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(RS6000) || defined(POWERPC)
  31 # include <ucontext.h>
  32 #endif
  33
  34 #if defined(__MWERKS__) && !defined(POWERPC)
  35
  36 asm static void PushMacRegisters()
  37 {
  38     sub.w   #4,sp                   // reserve space for one parameter.
  39     move.l  a2,(sp)
  40     jsr         GC_push_one
  41     move.l  a3,(sp)
  42     jsr         GC_push_one
  43     move.l  a4,(sp)
  44     jsr         GC_push_one
  45 #   if !__option(a6frames)
  46         // <pcb> perhaps a6 should be pushed if stack frames are not being used.
  47         move.l  a6,(sp)
  48         jsr             GC_push_one
  49 #   endif
  50         // skip a5 (globals), a6 (frame pointer), and a7 (stack pointer)
  51     move.l  d2,(sp)
  52     jsr         GC_push_one
  53     move.l  d3,(sp)
  54     jsr         GC_push_one
  55     move.l  d4,(sp)
  56     jsr         GC_push_one
  57     move.l  d5,(sp)
  58     jsr         GC_push_one
  59     move.l  d6,(sp)
  60     jsr         GC_push_one
  61     move.l  d7,(sp)
  62     jsr         GC_push_one
  63     add.w   #4,sp                   // fix stack.
  64     rts
  65 }
  66
  67 #endif /* __MWERKS__ */
  68
  69 # if defined(SPARC) || defined(IA64)
  70     /* Value returned from register flushing routine; either sp (SPARC) */
  71     /* or ar.bsp (IA64)                                                 */
  72     word GC_save_regs_ret_val;
  73 # endif
  74
  75 /* Routine to mark from registers that are preserved by the C compiler. */
  76 /* This must be ported to every new architecture.  There is a generic   */
  77 /* version at the end, that is likely, but not guaranteed to work       */
  78 /* on your architecture.  Run the test_setjmp program to see whether    */
  79 /* there is any chance it will work.                                    */
  80
  81 #if !defined(USE_GENERIC_PUSH_REGS) && !defined(USE_ASM_PUSH_REGS)
  82 #undef HAVE_PUSH_REGS
  83 void GC_push_regs()
  84 {
  85 #       ifdef RT
  86           register long TMP_SP; /* must be bound to r11 */
  87 #       endif
  88
  89 #       ifdef VAX
  90           /* VAX - generic code below does not work under 4.2 */
  91           /* r1 through r5 are caller save, and therefore     */
  92           /* on the stack or dead.                            */
  93           asm("pushl r11");     asm("calls $1,_GC_push_one");
  94           asm("pushl r10");     asm("calls $1,_GC_push_one");
  95           asm("pushl r9");      asm("calls $1,_GC_push_one");
  96           asm("pushl r8");      asm("calls $1,_GC_push_one");
  97           asm("pushl r7");      asm("calls $1,_GC_push_one");
  98           asm("pushl r6");      asm("calls $1,_GC_push_one");
  99 #         define HAVE_PUSH_REGS
 100 #       endif
 101 #       if defined(M68K) && (defined(SUNOS4) || defined(NEXT))
 102         /*  M68K SUNOS - could be replaced by generic code */
 103           /* a0, a1 and d1 are caller save          */
 104           /*  and therefore are on stack or dead.   */
 105
 106           asm("subqw #0x4,sp");         /* allocate word on top of stack */
 107
 108           asm("movl a2,sp@");   asm("jbsr _GC_push_one");
 109           asm("movl a3,sp@");   asm("jbsr _GC_push_one");
 110           asm("movl a4,sp@");   asm("jbsr _GC_push_one");
 111           asm("movl a5,sp@");   asm("jbsr _GC_push_one");
 112           /* Skip frame pointer and stack pointer */
 113           asm("movl d1,sp@");   asm("jbsr _GC_push_one");
 114           asm("movl d2,sp@");   asm("jbsr _GC_push_one");
 115           asm("movl d3,sp@");   asm("jbsr _GC_push_one");
 116           asm("movl d4,sp@");   asm("jbsr _GC_push_one");
 117           asm("movl d5,sp@");   asm("jbsr _GC_push_one");
