1 /* -----------------------------------------------------------------------------
3 * (c) The GHC Team, 1998-2003
7 * To run an STG function from C land, call
9 * rv = StgRun(f,BaseReg);
11 * where "f" is the STG function to call, and BaseReg is the address of the
12 * RegTable for this run (we might have separate RegTables if we're running
13 * multiple threads on an SMP machine).
15 * In the end, "f" must JMP to StgReturn (defined below),
16 * passing the return-value "rv" in R1,
17 * to return to the caller of StgRun returning "rv" in
18 * the whatever way C returns a value.
20 * NOTE: StgRun/StgReturn do *NOT* load or store Hp or any
21 * other registers (other than saving the C callee-saves
22 * registers). Instead, the called function "f" must do that
25 * GCC will have assumed that pushing/popping of C-stack frames is
26 * going on when it generated its code, and used stack space
27 * accordingly. However, we actually {\em post-process away} all
28 * such stack-framery (see \tr{ghc/driver/ghc-asm.lprl}). Things will
29 * be OK however, if we initially make sure there are
30 * @RESERVED_C_STACK_BYTES@ on the C-stack to begin with, for local
33 * -------------------------------------------------------------------------- */
35 #include "PosixSource.h"
39 * We define the following (unused) global register variables, because for
40 * some reason gcc generates sub-optimal code for StgRun() on the Alpha
41 * (unnecessarily saving extra registers on the stack) if we don't.
43 * Why do it at the top of this file, rather than near StgRun() below? Because
44 * gcc doesn't let us define global register variables after any function
45 * definition has been read. Any point after #include "Stg.h" would be too
48 * We define alpha_EXTRA_CAREFUL here to save $s6, $f8 and $f9 -- registers
49 * that we don't use but which are callee-save registers. The __divq() routine
50 * in libc.a clobbers $s6.
52 #include "ghcconfig.h"
53 #ifdef alpha_HOST_ARCH
54 #define alpha_EXTRA_CAREFUL
55 register long fake_ra __asm__("$26");
56 register long fake_gp __asm__("$29");
57 #ifdef alpha_EXTRA_CAREFUL
58 register long fake_s6 __asm__("$15");
59 register double fake_f8 __asm__("$f8");
60 register double fake_f9 __asm__("$f9");
64 /* include Stg.h first because we want real machine regs in here: we
65 * have to get the value of R1 back from Stg land to C land intact.
71 #include "OSThreads.h"
72 #include "Capability.h"
79 #ifdef USE_MINIINTERPRETER
81 /* -----------------------------------------------------------------------------
82 any architecture (using miniinterpreter)
83 -------------------------------------------------------------------------- */
85 StgThreadReturnCode StgRun(StgFunPtr f, StgRegTable *basereg STG_UNUSED)
88 if (RtsFlags[0].DebugFlags.interpreter) {
89 debugBelch("Jumping to ");
90 printPtr((P_)f); fflush(stdout);
93 f = (StgFunPtr) (f)();
95 return (StgThreadReturnCode)R1.i;
98 StgFunPtr StgReturn(void)
103 #else /* !USE_MINIINTERPRETER */
105 #ifdef LEADING_UNDERSCORE
106 #define STG_RETURN "_StgReturn"
108 #define STG_RETURN "StgReturn"
111 /* -----------------------------------------------------------------------------
113 -------------------------------------------------------------------------- */
115 #ifdef i386_HOST_ARCH
118 StgRun(StgFunPtr f, StgRegTable *basereg) {
120 unsigned char space[ RESERVED_C_STACK_BYTES + 4*sizeof(void *) ];
121 StgThreadReturnCode r;
125 * save callee-saves registers on behalf of the STG code.
127 "movl %%esp, %%eax\n\t"
129 "movl %%ebx,0(%%eax)\n\t"
130 "movl %%esi,4(%%eax)\n\t"
131 "movl %%edi,8(%%eax)\n\t"
132 "movl %%ebp,12(%%eax)\n\t"
138 * grab the function argument from the stack, and jump to it.
