From 2332d585583c1fd02f11346fcbd466b1c60d4501 Mon Sep 17 00:00:00 2001
From: Adam Nemet <anemet@caviumnetworks.com>
Date: Mon, 3 Apr 2006 18:12:15 +0000
Subject: [PATCH] simplify-rtx.c (simplify_unary_operation_1): When trying to
remove TRUNCATE check if all bits outside the new mode are...
* simplify-rtx.c (simplify_unary_operation_1) <TRUNCATE>: When
trying to remove TRUNCATE check if all bits outside the new mode
are identical to the sign bit.
From-SVN: r112643
---
gcc/ChangeLog | 6 ++++++
gcc/simplify-rtx.c | 3 ++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b264035e7c7a..d15763234bee 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2006-04-03 Adam Nemet <anemet@caviumnetworks.com>
+
+ * simplify-rtx.c (simplify_unary_operation_1) <TRUNCATE>: When
+ trying to remove TRUNCATE check if all bits outside the new mode
+ are identical to the sign bit.
+
2006-04-03 Jeff Law <law@redhat.com>
* tree-ssa-dom.c (propagate_rhs_into_lhs): Avoid useless folding
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index cac77ad1fce0..0ce033df208a 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -656,7 +656,8 @@ simplify_unary_operation_1 (enum rtx_code code, enum machine_mode mode, rtx op)
if ((TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
GET_MODE_BITSIZE (GET_MODE (op)))
? (num_sign_bit_copies (op, GET_MODE (op))
- >= (unsigned int) (GET_MODE_BITSIZE (mode) + 1))
+ > (unsigned int) (GET_MODE_BITSIZE (GET_MODE (op))
+ - GET_MODE_BITSIZE (mode)))
: truncated_to_mode (mode, op))
&& ! (GET_CODE (op) == LSHIFTRT
&& GET_CODE (XEXP (op, 0)) == MULT))
--
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