boehm-gc/mach_dep.c

   1 /*
   2  * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
   3  * Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
   4  *
   5  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   6  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   7  *
   8  * Permission is hereby granted to use or copy this program
   9  * for any purpose,  provided the above notices are retained on all copies.
  10  * Permission to modify the code and to distribute modified code is granted,
  11  * provided the above notices are retained, and a notice that the code was
  12  * modified is included with the above copyright notice.
  13  */
  14 /* Boehm, November 17, 1995 12:13 pm PST */
  15 # include "private/gc_priv.h"
  16 # include <stdio.h>
  17 # include <setjmp.h>
  18 # if defined(OS2) || defined(CX_UX)
  19 #   define _setjmp(b) setjmp(b)
  20 #   define _longjmp(b,v) longjmp(b,v)
  21 # endif
  22 # ifdef AMIGA
  23 #   ifndef __GNUC__
  24 #     include <dos.h>
  25 #   else
  26 #     include <machine/reg.h>
  27 #   endif
  28 # endif
  29
  30 #if defined(__MWERKS__) && !defined(POWERPC)
  31
  32 asm static void PushMacRegisters()
  33 {
  34     sub.w   #4,sp                   // reserve space for one parameter.
  35     move.l  a2,(sp)
  36     jsr         GC_push_one
  37     move.l  a3,(sp)
  38     jsr         GC_push_one
  39     move.l  a4,(sp)
  40     jsr         GC_push_one
  41 #   if !__option(a6frames)
  42         // <pcb> perhaps a6 should be pushed if stack frames are not being used.
  43         move.l  a6,(sp)
  44         jsr             GC_push_one
  45 #   endif
  46         // skip a5 (globals), a6 (frame pointer), and a7 (stack pointer)
  47     move.l  d2,(sp)
  48     jsr         GC_push_one
  49     move.l  d3,(sp)
  50     jsr         GC_push_one
  51     move.l  d4,(sp)
  52     jsr         GC_push_one
  53     move.l  d5,(sp)
  54     jsr         GC_push_one
  55     move.l  d6,(sp)
  56     jsr         GC_push_one
  57     move.l  d7,(sp)
  58     jsr         GC_push_one
  59     add.w   #4,sp                   // fix stack.
  60     rts
  61 }
  62
  63 #endif /* __MWERKS__ */
  64
  65 # if defined(SPARC) || defined(IA64)
  66     /* Value returned from register flushing routine; either sp (SPARC) */
  67     /* or ar.bsp (IA64)                                                 */
  68     word GC_save_regs_ret_val;
  69 # endif
  70
  71 /* Routine to mark from registers that are preserved by the C compiler. */
  72 /* This must be ported to every new architecture.  There is a generic   */
  73 /* version at the end, that is likely, but not guaranteed to work       */
  74 /* on your architecture.  Run the test_setjmp program to see whether    */
  75 /* there is any chance it will work.                                    */
  76
  77 #ifndef USE_GENERIC_PUSH_REGS
  78 void GC_push_regs()
  79 {
  80 #       ifdef RT
  81           register long TMP_SP; /* must be bound to r11 */
  82 #       endif
  83
  84 #       if defined(MIPS) && defined(LINUX)
  85           /* I'm not sure whether this has actually been tested. */
  86 #         define call_push(x)     asm("move $4," x ";"); asm("jal GC_push_one")
  87           call_push("$2");
  88           call_push("$3");
  89           call_push("$16");
  90           call_push("$17");
  91           call_push("$18");
  92           call_push("$19");
  93           call_push("$20");
  94           call_push("$21");
  95           call_push("$22");
  96           call_push("$23");
  97           call_push("$30");
  98 #         undef call_push
  99 #       endif   /* MIPS && LINUX */
 100
 101 #       ifdef VAX
 102           /* VAX - generic code below does not work under 4.2 */
 103           /* r1 through r5 are caller save, and therefore     */
 104           /* on the stack or dead.                            */
 105           asm("pushl r11");     asm("calls $1,_GC_push_one");
 106           asm("pushl r10");     asm("calls $1,_GC_push_one");
