From 89e64bc0305f36a4abe486ce07cbee7c13a6dc81 Mon Sep 17 00:00:00 2001
From: Richard Sandiford <richard.sandiford@arm.com>
Date: Tue, 15 Nov 2016 17:54:20 +0000
Subject: [PATCH] Move misplaced assignment in num_sign_bit_copies1
The old assignment to bitwidth was before we handled VOIDmode with:
if (mode == VOIDmode)
mode = GET_MODE (x);
so when VOIDmode was specified we would always use:
if (bitwidth < GET_MODE_PRECISION (GET_MODE (x)))
{
num0 = cached_num_sign_bit_copies (x, GET_MODE (x),
known_x, known_mode, known_ret);
return MAX (1,
num0 - (int) (GET_MODE_PRECISION (GET_MODE (x)) - bitwidth));
}
For a zero bitwidth this always returns 1 (which is the most
pessimistic result).
gcc/
2016-11-15 Richard Sandiford <richard.sandiford@arm.com>
Alan Hayward <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>
* rtlanal.c (num_sign_bit_copies1): Calculate bitwidth after
handling VOIDmode.
Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r242440
---
gcc/ChangeLog | 7 +++++++
gcc/rtlanal.c | 4 ++--
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f5ab2f3275fb..95e3dc5047c5 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2016-11-15 Richard Sandiford <richard.sandiford@arm.com>
+ Alan Hayward <alan.hayward@arm.com>
+ David Sherwood <david.sherwood@arm.com>
+
+ * rtlanal.c (num_sign_bit_copies1): Calculate bitwidth after
+ handling VOIDmode.
+
2016-11-15 Matthias Klose <doko@ubuntu.com>
* doc/install.texi: Remove references to gcj/libjava.
diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index 4617e8ee449d..e08f2be789b9 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -4795,7 +4795,6 @@ num_sign_bit_copies1 (const_rtx x, machine_mode mode, const_rtx known_x,
unsigned int known_ret)
{
enum rtx_code code = GET_CODE (x);
- unsigned int bitwidth = GET_MODE_PRECISION (mode);
machine_mode inner_mode;
int num0, num1, result;
unsigned HOST_WIDE_INT nonzero;
@@ -4811,7 +4810,8 @@ num_sign_bit_copies1 (const_rtx x, machine_mode mode, const_rtx known_x,
|| VECTOR_MODE_P (GET_MODE (x)) || VECTOR_MODE_P (mode))
return 1;
- /* For a smaller object, just ignore the high bits. */
+ /* For a smaller mode, just ignore the high bits. */
+ unsigned int bitwidth = GET_MODE_PRECISION (mode);
if (bitwidth < GET_MODE_PRECISION (GET_MODE (x)))
{
num0 = cached_num_sign_bit_copies (x, GET_MODE (x),
--
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