From 86d9571b8c64318fea4cc928d59abade80e2cc81 Mon Sep 17 00:00:00 2001 From: "J\"orn Rennecke" Date: Fri, 13 May 2005 12:25:28 +0000 Subject: re PR rtl-optimization/20756 (Clobbers of deleted insns are processed, but left out) PR rtl-optimization/20756: * basic-block.h (PROP_DEAD_INSN): Define. * flow.c (propagate_one_insn): Set during mark_set_regs call for a dead insn. (mark_set_1): Emit a clobber when we are about to delete a dead insn that kills a live register. From-SVN: r99655 --- gcc/flow.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'gcc/flow.c') diff --git a/gcc/flow.c b/gcc/flow.c index ff1d861..9eae74b 100644 --- a/gcc/flow.c +++ b/gcc/flow.c @@ -1692,8 +1692,12 @@ propagate_one_insn (struct propagate_block_info *pbi, rtx insn) fatal_insn ("Attempt to delete prologue/epilogue insn:", insn); /* Record sets. Do this even for dead instructions, since they - would have killed the values if they hadn't been deleted. */ + would have killed the values if they hadn't been deleted. To + be consistent, we also have to emit a clobber when we delete + an insn that clobbers a live register. */ + pbi->flags |= PROP_DEAD_INSN; mark_set_regs (pbi, PATTERN (insn), insn); + pbi->flags &= ~PROP_DEAD_INSN; /* CC0 is now known to be dead. Either this insn used it, in which case it doesn't anymore, or clobbered it, @@ -2960,6 +2964,8 @@ mark_set_1 (struct propagate_block_info *pbi, enum rtx_code code, rtx reg, rtx c } CLEAR_REGNO_REG_SET (pbi->reg_live, i); } + if (flags & PROP_DEAD_INSN) + emit_insn_after (gen_rtx_CLOBBER (VOIDmode, reg), insn); } } else if (REG_P (reg)) -- cgit v1.1