4.3BSD - /usr/src/new/emacs/src/alloca.s

   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: 	ia-sun2!david@cit-vax.arpa
 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 */

Defined functions

Defined macros