 118           asm("movl d6,sp@");   asm("jbsr _GC_push_one");
 119           asm("movl d7,sp@");   asm("jbsr _GC_push_one");
 120
 121           asm("addqw #0x4,sp");         /* put stack back where it was  */
 122 #         define HAVE_PUSH_REGS
 123 #       endif
 124
 125 #       if defined(M68K) && defined(HP)
 126         /*  M68K HP - could be replaced by generic code */
 127           /* a0, a1 and d1 are caller save.  */
 128
 129           asm("subq.w &0x4,%sp");       /* allocate word on top of stack */
 130
 131           asm("mov.l %a2,(%sp)"); asm("jsr _GC_push_one");
 132           asm("mov.l %a3,(%sp)"); asm("jsr _GC_push_one");
 133           asm("mov.l %a4,(%sp)"); asm("jsr _GC_push_one");
 134           asm("mov.l %a5,(%sp)"); asm("jsr _GC_push_one");
 135           /* Skip frame pointer and stack pointer */
 136           asm("mov.l %d1,(%sp)"); asm("jsr _GC_push_one");
 137           asm("mov.l %d2,(%sp)"); asm("jsr _GC_push_one");
 138           asm("mov.l %d3,(%sp)"); asm("jsr _GC_push_one");
 139           asm("mov.l %d4,(%sp)"); asm("jsr _GC_push_one");
 140           asm("mov.l %d5,(%sp)"); asm("jsr _GC_push_one");
 141           asm("mov.l %d6,(%sp)"); asm("jsr _GC_push_one");
 142           asm("mov.l %d7,(%sp)"); asm("jsr _GC_push_one");
 143
 144           asm("addq.w &0x4,%sp");       /* put stack back where it was  */
 145 #         define HAVE_PUSH_REGS
 146 #       endif /* M68K HP */
 147
 148 #       if defined(M68K) && defined(AMIGA)
 149          /*  AMIGA - could be replaced by generic code                  */
 150          /* a0, a1, d0 and d1 are caller save */
 151
 152 #        ifdef __GNUC__
 153           asm("subq.w &0x4,%sp");       /* allocate word on top of stack */
 154
 155           asm("mov.l %a2,(%sp)"); asm("jsr _GC_push_one");
 156           asm("mov.l %a3,(%sp)"); asm("jsr _GC_push_one");
 157           asm("mov.l %a4,(%sp)"); asm("jsr _GC_push_one");
 158           asm("mov.l %a5,(%sp)"); asm("jsr _GC_push_one");
 159           asm("mov.l %a6,(%sp)"); asm("jsr _GC_push_one");
 160           /* Skip frame pointer and stack pointer */
 161           asm("mov.l %d2,(%sp)"); asm("jsr _GC_push_one");
 162           asm("mov.l %d3,(%sp)"); asm("jsr _GC_push_one");
 163           asm("mov.l %d4,(%sp)"); asm("jsr _GC_push_one");
 164           asm("mov.l %d5,(%sp)"); asm("jsr _GC_push_one");
 165           asm("mov.l %d6,(%sp)"); asm("jsr _GC_push_one");
 166           asm("mov.l %d7,(%sp)"); asm("jsr _GC_push_one");
 167
 168           asm("addq.w &0x4,%sp");       /* put stack back where it was  */
 169 #         define HAVE_PUSH_REGS
 170 #        else /* !__GNUC__ */
 171           GC_push_one(getreg(REG_A2));
 172           GC_push_one(getreg(REG_A3));
 173 #         ifndef __SASC
 174               /* Can probably be changed to #if 0 -Kjetil M. (a4=globals)*/
 175             GC_push_one(getreg(REG_A4));
 176 #         endif
 177           GC_push_one(getreg(REG_A5));
 178           GC_push_one(getreg(REG_A6));
 179           /* Skip stack pointer */
 180           GC_push_one(getreg(REG_D2));
 181           GC_push_one(getreg(REG_D3));
 182           GC_push_one(getreg(REG_D4));
 183           GC_push_one(getreg(REG_D5));
 184           GC_push_one(getreg(REG_D6));
 185           GC_push_one(getreg(REG_D7));
 186 #         define HAVE_PUSH_REGS
 187 #        endif /* !__GNUC__ */
 188 #       endif /* AMIGA */
 189
 190 #       if defined(M68K) && defined(MACOS)
 191 #       if defined(THINK_C)
 192 #         define PushMacReg(reg) \
 193               move.l  reg,(sp) \
 194               jsr             GC_push_one
 195           asm {
 196               sub.w   #4,sp                   ; reserve space for one parameter.