143 ".global " STG_RETURN "\n"
146 "movl %%esi, %%eax\n\t" /* Return value in R1 */
149 * restore callee-saves registers. (Don't stomp on %%eax!)
151 "movl %%esp, %%edx\n\t"
153 "movl 0(%%edx),%%ebx\n\t" /* restore the registers saved above */
154 "movl 4(%%edx),%%esi\n\t"
155 "movl 8(%%edx),%%edi\n\t"
156 "movl 12(%%edx),%%ebp\n\t"
158 : "=&a" (r), "=m" (space)
159 : "m" (f), "m" (basereg), "i" (RESERVED_C_STACK_BYTES)
160 : "edx" /* stomps on %edx */
168 /* ----------------------------------------------------------------------------
169 x86-64 is almost the same as plain x86.
171 I've done it using entirely inline assembler, because I couldn't
172 get gcc to generate the correct subtraction from %rsp by using
173 the local array variable trick. It didn't seem to reserve
174 enough space. Oh well, it's not much harder this way.
176 ------------------------------------------------------------------------- */
178 #ifdef x86_64_HOST_ARCH
180 extern StgThreadReturnCode StgRun(StgFunPtr f, StgRegTable *basereg);
182 static void StgRunIsImplementedInAssembler(void)
186 * save callee-saves registers on behalf of the STG code.
191 "movq %%rsp, %%rax\n\t"
192 "addq %0-48, %%rax\n\t"
193 "movq %%rbx,0(%%rax)\n\t"
194 "movq %%rbp,8(%%rax)\n\t"
195 "movq %%r12,16(%%rax)\n\t"
196 "movq %%r13,24(%%rax)\n\t"
197 "movq %%r14,32(%%rax)\n\t"
198 "movq %%r15,40(%%rax)\n\t"
202 "movq %%rsi,%%rbx\n\t"
204 * grab the function argument from the stack, and jump to it.
206 "movq %%rdi,%%rax\n\t"
209 ".global " STG_RETURN "\n"
212 "movq %%r13, %%rax\n\t" /* Return value in R1 */
215 * restore callee-saves registers. (Don't stomp on %%rax!)
217 "movq %%rsp, %%rdx\n\t"
218 "addq %0-48, %%rdx\n\t"
219 "movq 0(%%rdx),%%rbx\n\t" /* restore the registers saved above */
220 "movq 8(%%rdx),%%rbp\n\t"
221 "movq 16(%%rdx),%%r12\n\t"
222 "movq 24(%%rdx),%%r13\n\t"
223 "movq 32(%%rdx),%%r14\n\t"
224 "movq 40(%%rdx),%%r15\n\t"
228 : : "i"(RESERVED_C_STACK_BYTES+48+8 /*stack frame size*/));
232 The x86_64 ABI specifies that on a procedure call, %rsp is
233 aligned on a 16-byte boundary + 8. That is, the first
234 argument on the stack after the return address will be
237 Which should be fine: RESERVED_C_STACK_BYTES+48 is a multiple
240 BUT... when we do a C-call from STG land, gcc likes to put the
241 stack alignment adjustment in the prolog. eg. if we're calling
242 a function with arguments in regs, gcc will insert 'subq $8,%rsp'
243 in the prolog, to keep %rsp aligned (the return address is 8
244 bytes, remember). The mangler throws away the prolog, so we
245 lose the stack alignment.
247 The hack is to add this extra 8 bytes to our %rsp adjustment
248 here, so that throughout STG code, %rsp is 16-byte aligned,
251 A quick way to see if this is wrong is to compile this code:
253 main = System.Exit.exitWith ExitSuccess
255 And run it with +RTS -sstderr. The stats code in the RTS, in
256 particular statsPrintf(), relies on the stack alignment because
257 it saves the %xmm regs on the stack, so it'll fall over if the
258 stack isn't aligned, and calling exitWith from Haskell invokes
259 shutdownHaskellAndExit using a C call.
