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 #if !defined(USE_GENERIC_PUSH_REGS) && !defined(USE_ASM_PUSH_REGS)
  78 #undef HAVE_PUSH_REGS
  79 void GC_push_regs()
  80 {
  81 #       ifdef RT
  82           register long TMP_SP; /* must be bound to r11 */
  83 #       endif
  84
  85 #       ifdef VAX
  86           /* VAX - generic code below does not work under 4.2 */
  87           /* r1 through r5 are caller save, and therefore     */
  88           /* on the stack or dead.                            */
  89           asm("pushl r11");     asm("calls $1,_GC_push_one");
  90           asm("pushl r10");     asm("calls $1,_GC_push_one");
  91           asm("pushl r9");      asm("calls $1,_GC_push_one");
  92           asm("pushl r8");      asm("calls $1,_GC_push_one");
  93           asm("pushl r7");      asm("calls $1,_GC_push_one");
  94           asm("pushl r6");      asm("calls $1,_GC_push_one");
  95 #         define HAVE_PUSH_REGS
  96 #       endif
  97 #       if defined(M68K) && (defined(SUNOS4) || defined(NEXT))
  98         /*  M68K SUNOS - could be replaced by generic code */
  99           /* a0, a1 and d1 are caller save          */
 100           /*  and therefore are on stack or dead.   */
 101
 102           asm("subqw #0x4,sp");         /* allocate word on top of stack */
 103
 104           asm("movl a2,sp@");   asm("jbsr _GC_push_one");
 105           asm("movl a3,sp@");   asm("jbsr _GC_push_one");
 106           asm("movl a4,sp@");   asm("jbsr _GC_push_one");
 107           asm("movl a5,sp@");   asm("jbsr _GC_push_one");
 108           /* Skip frame pointer and stack pointer */
 109           asm("movl d1,sp@");   asm("jbsr _GC_push_one");
 110           asm("movl d2,sp@");   asm("jbsr _GC_push_one");
 111           asm("movl d3,sp@");   asm("jbsr _GC_push_one");
 112           asm("movl d4,sp@");   asm("jbsr _GC_push_one");
 113           asm("movl d5,sp@");   asm("jbsr _GC_push_one");
 114           asm("movl d6,sp@");   asm("jbsr _GC_push_one");
 115           asm("movl d7,sp@");   asm("jbsr _GC_push_one");
 116
 117           asm("addqw #0x4,sp");         /* put stack back where it was  */
 118 #         define HAVE_PUSH_REGS
 119 #       endif
 120
 121 #       if defined(M68K) && defined(HP)
 122         /*  M68K HP - could be replaced by generic code */
 123           /* a0, a1 and d1 are caller save.  */
 124
 125           asm("subq.w &0x4,%sp");       /* allocate word on top of stack */
 126
 127           asm("mov.l %a2,(%sp)"); asm("jsr _GC_push_one");
 128           asm("mov.l %a3,(%sp)"); asm("jsr _GC_push_one");
 129           asm("mov.l %a4,(%sp)"); asm("jsr _GC_push_one");
 130           asm("mov.l %a5,(%sp)"); asm("jsr _GC_push_one");
 131           /* Skip frame pointer and stack pointer */
 132           asm("mov.l %d1,(%sp)"); asm("jsr _GC_push_one");
 133           asm("mov.l %d2,(%sp)"); asm("jsr _GC_push_one");
 134           asm("mov.l %d3,(%sp)"); asm("jsr _GC_push_one");
 135           asm("mov.l %d4,(%sp)"); asm("jsr _GC_push_one");
 136           asm("mov.l %d5,(%sp)"); asm("jsr _GC_push_one");