 197               PushMacReg(a2);
 198               PushMacReg(a3);
 199               PushMacReg(a4);
 200               ; skip a5 (globals), a6 (frame pointer), and a7 (stack pointer)
 201               PushMacReg(d2);
 202               PushMacReg(d3);
 203               PushMacReg(d4);
 204               PushMacReg(d5);
 205               PushMacReg(d6);
 206               PushMacReg(d7);
 207               add.w   #4,sp                   ; fix stack.
 208           }
 209 #         define HAVE_PUSH_REGS
 210 #         undef PushMacReg
 211 #       endif /* THINK_C */
 212 #       if defined(__MWERKS__)
 213           PushMacRegisters();
 214 #         define HAVE_PUSH_REGS
 215 #       endif   /* __MWERKS__ */
 216 #   endif       /* MACOS */
 217
 218 #       if defined(I386) &&!defined(OS2) &&!defined(SVR4) \
 219         && (defined(__MINGW32__) || !defined(MSWIN32)) \
 220         && !defined(SCO) && !defined(SCO_ELF) \
 221         && !(defined(LINUX) && defined(__ELF__)) \
 222         && !(defined(FREEBSD) && defined(__ELF__)) \
 223         && !(defined(NETBSD) && defined(__ELF__)) \
 224         && !(defined(OPENBSD) && defined(__ELF__)) \
 225         && !(defined(BEOS) && defined(__ELF__)) \
 226         && !defined(DOS4GW) && !defined(HURD)
 227         /* I386 code, generic code does not appear to work */
 228         /* It does appear to work under OS2, and asms dont */
 229         /* This is used for some 38g UNIX variants and for CYGWIN32 */
 230           asm("pushl %eax");  asm("call _GC_push_one"); asm("addl $4,%esp");
 231           asm("pushl %ecx");  asm("call _GC_push_one"); asm("addl $4,%esp");
 232           asm("pushl %edx");  asm("call _GC_push_one"); asm("addl $4,%esp");
 233           asm("pushl %ebp");  asm("call _GC_push_one"); asm("addl $4,%esp");
 234           asm("pushl %esi");  asm("call _GC_push_one"); asm("addl $4,%esp");
 235           asm("pushl %edi");  asm("call _GC_push_one"); asm("addl $4,%esp");
 236           asm("pushl %ebx");  asm("call _GC_push_one"); asm("addl $4,%esp");
 237 #         define HAVE_PUSH_REGS
 238 #       endif
 239
 240 #       if ( defined(I386) && defined(LINUX) && defined(__ELF__) ) \
 241         || ( defined(I386) && defined(FREEBSD) && defined(__ELF__) ) \
 242         || ( defined(I386) && defined(NETBSD) && defined(__ELF__) ) \
 243         || ( defined(I386) && defined(OPENBSD) && defined(__ELF__) ) \
 244         || ( defined(I386) && defined(HURD) && defined(__ELF__) ) \
 245         || ( defined(I386) && defined(DGUX) )
 246
 247         /* This is modified for Linux with ELF (Note: _ELF_ only) */
 248         /* This section handles FreeBSD with ELF. */
 249         /* Eax is caller-save and dead here.  Other caller-save         */
 250         /* registers could also be skipped.  We assume there are no     */
 251         /* pointers in MMX registers, etc.                              */
 252         /* We combine instructions in a single asm to prevent gcc from  */
 253         /* inserting code in the middle.                                */
 254           asm("pushl %ecx; call GC_push_one; addl $4,%esp");
 255           asm("pushl %edx; call GC_push_one; addl $4,%esp");
 256           asm("pushl %ebp; call GC_push_one; addl $4,%esp");
 257           asm("pushl %esi; call GC_push_one; addl $4,%esp");
 258           asm("pushl %edi; call GC_push_one; addl $4,%esp");
 259           asm("pushl %ebx; call GC_push_one; addl $4,%esp");
 260 #         define HAVE_PUSH_REGS
 261 #       endif
 262
 263 #       if ( defined(I386) && defined(BEOS) && defined(__ELF__) )
 264         /* As far as I can understand from                              */