261 Future gcc releases will almost certainly break this hack...
267 /* -----------------------------------------------------------------------------
271 OLD COMMENT from GHC-3.02:
273 We want tailjumps to be calls, because `call xxx' is the only Sparc
274 branch that allows an arbitrary label as a target. (Gcc's ``goto
275 *target'' construct ends up loading the label into a register and
276 then jumping, at the cost of two extra instructions for the 32-bit
279 When entering the threaded world, we stash our return address in a
280 known location so that \tr{%i7} is available as an extra
281 callee-saves register. Of course, we have to restore this when
282 coming out of the threaded world.
284 I hate this god-forsaken architecture. Since the top of the
285 reserved stack space is used for globals and the bottom is reserved
286 for outgoing arguments, we have to stick our return address
287 somewhere in the middle. Currently, I'm allowing 100 extra
288 outgoing arguments beyond the first 6. --JSM
290 Updated info (GHC 4.06): we don't appear to use %i7 any more, so
291 I'm not sure whether we still need to save it. Incedentally, what
292 does the last paragraph above mean when it says "the top of the
293 stack is used for globals"? What globals? --SDM
295 Updated info (GHC 4.08.2): not saving %i7 any more (see below).
296 -------------------------------------------------------------------------- */
298 #ifdef sparc_HOST_ARCH
301 StgRun(StgFunPtr f, StgRegTable *basereg) {
303 unsigned char space[RESERVED_C_STACK_BYTES];
305 register void *i7 __asm__("%i7");
306 ((void **)(space))[100] = i7;
311 ".global " STG_RETURN "\n"
313 : : : "l0","l1","l2","l3","l4","l5","l6","l7");
314 /* we tell the C compiler that l0-l7 are clobbered on return to
315 * StgReturn, otherwise it tries to use these to save eg. the
316 * address of space[100] across the call. The correct thing
317 * to do would be to save all the callee-saves regs, but we
318 * can't be bothered to do that.
320 * The code that gcc generates for this little fragment is now
321 * terrible. We could do much better by coding it directly in
325 /* updated 4.08.2: we don't save %i7 in the middle of the reserved
326 * space any more, since gcc tries to save its address across the
327 * call to f(), this gets clobbered in STG land and we end up
328 * dereferencing a bogus pointer in StgReturn.
330 __asm__ volatile ("ld %1,%0"
331 : "=r" (i7) : "m" (((void **)(space))[100]));
333 return (StgThreadReturnCode)R1.i;
338 /* -----------------------------------------------------------------------------
341 "The stack pointer (SP) must at all times denote an address that has octaword
342 alignment. (This restriction has the side effect that the in-memory portion
343 of the argument list, if any, will start on an octaword boundary.) Note that
344 the stack grows toward lower addresses. During a procedure invocation, SP
345 can never be set to a value that is higher than the value of SP at entry to
346 that procedure invocation.
348 "The contents of the stack, located above the portion of the argument list
349 (if any) that is passed in memory, belong to the calling procedure. Because
350 they are part of the calling procedure, they should not be read or written
351 by the called procedure, except as specified by indirect arguments or
352 language-controlled up-level references.
