mach_dep.c

A garbage collector for C and C

	  asm("pushl %ecx");  asm("call GC_push_one"); asm("addl $4,%esp");
	  asm("pushl %edx");  asm("call GC_push_one"); asm("addl $4,%esp");
	  asm("pushl %ebp");  asm("call GC_push_one"); asm("addl $4,%esp");
	  asm("pushl %esi");  asm("call GC_push_one"); asm("addl $4,%esp");
	  asm("pushl %edi");  asm("call GC_push_one"); asm("addl $4,%esp");
#	  define HAVE_PUSH_REGS
#       endif

#       ifdef NS32K
	  asm ("movd r3, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
	  asm ("movd r4, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
	  asm ("movd r5, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
	  asm ("movd r6, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
	  asm ("movd r7, tos"); asm ("bsr ?_GC_push_one"); asm ("adjspb $-4");
#	  define HAVE_PUSH_REGS
#       endif

#       if defined(SPARC)
	  GC_save_regs_ret_val = GC_save_regs_in_stack();
#	  define HAVE_PUSH_REGS
#       endif

#	ifdef RT
	    GC_push_one(TMP_SP);    /* GC_push_one from r11 */

	    asm("cas r11, r6, r0"); GC_push_one(TMP_SP);	/* r6 */
	    asm("cas r11, r7, r0"); GC_push_one(TMP_SP);	/* through */
	    asm("cas r11, r8, r0"); GC_push_one(TMP_SP);	/* r10 */
	    asm("cas r11, r9, r0"); GC_push_one(TMP_SP);
	    asm("cas r11, r10, r0"); GC_push_one(TMP_SP);

	    asm("cas r11, r12, r0"); GC_push_one(TMP_SP); /* r12 */
	    asm("cas r11, r13, r0"); GC_push_one(TMP_SP); /* through */
	    asm("cas r11, r14, r0"); GC_push_one(TMP_SP); /* r15 */
	    asm("cas r11, r15, r0"); GC_push_one(TMP_SP);
#	    define HAVE_PUSH_REGS
#       endif

#       if defined(M68K) && defined(SYSV)
  	/*  Once again similar to SUN and HP, though setjmp appears to work.
  		--Parag
  	 */
#        ifdef __GNUC__
  	  asm("subqw #0x4,%sp");	/* allocate word on top of stack */
  
  	  asm("movl %a2,%sp@");	asm("jbsr GC_push_one");
  	  asm("movl %a3,%sp@");	asm("jbsr GC_push_one");
  	  asm("movl %a4,%sp@");	asm("jbsr GC_push_one");
  	  asm("movl %a5,%sp@");	asm("jbsr GC_push_one");
  	  /* Skip frame pointer and stack pointer */
  	  asm("movl %d1,%sp@");	asm("jbsr GC_push_one");
  	  asm("movl %d2,%sp@");	asm("jbsr GC_push_one");
  	  asm("movl %d3,%sp@");	asm("jbsr GC_push_one");
  	  asm("movl %d4,%sp@");	asm("jbsr GC_push_one");
  	  asm("movl %d5,%sp@");	asm("jbsr GC_push_one");
  	  asm("movl %d6,%sp@");	asm("jbsr GC_push_one");
  	  asm("movl %d7,%sp@");	asm("jbsr GC_push_one");
  
  	  asm("addqw #0x4,%sp");	/* put stack back where it was	*/
#	  define HAVE_PUSH_REGS
#        else /* !__GNUC__*/
  	  asm("subq.w &0x4,%sp");	/* allocate word on top of stack */
  
  	  asm("mov.l %a2,(%sp)"); asm("jsr GC_push_one");
  	  asm("mov.l %a3,(%sp)"); asm("jsr GC_push_one");
  	  asm("mov.l %a4,(%sp)"); asm("jsr GC_push_one");
  	  asm("mov.l %a5,(%sp)"); asm("jsr GC_push_one");
  	  /* Skip frame pointer and stack pointer */
  	  asm("mov.l %d1,(%sp)"); asm("jsr GC_push_one");
  	  asm("mov.l %d2,(%sp)"); asm("jsr GC_push_one");
  	  asm("mov.l %d3,(%sp)"); asm("jsr GC_push_one");
  	  asm("mov.l %d4,(%sp)"); asm("jsr GC_push_one");
  	  asm("mov.l %d5,(%sp)"); asm("jsr GC_push_one");
   	  asm("mov.l %d6,(%sp)"); asm("jsr GC_push_one");
  	  asm("mov.l %d7,(%sp)"); asm("jsr GC_push_one");
  
  	  asm("addq.w &0x4,%sp");	/* put stack back where it was	*/
#	  define HAVE_PUSH_REGS
#        endif /* !__GNUC__ */
#       endif /* M68K/SYSV */

