PR target/24419 * i386.c (pro_epilogue_adjust_stack): Add another argument to indicate if memory should be clobbered or not. Adjust stack pointer directly if memory shouldn't be clobbered. (ix86_expand_prologue): Updated. Don't clobber member if adjusting stack after registers have been saved on stack. (ix86_expand_epilogue): Updated to call pro_epilogue_adjust_stack with memory clobbered. * i386.md: Don't convert stack pointer subtractions to push when memory isn't clobbered if red zone is enabled. --- gcc/gcc/config/i386/i386.c 2005-10-18 17:26:40.000000000 -0700 +++ gcc/gcc/config/i386/i386.c 2005-10-18 20:35:19.000000000 -0700 @@ -4761,22 +4761,38 @@ ix86_emit_save_regs_using_mov (rtx point otherwise. */ static void -pro_epilogue_adjust_stack (rtx dest, rtx src, rtx offset, int style) +pro_epilogue_adjust_stack (rtx dest, rtx src, rtx offset, int style, + bool clobber_memory) { rtx insn; if (! TARGET_64BIT) - insn = emit_insn (gen_pro_epilogue_adjust_stack_1 (dest, src, offset)); + { + if (clobber_memory) + insn = emit_insn (gen_pro_epilogue_adjust_stack_1 (dest, src, + offset)); + else + insn = emit_insn (gen_addsi3 (dest, src, offset)); + } else if (x86_64_immediate_operand (offset, DImode)) - insn = emit_insn (gen_pro_epilogue_adjust_stack_rex64 (dest, src, offset)); + { + if (clobber_memory) + insn = emit_insn (gen_pro_epilogue_adjust_stack_rex64 (dest, + src, + offset)); + else + insn = emit_insn (gen_adddi3 (dest, src, offset)); + } else { rtx r11; /* r11 is used by indirect sibcall return as well, set before the epilogue and used after the epilogue. ATM indirect sibcall shouldn't be used together with huge frame sizes in one - function because of the frame_size check in sibcall.c. */ - gcc_assert (style); + function because of the frame_size check in sibcall.c. If + huge frame size is used, memory should always be clobbered + when stack is adjusted. */ + gcc_assert (style && clobber_memory); r11 = gen_rtx_REG (DImode, FIRST_REX_INT_REG + 3 /* R11 */); insn = emit_insn (gen_rtx_SET (DImode, r11, offset)); if (style < 0) @@ -4797,6 +4813,7 @@ ix86_expand_prologue (void) bool pic_reg_used; struct ix86_frame frame; HOST_WIDE_INT allocate; + bool using_mov; ix86_compute_frame_layout (&frame); @@ -4821,7 +4838,8 @@ ix86_expand_prologue (void) /* When using red zone we may start register saving before allocating the stack frame saving one cycle of the prologue. */ - if (TARGET_RED_ZONE && frame.save_regs_using_mov) + using_mov = TARGET_RED_ZONE && frame.save_regs_using_mov; + if (using_mov) ix86_emit_save_regs_using_mov (frame_pointer_needed ? hard_frame_pointer_rtx : stack_pointer_rtx, -frame.nregs * UNITS_PER_WORD); @@ -4830,7 +4848,7 @@ ix86_expand_prologue (void) ; else if (! TARGET_STACK_PROBE || allocate < CHECK_STACK_LIMIT) pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx, - GEN_INT (-allocate), -1); + GEN_INT (-allocate), -1, !using_mov); else { /* Only valid for Win32. */ @@ -5011,7 +5029,7 @@ ix86_expand_epilogue (int style) emit_move_insn (hard_frame_pointer_rtx, tmp); pro_epilogue_adjust_stack (stack_pointer_rtx, sa, - const0_rtx, style); + const0_rtx, style, true); } else { @@ -5025,7 +5043,7 @@ ix86_expand_epilogue (int style) pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx, GEN_INT (frame.to_allocate + frame.nregs * UNITS_PER_WORD), - style); + style, true); /* If not an i386, mov & pop is faster than "leave". */ else if (TARGET_USE_LEAVE || optimize_size || !cfun->machine->use_fast_prologue_epilogue) @@ -5034,7 +5052,7 @@ ix86_expand_epilogue (int style) { pro_epilogue_adjust_stack (stack_pointer_rtx, hard_frame_pointer_rtx, - const0_rtx, style); + const0_rtx, style, true); if (TARGET_64BIT) emit_insn (gen_popdi1 (hard_frame_pointer_rtx)); else @@ -5050,11 +5068,12 @@ ix86_expand_epilogue (int style) gcc_assert (frame_pointer_needed); pro_epilogue_adjust_stack (stack_pointer_rtx, hard_frame_pointer_rtx, - GEN_INT (offset), style); + GEN_INT (offset), style, true); } else if (frame.to_allocate) pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx, - GEN_INT (frame.to_allocate), style); + GEN_INT (frame.to_allocate), style, + true); for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) if (ix86_save_reg (regno, false)) --- gcc/gcc/config/i386/i386.md 2005-10-18 17:26:40.000000000 -0700 +++ gcc/gcc/config/i386/i386.md 2005-10-18 17:26:40.000000000 -0700 @@ -19532,11 +19532,15 @@ (clobber (mem:BLK (scratch)))])]) ;; Convert esp subtractions to push. +;; This conversion is safe only under assumption that unallocated stack is +;; implicitly clobbered as specified by 32bit ABI (for signal handlers and such). +;; This is not valid with red zone, but we can work harder and enable the +;; optimization for functions that are not using it. (define_peephole2 [(match_scratch:SI 0 "r") (parallel [(set (reg:SI SP_REG) (plus:SI (reg:SI SP_REG) (const_int -4))) (clobber (reg:CC FLAGS_REG))])] - "optimize_size || !TARGET_SUB_ESP_4" + "(optimize_size || !TARGET_SUB_ESP_4) && !TARGET_RED_ZONE" [(clobber (match_dup 0)) (set (mem:SI (pre_dec:SI (reg:SI SP_REG))) (match_dup 0))]) @@ -19544,7 +19548,7 @@ [(match_scratch:SI 0 "r") (parallel [(set (reg:SI SP_REG) (plus:SI (reg:SI SP_REG) (const_int -8))) (clobber (reg:CC FLAGS_REG))])] - "optimize_size || !TARGET_SUB_ESP_8" + "(optimize_size || !TARGET_SUB_ESP_8) && !TARGET_RED_ZONE" [(clobber (match_dup 0)) (set (mem:SI (pre_dec:SI (reg:SI SP_REG))) (match_dup 0)) (set (mem:SI (pre_dec:SI (reg:SI SP_REG))) (match_dup 0))]) @@ -19664,11 +19668,15 @@ (clobber (mem:BLK (scratch)))])]) ;; Convert esp subtractions to push. +;; This conversion is safe only under assumption that unallocated stack is +;; implicitly clobbered as specified by 32bit ABI (for signal handlers and such). +;; This is not valid with red zone, but we can work harder and enable the +;; optimization for functions that are not using it. (define_peephole2 [(match_scratch:DI 0 "r") (parallel [(set (reg:DI SP_REG) (plus:DI (reg:DI SP_REG) (const_int -8))) (clobber (reg:CC FLAGS_REG))])] - "optimize_size || !TARGET_SUB_ESP_4" + "(optimize_size || !TARGET_SUB_ESP_4) && !TARGET_RED_ZONE" [(clobber (match_dup 0)) (set (mem:DI (pre_dec:DI (reg:DI SP_REG))) (match_dup 0))]) @@ -19676,7 +19684,7 @@ [(match_scratch:DI 0 "r") (parallel [(set (reg:DI SP_REG) (plus:DI (reg:DI SP_REG) (const_int -16))) (clobber (reg:CC FLAGS_REG))])] - "optimize_size || !TARGET_SUB_ESP_8" + "(optimize_size || !TARGET_SUB_ESP_8) && !TARGET_RED_ZONE" [(clobber (match_dup 0)) (set (mem:DI (pre_dec:DI (reg:DI SP_REG))) (match_dup 0)) (set (mem:DI (pre_dec:DI (reg:DI SP_REG))) (match_dup 0))])