 107           asm("pushl r9");      asm("calls $1,_GC_push_one");
 108           asm("pushl r8");      asm("calls $1,_GC_push_one");
 109           asm("pushl r7");      asm("calls $1,_GC_push_one");
 110           asm("pushl r6");      asm("calls $1,_GC_push_one");
 111 #       endif
 112 #       if defined(M68K) && (defined(SUNOS4) || defined(NEXT))
 113         /*  M68K SUNOS - could be replaced by generic code */
 114           /* a0, a1 and d1 are caller save          */
 115           /*  and therefore are on stack or dead.   */
 116
 117           asm("subqw #0x4,sp");         /* allocate word on top of stack */
 118
 119           asm("movl a2,sp@");   asm("jbsr _GC_push_one");
 120           asm("movl a3,sp@");   asm("jbsr _GC_push_one");
 121           asm("movl a4,sp@");   asm("jbsr _GC_push_one");
 122           asm("movl a5,sp@");   asm("jbsr _GC_push_one");
 123           /* Skip frame pointer and stack pointer */
 124           asm("movl d1,sp@");   asm("jbsr _GC_push_one");
 125           asm("movl d2,sp@");   asm("jbsr _GC_push_one");
 126           asm("movl d3,sp@");   asm("jbsr _GC_push_one");
 127           asm("movl d4,sp@");   asm("jbsr _GC_push_one");
 128           asm("movl d5,sp@");   asm("jbsr _GC_push_one");
 129           asm("movl d6,sp@");   asm("jbsr _GC_push_one");
 130           asm("movl d7,sp@");   asm("jbsr _GC_push_one");
 131
 132           asm("addqw #0x4,sp");         /* put stack back where it was  */
 133 #       endif
 134
 135 #       if defined(M68K) && defined(HP)
 136         /*  M68K HP - could be replaced by generic code */
 137           /* a0, a1 and d1 are caller save.  */
 138
 139           asm("subq.w &0x4,%sp");       /* allocate word on top of stack */
 140
 141           asm("mov.l %a2,(%sp)"); asm("jsr _GC_push_one");
 142           asm("mov.l %a3,(%sp)"); asm("jsr _GC_push_one");
 143           asm("mov.l %a4,(%sp)"); asm("jsr _GC_push_one");
 144           asm("mov.l %a5,(%sp)"); asm("jsr _GC_push_one");
 145           /* Skip frame pointer and stack pointer */
 146           asm("mov.l %d1,(%sp)"); asm("jsr _GC_push_one");
 147           asm("mov.l %d2,(%sp)"); asm("jsr _GC_push_one");
 148           asm("mov.l %d3,(%sp)"); asm("jsr _GC_push_one");
 149           asm("mov.l %d4,(%sp)"); asm("jsr _GC_push_one");
 150           asm("mov.l %d5,(%sp)"); asm("jsr _GC_push_one");
 151           asm("mov.l %d6,(%sp)"); asm("jsr _GC_push_one");
 152           asm("mov.l %d7,(%sp)"); asm("jsr _GC_push_one");
 153
 154           asm("addq.w &0x4,%sp");       /* put stack back where it was  */
 155 #       endif /* M68K HP */
 156
 157 #       if defined(M68K) && defined(AMIGA)
 158          /*  AMIGA - could be replaced by generic code                  */
 159          /* a0, a1, d0 and d1 are caller save */
 160
 161 #        ifdef __GNUC__
 162           asm("subq.w &0x4,%sp");       /* allocate word on top of stack */
 163
 164           asm("mov.l %a2,(%sp)"); asm("jsr _GC_push_one");
 165           asm("mov.l %a3,(%sp)"); asm("jsr _GC_push_one");
 166           asm("mov.l %a4,(%sp)"); asm("jsr _GC_push_one");
 167           asm("mov.l %a5,(%sp)"); asm("jsr _GC_push_one");
 168           asm("mov.l %a6,(%sp)"); asm("jsr _GC_push_one");
 169           /* Skip frame pointer and stack pointer */
 170           asm("mov.l %d2,(%sp)"); asm("jsr _GC_push_one");
 171           asm("mov.l %d3,(%sp)"); asm("jsr _GC_push_one");
 172           asm("mov.l %d4,(%sp)"); asm("jsr _GC_push_one");
 173           asm("mov.l %d5,(%sp)"); asm("jsr _GC_push_one");
 174           asm("mov.l %d6,(%sp)"); asm("jsr _GC_push_one");
 175           asm("mov.l %d7,(%sp)"); asm("jsr _GC_push_one");
 176
 177           asm("addq.w &0x4,%sp");       /* put stack back where it was  */
 178 #        else /* !__GNUC__ */
 179           GC_push_one(getreg(REG_A2));
 180           GC_push_one(getreg(REG_A3));
 181 #         ifndef __SASC
 182               /* Can probably be changed to #if 0 -Kjetil M. (a4=globals)*/
 183             GC_push_one(getreg(REG_A4));