#     if defined(PJ)
	{
	    register int * sp asm ("optop");
	    extern int *__libc_stack_end;

	    GC_push_all_stack (sp, __libc_stack_end);
#	    define HAVE_PUSH_REGS
	    /* Isn't this redundant with the code to push the stack? */
        }
#     endif

      /* other machines... */
#       if !defined(HAVE_PUSH_REGS)
	    --> We just generated an empty GC_push_regs, which
	    --> is almost certainly broken.  Try defining
	    --> USE_GENERIC_PUSH_REGS instead.
#       endif
}
#endif /* !USE_GENERIC_PUSH_REGS && !USE_ASM_PUSH_REGS */

#if defined(USE_GENERIC_PUSH_REGS)
void GC_generic_push_regs(cold_gc_frame)
ptr_t cold_gc_frame;
{
	{
	    word dummy;

#	    ifdef HAVE_BUILTIN_UNWIND_INIT
	      /* This was suggested by Richard Henderson as the way to	*/
	      /* force callee-save registers and register windows onto	*/
	      /* the stack.						*/
	      __builtin_unwind_init();
#	    else /* !HAVE_BUILTIN_UNWIND_INIT */
	      /* Generic code                          */
	      /* The idea is due to Parag Patel at HP. */
	      /* We're not sure whether he would like  */
	      /* to be he acknowledged for it or not.  */
	      jmp_buf regs;
	      register word * i = (word *) regs;
	      register ptr_t lim = (ptr_t)(regs) + (sizeof regs);

	      /* Setjmp doesn't always clear all of the buffer.		*/
	      /* That tends to preserve garbage.  Clear it.   		*/
		for (; (char *)i < lim; i++) {
		    *i = 0;
		}
#	      if defined(POWERPC) || defined(MSWIN32) || defined(MSWINCE) \
                || defined(UTS4) || defined(LINUX) || defined(EWS4800)
		  (void) setjmp(regs);
#	      else
	          (void) _setjmp(regs);
		  /* We don't want to mess with signals. According to	*/
		  /* SUSV3, setjmp() may or may not save signal mask.	*/
		  /* _setjmp won't, but is less portable.		*/
#	      endif
#	    endif /* !HAVE_BUILTIN_UNWIND_INIT */
#           if (defined(SPARC) && !defined(HAVE_BUILTIN_UNWIND_INIT)) \
		|| defined(IA64)
	      /* On a register window machine, we need to save register	*/
	      /* contents on the stack for this to work.  The setjmp	*/
	      /* is probably not needed on SPARC, since pointers are	*/
	      /* only stored in windowed or scratch registers.  It is	*/
	      /* needed on IA64, since some non-windowed registers are	*/
	      /* preserved.						*/
	      {
	        GC_save_regs_ret_val = GC_save_regs_in_stack();
		/* On IA64 gcc, could use __builtin_ia64_flushrs() and	*/
		/* __builtin_ia64_flushrs().  The latter will be done	*/
		/* implicitly by __builtin_unwind_init() for gcc3.0.1	*/
		/* and later.						*/
	      }
#           endif
	    GC_push_current_stack(cold_gc_frame);
	    /* Strongly discourage the compiler from treating the above	*/
	    /* as a tail-call, since that would pop the register 	*/
	    /* contents before we get a chance to look at them.		*/
	    GC_noop1((word)(&dummy));
	}
}
#endif /* USE_GENERIC_PUSH_REGS */

/* On register window machines, we need a way to force registers into 	*/
/* the stack.	Return sp.						*/
# ifdef SPARC
    asm("	.seg 	\"text\"");
#   if defined(SVR4) || defined(NETBSD) || defined(FREEBSD)
      asm("	.globl	GC_save_regs_in_stack");
      asm("GC_save_regs_in_stack:");
      asm("	.type GC_save_regs_in_stack,#function");
#   else
      asm("	.globl	_GC_save_regs_in_stack");
      asm("_GC_save_regs_in_stack:");
#   endif
#   if defined(__arch64__) || defined(__sparcv9)
      asm("	save	%sp,-128,%sp");
      asm("	flushw");
      asm("	ret");
      asm("	restore %sp,2047+128,%o0");
#   else
      asm("	ta	0x3   ! ST_FLUSH_WINDOWS");
      asm("	retl");
      asm("	mov	%sp,%o0");
#   endif
#   ifdef SVR4
      asm("	.GC_save_regs_in_stack_end:");
      asm("	.size GC_save_regs_in_stack,.GC_save_regs_in_stack_end-GC_save_regs_in_stack");
#   endif
#   ifdef LINT
	word GC_save_regs_in_stack() { return(0 /* sp really */);}
#   endif
# endif

