From db87f8200d54ef230646fdcc3e80bb9b9508b4ee Mon Sep 17 00:00:00 2001
From: nemet <nemet@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Tue, 3 Jan 2006 05:05:06 +0000
Subject: [PATCH] * combine.c (apply_distributive_law <SUBREG>): Check
TRULY_NOOP_TRUNCATION.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@109261 138bc75d-0d04-0410-961f-82ee72b054a4
---
gcc/ChangeLog | 5 +++++
gcc/combine.c | 7 ++++++-
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index cac247956039..1be3f95da3ff 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2006-01-02 Adam Nemet <anemet@caviumnetworks.com>
+
+ * combine.c (apply_distributive_law <SUBREG>): Check
+ TRULY_NOOP_TRUNCATION.
+
2006-01-02 Geoffrey Keating <geoffk@apple.com>
* dwarf2out.c (have_switched_text_section): Delete.
diff --git a/gcc/combine.c b/gcc/combine.c
index 1361b10d27c0..e9bd66767924 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -7798,7 +7798,12 @@ apply_distributive_law (rtx x)
|| (GET_MODE_SIZE (GET_MODE (lhs))
> GET_MODE_SIZE (GET_MODE (SUBREG_REG (lhs))))
|| VECTOR_MODE_P (GET_MODE (lhs))
- || GET_MODE_SIZE (GET_MODE (SUBREG_REG (lhs))) > UNITS_PER_WORD)
+ || GET_MODE_SIZE (GET_MODE (SUBREG_REG (lhs))) > UNITS_PER_WORD
+ /* Result might need to be truncated. Don't change mode if
+ explicit truncation is needed. */
+ || !TRULY_NOOP_TRUNCATION
+ (GET_MODE_BITSIZE (GET_MODE (x)),
+ GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (lhs)))))
return x;
tem = simplify_gen_binary (code, GET_MODE (SUBREG_REG (lhs)),
--
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