 184 #         endif
 185           GC_push_one(getreg(REG_A5));
 186           GC_push_one(getreg(REG_A6));
 187           /* Skip stack pointer */
 188           GC_push_one(getreg(REG_D2));
 189           GC_push_one(getreg(REG_D3));
 190           GC_push_one(getreg(REG_D4));
 191           GC_push_one(getreg(REG_D5));
 192           GC_push_one(getreg(REG_D6));
 193           GC_push_one(getreg(REG_D7));
 194 #        endif /* !__GNUC__ */
 195 #       endif /* AMIGA */
 196
 197 #       if defined(M68K) && defined(MACOS)
 198 #       if defined(THINK_C)
 199 #         define PushMacReg(reg) \
 200               move.l  reg,(sp) \
 201               jsr             GC_push_one
 202           asm {
 203               sub.w   #4,sp                   ; reserve space for one parameter.
 204               PushMacReg(a2);
 205               PushMacReg(a3);
 206               PushMacReg(a4);
 207               ; skip a5 (globals), a6 (frame pointer), and a7 (stack pointer)
 208               PushMacReg(d2);
 209               PushMacReg(d3);
 210               PushMacReg(d4);
 211               PushMacReg(d5);
 212               PushMacReg(d6);
 213               PushMacReg(d7);
 214               add.w   #4,sp                   ; fix stack.
 215           }
 216 #         undef PushMacReg
 217 #       endif /* THINK_C */
 218 #       if defined(__MWERKS__)
 219           PushMacRegisters();
 220 #       endif   /* __MWERKS__ */
 221 #   endif       /* MACOS */
 222
 223 #       if defined(I386) &&!defined(OS2) &&!defined(SVR4) \
 224         && (defined(__MINGW32__) || !defined(MSWIN32)) \
 225         && !defined(SCO) && !defined(SCO_ELF) \
 226         && !(defined(LINUX) && defined(__ELF__)) \
 227         && !(defined(FREEBSD) && defined(__ELF__)) \
 228         && !(defined(NETBSD) && defined(__ELF__)) \
 229         && !(defined(OPENBSD) && defined(__ELF__)) \
 230         && !(defined(BEOS) && defined(__ELF__)) \
 231         && !defined(DOS4GW) && !defined(HURD)
 232         /* I386 code, generic code does not appear to work */
 233         /* It does appear to work under OS2, and asms dont */
 234         /* This is used for some 38g UNIX variants and for CYGWIN32 */
 235           asm("pushl %eax");  asm("call _GC_push_one"); asm("addl $4,%esp");
 236           asm("pushl %ecx");  asm("call _GC_push_one"); asm("addl $4,%esp");
 237           asm("pushl %edx");  asm("call _GC_push_one"); asm("addl $4,%esp");
 238           asm("pushl %ebp");  asm("call _GC_push_one"); asm("addl $4,%esp");
 239           asm("pushl %esi");  asm("call _GC_push_one"); asm("addl $4,%esp");
 240           asm("pushl %edi");  asm("call _GC_push_one"); asm("addl $4,%esp");
 241           asm("pushl %ebx");  asm("call _GC_push_one"); asm("addl $4,%esp");
 242 #       endif
 243
 244 #       if ( defined(I386) && defined(LINUX) && defined(__ELF__) ) \
 245         || ( defined(I386) && defined(FREEBSD) && defined(__ELF__) ) \
 246         || ( defined(I386) && defined(NETBSD) && defined(__ELF__) ) \
 247         || ( defined(I386) && defined(OPENBSD) && defined(__ELF__) ) \
 248         || ( defined(I386) && defined(HURD) && defined(__ELF__) )
 249
 250         /* This is modified for Linux with ELF (Note: _ELF_ only) */
 251         /* This section handles FreeBSD with ELF. */
 252         /* Eax is caller-save and dead here.  Other caller-save         */
 253         /* registers could also be skipped.  We assume there are no     */
 254         /* pointers in MMX registers, etc.                              */
 255         /* We combine instructions in a single asm to prevent gcc from  */
 256         /* inserting code in the middle.                                */
 257           asm("pushl %ecx; call GC_push_one; addl $4,%esp");
 258           asm("pushl %edx; call GC_push_one; addl $4,%esp");
 259           asm("pushl %ebp; call GC_push_one; addl $4,%esp");
 260           asm("pushl %esi; call GC_push_one; addl $4,%esp");
 261           asm("pushl %edi; call GC_push_one; addl $4,%esp");