 265         /* http://www.beunited.org/articles/jbq/nasm.shtml,             */
 266         /* only ebp, esi, edi and ebx are not scratch. How MMX          */
 267         /* etc. registers should be treated, I have no idea.            */
 268           asm("pushl %ebp; call GC_push_one; addl $4,%esp");
 269           asm("pushl %esi; call GC_push_one; addl $4,%esp");
 270           asm("pushl %edi; call GC_push_one; addl $4,%esp");
 271           asm("pushl %ebx; call GC_push_one; addl $4,%esp");
 272 #         define HAVE_PUSH_REGS
 273 #       endif
 274
 275 #       if defined(I386) && defined(MSWIN32) && !defined(__MINGW32__) \
 276            && !defined(USE_GENERIC)
 277         /* I386 code, Microsoft variant         */
 278           __asm  push eax
 279           __asm  call GC_push_one
 280           __asm  add esp,4
 281           __asm  push ebx
 282           __asm  call GC_push_one
 283           __asm  add esp,4
 284           __asm  push ecx
 285           __asm  call GC_push_one
 286           __asm  add esp,4
 287           __asm  push edx
 288           __asm  call GC_push_one
 289           __asm  add esp,4
 290           __asm  push ebp
 291           __asm  call GC_push_one
 292           __asm  add esp,4
 293           __asm  push esi
 294           __asm  call GC_push_one
 295           __asm  add esp,4
 296           __asm  push edi
 297           __asm  call GC_push_one
 298           __asm  add esp,4
 299 #         define HAVE_PUSH_REGS
 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 #         define HAVE_PUSH_REGS
 312 #       endif
 313
 314 #       ifdef NS32K
 315           asm ("movd r3, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 316           asm ("movd r4, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 317           asm ("movd r5, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 318           asm ("movd r6, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 319           asm ("movd r7, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
 320 #         define HAVE_PUSH_REGS
 321 #       endif
 322
 323 #       if defined(SPARC)
 324           GC_save_regs_ret_val = GC_save_regs_in_stack();
 325 #         define HAVE_PUSH_REGS
 326 #       endif
 327
 328 #       ifdef RT
 329             GC_push_one(TMP_SP);    /* GC_push_one from r11 */
 330
 331             asm("cas r11, r6, r0"); GC_push_one(TMP_SP);        /* r6 */
 332             asm("cas r11, r7, r0"); GC_push_one(TMP_SP);        /* through */
 333             asm("cas r11, r8, r0"); GC_push_one(TMP_SP);        /* r10 */
 334             asm("cas r11, r9, r0"); GC_push_one(TMP_SP);
 335             asm("cas r11, r10, r0"); GC_push_one(TMP_SP);
 336
 337             asm("cas r11, r12, r0"); GC_push_one(TMP_SP); /* r12 */
 338             asm("cas r11, r13, r0"); GC_push_one(TMP_SP); /* through */
 339             asm("cas r11, r14, r0"); GC_push_one(TMP_SP); /* r15 */
 340             asm("cas r11, r15, r0"); GC_push_one(TMP_SP);
 341 #           define HAVE_PUSH_REGS
 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 #         define HAVE_PUSH_REGS
 366 #        else /* !__GNUC__*/
 367           asm("subq.w &0x4,%sp");       /* allocate word on top of stack */
 368
 369           asm("mov.l %a2,(%sp)"); asm("jsr GC_push_one");
 370           asm("mov.l %a3,(%sp)"); asm("jsr GC_push_one");
 371           asm("mov.l %a4,(%sp)"); asm("jsr GC_push_one");
 372           asm("mov.l %a5,(%sp)"); asm("jsr GC_push_one");
 373           /* Skip frame pointer and stack pointer */
 374           asm("mov.l %d1,(%sp)"); asm("jsr GC_push_one");
 375           asm("mov.l %d2,(%sp)"); asm("jsr GC_push_one");