354 "The SP value might be used by the hardware when raising exceptions and
355 asynchronous interrupts. It must be assumed that the contents of the stack
356 below the current SP value and within the stack for the current thread are
357 continually and unpredictably modified, as specified in the _Alpha
358 Architecture Reference Manual_, and as a result of asynchronous software
361 -- Compaq Computer Corporation, Houston. Tru64 UNIX Calling Standard for
362 Alpha Systems, 5.1 edition, August 2000, section 3.2.1. http://www.
363 tru64unix.compaq.com/docs/base_doc/DOCUMENTATION/V51_PDF/ARH9MBTE.PDF
364 -------------------------------------------------------------------------- */
366 #ifdef alpha_HOST_ARCH
369 StgRun(StgFunPtr f, StgRegTable *basereg)
371 register long real_ra __asm__("$26"); volatile long save_ra;
372 register long real_gp __asm__("$29"); volatile long save_gp;
374 register long real_s0 __asm__("$9" ); volatile long save_s0;
375 register long real_s1 __asm__("$10"); volatile long save_s1;
376 register long real_s2 __asm__("$11"); volatile long save_s2;
377 register long real_s3 __asm__("$12"); volatile long save_s3;
378 register long real_s4 __asm__("$13"); volatile long save_s4;
379 register long real_s5 __asm__("$14"); volatile long save_s5;
380 #ifdef alpha_EXTRA_CAREFUL
381 register long real_s6 __asm__("$15"); volatile long save_s6;
384 register double real_f2 __asm__("$f2"); volatile double save_f2;
385 register double real_f3 __asm__("$f3"); volatile double save_f3;
386 register double real_f4 __asm__("$f4"); volatile double save_f4;
387 register double real_f5 __asm__("$f5"); volatile double save_f5;
388 register double real_f6 __asm__("$f6"); volatile double save_f6;
389 register double real_f7 __asm__("$f7"); volatile double save_f7;
390 #ifdef alpha_EXTRA_CAREFUL
391 register double real_f8 __asm__("$f8"); volatile double save_f8;
392 register double real_f9 __asm__("$f9"); volatile double save_f9;
395 register StgFunPtr real_pv __asm__("$27");
397 StgThreadReturnCode ret;
408 #ifdef alpha_EXTRA_CAREFUL
418 #ifdef alpha_EXTRA_CAREFUL
425 __asm__ volatile( "lda $30,-%0($30)" "\n"
426 "\t" "jmp ($27)" "\n"
428 ".globl " STG_RETURN "\n"
430 "\t" "lda $30,%0($30)" "\n"
431 : : "K" (RESERVED_C_STACK_BYTES));
441 #ifdef alpha_EXTRA_CAREFUL
451 #ifdef alpha_EXTRA_CAREFUL
462 #endif /* alpha_HOST_ARCH */
464 /* -----------------------------------------------------------------------------
466 -------------------------------------------------------------------------- */
468 #ifdef hppa1_1_HOST_ARCH
471 StgRun(StgFunPtr f, StgRegTable *basereg)
473 StgChar space[RESERVED_C_STACK_BYTES+16*sizeof(long)+10*sizeof(double)];
474 StgThreadReturnCode ret;
476 __asm__ volatile ("ldo %0(%%r30),%%r19\n"
477 "\tstw %%r3, 0(0,%%r19)\n"
