gcc/gcc44-pr44199.patch

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2010-05-25 22:50:28 +00:00
2010-05-20 Jakub Jelinek <jakub@redhat.com>
PR target/44199
* config/rs6000/rs6000.c (rs6000_emit_epilogue): If cfun->calls_alloca
or total_size is larger than red zone size for non-V4 ABI, emit a
stack_tie resp. frame_tie insn before stack pointer restore.
* config/rs6000/rs6000.md (frame_tie): New insn.
--- gcc/config/rs6000/rs6000.c.jj 2010-05-17 07:52:06.000000000 +0200
+++ gcc/config/rs6000/rs6000.c 2010-05-19 22:15:53.000000000 +0200
@@ -19775,6 +19775,16 @@ rs6000_emit_epilogue (int sibcall)
frame_reg_rtx = sp_reg_rtx;
if (DEFAULT_ABI == ABI_V4)
frame_reg_rtx = gen_rtx_REG (Pmode, 11);
+ /* Prevent reordering memory accesses against stack pointer restore. */
+ else if (cfun->calls_alloca
+ || offset_below_red_zone_p (-info->total_size))
+ {
+ rtx mem1 = gen_rtx_MEM (BLKmode, hard_frame_pointer_rtx);
+ rtx mem2 = gen_rtx_MEM (BLKmode, sp_reg_rtx);
+ MEM_NOTRAP_P (mem1) = 1;
+ MEM_NOTRAP_P (mem2) = 1;
+ emit_insn (gen_frame_tie (mem1, mem2));
+ }
insn = emit_insn (gen_add3_insn (frame_reg_rtx, hard_frame_pointer_rtx,
GEN_INT (info->total_size)));
@@ -19784,6 +19794,14 @@ rs6000_emit_epilogue (int sibcall)
&& DEFAULT_ABI != ABI_V4
&& !crtl->calls_eh_return)
{
+ /* Prevent reordering memory accesses against stack pointer restore. */
+ if (cfun->calls_alloca
+ || offset_below_red_zone_p (-info->total_size))
+ {
+ rtx mem = gen_rtx_MEM (BLKmode, sp_reg_rtx);
+ MEM_NOTRAP_P (mem) = 1;
+ emit_insn (gen_stack_tie (mem));
+ }
insn = emit_insn (gen_add3_insn (sp_reg_rtx, sp_reg_rtx,
GEN_INT (info->total_size)));
sp_offset = 0;
--- gcc/config/rs6000/rs6000.md.jj 2010-03-26 17:13:37.000000000 +0100
+++ gcc/config/rs6000/rs6000.md 2010-05-19 22:15:19.000000000 +0200
@@ -15286,6 +15286,15 @@ (define_insn "stack_tie"
""
[(set_attr "length" "0")])
+; Like stack_tie, but depend on both fp and sp based memory.
+(define_insn "frame_tie"
+ [(set (match_operand:BLK 0 "memory_operand" "+m")
+ (unspec:BLK [(match_dup 0)
+ (match_operand:BLK 1 "memory_operand" "m")] UNSPEC_TIE))]
+ ""
+ ""
+ [(set_attr "length" "0")])
+
(define_expand "epilogue"
[(use (const_int 0))]