From 8d71a51026ad5ce87d51be1915a2eb2ae88f9cd8 Mon Sep 17 00:00:00 2001
From: Jeffrey A Law <law@cygnus.com>
Date: Mon, 6 Sep 1999 08:44:50 +0000
Subject: [PATCH] cse.c (delete_trivially_dead_insns): Do not skip the last
insn if it is a real insn.
* cse.c (delete_trivially_dead_insns): Do not skip the last
insn if it is a real insn.
From-SVN: r29138
---
gcc/ChangeLog | 5 +++++
gcc/cse.c | 12 ++++++++++--
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 430e62bc6cb9..5e40c62f8a7f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+Mon Sep 6 02:42:36 1999 Jeffrey A Law (law@cygnus.com)
+
+ * cse.c (delete_trivially_dead_insns): Do not skip the last
+ insn if it is a real insn.
+
Sun Sep 5 18:57:42 1999 Mark Mitchell <mark@codesourcery.com>
* Makefile.in (ggc-simple.o): Depend on hash.h.
diff --git a/gcc/cse.c b/gcc/cse.c
index 68fe7b04a924..d1a2487cb410 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -9135,8 +9135,16 @@ delete_trivially_dead_insns (insns, nreg)
/* Go from the last insn to the first and delete insns that only set unused
registers or copy a register to itself. As we delete an insn, remove
- usage counts for registers it uses. */
- for (insn = prev_real_insn (get_last_insn ()); insn; insn = prev)
+ usage counts for registers it uses.
+
+ The first jump optimization pass may leave a real insn as the last
+ insn in the function. We must not skip that insn or we may end
+ up deleting code that is not really dead. */
+ insn = get_last_insn ();
+ if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
+ insn = prev_real_insn (insn);
+
+ for ( ; insn; insn = prev)
{
int live_insn = 0;
rtx note;
--
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