478 "\tstw %%r4, 4(0,%%r19)\n"
479 "\tstw %%r5, 8(0,%%r19)\n"
480 "\tstw %%r6,12(0,%%r19)\n"
481 "\tstw %%r7,16(0,%%r19)\n"
482 "\tstw %%r8,20(0,%%r19)\n"
483 "\tstw %%r9,24(0,%%r19)\n"
484 "\tstw %%r10,28(0,%%r19)\n"
485 "\tstw %%r11,32(0,%%r19)\n"
486 "\tstw %%r12,36(0,%%r19)\n"
487 "\tstw %%r13,40(0,%%r19)\n"
488 "\tstw %%r14,44(0,%%r19)\n"
489 "\tstw %%r15,48(0,%%r19)\n"
490 "\tstw %%r16,52(0,%%r19)\n"
491 "\tstw %%r17,56(0,%%r19)\n"
492 "\tstw %%r18,60(0,%%r19)\n"
493 "\tldo 80(%%r19),%%r19\n"
494 "\tfstds %%fr12,-16(0,%%r19)\n"
495 "\tfstds %%fr13, -8(0,%%r19)\n"
496 "\tfstds %%fr14, 0(0,%%r19)\n"
497 "\tfstds %%fr15, 8(0,%%r19)\n"
498 "\tldo 32(%%r19),%%r19\n"
499 "\tfstds %%fr16,-16(0,%%r19)\n"
500 "\tfstds %%fr17, -8(0,%%r19)\n"
501 "\tfstds %%fr18, 0(0,%%r19)\n"
502 "\tfstds %%fr19, 8(0,%%r19)\n"
503 "\tldo 32(%%r19),%%r19\n"
504 "\tfstds %%fr20,-16(0,%%r19)\n"
505 "\tfstds %%fr21, -8(0,%%r19)\n" : :
506 "n" (-(116 * sizeof(long) + 10 * sizeof(double))) : "%r19"
511 __asm__ volatile (".align 4\n"
512 "\t.EXPORT " STG_RETURN ",CODE\n"
513 "\t.EXPORT " STG_RETURN ",ENTRY,PRIV_LEV=3\n"
515 /* "\tldo %0(%%r3),%%r19\n" */
516 "\tldo %1(%%r30),%%r19\n"
517 "\tcopy %%r11, %0\n" /* save R1 */
518 "\tldw 0(0,%%r19),%%r3\n"
519 "\tldw 4(0,%%r19),%%r4\n"
520 "\tldw 8(0,%%r19),%%r5\n"
521 "\tldw 12(0,%%r19),%%r6\n"
522 "\tldw 16(0,%%r19),%%r7\n"
523 "\tldw 20(0,%%r19),%%r8\n"
524 "\tldw 24(0,%%r19),%%r9\n"
525 "\tldw 28(0,%%r19),%%r10\n"
526 "\tldw 32(0,%%r19),%%r11\n"
527 "\tldw 36(0,%%r19),%%r12\n"
528 "\tldw 40(0,%%r19),%%r13\n"
529 "\tldw 44(0,%%r19),%%r14\n"
530 "\tldw 48(0,%%r19),%%r15\n"
531 "\tldw 52(0,%%r19),%%r16\n"
532 "\tldw 56(0,%%r19),%%r17\n"
533 "\tldw 60(0,%%r19),%%r18\n"
534 "\tldo 80(%%r19),%%r19\n"
535 "\tfldds -16(0,%%r19),%%fr12\n"
536 "\tfldds -8(0,%%r19),%%fr13\n"
537 "\tfldds 0(0,%%r19),%%fr14\n"
538 "\tfldds 8(0,%%r19),%%fr15\n"
539 "\tldo 32(%%r19),%%r19\n"
540 "\tfldds -16(0,%%r19),%%fr16\n"
541 "\tfldds -8(0,%%r19),%%fr17\n"
542 "\tfldds 0(0,%%r19),%%fr18\n"
543 "\tfldds 8(0,%%r19),%%fr19\n"
544 "\tldo 32(%%r19),%%r19\n"
545 "\tfldds -16(0,%%r19),%%fr20\n"
546 "\tfldds -8(0,%%r19),%%fr21\n"
548 : "n" (-(116 * sizeof(long) + 10 * sizeof(double)))
555 #endif /* hppa1_1_HOST_ARCH */
557 /* -----------------------------------------------------------------------------
560 Everything is in assembler, so we don't have to deal with GCC...
562 -------------------------------------------------------------------------- */
564 #ifdef powerpc_HOST_ARCH
566 extern StgThreadReturnCode StgRun(StgFunPtr f, StgRegTable *basereg);
568 #ifdef darwin_HOST_OS
569 static void StgRunIsImplementedInAssembler(void)
571 #if HAVE_SUBSECTIONS_VIA_SYMBOLS
572 // if the toolchain supports deadstripping, we have to
573 // prevent it here (it tends to get confused here).
