path: root/rts/StgCRun.c

/* -----------------------------------------------------------------------------
 *
 * (c) The GHC Team, 1998-2003
 *
 * STG-to-C glue.
 *
 * To run an STG function from C land, call
 *
 *		rv = StgRun(f,BaseReg);
 *
 * where "f" is the STG function to call, and BaseReg is the address of the
 * RegTable for this run (we might have separate RegTables if we're running
 * multiple threads on an SMP machine).
 *
 * In the end, "f" must JMP to StgReturn (defined below),
 * passing the return-value "rv" in R1,
 * to return to the caller of StgRun returning "rv" in
 * the whatever way C returns a value.
 *
 * NOTE: StgRun/StgReturn do *NOT* load or store Hp or any
 * other registers (other than saving the C callee-saves
 * registers).  Instead, the called function "f" must do that
 * in STG land.
 *
 * GCC will have assumed that pushing/popping of C-stack frames is
 * going on when it generated its code, and used stack space
 * accordingly.  However, we actually {\em post-process away} all
 * such stack-framery (see \tr{ghc/driver/ghc-asm.lprl}). Things will
 * be OK however, if we initially make sure there are
 * @RESERVED_C_STACK_BYTES@ on the C-stack to begin with, for local
 * variables.
 *
 * -------------------------------------------------------------------------- */

#include "PosixSource.h"


/*
 * We define the following (unused) global register variables, because for
 * some reason gcc generates sub-optimal code for StgRun() on the Alpha
 * (unnecessarily saving extra registers on the stack) if we don't.
 *
 * Why do it at the top of this file, rather than near StgRun() below?  Because
 * gcc doesn't let us define global register variables after any function
 * definition has been read.  Any point after #include "Stg.h" would be too
 * late.
 *
 * We define alpha_EXTRA_CAREFUL here to save $s6, $f8 and $f9 -- registers
 * that we don't use but which are callee-save registers.  The __divq() routine
 * in libc.a clobbers $s6.
 */
#include "ghcconfig.h"
#ifndef USE_MINIINTERPRETER
#ifdef alpha_HOST_ARCH
#define alpha_EXTRA_CAREFUL
register long   fake_ra __asm__("$26");
register long   fake_gp __asm__("$29");
#ifdef alpha_EXTRA_CAREFUL
register long   fake_s6 __asm__("$15");
register double fake_f8 __asm__("$f8");
register double fake_f9 __asm__("$f9");
#endif
#endif
#endif

/* include Stg.h first because we want real machine regs in here: we
 * have to get the value of R1 back from Stg land to C land intact.
 */
// yeuch
#define IN_STGCRUN 1
#include "Stg.h"
#include "Rts.h"
#include "StgRun.h"
#include "RtsFlags.h"
#include "OSThreads.h"
#include "Capability.h"

#ifdef DEBUG
#include "RtsUtils.h"
#include "Printer.h"
#endif

#ifdef USE_MINIINTERPRETER

/* -----------------------------------------------------------------------------
   any architecture (using miniinterpreter)
   -------------------------------------------------------------------------- */

StgRegTable * StgRun(StgFunPtr f, StgRegTable *basereg STG_UNUSED)
{
    while (f) {
	IF_DEBUG(interpreter,
	    debugBelch("Jumping to ");
	    printPtr((P_)f); fflush(stdout);
	    debugBelch("\n");
	    );
	f = (StgFunPtr) (f)();
    }
    return (StgRegTable *)R1.p;
}

StgFunPtr StgReturn(void)
{
    return 0;
}

#else /* !USE_MINIINTERPRETER */

#ifdef LEADING_UNDERSCORE
#define STG_RUN "_StgRun"
#else
#define STG_RUN "StgRun"
#endif

#ifdef LEADING_UNDERSCORE
#define STG_RETURN "_StgReturn"
#else
#define STG_RETURN "StgReturn"
#endif

/* -----------------------------------------------------------------------------
   x86 architecture
   -------------------------------------------------------------------------- */

#ifdef i386_HOST_ARCH

#ifdef darwin_TARGET_OS
#define STG_GLOBAL ".globl "
#else
#define STG_GLOBAL ".global "
#endif

StgRegTable *
StgRun(StgFunPtr f, StgRegTable *basereg) {

    unsigned char space[ RESERVED_C_STACK_BYTES + 4*sizeof(void *) ];
    StgRegTable * r;

    __asm__ volatile (
	/*
	 * save callee-saves registers on behalf of the STG code.
	 */
	"movl %%esp, %%eax\n\t"
	"addl %4, %%eax\n\t"
        "movl %%ebx,0(%%eax)\n\t"
        "movl %%esi,4(%%eax)\n\t"
        "movl %%edi,8(%%eax)\n\t"
        "movl %%ebp,12(%%eax)\n\t"
	/*
	 * Set BaseReg
	 */
	"movl %3,%%ebx\n\t"
	/*
	 * grab the function argument from the stack
	 */
        "movl %2,%%eax\n\t"
        