 376           asm("mov.l %d3,(%sp)"); asm("jsr GC_push_one");
 377           asm("mov.l %d4,(%sp)"); asm("jsr GC_push_one");
 378           asm("mov.l %d5,(%sp)"); asm("jsr GC_push_one");
 379           asm("mov.l %d6,(%sp)"); asm("jsr GC_push_one");
 380           asm("mov.l %d7,(%sp)"); asm("jsr GC_push_one");
 381
 382           asm("addq.w &0x4,%sp");       /* put stack back where it was  */
 383 #         define HAVE_PUSH_REGS
 384 #        endif /* !__GNUC__ */
 385 #       endif /* M68K/SYSV */
 386
 387 #     if defined(PJ)
 388         {
 389             register int * sp asm ("optop");
 390             extern int *__libc_stack_end;
 391
 392             GC_push_all_stack (sp, __libc_stack_end);
 393 #           define HAVE_PUSH_REGS
 394             /* Isn't this redundant with the code to push the stack? */
 395         }
 396 #     endif
 397
 398       /* other machines... */
 399 #       if !defined(HAVE_PUSH_REGS)
 400             --> We just generated an empty GC_push_regs, which
 401             --> is almost certainly broken.  Try defining
 402             --> USE_GENERIC_PUSH_REGS instead.
 403 #       endif
 404 }
 405 #endif /* !USE_GENERIC_PUSH_REGS && !USE_ASM_PUSH_REGS */
 406
 407 void GC_with_callee_saves_pushed(fn, arg)
 408 void (*fn)();
 409 ptr_t arg;
 410 {
 411     word dummy;
 412
 413 #   if defined(USE_GENERIC_PUSH_REGS)
 414 #     ifdef HAVE_BUILTIN_UNWIND_INIT
 415         /* This was suggested by Richard Henderson as the way to        */
 416         /* force callee-save registers and register windows onto        */
 417         /* the stack.                                           */
 418         __builtin_unwind_init();
 419 #     else /* !HAVE_BUILTIN_UNWIND_INIT */
 420 #      if defined(RS6000) || defined(POWERPC)
 421         /* FIXME: RS6000 means AIX.                             */
 422         /* This should probably be used in all Posix/non-gcc    */
 423         /* settings.  We defer that change to minimize risk.    */
 424         ucontext_t ctxt;
 425         getcontext(&ctxt);
 426 #      else
 427         /* Generic code                          */
 428         /* The idea is due to Parag Patel at HP. */
 429         /* We're not sure whether he would like  */
 430         /* to be he acknowledged for it or not.  */
 431         jmp_buf regs;
 432         register word * i = (word *) regs;
 433         register ptr_t lim = (ptr_t)(regs) + (sizeof regs);
 434
 435         /* Setjmp doesn't always clear all of the buffer.               */
 436         /* That tends to preserve garbage.  Clear it.                   */
 437         for (; (char *)i < lim; i++) {
 438             *i = 0;
 439         }
 440 #       if defined(MSWIN32) || defined(MSWINCE) \
 441                   || defined(UTS4) || defined(LINUX) || defined(EWS4800)
 442           (void) setjmp(regs);
 443 #       else
 444             (void) _setjmp(regs);
 445           /* We don't want to mess with signals. According to   */
 446           /* SUSV3, setjmp() may or may not save signal mask.   */
 447           /* _setjmp won't, but is less portable.               */
 448 #       endif
 449 #      endif /* !AIX ... */
 450 #     endif /* !HAVE_BUILTIN_UNWIND_INIT */
 451 #   else
 452 #     if defined(PTHREADS) && !defined(MSWIN32) /* !USE_GENERIC_PUSH_REGS */
 453         /* We may still need this to save thread contexts.      */
 454         ucontext_t ctxt;
 455         getcontext(&ctxt);
 456 #     else  /* Shouldn't be needed */
 457         ABORT("Unexpected call to GC_with_callee_saves_pushed");
 458 #     endif
 459 #   endif
 460 #   if (defined(SPARC) && !defined(HAVE_BUILTIN_UNWIND_INIT)) \