574 __asm__ volatile (".no_dead_strip _StgRunIsImplementedInAssembler");
580 "\tbl saveFP # f14\n"
581 "\tstmw r13,-220(r1)\n"
582 "\tstwu r1,-%0(r1)\n"
583 "\tmr r27,r4\n" // BaseReg == r27
587 ".globl _StgReturn\n"
591 "\tlmw r13,-220(r1)\n"
593 : : "i"(RESERVED_C_STACK_BYTES+224 /*stack frame size*/));
597 // This version is for PowerPC Linux.
599 // Differences from the Darwin/Mac OS X version:
600 // *) Different Assembler Syntax
601 // *) Doesn't use Register Saving Helper Functions (although they exist somewhere)
602 // *) We may not access positive stack offsets
603 // (no "Red Zone" as in the Darwin ABI)
604 // *) The Link Register is saved to a different offset in the caller's stack frame
605 // (Linux: 4(r1), Darwin 8(r1))
607 static void StgRunIsImplementedInAssembler(void)
611 "\t.type StgRun,@function\n"
617 "\tstmw 13,-220(5)\n"
618 "\tstfd 14,-144(5)\n"
619 "\tstfd 15,-136(5)\n"
620 "\tstfd 16,-128(5)\n"
621 "\tstfd 17,-120(5)\n"
622 "\tstfd 18,-112(5)\n"
623 "\tstfd 19,-104(5)\n"
636 "\tmr 27,4\n" // BaseReg == r27
641 "\t.type StgReturn,@function\n"
668 : : "i"(RESERVED_C_STACK_BYTES+224 /*stack frame size*/));
674 /* -----------------------------------------------------------------------------
675 PowerPC 64 architecture
677 Everything is in assembler, so we don't have to deal with GCC...
679 -------------------------------------------------------------------------- */
681 #ifdef powerpc64_HOST_ARCH
684 extern StgThreadReturnCode StgRun(StgFunPtr f, StgRegTable *basereg);
686 static void StgRunIsImplementedInAssembler(void)
690 // r2 toc - needs to be saved
691 // r3-r10 argument passing, volatile
692 // r11, r12 very volatile (not saved across cross-module calls)
693 // r13 thread local state (never modified, don't need to save)
694 // r14-r31 callee-save
696 ".section \".opd\",\"aw\"\n"
700 "\t.quad\t.StgRun,.TOC.@tocbase,0\n"
701 "\t.size StgRun,24\n"
704 "\t.quad\t.StgReturn,.TOC.@tocbase,0\n"
705 "\t.size StgReturn,24\n"
708 ".type .StgRun,@function\n"
715 "\tstd 14, -288(5)\n"
716 "\tstd 15, -280(5)\n"
717 "\tstd 16, -272(5)\n"
718 "\tstd 17, -264(5)\n"
719 "\tstd 18, -256(5)\n"
720 "\tstd 19, -248(5)\n"
721 "\tstd 20, -240(5)\n"
722 "\tstd 21, -232(5)\n"
723 "\tstd 22, -224(5)\n"
724 "\tstd 23, -216(5)\n"
725 "\tstd 24, -208(5)\n"
726 "\tstd 25, -200(5)\n"
727 "\tstd 26, -192(5)\n"
728 "\tstd 27, -184(5)\n"
729 "\tstd 28, -176(5)\n"
730 "\tstd 29, -168(5)\n"
731 "\tstd 30, -160(5)\n"
732 "\tstd 31, -152(5)\n"
733 "\tstfd 14, -144(5)\n"
734 "\tstfd 15, -136(5)\n"
735 "\tstfd 16, -128(5)\n"
736 "\tstfd 17, -120(5)\n"
737 "\tstfd 18, -112(5)\n"
738 "\tstfd 19, -104(5)\n"
739 "\tstfd 20, -96(5)\n"
740 "\tstfd 21, -88(5)\n"
741 "\tstfd 22, -80(5)\n"
742 "\tstfd 23, -72(5)\n"
743 "\tstfd 24, -64(5)\n"
744 "\tstfd 25, -56(5)\n"
745 "\tstfd 26, -48(5)\n"
746 "\tstfd 27, -40(5)\n"
747 "\tstfd 28, -32(5)\n"
748 "\tstfd 29, -24(5)\n"
749 "\tstfd 30, -16(5)\n"
751 "\tmr 27, 4\n" // BaseReg == r27
756 ".globl .StgReturn\n"
757 ".type .StgReturn,@function\n"
760 "\tla 5, %0(1)\n" // load address == addi r5, r1, %0
780 "\tlfd 14, -144(5)\n"
781 "\tlfd 15, -136(5)\n"
782 "\tlfd 16, -128(5)\n"
783 "\tlfd 17, -120(5)\n"
784 "\tlfd 18, -112(5)\n"
785 "\tlfd 19, -104(5)\n"
802 : : "i"(RESERVED_C_STACK_BYTES+304 /*stack frame size*/));
804 #else // linux_HOST_OS
805 #error Only linux support for power64 right now.