 137           asm("mov.l %d6,(%sp)"); asm("jsr _GC_push_one");
 138           asm("mov.l %d7,(%sp)"); asm("jsr _GC_push_one");
 139
 140           asm("addq.w &0x4,%sp");       /* put stack back where it was  */
 141 #         define HAVE_PUSH_REGS
 142 #       endif /* M68K HP */
 143
 144 #       if defined(M68K) && defined(AMIGA)
 145          /*  AMIGA - could be replaced by generic code                  */
 146          /* a0, a1, d0 and d1 are caller save */
 147
 148 #        ifdef __GNUC__
 149           asm("subq.w &0x4,%sp");       /* allocate word on top of stack */
 150
 151           asm("mov.l %a2,(%sp)"); asm("jsr _GC_push_one");
 152           asm("mov.l %a3,(%sp)"); asm("jsr _GC_push_one");
 153           asm("mov.l %a4,(%sp)"); asm("jsr _GC_push_one");
 154           asm("mov.l %a5,(%sp)"); asm("jsr _GC_push_one");
 155           asm("mov.l %a6,(%sp)"); asm("jsr _GC_push_one");
 156           /* Skip frame pointer and stack pointer */
 157           asm("mov.l %d2,(%sp)"); asm("jsr _GC_push_one");
 158           asm("mov.l %d3,(%sp)"); asm("jsr _GC_push_one");
 159           asm("mov.l %d4,(%sp)"); asm("jsr _GC_push_one");
 160           asm("mov.l %d5,(%sp)"); asm("jsr _GC_push_one");
 161           asm("mov.l %d6,(%sp)"); asm("jsr _GC_push_one");
 162           asm("mov.l %d7,(%sp)"); asm("jsr _GC_push_one");
 163
 164           asm("addq.w &0x4,%sp");       /* put stack back where it was  */
 165 #         define HAVE_PUSH_REGS
 166 #        else /* !__GNUC__ */
 167           GC_push_one(getreg(REG_A2));
 168           GC_push_one(getreg(REG_A3));
 169 #         ifndef __SASC
 170               /* Can probably be changed to #if 0 -Kjetil M. (a4=globals)*/
 171             GC_push_one(getreg(REG_A4));
 172 #         endif
 173           GC_push_one(getreg(REG_A5));
 174           GC_push_one(getreg(REG_A6));
 175           /* Skip stack pointer */
 176           GC_push_one(getreg(REG_D2));
 177           GC_push_one(getreg(REG_D3));
 178           GC_push_one(getreg(REG_D4));
 179           GC_push_one(getreg(REG_D5));
 180           GC_push_one(getreg(REG_D6));
 181           GC_push_one(getreg(REG_D7));
 182 #         define HAVE_PUSH_REGS
 183 #        endif /* !__GNUC__ */
 184 #       endif /* AMIGA */
 185
 186 #       if defined(M68K) && defined(MACOS)
 187 #       if defined(THINK_C)
 188 #         define PushMacReg(reg) \
 189               move.l  reg,(sp) \
 190               jsr             GC_push_one
 191           asm {
 192               sub.w   #4,sp                   ; reserve space for one parameter.
 193               PushMacReg(a2);
 194               PushMacReg(a3);
 195               PushMacReg(a4);
 196               ; skip a5 (globals), a6 (frame pointer), and a7 (stack pointer)
 197               PushMacReg(d2);
 198               PushMacReg(d3);
 199               PushMacReg(d4);
 200               PushMacReg(d5);
 201               PushMacReg(d6);
 202               PushMacReg(d7);
 203               add.w   #4,sp                   ; fix stack.