	/*
	 * Darwin note:
	 * The stack pointer has to be aligned to a multiple of 16 bytes at
	 * this point. This works out correctly with gcc 4.0.1, but it might
	 * break at any time in the future. TODO: Make this future-proof.
	 */

	/*
	 * jump to it
	 */
        "jmp *%%eax\n\t"

	STG_GLOBAL STG_RETURN "\n"
       	STG_RETURN ":\n\t"

	"movl %%esi, %%eax\n\t"   /* Return value in R1  */

	/*
	 * restore callee-saves registers.  (Don't stomp on %%eax!)
	 */
	"movl %%esp, %%edx\n\t"
	"addl %4, %%edx\n\t"
        "movl 0(%%edx),%%ebx\n\t"	/* restore the registers saved above */
        "movl 4(%%edx),%%esi\n\t"
        "movl 8(%%edx),%%edi\n\t"
        "movl 12(%%edx),%%ebp\n\t"

      : "=&a" (r), "=m" (space)
      : "m" (f), "m" (basereg), "i" (RESERVED_C_STACK_BYTES)
      : "edx" /* stomps on %edx */
    );

    return r;
}

#endif

/* ----------------------------------------------------------------------------
   x86-64 is almost the same as plain x86.

   I've done it using entirely inline assembler, because I couldn't
   get gcc to generate the correct subtraction from %rsp by using
   the local array variable trick.  It didn't seem to reserve
   enough space.  Oh well, it's not much harder this way.

   ------------------------------------------------------------------------- */

#ifdef x86_64_HOST_ARCH

extern StgRegTable * StgRun(StgFunPtr f, StgRegTable *basereg);

static void GNUC3_ATTRIBUTE(used)
StgRunIsImplementedInAssembler(void)
{
    __asm__ volatile (
	/*
	 * save callee-saves registers on behalf of the STG code.
	 */
	".globl " STG_RUN "\n"
	STG_RUN ":\n\t"
	"subq %0, %%rsp\n\t"
	"movq %%rsp, %%rax\n\t"
	"addq %0-48, %%rax\n\t"
        "movq %%rbx,0(%%rax)\n\t"
        "movq %%rbp,8(%%rax)\n\t"
        "movq %%r12,16(%%rax)\n\t"
        "movq %%r13,24(%%rax)\n\t"
        "movq %%r14,32(%%rax)\n\t"
        "movq %%r15,40(%%rax)\n\t"
	/*
	 * Set BaseReg
	 */
	"movq %%rsi,%%r13\n\t"
	/*
	 * grab the function argument from the stack, and jump to it.
	 */
        "movq %%rdi,%%rax\n\t"
        "jmp *%%rax\n\t"

	".globl " STG_RETURN "\n"
       	STG_RETURN ":\n\t"

	"movq %%rbx, %%rax\n\t"   /* Return value in R1  */

	/*
	 * restore callee-saves registers.  (Don't stomp on %%rax!)
	 */
	"movq %%rsp, %%rdx\n\t"
	"addq %0-48, %%rdx\n\t"
        "movq 0(%%rdx),%%rbx\n\t"	/* restore the registers saved above */
        "movq 8(%%rdx),%%rbp\n\t"
        "movq 16(%%rdx),%%r12\n\t"
        "movq 24(%%rdx),%%r13\n\t"
        "movq 32(%%rdx),%%r14\n\t"
        "movq 40(%%rdx),%%r15\n\t"
	"addq %0, %%rsp\n\t"
	"retq"

	: : "i"(RESERVED_C_STACK_BYTES+48+8 /*stack frame size*/));
    /* 
       HACK alert!

       The x86_64 ABI specifies that on a procedure call, %rsp is
       aligned on a 16-byte boundary + 8.  That is, the first
       argument on the stack after the return address will be
       16-byte aligned.  
       
       Which should be fine: RESERVED_C_STACK_BYTES+48 is a multiple
       of 16 bytes.  
       
       BUT... when we do a C-call from STG land, gcc likes to put the
       stack alignment adjustment in the prolog.  eg. if we're calling
       a function with arguments in regs, gcc will insert 'subq $8,%rsp'
       in the prolog, to keep %rsp aligned (the return address is 8
       bytes, remember).  The mangler throws away the prolog, so we
       lose the stack alignment.

       The hack is to add this extra 8 bytes to our %rsp adjustment
       here, so that throughout STG code, %rsp is 16-byte aligned,
       ready for a C-call.  