 262           asm("pushl %ebx; call GC_push_one; addl $4,%esp");
 263 #       endif
 264
 265 #       if ( defined(I386) && defined(BEOS) && defined(__ELF__) )
 266         /* As far as I can understand from                              */
 267         /* http://www.beunited.org/articles/jbq/nasm.shtml,             */
 268         /* only ebp, esi, edi and ebx are not scratch. How MMX          */
 269         /* etc. registers should be treated, I have no idea.            */
 270           asm("pushl %ebp; call GC_push_one; addl $4,%esp");
 271           asm("pushl %esi; call GC_push_one; addl $4,%esp");
 272           asm("pushl %edi; call GC_push_one; addl $4,%esp");
 273           asm("pushl %ebx; call GC_push_one; addl $4,%esp");
 274 #       endif
 275
 276 #       if defined(I386) && defined(MSWIN32) && !defined(__MINGW32__) \
 277            && !defined(USE_GENERIC)
 278         /* I386 code, Microsoft variant         */
 279           __asm  push eax
 280           __asm  call GC_push_one
 281           __asm  add esp,4
 282           __asm  push ebx
 283           __asm  call GC_push_one
 284           __asm  add esp,4
 285           __asm  push ecx
 286           __asm  call GC_push_one
 287           __asm  add esp,4
 288           __asm  push edx
 289           __asm  call GC_push_one
 290           __asm  add esp,4
 291           __asm  push ebp
 292           __asm  call GC_push_one
 293           __asm  add esp,4
 294           __asm  push esi
 295           __asm  call GC_push_one
 296           __asm  add esp,4
 297           __asm  push edi
 298           __asm  call GC_push_one
 299           __asm  add esp,4
 300 #       endif
 301
 302 #       if defined(I386) && (defined(SVR4) || defined(SCO) || defined(SCO_ELF))
 303         /* I386 code, SVR4 variant, generic code does not appear to work */
 304           asm("pushl %eax");  asm("call GC_push_one"); asm("addl $4,%esp");
 305           asm("pushl %ebx");  asm("call GC_push_one"); asm("addl $4,%esp");
 306           asm("pushl %ecx");  asm("call GC_push_one"); asm("addl $4,%esp");
 307           asm("pushl %edx");  asm("call GC_push_one"); asm("addl $4,%esp");
 308           asm("pushl %ebp");  asm("call GC_push_one"); asm("addl $4,%esp");
 309           asm("pushl %esi");  asm("call GC_push_one"); asm("addl $4,%esp");
 310           asm("pushl %edi");  asm("call GC_push_one"); asm("addl $4,%esp");
 311 #       endif
 312
 313 #       ifdef NS32K
 314           asm ("movd r3, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 315           asm ("movd r4, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 316           asm ("movd r5, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 317           asm ("movd r6, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 318           asm ("movd r7, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 319 #       endif
 320
 321 #       if defined(SPARC)
 322           {
 323               word GC_save_regs_in_stack();
 324
 325               GC_save_regs_ret_val = GC_save_regs_in_stack();
 326           }
 327 #       endif
 328
 329 #       ifdef RT
 330             GC_push_one(TMP_SP);    /* GC_push_one from r11 */
 331
 332             asm("cas r11, r6, r0"); GC_push_one(TMP_SP);        /* r6 */
 333             asm("cas r11, r7, r0"); GC_push_one(TMP_SP);        /* through */
 334             asm("cas r11, r8, r0"); GC_push_one(TMP_SP);        /* r10 */
 335             asm("cas r11, r9, r0"); GC_push_one(TMP_SP);
 336             asm("cas r11, r10, r0"); GC_push_one(TMP_SP);
 337
 338             asm("cas r11, r12, r0"); GC_push_one(TMP_SP); /* r12 */
 339             asm("cas r11, r13, r0"); GC_push_one(TMP_SP); /* through */
 340             asm("cas r11, r14, r0"); GC_push_one(TMP_SP); /* r15 */
 341             asm("cas r11, r15, r0"); GC_push_one(TMP_SP);
 342 #       endif
 343
 344 #       if defined(M68K) && defined(SYSV)
 345         /*  Once again similar to SUN and HP, though setjmp appears to work.