 461         || defined(IA64)
 462       /* On a register window machine, we need to save register */
 463       /* contents on the stack for this to work.  The setjmp    */
 464       /* is probably not needed on SPARC, since pointers are    */
 465       /* only stored in windowed or scratch registers.  It is   */
 466       /* needed on IA64, since some non-windowed registers are  */
 467       /* preserved.                                             */
 468       {
 469         GC_save_regs_ret_val = GC_save_regs_in_stack();
 470         /* On IA64 gcc, could use __builtin_ia64_flushrs() and  */
 471         /* __builtin_ia64_flushrs().  The latter will be done   */
 472         /* implicitly by __builtin_unwind_init() for gcc3.0.1   */
 473         /* and later.                                           */
 474       }
 475 #   endif
 476     fn(arg);
 477     /* Strongly discourage the compiler from treating the above */
 478     /* as a tail-call, since that would pop the register        */
 479     /* contents before we get a chance to look at them.         */
 480     GC_noop1((word)(&dummy));
 481 }
 482
 483 #if defined(USE_GENERIC_PUSH_REGS)
 484 void GC_generic_push_regs(cold_gc_frame)
 485 ptr_t cold_gc_frame;
 486 {
 487     GC_with_callee_saves_pushed(GC_push_current_stack, cold_gc_frame);
 488 }
 489 #endif /* USE_GENERIC_PUSH_REGS */
 490
 491 /* On register window machines, we need a way to force registers into   */
 492 /* the stack.   Return sp.                                              */
 493 # ifdef SPARC
 494     asm("       .seg    \"text\"");
 495 #   if defined(SVR4) || defined(NETBSD) || defined(FREEBSD)
 496       asm("     .globl  GC_save_regs_in_stack");
 497       asm("GC_save_regs_in_stack:");
 498       asm("     .type GC_save_regs_in_stack,#function");
 499 #   else
 500       asm("     .globl  _GC_save_regs_in_stack");
 501       asm("_GC_save_regs_in_stack:");
 502 #   endif
 503 #   if defined(__arch64__) || defined(__sparcv9)
 504       asm("     save    %sp,-128,%sp");
 505       asm("     flushw");
 506       asm("     ret");
 507       asm("     restore %sp,2047+128,%o0");
 508 #   else
 509       asm("     ta      0x3   ! ST_FLUSH_WINDOWS");
 510       asm("     retl");
 511       asm("     mov     %sp,%o0");
 512 #   endif
 513 #   ifdef SVR4
 514       asm("     .GC_save_regs_in_stack_end:");
 515       asm("     .size GC_save_regs_in_stack,.GC_save_regs_in_stack_end-GC_save_regs_in_stack");
 516 #   endif
 517 #   ifdef LINT
 518         word GC_save_regs_in_stack() { return(0 /* sp really */);}
 519 #   endif
 520 # endif
 521
 522 /* On IA64, we also need to flush register windows.  But they end       */
 523 /* up on the other side of the stack segment.                           */
 524 /* Returns the backing store pointer for the register stack.            */
 525 /* We now implement this as a separate assembly file, since inline      */
 526 /* assembly code here doesn't work with either the Intel or HP          */
 527 /* compilers.                                                           */
 528 # if 0
 529 #   ifdef LINUX
 530         asm("        .text");
 531         asm("        .psr abi64");
 532         asm("        .psr lsb");
 533         asm("        .lsb");
 534         asm("");
 535         asm("        .text");
 536         asm("        .align 16");
 537         asm("        .global GC_save_regs_in_stack");
 538         asm("        .proc GC_save_regs_in_stack");
 539         asm("GC_save_regs_in_stack:");
 540         asm("        .body");
 541         asm("        flushrs");
 542         asm("        ;;");