       A quick way to see if this is wrong is to compile this code:

          main = System.Exit.exitWith ExitSuccess

       And run it with +RTS -sstderr.  The stats code in the RTS, in
       particular statsPrintf(), relies on the stack alignment because
       it saves the %xmm regs on the stack, so it'll fall over if the
       stack isn't aligned, and calling exitWith from Haskell invokes
       shutdownHaskellAndExit using a C call.

       Future gcc releases will almost certainly break this hack...
    */
}

#endif /* x86-64 */

/* -----------------------------------------------------------------------------
   Sparc architecture

   --
   OLD COMMENT from GHC-3.02:

   We want tailjumps to be calls, because `call xxx' is the only Sparc
   branch that allows an arbitrary label as a target.  (Gcc's ``goto
   *target'' construct ends up loading the label into a register and
   then jumping, at the cost of two extra instructions for the 32-bit
   load.)

   When entering the threaded world, we stash our return address in a
   known location so that \tr{%i7} is available as an extra
   callee-saves register.  Of course, we have to restore this when
   coming out of the threaded world.

   I hate this god-forsaken architecture.  Since the top of the
   reserved stack space is used for globals and the bottom is reserved
   for outgoing arguments, we have to stick our return address
   somewhere in the middle.  Currently, I'm allowing 100 extra
   outgoing arguments beyond the first 6.  --JSM

   Updated info (GHC 4.06): we don't appear to use %i7 any more, so
   I'm not sure whether we still need to save it.  Incedentally, what
   does the last paragraph above mean when it says "the top of the
   stack is used for globals"?  What globals?  --SDM

   Updated info (GHC 4.08.2): not saving %i7 any more (see below).
   -------------------------------------------------------------------------- */

#ifdef sparc_HOST_ARCH

StgRegTable *
StgRun(StgFunPtr f, StgRegTable *basereg) {

    unsigned char space[RESERVED_C_STACK_BYTES];
#if 0
    register void *i7 __asm__("%i7");
    ((void **)(space))[100] = i7;
#endif
    f();
    __asm__ volatile (
	    ".align 4\n"
            ".global " STG_RETURN "\n"
       	    STG_RETURN ":"
	    : : "p" (space) : "l0","l1","l2","l3","l4","l5","l6","l7");
    /* we tell the C compiler that l0-l7 are clobbered on return to
     * StgReturn, otherwise it tries to use these to save eg. the
     * address of space[100] across the call.  The correct thing
     * to do would be to save all the callee-saves regs, but we
     * can't be bothered to do that.
     *
     * We also explicitly mark space as used since gcc eliminates it
     * otherwise.
     *
     * The code that gcc generates for this little fragment is now
     * terrible.  We could do much better by coding it directly in
     * assembler.
     */
#if 0
    /* updated 4.08.2: we don't save %i7 in the middle of the reserved
     * space any more, since gcc tries to save its address across the
     * call to f(), this gets clobbered in STG land and we end up
     * dereferencing a bogus pointer in StgReturn.
     */
    __asm__ volatile ("ld %1,%0"
		      : "=r" (i7) : "m" (((void **)(space))[100]));
#endif
    return (StgRegTable *)R1.i;
}

#endif

/* -----------------------------------------------------------------------------
   alpha architecture

   "The stack pointer (SP) must at all times denote an address that has octaword
    alignment. (This restriction has the side effect that the in-memory portion
    of the argument list, if any, will start on an octaword boundary.) Note that
    the stack grows toward lower addresses. During a procedure invocation, SP
    can never be set to a value that is higher than the value of SP at entry to
    that procedure invocation.

   "The contents of the stack, located above the portion of the argument list
    (if any) that is passed in memory, belong to the calling procedure. Because
    they are part of the calling procedure, they should not be read or written
    by the called procedure, except as specified by indirect arguments or
    language-controlled up-level references.

   "The SP value might be used by the hardware when raising exceptions and
    asynchronous interrupts. It must be assumed that the contents of the stack
    below the current SP value and within the stack for the current thread are
    continually and unpredictably modified, as specified in the _Alpha
    Architecture Reference Manual_, and as a result of asynchronous software
    actions."

   -- Compaq Computer Corporation, Houston. Tru64 UNIX Calling Standard for
      Alpha Systems, 5.1 edition, August 2000, section 3.2.1.  http://www.
      tru64unix.compaq.com/docs/base_doc/DOCUMENTATION/V51_PDF/ARH9MBTE.PDF
   -------------------------------------------------------------------------- */

