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authorJ"orn Rennecke <joern.rennecke@st.com>2005-05-13 12:25:28 +0000
committerJoern Rennecke <amylaar@gcc.gnu.org>2005-05-13 13:25:28 +0100
commit86d9571b8c64318fea4cc928d59abade80e2cc81 (patch)
treed0c2231c504647c3430df625b25f132830d3501f
parenta1aed706562a160e9d304a6806ce5ac70de89910 (diff)
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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
-rw-r--r--gcc/ChangeLog9
-rw-r--r--gcc/flow.c8
2 files changed, 16 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 00f3607..d11964b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2005-05-13 J"orn Rennecke <joern.rennecke@st.com>
+
+ 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.
+
2005-05-13 Adrian Straetling <straetling@de.ibm.com>
* config/s390.md: ("DBL"): New mode attribute.
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))