 204           }
 205 #         define HAVE_PUSH_REGS
 206 #         undef PushMacReg
 207 #       endif /* THINK_C */
 208 #       if defined(__MWERKS__)
 209           PushMacRegisters();
 210 #         define HAVE_PUSH_REGS
 211 #       endif   /* __MWERKS__ */
 212 #   endif       /* MACOS */
 213
 214 #       if defined(I386) &&!defined(OS2) &&!defined(SVR4) \
 215         && (defined(__MINGW32__) || !defined(MSWIN32)) \
 216         && !defined(SCO) && !defined(SCO_ELF) \
 217         && !(defined(LINUX) && defined(__ELF__)) \
 218         && !(defined(FREEBSD) && defined(__ELF__)) \
 219         && !(defined(NETBSD) && defined(__ELF__)) \
 220         && !(defined(OPENBSD) && defined(__ELF__)) \
 221         && !(defined(BEOS) && defined(__ELF__)) \
 222         && !defined(DOS4GW) && !defined(HURD)
 223         /* I386 code, generic code does not appear to work */
 224         /* It does appear to work under OS2, and asms dont */
 225         /* This is used for some 38g UNIX variants and for CYGWIN32 */
 226           asm("pushl %eax");  asm("call _GC_push_one"); asm("addl $4,%esp");
 227           asm("pushl %ecx");  asm("call _GC_push_one"); asm("addl $4,%esp");
 228           asm("pushl %edx");  asm("call _GC_push_one"); asm("addl $4,%esp");
 229           asm("pushl %ebp");  asm("call _GC_push_one"); asm("addl $4,%esp");
 230           asm("pushl %esi");  asm("call _GC_push_one"); asm("addl $4,%esp");
 231           asm("pushl %edi");  asm("call _GC_push_one"); asm("addl $4,%esp");
 232           asm("pushl %ebx");  asm("call _GC_push_one"); asm("addl $4,%esp");
 233 #         define HAVE_PUSH_REGS
 234 #       endif
 235
 236 #       if ( defined(I386) && defined(LINUX) && defined(__ELF__) ) \
 237         || ( defined(I386) && defined(FREEBSD) && defined(__ELF__) ) \
 238         || ( defined(I386) && defined(NETBSD) && defined(__ELF__) ) \
 239         || ( defined(I386) && defined(OPENBSD) && defined(__ELF__) ) \
 240         || ( defined(I386) && defined(HURD) && defined(__ELF__) ) \
 241         || ( defined(I386) && defined(DGUX) )
 242
 243         /* This is modified for Linux with ELF (Note: _ELF_ only) */
 244         /* This section handles FreeBSD with ELF. */
 245         /* Eax is caller-save and dead here.  Other caller-save         */
 246         /* registers could also be skipped.  We assume there are no     */
 247         /* pointers in MMX registers, etc.                              */
 248         /* We combine instructions in a single asm to prevent gcc from  */
 249         /* inserting code in the middle.                                */
 250           asm("pushl %ecx; call GC_push_one; addl $4,%esp");
 251           asm("pushl %edx; call GC_push_one; addl $4,%esp");
 252           asm("pushl %ebp; call GC_push_one; addl $4,%esp");
 253           asm("pushl %esi; call GC_push_one; addl $4,%esp");
 254           asm("pushl %edi; call GC_push_one; addl $4,%esp");
 255           asm("pushl %ebx; call GC_push_one; addl $4,%esp");
 256 #         define HAVE_PUSH_REGS
 257 #       endif
 258
 259 #       if ( defined(I386) && defined(BEOS) && defined(__ELF__) )
 260         /* As far as I can understand from                              */
 261         /* http://www.beunited.org/articles/jbq/nasm.shtml,             */
 262         /* only ebp, esi, edi and ebx are not scratch. How MMX          */
 263         /* etc. registers should be treated, I have no idea.            */
 264           asm("pushl %ebp; call GC_push_one; addl $4,%esp");