#ifdef alpha_HOST_ARCH

StgRegTable *
StgRun(StgFunPtr f, StgRegTable *basereg)
{
    register long   real_ra __asm__("$26"); volatile long   save_ra;
    register long   real_gp __asm__("$29"); volatile long   save_gp;

    register long   real_s0 __asm__("$9" ); volatile long   save_s0;
    register long   real_s1 __asm__("$10"); volatile long   save_s1;
    register long   real_s2 __asm__("$11"); volatile long   save_s2;
    register long   real_s3 __asm__("$12"); volatile long   save_s3;
    register long   real_s4 __asm__("$13"); volatile long   save_s4;
    register long   real_s5 __asm__("$14"); volatile long   save_s5;
#ifdef alpha_EXTRA_CAREFUL
    register long   real_s6 __asm__("$15"); volatile long   save_s6;
#endif

    register double real_f2 __asm__("$f2"); volatile double save_f2;
    register double real_f3 __asm__("$f3"); volatile double save_f3;
    register double real_f4 __asm__("$f4"); volatile double save_f4;
    register double real_f5 __asm__("$f5"); volatile double save_f5;
    register double real_f6 __asm__("$f6"); volatile double save_f6;
    register double real_f7 __asm__("$f7"); volatile double save_f7;
#ifdef alpha_EXTRA_CAREFUL
    register double real_f8 __asm__("$f8"); volatile double save_f8;
    register double real_f9 __asm__("$f9"); volatile double save_f9;
#endif

    register StgFunPtr real_pv __asm__("$27");

    StgRegTable * ret;

    save_ra = real_ra;
    save_gp = real_gp;

    save_s0 = real_s0;
    save_s1 = real_s1;
    save_s2 = real_s2;
    save_s3 = real_s3;
    save_s4 = real_s4;
    save_s5 = real_s5;
#ifdef alpha_EXTRA_CAREFUL
    save_s6 = real_s6;
#endif

    save_f2 = real_f2;
    save_f3 = real_f3;
    save_f4 = real_f4;
    save_f5 = real_f5;
    save_f6 = real_f6;
    save_f7 = real_f7;
#ifdef alpha_EXTRA_CAREFUL
    save_f8 = real_f8;
    save_f9 = real_f9;
#endif

    real_pv = f;

    __asm__ volatile(	"lda $30,-%0($30)"	"\n"
		"\t"	"jmp ($27)"		"\n"
		"\t"	".align 3"		"\n"
		".globl " STG_RETURN		"\n"
		STG_RETURN ":"			"\n"
		"\t"	"lda $30,%0($30)"	"\n"
		: : "K" (RESERVED_C_STACK_BYTES));

    ret = real_s5;

    real_s0 = save_s0;
    real_s1 = save_s1;
    real_s2 = save_s2;
    real_s3 = save_s3;
    real_s4 = save_s4;
    real_s5 = save_s5;
#ifdef alpha_EXTRA_CAREFUL
    real_s6 = save_s6;
#endif

    real_f2 = save_f2;
    real_f3 = save_f3;
    real_f4 = save_f4;
    real_f5 = save_f5;
    real_f6 = save_f6;
    real_f7 = save_f7;
#ifdef alpha_EXTRA_CAREFUL
    real_f8 = save_f8;
    real_f9 = save_f9;
#endif

    real_ra = save_ra;
    real_gp = save_gp;

    return ret;
}

#endif /* alpha_HOST_ARCH */

/* -----------------------------------------------------------------------------
   HP-PA architecture
   -------------------------------------------------------------------------- */

#ifdef hppa1_1_HOST_ARCH

StgRegTable *
StgRun(StgFunPtr f, StgRegTable *basereg)
{
    StgChar space[RESERVED_C_STACK_BYTES+16*sizeof(long)+10*sizeof(double)];
    StgRegTable * ret;

    __asm__ volatile ("ldo %0(%%r30),%%r19\n"
		      "\tstw %%r3, 0(0,%%r19)\n"
                      "\tstw %%r4, 4(0,%%r19)\n"
                      "\tstw %%r5, 8(0,%%r19)\n"
                      "\tstw %%r6,12(0,%%r19)\n"
                      "\tstw %%r7,16(0,%%r19)\n"
                      "\tstw %%r8,20(0,%%r19)\n"
                      "\tstw %%r9,24(0,%%r19)\n"
		      "\tstw %%r10,28(0,%%r19)\n"
                      "\tstw %%r11,32(0,%%r19)\n"
                      "\tstw %%r12,36(0,%%r19)\n"
                      "\tstw %%r13,40(0,%%r19)\n"
                      "\tstw %%r14,44(0,%%r19)\n"
                      "\tstw %%r15,48(0,%%r19)\n"
                      "\tstw %%r16,52(0,%%r19)\n"
                      "\tstw %%r17,56(0,%%r19)\n"
                      "\tstw %%r18,60(0,%%r19)\n"
		      "\tldo 80(%%r19),%%r19\n"
		      "\tfstds %%fr12,-16(0,%%r19)\n"
		      "\tfstds %%fr13, -8(0,%%r19)\n"
		      "\tfstds %%fr14,  0(0,%%r19)\n"
		      "\tfstds %%fr15,  8(0,%%r19)\n"
		      "\tldo 32(%%r19),%%r19\n"
		      "\tfstds %%fr16,-16(0,%%r19)\n"
		      "\tfstds %%fr17, -8(0,%%r19)\n"
		      "\tfstds %%fr18,  0(0,%%r19)\n"
		      "\tfstds %%fr19,  8(0,%%r19)\n"
		      "\tldo 32(%%r19),%%r19\n"
		      "\tfstds %%fr20,-16(0,%%r19)\n"
		      "\tfstds %%fr21, -8(0,%%r19)\n" : :
                      "n" (-(116 * sizeof(long) + 10 * sizeof(double))) : "%r19"
		      );

    f();

