![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to alloca.s CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [CSRG BSD Unix] / 43BSD / contrib / emacs / src|
Return to alloca.s CVS log | Up to [CSRG BSD Unix] / 43BSD / contrib / emacs / src |
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.