 346                 --Parag
 347          */
 348 #        ifdef __GNUC__
 349           asm("subqw #0x4,%sp");        /* allocate word on top of stack */
 350
 351           asm("movl %a2,%sp@"); asm("jbsr GC_push_one");
 352           asm("movl %a3,%sp@"); asm("jbsr GC_push_one");
 353           asm("movl %a4,%sp@"); asm("jbsr GC_push_one");
 354           asm("movl %a5,%sp@"); asm("jbsr GC_push_one");
 355           /* Skip frame pointer and stack pointer */
 356           asm("movl %d1,%sp@"); asm("jbsr GC_push_one");
 357           asm("movl %d2,%sp@"); asm("jbsr GC_push_one");
 358           asm("movl %d3,%sp@"); asm("jbsr GC_push_one");
 359           asm("movl %d4,%sp@"); asm("jbsr GC_push_one");
 360           asm("movl %d5,%sp@"); asm("jbsr GC_push_one");
 361           asm("movl %d6,%sp@"); asm("jbsr GC_push_one");
 362           asm("movl %d7,%sp@"); asm("jbsr GC_push_one");
 363
 364           asm("addqw #0x4,%sp");        /* put stack back where it was  */
 365 #        else /* !__GNUC__*/
 366           asm("subq.w &0x4,%sp");       /* allocate word on top of stack */
 367
 368           asm("mov.l %a2,(%sp)"); asm("jsr GC_push_one");
 369           asm("mov.l %a3,(%sp)"); asm("jsr GC_push_one");
 370           asm("mov.l %a4,(%sp)"); asm("jsr GC_push_one");
 371           asm("mov.l %a5,(%sp)"); asm("jsr GC_push_one");
 372           /* Skip frame pointer and stack pointer */
 373           asm("mov.l %d1,(%sp)"); asm("jsr GC_push_one");
 374           asm("mov.l %d2,(%sp)"); asm("jsr GC_push_one");
 375           asm("mov.l %d3,(%sp)"); asm("jsr GC_push_one");
 376           asm("mov.l %d4,(%sp)"); asm("jsr GC_push_one");
 377           asm("mov.l %d5,(%sp)"); asm("jsr GC_push_one");
 378           asm("mov.l %d6,(%sp)"); asm("jsr GC_push_one");
 379           asm("mov.l %d7,(%sp)"); asm("jsr GC_push_one");
 380
 381           asm("addq.w &0x4,%sp");       /* put stack back where it was  */
 382 #        endif /* !__GNUC__ */
 383 #       endif /* M68K/SYSV */
 384
 385 #     if defined(PJ)
 386         {
 387             register int * sp asm ("optop");
 388             extern int *__libc_stack_end;
 389
 390             GC_push_all_stack (sp, __libc_stack_end);
 391         }
 392 #     endif
 393
 394       /* other machines... */
 395 #       if !defined(M68K) && !defined(VAX) && !defined(RT)
 396 #       if !defined(SPARC) && !defined(I386) && !defined(NS32K)
 397 #       if !defined(POWERPC) && !defined(UTS4)
 398 #       if !defined(PJ) && !(defined(MIPS) && defined(LINUX))
 399             --> bad news <--
 400 #       endif
 401 #       endif
 402 #       endif
 403 #       endif
 404 }
 405 #endif /* !USE_GENERIC_PUSH_REGS */
 406
 407 #if defined(USE_GENERIC_PUSH_REGS)
 408 void GC_generic_push_regs(cold_gc_frame)
 409 ptr_t cold_gc_frame;
 410 {
 411         {
 412 #           ifdef HAVE_BUILTIN_UNWIND_INIT
 413               /* This was suggested by Richard Henderson as the way to  */
 414               /* force callee-save registers and register windows onto  */
 415               /* the stack.                                             */
 416               __builtin_unwind_init();
 417 #           else /* !HAVE_BUILTIN_UNWIND_INIT */
 418               /* Generic code                          */
 419               /* The idea is due to Parag Patel at HP. */
 420               /* We're not sure whether he would like  */
 421               /* to be he acknowledged for it or not.  */
 422               jmp_buf regs;
 423               register word * i = (word *) regs;