    __asm__ volatile (".align 4\n"
               	      "\t.EXPORT " STG_RETURN ",CODE\n"
		      "\t.EXPORT " STG_RETURN ",ENTRY,PRIV_LEV=3\n"
                      STG_RETURN "\n"
                      /* "\tldo %0(%%r3),%%r19\n" */
                      "\tldo %1(%%r30),%%r19\n"
                      "\tcopy %%r11, %0\n"  /* save R1 */
		      "\tldw  0(0,%%r19),%%r3\n"
                      "\tldw  4(0,%%r19),%%r4\n"
                      "\tldw  8(0,%%r19),%%r5\n"
                      "\tldw 12(0,%%r19),%%r6\n"
                      "\tldw 16(0,%%r19),%%r7\n"
                      "\tldw 20(0,%%r19),%%r8\n"
                      "\tldw 24(0,%%r19),%%r9\n"
		      "\tldw 28(0,%%r19),%%r10\n"
                      "\tldw 32(0,%%r19),%%r11\n"
                      "\tldw 36(0,%%r19),%%r12\n"
                      "\tldw 40(0,%%r19),%%r13\n"
                      "\tldw 44(0,%%r19),%%r14\n"
                      "\tldw 48(0,%%r19),%%r15\n"
                      "\tldw 52(0,%%r19),%%r16\n"
                      "\tldw 56(0,%%r19),%%r17\n"
                      "\tldw 60(0,%%r19),%%r18\n"
		      "\tldo 80(%%r19),%%r19\n"
		      "\tfldds -16(0,%%r19),%%fr12\n"
		      "\tfldds  -8(0,%%r19),%%fr13\n"
		      "\tfldds   0(0,%%r19),%%fr14\n"
		      "\tfldds   8(0,%%r19),%%fr15\n"
		      "\tldo 32(%%r19),%%r19\n"
		      "\tfldds -16(0,%%r19),%%fr16\n"
		      "\tfldds  -8(0,%%r19),%%fr17\n"
		      "\tfldds   0(0,%%r19),%%fr18\n"
		      "\tfldds   8(0,%%r19),%%fr19\n"
		      "\tldo 32(%%r19),%%r19\n"
		      "\tfldds -16(0,%%r19),%%fr20\n"
		      "\tfldds  -8(0,%%r19),%%fr21\n"
		         : "=r" (ret)
		         : "n" (-(116 * sizeof(long) + 10 * sizeof(double)))
		         : "%r19"
		      );

    return ret;
}

#endif /* hppa1_1_HOST_ARCH */

/* -----------------------------------------------------------------------------
   PowerPC architecture

   Everything is in assembler, so we don't have to deal with GCC...
   
   -------------------------------------------------------------------------- */

#ifdef powerpc_HOST_ARCH

extern StgRegTable * StgRun(StgFunPtr f, StgRegTable *basereg);

#ifdef darwin_HOST_OS
void StgRunIsImplementedInAssembler(void)
{
#if HAVE_SUBSECTIONS_VIA_SYMBOLS
            // if the toolchain supports deadstripping, we have to
            // prevent it here (it tends to get confused here).
        __asm__ volatile (".no_dead_strip _StgRunIsImplementedInAssembler");
#endif
	__asm__ volatile (
		"\n.globl _StgRun\n"
		"_StgRun:\n"
		"\tmflr r0\n"
		"\tbl saveFP # f14\n"
		"\tstmw r13,-220(r1)\n"
		"\tstwu r1,-%0(r1)\n"
                "\tmr r27,r4\n" // BaseReg == r27
		"\tmtctr r3\n"
		"\tmr r12,r3\n"
		"\tbctr\n"
		".globl _StgReturn\n"
		"_StgReturn:\n"
		"\tmr r3,r14\n"
		"\tla r1,%0(r1)\n"
		"\tlmw r13,-220(r1)\n"
		"\tb restFP # f14\n"
	: : "i"(RESERVED_C_STACK_BYTES+224 /*stack frame size*/));
}
#else

// This version is for PowerPC Linux.