 265           asm("pushl %esi; call GC_push_one; addl $4,%esp");
 266           asm("pushl %edi; call GC_push_one; addl $4,%esp");
 267           asm("pushl %ebx; call GC_push_one; addl $4,%esp");
 268 #         define HAVE_PUSH_REGS
 269 #       endif
 270
 271 #       if defined(I386) && defined(MSWIN32) && !defined(__MINGW32__) \
 272            && !defined(USE_GENERIC)
 273         /* I386 code, Microsoft variant         */
 274           __asm  push eax
 275           __asm  call GC_push_one
 276           __asm  add esp,4
 277           __asm  push ebx
 278           __asm  call GC_push_one
 279           __asm  add esp,4
 280           __asm  push ecx
 281           __asm  call GC_push_one
 282           __asm  add esp,4
 283           __asm  push edx
 284           __asm  call GC_push_one
 285           __asm  add esp,4
 286           __asm  push ebp
 287           __asm  call GC_push_one
 288           __asm  add esp,4
 289           __asm  push esi
 290           __asm  call GC_push_one
 291           __asm  add esp,4
 292           __asm  push edi
 293           __asm  call GC_push_one
 294           __asm  add esp,4
 295 #         define HAVE_PUSH_REGS
 296 #       endif
 297
 298 #       if defined(I386) && (defined(SVR4) || defined(SCO) || defined(SCO_ELF))
 299         /* I386 code, SVR4 variant, generic code does not appear to work */
 300           asm("pushl %eax");  asm("call GC_push_one"); asm("addl $4,%esp");
 301           asm("pushl %ebx");  asm("call GC_push_one"); asm("addl $4,%esp");
 302           asm("pushl %ecx");  asm("call GC_push_one"); asm("addl $4,%esp");
 303           asm("pushl %edx");  asm("call GC_push_one"); asm("addl $4,%esp");
 304           asm("pushl %ebp");  asm("call GC_push_one"); asm("addl $4,%esp");
 305           asm("pushl %esi");  asm("call GC_push_one"); asm("addl $4,%esp");
 306           asm("pushl %edi");  asm("call GC_push_one"); asm("addl $4,%esp");
 307 #         define HAVE_PUSH_REGS
 308 #       endif
 309
 310 #       ifdef NS32K
 311           asm ("movd r3, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 312           asm ("movd r4, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 313           asm ("movd r5, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 314           asm ("movd r6, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 315           asm ("movd r7, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 316 #         define HAVE_PUSH_REGS
 317 #       endif
 318
 319 #       if defined(SPARC)
 320           GC_save_regs_ret_val = GC_save_regs_in_stack();
 321 #         define HAVE_PUSH_REGS
 322 #       endif
 323
 324 #       ifdef RT
 325             GC_push_one(TMP_SP);    /* GC_push_one from r11 */
 326
 327             asm("cas r11, r6, r0"); GC_push_one(TMP_SP);        /* r6 */
 328             asm("cas r11, r7, r0"); GC_push_one(TMP_SP);        /* through */
 329             asm("cas r11, r8, r0"); GC_push_one(TMP_SP);        /* r10 */
 330             asm("cas r11, r9, r0"); GC_push_one(TMP_SP);
 331             asm("cas r11, r10, r0"); GC_push_one(TMP_SP);
 332
 333             asm("cas r11, r12, r0"); GC_push_one(TMP_SP); /* r12 */
 334             asm("cas r11, r13, r0"); GC_push_one(TMP_SP); /* through */
 335             asm("cas r11, r14, r0"); GC_push_one(TMP_SP); /* r15 */
 336             asm("cas r11, r15, r0"); GC_push_one(TMP_SP);
 337 #           define HAVE_PUSH_REGS
 338 #       endif
 339
 340 #       if defined(M68K) && defined(SYSV)
 341         /*  Once again similar to SUN and HP, though setjmp appears to work.