 543         asm("        mov r8=ar.bsp");
 544         asm("        br.ret.sptk.few rp");
 545         asm("        .endp GC_save_regs_in_stack");
 546 #   endif /* LINUX */
 547 #   if 0 /* Other alternatives that don't work on HP/UX */
 548         word GC_save_regs_in_stack() {
 549 #         if USE_BUILTINS
 550             __builtin_ia64_flushrs();
 551             return __builtin_ia64_bsp();
 552 #         else
 553 #           ifdef HPUX
 554               _asm("        flushrs");
 555               _asm("        ;;");
 556               _asm("        mov r8=ar.bsp");
 557               _asm("        br.ret.sptk.few rp");
 558 #           else
 559               asm("        flushrs");
 560               asm("        ;;");
 561               asm("        mov r8=ar.bsp");
 562               asm("        br.ret.sptk.few rp");
 563 #           endif
 564 #         endif
 565         }
 566 #   endif
 567 # endif
 568
 569 /* GC_clear_stack_inner(arg, limit) clears stack area up to limit and   */
 570 /* returns arg.  Stack clearing is crucial on SPARC, so we supply       */
 571 /* an assembly version that's more careful.  Assumes limit is hotter    */
 572 /* than sp, and limit is 8 byte aligned.                                */
 573 #if defined(ASM_CLEAR_CODE)
 574 #ifndef SPARC
 575         --> fix it
 576 #endif
 577 # ifdef SUNOS4
 578     asm(".globl _GC_clear_stack_inner");
 579     asm("_GC_clear_stack_inner:");
 580 # else
 581     asm(".globl GC_clear_stack_inner");
 582     asm("GC_clear_stack_inner:");
 583     asm(".type GC_save_regs_in_stack,#function");
 584 # endif
 585 #if defined(__arch64__) || defined(__sparcv9)
 586   asm("mov %sp,%o2");           /* Save sp                      */
 587   asm("add %sp,2047-8,%o3");    /* p = sp+bias-8                */
 588   asm("add %o1,-2047-192,%sp"); /* Move sp out of the way,      */
 589                                 /* so that traps still work.    */
 590                                 /* Includes some extra words    */
 591                                 /* so we can be sloppy below.   */
 592   asm("loop:");
 593   asm("stx %g0,[%o3]");         /* *(long *)p = 0               */
 594   asm("cmp %o3,%o1");
 595   asm("bgu,pt %xcc, loop");     /* if (p > limit) goto loop     */
 596     asm("add %o3,-8,%o3");      /* p -= 8 (delay slot) */
 597   asm("retl");
 598     asm("mov %o2,%sp");         /* Restore sp., delay slot      */
 599 #else
 600   asm("mov %sp,%o2");           /* Save sp      */
 601   asm("add %sp,-8,%o3");        /* p = sp-8     */
 602   asm("clr %g1");               /* [g0,g1] = 0  */
 603   asm("add %o1,-0x60,%sp");     /* Move sp out of the way,      */
 604                                 /* so that traps still work.    */
 605                                 /* Includes some extra words    */
 606                                 /* so we can be sloppy below.   */
 607   asm("loop:");
 608   asm("std %g0,[%o3]");         /* *(long long *)p = 0  */
 609   asm("cmp %o3,%o1");
 610   asm("bgu loop ");             /* if (p > limit) goto loop     */
 611     asm("add %o3,-8,%o3");      /* p -= 8 (delay slot) */
 612   asm("retl");
 613     asm("mov %o2,%sp");         /* Restore sp., delay slot      */
 614 #endif /* old SPARC */
 615   /* First argument = %o0 = return value */
 616 #   ifdef SVR4
 617       asm("     .GC_clear_stack_inner_end:");
 618       asm("     .size GC_clear_stack_inner,.GC_clear_stack_inner_end-GC_clear_stack_inner");
 619 #   endif
 620
 621 # ifdef LINT
 622     /*ARGSUSED*/
 623     ptr_t GC_clear_stack_inner(arg, limit)
 624     ptr_t arg; word limit;
 625     { return(arg); }
 626 # endif
 627 #endif