// Differences from the Darwin/Mac OS X version:
// *) Different Assembler Syntax
// *) Doesn't use Register Saving Helper Functions (although they exist somewhere)
// *) We may not access positive stack offsets
//    (no "Red Zone" as in the Darwin ABI)
// *) The Link Register is saved to a different offset in the caller's stack frame
//    (Linux: 4(r1), Darwin 8(r1))

static void GNUC3_ATTRIBUTE(used)
StgRunIsImplementedInAssembler(void)
{
	__asm__ volatile (
		"\t.globl StgRun\n"
		"\t.type StgRun,@function\n"
		"StgRun:\n"
		"\tmflr 0\n"
		"\tstw 0,4(1)\n"
		"\tmr 5,1\n"
		"\tstwu 1,-%0(1)\n"
		"\tstmw 13,-220(5)\n"
		"\tstfd 14,-144(5)\n"
		"\tstfd 15,-136(5)\n"
		"\tstfd 16,-128(5)\n"
		"\tstfd 17,-120(5)\n"
		"\tstfd 18,-112(5)\n"
		"\tstfd 19,-104(5)\n"
		"\tstfd 20,-96(5)\n"
		"\tstfd 21,-88(5)\n"
		"\tstfd 22,-80(5)\n"
		"\tstfd 23,-72(5)\n"
		"\tstfd 24,-64(5)\n"
		"\tstfd 25,-56(5)\n"
		"\tstfd 26,-48(5)\n"
		"\tstfd 27,-40(5)\n"
		"\tstfd 28,-32(5)\n"
		"\tstfd 29,-24(5)\n"
		"\tstfd 30,-16(5)\n"
		"\tstfd 31,-8(5)\n"
		"\tmr 27,4\n"  // BaseReg == r27
		"\tmtctr 3\n"
		"\tmr 12,3\n"
		"\tbctr\n"
		".globl StgReturn\n"
		"\t.type StgReturn,@function\n"
		"StgReturn:\n"
		"\tmr 3,14\n"
		"\tla 5,%0(1)\n"
		"\tlmw 13,-220(5)\n"
		"\tlfd 14,-144(5)\n"
		"\tlfd 15,-136(5)\n"
		"\tlfd 16,-128(5)\n"
		"\tlfd 17,-120(5)\n"
		"\tlfd 18,-112(5)\n"
		"\tlfd 19,-104(5)\n"
		"\tlfd 20,-96(5)\n"
		"\tlfd 21,-88(5)\n"
		"\tlfd 22,-80(5)\n"
		"\tlfd 23,-72(5)\n"
		"\tlfd 24,-64(5)\n"
		"\tlfd 25,-56(5)\n"
		"\tlfd 26,-48(5)\n"
		"\tlfd 27,-40(5)\n"
		"\tlfd 28,-32(5)\n"
		"\tlfd 29,-24(5)\n"
		"\tlfd 30,-16(5)\n"
		"\tlfd 31,-8(5)\n"
		"\tmr 1,5\n"
		"\tlwz 0,4(1)\n"
		"\tmtlr 0\n"
		"\tblr\n"
	: : "i"(RESERVED_C_STACK_BYTES+224 /*stack frame size*/));
}
#endif

#endif

/* -----------------------------------------------------------------------------
   PowerPC 64 architecture

   Everything is in assembler, so we don't have to deal with GCC...
   
   -------------------------------------------------------------------------- */

#ifdef powerpc64_HOST_ARCH

#ifdef linux_HOST_OS
extern StgRegTable * StgRun(StgFunPtr f, StgRegTable *basereg);

