code.
        !           184:      There are no arguments to the call
        !           185:  
        !           186:        David Robinson
        !           187:        Jet Propulsion Laboratory
        !           188:        [email protected]
        !           189:  
        !           190:   WARNING: Very SUN dependant Only tested under SUN 2.0
        !           191: */
        !           192: #ifdef sun2
        !           193: .globl _hack_sky
        !           194: 
        !           195: _hack_sky:
        !           196:        moveml  #0xC0C0,sp@-    |save registers <d0,d1,a0,a1>
        !           197:        clrl    __skybase       |clear out old sky status
        !           198:        jsr     __skyinit       |initialize sky board
        !           199:        tstl    d0              |check if successful
        !           200:        lea     floatflavor,a1  
        !           201:        beqs    hack1           
        !           202:        lea     a1@(0x7e),a0    |Sky board exists
        !           203:        bras    hack2
        !           204: hack1: lea     a1@(0x12),a0    |No Sky board
        !           205: hack2: movw    #0x1a,d0
        !           206:        lea     fvflti,a1       |load destination
        !           207: hack3: movl    a0@+,a1@+       |copy table
        !           208:        dbra    d0,hack3
        !           209:        moveml  sp@+,#0x0303    |restore registers
        !           210:        rts
        !           211: #endif /* sun2 */
        !           212: 
        !           213: #endif /* not HAVE_ALLOCA */

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.