 424               register ptr_t lim = (ptr_t)(regs) + (sizeof regs);
 425
 426               /* Setjmp doesn't always clear all of the buffer.         */
 427               /* That tends to preserve garbage.  Clear it.             */
 428                 for (; (char *)i < lim; i++) {
 429                     *i = 0;
 430                 }
 431 #             if defined(POWERPC) || defined(MSWIN32) || defined(MSWINCE) \
 432                  || defined(UTS4) || defined(LINUX)
 433                   (void) setjmp(regs);
 434 #             else
 435                   (void) _setjmp(regs);
 436 #             endif
 437 #           endif /* !HAVE_BUILTIN_UNWIND_INIT */
 438 #           if (defined(SPARC) && !defined(HAVE_BUILTIN_UNWIND_INIT)) \
 439                 || defined(IA64)
 440               /* On a register window machine, we need to save register */
 441               /* contents on the stack for this to work.  The setjmp    */
 442               /* is probably not needed on SPARC, since pointers are    */
 443               /* only stored in windowed or scratch registers.  It is   */
 444               /* needed on IA64, since some non-windowed registers are  */
 445               /* preserved.                                             */
 446               {
 447                 word GC_save_regs_in_stack();
 448
 449                 GC_save_regs_ret_val = GC_save_regs_in_stack();
 450                 /* On IA64 gcc, could use __builtin_ia64_flushrs() and  */
 451                 /* __builtin_ia64_flushrs().  The latter will be done   */
 452                 /* implicitly by __builtin_unwind_init() for gcc3.0.1   */
 453                 /* and later.                                           */
 454               }
 455 #           endif
 456             GC_push_current_stack(cold_gc_frame);
 457         }
 458 }
 459 #endif /* USE_GENERIC_PUSH_REGS */
 460
 461 /* On register window machines, we need a way to force registers into   */
 462 /* the stack.   Return sp.                                              */
 463 # ifdef SPARC
 464     asm("       .seg    \"text\"");
 465 #   ifdef SVR4
 466       asm("     .globl  GC_save_regs_in_stack");
 467       asm("GC_save_regs_in_stack:");
 468       asm("     .type GC_save_regs_in_stack,#function");
 469 #   else
 470       asm("     .globl  _GC_save_regs_in_stack");
 471       asm("_GC_save_regs_in_stack:");
 472 #   endif
 473 #   if defined(__arch64__) || defined(__sparcv9)
 474       asm("     save    %sp,-128,%sp");
 475       asm("     flushw");
 476       asm("     ret");
 477       asm("     restore %sp,2047+128,%o0");
 478 #   else
 479       asm("     ta      0x3   ! ST_FLUSH_WINDOWS");
 480       asm("     retl");
 481       asm("     mov     %sp,%o0");
 482 #   endif
 483 #   ifdef SVR4
 484       asm("     .GC_save_regs_in_stack_end:");
 485       asm("     .size GC_save_regs_in_stack,.GC_save_regs_in_stack_end-GC_save_regs_in_stack");
 486 #   endif
 487 #   ifdef LINT
 488         word GC_save_regs_in_stack() { return(0 /* sp really */);}
 489 #   endif
 490 # endif
 491
 492 /* On IA64, we also need to flush register windows.  But they end       */
 493 /* up on the other side of the stack segment.                           */
 494 /* Returns the backing store pointer for the register stack.            */
 495 # ifdef IA64
 496 #   ifdef __GNUC__
 497         asm("        .text");
 498         asm("        .psr abi64");
 499         asm("        .psr lsb");
 500         asm("        .lsb");