static void GNUC3_ATTRIBUTE(used)
StgRunIsImplementedInAssembler(void)
{
        // r0 volatile
	// r1 stack pointer
	// r2 toc - needs to be saved
	// r3-r10 argument passing, volatile
	// r11, r12 very volatile (not saved across cross-module calls)
	// r13 thread local state (never modified, don't need to save)
	// r14-r31 callee-save
	__asm__ volatile (
		".section \".opd\",\"aw\"\n"
		".align 3\n"
		".globl StgRun\n"
		"StgRun:\n"
			"\t.quad\t.StgRun,.TOC.@tocbase,0\n"
			"\t.size StgRun,24\n"
		".globl StgReturn\n"
		"StgReturn:\n"
			"\t.quad\t.StgReturn,.TOC.@tocbase,0\n"
			"\t.size StgReturn,24\n"
		".previous\n"
		".globl .StgRun\n"
		".type .StgRun,@function\n"
		".StgRun:\n"
			"\tmflr 0\n"
			"\tmr 5, 1\n"
			"\tstd 0, 16(1)\n"
			"\tstdu 1, -%0(1)\n"
			"\tstd 2, -296(5)\n"
			"\tstd 14, -288(5)\n"
			"\tstd 15, -280(5)\n"
			"\tstd 16, -272(5)\n"
			"\tstd 17, -264(5)\n"
			"\tstd 18, -256(5)\n"
			"\tstd 19, -248(5)\n"
			"\tstd 20, -240(5)\n"
			"\tstd 21, -232(5)\n"
			"\tstd 22, -224(5)\n"
			"\tstd 23, -216(5)\n"
			"\tstd 24, -208(5)\n"
			"\tstd 25, -200(5)\n"
			"\tstd 26, -192(5)\n"
			"\tstd 27, -184(5)\n"
			"\tstd 28, -176(5)\n"
			"\tstd 29, -168(5)\n"
			"\tstd 30, -160(5)\n"
			"\tstd 31, -152(5)\n"
			"\tstfd 14, -144(5)\n"
			"\tstfd 15, -136(5)\n"
			"\tstfd 16, -128(5)\n"
			"\tstfd 17, -120(5)\n"
			"\tstfd 18, -112(5)\n"
			"\tstfd 19, -104(5)\n"
			"\tstfd 20, -96(5)\n"
			"\tstfd 21, -88(5)\n"
			"\tstfd 22, -80(5)\n"
			"\tstfd 23, -72(5)\n"
			"\tstfd 24, -64(5)\n"
			"\tstfd 25, -56(5)\n"
			"\tstfd 26, -48(5)\n"
			"\tstfd 27, -40(5)\n"
			"\tstfd 28, -32(5)\n"
			"\tstfd 29, -24(5)\n"
			"\tstfd 30, -16(5)\n"
			"\tstfd 31, -8(5)\n"
			"\tmr 27, 4\n"  // BaseReg == r27
			"\tld 2, 8(3)\n"
			"\tld 3, 0(3)\n"
			"\tmtctr 3\n"
			"\tbctr\n"
		".globl .StgReturn\n"
		".type .StgReturn,@function\n"
		".StgReturn:\n"
			"\tmr 3,14\n"
			"\tla 5, %0(1)\n" // load address == addi r5, r1, %0
			"\tld 2, -296(5)\n"
			"\tld 14, -288(5)\n"
			"\tld 15, -280(5)\n"
			"\tld 16, -272(5)\n"
			"\tld 17, -264(5)\n"
			"\tld 18, -256(5)\n"
			"\tld 19, -248(5)\n"
			"\tld 20, -240(5)\n"
			"\tld 21, -232(5)\n"
			"\tld 22, -224(5)\n"
			"\tld 23, -216(5)\n"
			"\tld 24, -208(5)\n"
			"\tld 25, -200(5)\n"
			"\tld 26, -192(5)\n"
			"\tld 27, -184(5)\n"
			"\tld 28, -176(5)\n"
			"\tld 29, -168(5)\n"
			"\tld 30, -160(5)\n"
			"\tld 31, -152(5)\n"
			"\tlfd 14, -144(5)\n"
			"\tlfd 15, -136(5)\n"
			"\tlfd 16, -128(5)\n"
			"\tlfd 17, -120(5)\n"
			"\tlfd 18, -112(5)\n"
			"\tlfd 19, -104(5)\n"
			"\tlfd 20, -96(5)\n"
			"\tlfd 21, -88(5)\n"
			"\tlfd 22, -80(5)\n"
			"\tlfd 23, -72(5)\n"
			"\tlfd 24, -64(5)\n"
			"\tlfd 25, -56(5)\n"
			"\tlfd 26, -48(5)\n"
			"\tlfd 27, -40(5)\n"
			"\tlfd 28, -32(5)\n"
			"\tlfd 29, -24(5)\n"
			"\tlfd 30, -16(5)\n"
			"\tlfd 31, -8(5)\n"
			"\tmr 1, 5\n"
			"\tld 0, 16(1)\n"
			"\tmtlr 0\n"
			"\tblr\n"
	: : "i"(RESERVED_C_STACK_BYTES+304 /*stack frame size*/));
}
#else // linux_HOST_OS
#error Only linux support for power64 right now.
#endif

#endif

/* -----------------------------------------------------------------------------
   IA64 architecture

   Again, in assembler - so we can fiddle with the register stack, and because
   gcc doesn't handle asm-clobbered callee-saves correctly.

   loc0  - loc15: preserved locals
   loc16 - loc28: STG registers
           loc29: saved ar.pfs
           loc30: saved b0
           loc31: saved gp (gcc 3.3 uses this slot)
           loc32: saved ar.lc
           loc33: saved pr
       f2  -  f5: preserved floating-point registers
       f16 - f23: preserved floating-point registers
   -------------------------------------------------------------------------- */

#ifdef ia64_HOST_ARCH

/* the memory stack is rarely used, so 16K is excessive */
#undef RESERVED_C_STACK_BYTES
#define RESERVED_C_STACK_BYTES 1024