/* On IA64, we also need to flush register windows.  But they end	*/
/* up on the other side of the stack segment.				*/
/* Returns the backing store pointer for the register stack.		*/
/* We now implement this as a separate assembly file, since inline	*/
/* assembly code here doesn't work with either the Intel or HP 		*/
/* compilers.								*/
# if 0
#   ifdef LINUX
	asm("        .text");
	asm("        .psr abi64");
	asm("        .psr lsb");
	asm("        .lsb");
	asm("");
	asm("        .text");
	asm("        .align 16");
	asm("        .global GC_save_regs_in_stack");
	asm("        .proc GC_save_regs_in_stack");
	asm("GC_save_regs_in_stack:");
	asm("        .body");
	asm("        flushrs");
	asm("        ;;");
	asm("        mov r8=ar.bsp");
	asm("        br.ret.sptk.few rp");
	asm("        .endp GC_save_regs_in_stack");
#   endif /* LINUX */
#   if 0 /* Other alternatives that don't work on HP/UX */
	word GC_save_regs_in_stack() {
#	  if USE_BUILTINS
	    __builtin_ia64_flushrs();
	    return __builtin_ia64_bsp();
#	  else
#	    ifdef HPUX
	      _asm("        flushrs");
	      _asm("        ;;");
	      _asm("        mov r8=ar.bsp");
	      _asm("        br.ret.sptk.few rp");
#	    else
	      asm("        flushrs");
	      asm("        ;;");
	      asm("        mov r8=ar.bsp");
	      asm("        br.ret.sptk.few rp");
#	    endif
#	  endif
	}
#   endif
# endif

/* GC_clear_stack_inner(arg, limit) clears stack area up to limit and	*/
/* returns arg.  Stack clearing is crucial on SPARC, so we supply	*/
/* an assembly version that's more careful.  Assumes limit is hotter	*/
/* than sp, and limit is 8 byte aligned.				*/
#if defined(ASM_CLEAR_CODE)
#ifndef SPARC
	--> fix it
#endif
# ifdef SUNOS4
    asm(".globl _GC_clear_stack_inner");
    asm("_GC_clear_stack_inner:");
# else
    asm(".globl GC_clear_stack_inner");
    asm("GC_clear_stack_inner:");
    asm(".type GC_save_regs_in_stack,#function");
# endif
#if defined(__arch64__) || defined(__sparcv9)
  asm("mov %sp,%o2");		/* Save sp			*/
  asm("add %sp,2047-8,%o3");	/* p = sp+bias-8		*/
  asm("add %o1,-2047-192,%sp");	/* Move sp out of the way,	*/
  				/* so that traps still work.	*/
  				/* Includes some extra words	*/
  				/* so we can be sloppy below.	*/
  asm("loop:");
  asm("stx %g0,[%o3]");		/* *(long *)p = 0		*/
  asm("cmp %o3,%o1");
  asm("bgu,pt %xcc, loop");	/* if (p > limit) goto loop	*/
    asm("add %o3,-8,%o3");	/* p -= 8 (delay slot) */
  asm("retl");
    asm("mov %o2,%sp");		/* Restore sp., delay slot	*/
#else
  asm("mov %sp,%o2");		/* Save sp	*/
  asm("add %sp,-8,%o3");	/* p = sp-8	*/
  asm("clr %g1");		/* [g0,g1] = 0	*/
  asm("add %o1,-0x60,%sp");	/* Move sp out of the way,	*/
  				/* so that traps still work.	*/
  				/* Includes some extra words	*/
  				/* so we can be sloppy below.	*/
  asm("loop:");
  asm("std %g0,[%o3]");		/* *(long long *)p = 0	*/
  asm("cmp %o3,%o1");
  asm("bgu loop	");		/* if (p > limit) goto loop	*/
    asm("add %o3,-8,%o3");	/* p -= 8 (delay slot) */
  asm("retl");
    asm("mov %o2,%sp");		/* Restore sp., delay slot	*/
#endif /* old SPARC */
  /* First argument = %o0 = return value */
#   ifdef SVR4
      asm("	.GC_clear_stack_inner_end:");
      asm("	.size GC_clear_stack_inner,.GC_clear_stack_inner_end-GC_clear_stack_inner");
#   endif
  
# ifdef LINT
    /*ARGSUSED*/
    ptr_t GC_clear_stack_inner(arg, limit)
    ptr_t arg; word limit;
    { return(arg); }
# endif
#endif