 501         asm("");
 502         asm("        .text");
 503         asm("        .align 16");
 504         asm("        .global GC_save_regs_in_stack");
 505         asm("        .proc GC_save_regs_in_stack");
 506         asm("GC_save_regs_in_stack:");
 507         asm("        .body");
 508         asm("        flushrs");
 509         asm("        ;;");
 510         asm("        mov r8=ar.bsp");
 511         asm("        br.ret.sptk.few rp");
 512         asm("        .endp GC_save_regs_in_stack");
 513 #   else
 514         void GC_save_regs_in_stack() {
 515           asm("        flushrs");
 516           asm("        ;;");
 517           asm("        mov r8=ar.bsp");
 518           asm("        br.ret.sptk.few rp");
 519         }
 520 #   endif
 521 # endif
 522
 523 /* GC_clear_stack_inner(arg, limit) clears stack area up to limit and   */
 524 /* returns arg.  Stack clearing is crucial on SPARC, so we supply       */
 525 /* an assembly version that's more careful.  Assumes limit is hotter    */
 526 /* than sp, and limit is 8 byte aligned.                                */
 527 #if defined(ASM_CLEAR_CODE)
 528 #ifndef SPARC
 529         --> fix it
 530 #endif
 531 # ifdef SUNOS4
 532     asm(".globl _GC_clear_stack_inner");
 533     asm("_GC_clear_stack_inner:");
 534 # else
 535     asm(".globl GC_clear_stack_inner");
 536     asm("GC_clear_stack_inner:");
 537     asm(".type GC_save_regs_in_stack,#function");
 538 # endif
 539 #if defined(__arch64__) || defined(__sparcv9)
 540   asm("mov %sp,%o2");           /* Save sp                      */
 541   asm("add %sp,2047-8,%o3");    /* p = sp+bias-8                */
 542   asm("add %o1,-2047-192,%sp"); /* Move sp out of the way,      */
 543                                 /* so that traps still work.    */
 544                                 /* Includes some extra words    */
 545                                 /* so we can be sloppy below.   */
 546   asm("loop:");
 547   asm("stx %g0,[%o3]");         /* *(long *)p = 0               */
 548   asm("cmp %o3,%o1");
 549   asm("bgu,pt %xcc, loop");     /* if (p > limit) goto loop     */
 550     asm("add %o3,-8,%o3");      /* p -= 8 (delay slot) */
 551   asm("retl");
 552     asm("mov %o2,%sp");         /* Restore sp., delay slot      */
 553 #else
 554   asm("mov %sp,%o2");           /* Save sp      */
 555   asm("add %sp,-8,%o3");        /* p = sp-8     */
 556   asm("clr %g1");               /* [g0,g1] = 0  */
 557   asm("add %o1,-0x60,%sp");     /* Move sp out of the way,      */
 558                                 /* so that traps still work.    */
 559                                 /* Includes some extra words    */
 560                                 /* so we can be sloppy below.   */
 561   asm("loop:");
 562   asm("std %g0,[%o3]");         /* *(long long *)p = 0  */
 563   asm("cmp %o3,%o1");
 564   asm("bgu loop ");             /* if (p > limit) goto loop     */
 565     asm("add %o3,-8,%o3");      /* p -= 8 (delay slot) */
 566   asm("retl");
 567     asm("mov %o2,%sp");         /* Restore sp., delay slot      */
 568 #endif /* old SPARC */
 569   /* First argument = %o0 = return value */
 570 #   ifdef SVR4
 571       asm("     .GC_clear_stack_inner_end:");
 572       asm("     .size GC_clear_stack_inner,.GC_clear_stack_inner_end-GC_clear_stack_inner");
 573 #   endif
 574
 575 # ifdef LINT
 576     /*ARGSUSED*/
 577     ptr_t GC_clear_stack_inner(arg, limit)
 578     ptr_t arg; word limit;
 579     { return(arg); }
 580 # endif
 581 #endif