 342                 --Parag
 343          */
 344 #        ifdef __GNUC__
 345           asm("subqw #0x4,%sp");        /* allocate word on top of stack */
 346
 347           asm("movl %a2,%sp@"); asm("jbsr GC_push_one");
 348           asm("movl %a3,%sp@"); asm("jbsr GC_push_one");
 349           asm("movl %a4,%sp@"); asm("jbsr GC_push_one");
 350           asm("movl %a5,%sp@"); asm("jbsr GC_push_one");
 351           /* Skip frame pointer and stack pointer */
 352           asm("movl %d1,%sp@"); asm("jbsr GC_push_one");
 353           asm("movl %d2,%sp@"); asm("jbsr GC_push_one");
 354           asm("movl %d3,%sp@"); asm("jbsr GC_push_one");
 355           asm("movl %d4,%sp@"); asm("jbsr GC_push_one");
 356           asm("movl %d5,%sp@"); asm("jbsr GC_push_one");
 357           asm("movl %d6,%sp@"); asm("jbsr GC_push_one");
 358           asm("movl %d7,%sp@"); asm("jbsr GC_push_one");
 359
 360           asm("addqw #0x4,%sp");        /* put stack back where it was  */
 361 #         define HAVE_PUSH_REGS
 362 #        else /* !__GNUC__*/
 363           asm("subq.w &0x4,%sp");       /* allocate word on top of stack */
 364
 365           asm("mov.l %a2,(%sp)"); asm("jsr GC_push_one");
 366           asm("mov.l %a3,(%sp)"); asm("jsr GC_push_one");
 367           asm("mov.l %a4,(%sp)"); asm("jsr GC_push_one");
 368           asm("mov.l %a5,(%sp)"); asm("jsr GC_push_one");
 369           /* Skip frame pointer and stack pointer */
 370           asm("mov.l %d1,(%sp)"); asm("jsr GC_push_one");
 371           asm("mov.l %d2,(%sp)"); asm("jsr GC_push_one");
 372           asm("mov.l %d3,(%sp)"); asm("jsr GC_push_one");
 373           asm("mov.l %d4,(%sp)"); asm("jsr GC_push_one");
 374           asm("mov.l %d5,(%sp)"); asm("jsr GC_push_one");
 375           asm("mov.l %d6,(%sp)"); asm("jsr GC_push_one");
 376           asm("mov.l %d7,(%sp)"); asm("jsr GC_push_one");
 377
 378           asm("addq.w &0x4,%sp");       /* put stack back where it was  */
 379 #         define HAVE_PUSH_REGS
 380 #        endif /* !__GNUC__ */
 381 #       endif /* M68K/SYSV */
 382
 383 #     if defined(PJ)
 384         {
 385             register int * sp asm ("optop");
 386             extern int *__libc_stack_end;
 387
 388             GC_push_all_stack (sp, __libc_stack_end);
 389 #           define HAVE_PUSH_REGS
 390             /* Isn't this redundant with the code to push the stack? */
 391         }
 392 #     endif
 393
 394       /* other machines... */
 395 #       if !defined(HAVE_PUSH_REGS)
 396             --> We just generated an empty GC_push_regs, which
 397             --> is almost certainly broken.  Try defining
 398             --> USE_GENERIC_PUSH_REGS instead.
 399 #       endif
 400 }
 401 #endif /* !USE_GENERIC_PUSH_REGS && !USE_ASM_PUSH_REGS */
 402
 403 #if defined(USE_GENERIC_PUSH_REGS)
 404 void GC_generic_push_regs(cold_gc_frame)
 405 ptr_t cold_gc_frame;
 406 {
 407         {
 408 #           ifdef HAVE_BUILTIN_UNWIND_INIT
 409               /* This was suggested by Richard Henderson as the way to  */
 410               /* force callee-save registers and register windows onto  */
 411               /* the stack.                                             */
 412               __builtin_unwind_init();
 413 #           else /* !HAVE_BUILTIN_UNWIND_INIT */
 414               /* Generic code                          */
 415               /* The idea is due to Parag Patel at HP. */
 416               /* We're not sure whether he would like  */
 417               /* to be he acknowledged for it or not.  */
 418               jmp_buf regs;
 419               register word * i = (word *) regs;
 420               register ptr_t lim = (ptr_t)(regs) + (sizeof regs);
 421
 422               /* Setjmp doesn't always clear all of the buffer.         */