810 /* -----------------------------------------------------------------------------
813 Again, in assembler - so we can fiddle with the register stack, and because
814 gcc doesn't handle asm-clobbered callee-saves correctly.
816 loc0 - loc15: preserved locals
817 loc16 - loc28: STG registers
820 loc31: saved gp (gcc 3.3 uses this slot)
821 -------------------------------------------------------------------------- */
823 #ifdef ia64_HOST_ARCH
825 /* the memory stack is rarely used, so 16K is excessive */
826 #undef RESERVED_C_STACK_BYTES
827 #define RESERVED_C_STACK_BYTES 1024
829 #if ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 3)) || (__GNUC__ > 3)
830 /* gcc 3.3+: leave an extra slot for gp saves */
836 static void StgRunIsImplementedInAssembler(void)
841 "\talloc loc29 = ar.pfs, 0, %1, 8, 0\n" /* setup register frame */
842 "\tld8 r18 = [r32],8\n" /* get procedure address */
843 "\tadds sp = -%0, sp ;;\n" /* setup stack */
844 "\tld8 gp = [r32]\n" /* get procedure GP */
845 "\tadds r16 = %0-(6*16), sp\n"
846 "\tadds r17 = %0-(5*16), sp ;;\n"
847 "\tstf.spill [r16] = f16,32\n" /* spill callee-saved fp regs */
848 "\tstf.spill [r17] = f17,32\n"
849 "\tmov b6 = r18 ;;\n" /* set target address */
850 "\tstf.spill [r16] = f18,32\n"
851 "\tstf.spill [r17] = f19,32\n"
852 "\tmov loc30 = b0 ;;\n" /* save return address */
853 "\tstf.spill [r16] = f20,32\n"
854 "\tstf.spill [r17] = f21,32\n"
855 "\tbr.few b6 ;;\n" /* branch to function */
856 ".global StgReturn\n"
858 "\tmov r8 = loc16\n" /* return value in r8 */
859 "\tadds r16 = %0-(6*16), sp\n"
860 "\tadds r17 = %0-(5*16), sp ;;\n"
861 "\tldf.fill f16 = [r16],32\n" /* start restoring fp regs */
862 "\tldf.fill f17 = [r17],32\n"
863 "\tmov ar.pfs = loc29 ;;\n" /* restore register frame */
864 "\tldf.fill f18 = [r16],32\n"
865 "\tldf.fill f19 = [r17],32\n"
866 "\tmov b0 = loc30 ;;\n" /* restore return address */
867 "\tldf.fill f20 = [r16],32\n"
868 "\tldf.fill f21 = [r17],32\n"
869 "\tadds sp = %0, sp\n" /* restore stack */
870 "\tbr.ret.sptk.many b0 ;;\n" /* return */
871 : : "i"(RESERVED_C_STACK_BYTES + 6*16), "i"(LOCALS));
876 #endif /* !USE_MINIINTERPRETER */