/* We don't spill all the callee-save FP registers, only the ones that
 * gcc has been observed to use */
#define PRESERVED_FP_REGISTERS 12

/* We always allocate 34 local and 8 output registers.  As long as gcc used
 * fewer than 32 locals, the mangler will adjust the stack frame accordingly. */
#define LOCALS 34

static void GNUC3_ATTRIBUTE(used)
StgRunIsImplementedInAssembler(void)
{
    __asm__ volatile(
		".global StgRun\n"
		"StgRun:\n"
		"\talloc loc29 = ar.pfs, 0, %1, 8, 0\n"	/* setup register frame */
		"\tld8 r18 = [r32],8\n"			/* get procedure address */
		"\tadds sp = -%0, sp ;;\n"		/* setup stack */
		"\tld8 gp = [r32]\n"			/* get procedure GP */
		"\tadds r16 = %0-(%2*16), sp\n"
		"\tadds r17 = %0-((%2-1)*16), sp ;;\n"
		"\tstf.spill [r16] = f16,32\n"		/* spill callee-saved fp regs */
		"\tstf.spill [r17] = f17,32\n"
		"\tmov b6 = r18 ;;\n"			/* set target address */
		"\tstf.spill [r16] = f18,32\n"
		"\tstf.spill [r17] = f19,32\n"
		"\tmov loc30 = b0 ;;\n"			/* save return address */
		"\tstf.spill [r16] = f20,32\n"
		"\tstf.spill [r17] = f21,32 ;;\n"
		"\tstf.spill [r16] = f22,32\n"
		"\tstf.spill [r17] = f23,32\n"
                "\tmov loc32 = ar.lc ;;\n"		/* save loop counter */
		"\tstf.spill [r16] = f2,32\n"
		"\tstf.spill [r17] = f3,32\n"
                "\tmov loc33 = pr ;;\n"			/* save predicate registers */
		"\tstf.spill [r16] = f4,32\n"
		"\tstf.spill [r17] = f5,32\n"
		"\tbr.few b6 ;;\n"			/* branch to function */
		".global StgReturn\n"
		"StgReturn:\n"
		"\tmov r8 = loc16\n"		/* return value in r8 */
		"\tadds r16 = %0-(%2*16), sp\n"
	    	"\tadds r17 = %0-((%2-1)*16), sp ;;\n"
		"\tldf.fill f16 = [r16],32\n"	/* start restoring fp regs */
		"\tldf.fill f17 = [r17],32\n"
		"\tmov ar.pfs = loc29 ;;\n"	/* restore register frame */
		"\tldf.fill f18 = [r16],32\n"
		"\tldf.fill f19 = [r17],32\n"
		"\tmov b0 = loc30 ;;\n"		/* restore return address */
		"\tldf.fill f20 = [r16],32\n"
		"\tldf.fill f21 = [r17],32\n"
                "\tmov ar.lc = loc32 ;;\n"	/* restore loop counter */
		"\tldf.fill f22 = [r16],32\n"
		"\tldf.fill f23 = [r17],32\n"
		"\tmov pr = loc33 ;;\n"		/* restore predicate registers */
		"\tldf.fill f2 = [r16],32\n"
		"\tldf.fill f3 = [r17],32\n"
		"\tadds sp = %0, sp ;;\n"	/* restore stack */
		"\tldf.fill f4 = [r16],32\n"
		"\tldf.fill f5 = [r17],32\n"
		"\tbr.ret.sptk.many b0 ;;\n"	/* return */
	: : "i"(RESERVED_C_STACK_BYTES + PRESERVED_FP_REGISTERS*16),
            "i"(LOCALS),
            "i"(PRESERVED_FP_REGISTERS));
}

#endif

/* -----------------------------------------------------------------------------
   MIPS architecture
   -------------------------------------------------------------------------- */

#ifdef mips_HOST_ARCH

StgThreadReturnCode
StgRun(StgFunPtr f, StgRegTable *basereg)
{
    register StgThreadReturnCode __v0 __asm__("$2");

    __asm__ __volatile__(
	"	la	$25, %1			\n"
	"	move	$30, %2			\n"
	"	jr	%1			\n"
	"	.align 3			\n"
	"	.globl " STG_RETURN "		\n"
	"	.aent " STG_RETURN "		\n"
	STG_RETURN ":				\n"
	"	move	%0, $16			\n"
	"	move	$3, $17			\n"
	: "=r" (__v0),
	: "r" (f), "r" (basereg)
	"$16", "$17", "$18", "$19", "$20", "$21", "$22", "$23",
	"$25", "$28", "$30",
	"$f20", "$f22", "$f24", "$f26", "$f28", "$f30",
	"memory");

    return __v0;
}

#endif /* mips_HOST_ARCH */

#endif /* !USE_MINIINTERPRETER */