 423               /* That tends to preserve garbage.  Clear it.             */
 424                 for (; (char *)i < lim; i++) {
 425                     *i = 0;
 426                 }
 427 #             if defined(POWERPC) || defined(MSWIN32) || defined(MSWINCE) \
 428                 || defined(UTS4) || defined(LINUX) || defined(EWS4800)
 429                   (void) setjmp(regs);
 430 #             else
 431                   (void) _setjmp(regs);
 432 #             endif
 433 #           endif /* !HAVE_BUILTIN_UNWIND_INIT */
 434 #           if (defined(SPARC) && !defined(HAVE_BUILTIN_UNWIND_INIT)) \
 435                 || defined(IA64)
 436               /* On a register window machine, we need to save register */
 437               /* contents on the stack for this to work.  The setjmp    */
 438               /* is probably not needed on SPARC, since pointers are    */
 439               /* only stored in windowed or scratch registers.  It is   */
 440               /* needed on IA64, since some non-windowed registers are  */
 441               /* preserved.                                             */
 442               {
 443                 GC_save_regs_ret_val = GC_save_regs_in_stack();
 444                 /* On IA64 gcc, could use __builtin_ia64_flushrs() and  */
 445                 /* __builtin_ia64_flushrs().  The latter will be done   */
 446                 /* implicitly by __builtin_unwind_init() for gcc3.0.1   */
 447                 /* and later.                                           */
 448               }
 449 #           endif
 450             GC_push_current_stack(cold_gc_frame);
 451         }
 452 }
 453 #endif /* USE_GENERIC_PUSH_REGS */
 454
 455 /* On register window machines, we need a way to force registers into   */
 456 /* the stack.   Return sp.                                              */
 457 # ifdef SPARC
 458     asm("       .seg    \"text\"");
 459 #   if defined(SVR4) || defined(NETBSD)
 460       asm("     .globl  GC_save_regs_in_stack");
 461       asm("GC_save_regs_in_stack:");
 462       asm("     .type GC_save_regs_in_stack,#function");
 463 #   else
 464       asm("     .globl  _GC_save_regs_in_stack");
 465       asm("_GC_save_regs_in_stack:");
 466 #   endif
 467 #   if defined(__arch64__) || defined(__sparcv9)
 468       asm("     save    %sp,-128,%sp");
 469       asm("     flushw");
 470       asm("     ret");
 471       asm("     restore %sp,2047+128,%o0");
 472 #   else
 473       asm("     ta      0x3   ! ST_FLUSH_WINDOWS");
 474       asm("     retl");
 475       asm("     mov     %sp,%o0");
 476 #   endif
 477 #   ifdef SVR4
 478       asm("     .GC_save_regs_in_stack_end:");
 479       asm("     .size GC_save_regs_in_stack,.GC_save_regs_in_stack_end-GC_save_regs_in_stack");
 480 #   endif
 481 #   ifdef LINT
 482         word GC_save_regs_in_stack() { return(0 /* sp really */);}
 483 #   endif
 484 # endif
 485
 486 /* On IA64, we also need to flush register windows.  But they end       */
 487 /* up on the other side of the stack segment.                           */
 488 /* Returns the backing store pointer for the register stack.            */
 489 /* We now implement this as a separate assembly file, since inline      */
 490 /* assembly code here doesn't work with either the Intel or HP          */
 491 /* compilers.                                                           */
 492 # if 0
 493 #   ifdef LINUX
 494         asm("        .text");
 495         asm("        .psr abi64");
 496         asm("        .psr lsb");
 497         asm("        .lsb");
 498         asm("");
 499         asm("        .text");
 500         asm("        .align 16");
 501         asm("        .global GC_save_regs_in_stack");
 502         asm("        .proc GC_save_regs_in_stack");
 503         asm("GC_save_regs_in_stack:");
 504         asm("        .body");
 505         asm("        flushrs");
 506         asm("        ;;");
 507         asm("        mov r8=ar.bsp");
 508         asm("        br.ret.sptk.few rp");
 509         asm("        .endp GC_save_regs_in_stack");
 510 #   endif /* LINUX */
 511 #   if 0 /* Other alternatives that don't work on HP/UX */
 512         word GC_save_regs_in_stack() {
 513 #         if USE_BUILTINS
 514             __builtin_ia64_flushrs();
 515             return __builtin_ia64_bsp();
 516 #         else
 517 #           ifdef HPUX
 518               _asm("        flushrs");
 519               _asm("        ;;");
 520               _asm("        mov r8=ar.bsp");
 521               _asm("        br.ret.sptk.few rp");
 522 #           else
 523               asm("        flushrs");
 524               asm("        ;;");
 525               asm("        mov r8=ar.bsp");
 526               asm("        br.ret.sptk.few rp");
 527 #           endif
 528 #         endif
 529         }
 530 #   endif
 531 # endif
 532
 533 /* GC_clear_stack_inner(arg, limit) clears stack area up to limit and   */
 534 /* returns arg.  Stack clearing is crucial on SPARC, so we supply       */
 535 /* an assembly version that's more careful.  Assumes limit is hotter    */
 536 /* than sp, and limit is 8 byte aligned.                                */
 537 #if defined(ASM_CLEAR_CODE)
 538 #ifndef SPARC
 539         --> fix it
 540 #endif
 541 # ifdef SUNOS4
 542     asm(".globl _GC_clear_stack_inner");
 543     asm("_GC_clear_stack_inner:");
 544 # else
 545     asm(".globl GC_clear_stack_inner");
 546     asm("GC_clear_stack_inner:");
 547     asm(".type GC_save_regs_in_stack,#function");
 548 # endif
 549 #if defined(__arch64__) || defined(__sparcv9)
 550   asm("mov %sp,%o2");           /* Save sp                      */
 551   asm("add %sp,2047-8,%o3");    /* p = sp+bias-8                */
 552   asm("add %o1,-2047-192,%sp"); /* Move sp out of the way,      */
 553                                 /* so that traps still work.    */
 554                                 /* Includes some extra words    */
 555                                 /* so we can be sloppy below.   */
 556   asm("loop:");
 557   asm("stx %g0,[%o3]");         /* *(long *)p = 0               */
 558   asm("cmp %o3,%o1");
 559   asm("bgu,pt %xcc, loop");     /* if (p > limit) goto loop     */
 560     asm("add %o3,-8,%o3");      /* p -= 8 (delay slot) */
 561   asm("retl");
 562     asm("mov %o2,%sp");         /* Restore sp., delay slot      */
 563 #else
 564   asm("mov %sp,%o2");           /* Save sp      */
 565   asm("add %sp,-8,%o3");        /* p = sp-8     */
 566   asm("clr %g1");               /* [g0,g1] = 0  */
 567   asm("add %o1,-0x60,%sp");     /* Move sp out of the way,      */
 568                                 /* so that traps still work.    */
 569                                 /* Includes some extra words    */
 570                                 /* so we can be sloppy below.   */
 571   asm("loop:");
 572   asm("std %g0,[%o3]");         /* *(long long *)p = 0  */
 573   asm("cmp %o3,%o1");
 574   asm("bgu loop ");             /* if (p > limit) goto loop     */
 575     asm("add %o3,-8,%o3");      /* p -= 8 (delay slot) */
 576   asm("retl");
 577     asm("mov %o2,%sp");         /* Restore sp., delay slot      */
 578 #endif /* old SPARC */
 579   /* First argument = %o0 = return value */
 580 #   ifdef SVR4
 581       asm("     .GC_clear_stack_inner_end:");
 582       asm("     .size GC_clear_stack_inner,.GC_clear_stack_inner_end-GC_clear_stack_inner");
 583 #   endif
 584
 585 # ifdef LINT
 586     /*ARGSUSED*/
 587     ptr_t GC_clear_stack_inner(arg, limit)
 588     ptr_t arg; word limit;
 589     { return(arg); }
 590 # endif
 591 #endif