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* [Bug target/43137] New: redundant register move for sign extending
@ 2010-02-22 9:39 carrot at google dot com
2010-02-22 14:33 ` [Bug target/43137] " ramana at gcc dot gnu dot org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: carrot at google dot com @ 2010-02-22 9:39 UTC (permalink / raw)
To: gcc-bugs
Compile following code with options -march=armv7-a -mthumb -Os
int foo();
long long bar22()
{
int result = foo();
return result;
}
GCC generates:
bar22:
push {r3, lr}
bl foo
asrs r3, r0, #31 // A
mov r1, r3 // B
pop {r3, pc}
Instruction A,B can be simplified to "asrs r1, r0, #31".
In rtl expand, result was first extended to a DI register and then the DI
register was moved to return register. In later passs the low half of the
return value and variable result were recognized as in the same register, so
the low part move was removed. After register allocation I get:
(call_insn 5 2 7 2 src/t5.c:5 (parallel [
(set (reg:SI 0 r0)
(call (mem:SI (symbol_ref:SI ("foo") [flags 0x41]
<function_decl 0x7f6e60fe0600 foo>) [0 S4 A32])
(const_int 0 [0x0])))
(use (const_int 0 [0x0]))
(clobber (reg:SI 14 lr))
]) 255 {*call_value_insn} (nil)
(nil))
(insn 7 5 22 2 src/t5.c:5 (set (reg:DI 2 r2 [orig:136 result ] [136])
(sign_extend:DI (reg/v:SI 0 r0 [orig:133 result ] [133]))) 691
{*thumb2_extendsidi2} (nil))
(insn 22 7 15 2 src/t5.c:7 (set (reg:SI 1 r1 [+4 ])
(reg:SI 3 r3 [ result+4 ])) 658 {*thumb2_movsi_insn} (nil))
The high part register move didn't get any chance to be removed until the end
of compilation.
--
Summary: redundant register move for sign extending
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: carrot at google dot com
GCC build triplet: i686-linux
GCC host triplet: i686-linux
GCC target triplet: arm-eabi
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43137
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/43137] redundant register move for sign extending
2010-02-22 9:39 [Bug target/43137] New: redundant register move for sign extending carrot at google dot com
@ 2010-02-22 14:33 ` ramana at gcc dot gnu dot org
2010-09-06 22:32 ` bernds at gcc dot gnu dot org
2010-09-07 11:17 ` bernds at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: ramana at gcc dot gnu dot org @ 2010-02-22 14:33 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from ramana at gcc dot gnu dot org 2010-02-22 14:32 -------
Confirmed.
--
ramana at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2010-02-22 14:32:54
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43137
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/43137] redundant register move for sign extending
2010-02-22 9:39 [Bug target/43137] New: redundant register move for sign extending carrot at google dot com
2010-02-22 14:33 ` [Bug target/43137] " ramana at gcc dot gnu dot org
@ 2010-09-06 22:32 ` bernds at gcc dot gnu dot org
2010-09-07 11:17 ` bernds at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: bernds at gcc dot gnu dot org @ 2010-09-06 22:32 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from bernds at gcc dot gnu dot org 2010-09-06 22:32 -------
Subject: Bug 43137
Author: bernds
Date: Mon Sep 6 22:32:26 2010
New Revision: 163935
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=163935
Log:
PR target/43137
* config/arm/iterators.md (qhs_zextenddi_cond, qhs_sextenddi_cond):
New define_mode_attrs.
* config/arm/arm.md (zero_extendsidi2, arm_zero_extendsidi2,
arm_exxtendsidi2, arm_extendsidi2): Delete patterns.
(zero_extend<mode>di2, extend<mode>di2 and related splits): New.
(thumb1_zero_extendhisi2): Remove code to handle LABEL_REFs.
Remove pool_range attribute.
(arm_zero_extendhisi2, arm_zero_extendhisi2_v6, arm_zero_extendqisi2,
arm_zero_extendqisi2_v6, thumb1_zero_extendqisi2_v6): Remove
pool_range and neg_pool_range attributes.
* config/arm/thumb2.md (thumb2_zero_extendsidi2,
thumb2_zero_extendhidi2, thumb2_zero_extendqidi2, thumb2_extendsidi2,
thumb2_extendhidi2, thumb2_extendqidi2): Delete.
PR target/43137
* gcc.target/arm/pr43137.c: New test.
Added:
trunk/gcc/testsuite/gcc.target/arm/pr43137.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/config/arm/arm.md
trunk/gcc/config/arm/iterators.md
trunk/gcc/config/arm/thumb2.md
trunk/gcc/testsuite/ChangeLog
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43137
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/43137] redundant register move for sign extending
2010-02-22 9:39 [Bug target/43137] New: redundant register move for sign extending carrot at google dot com
2010-02-22 14:33 ` [Bug target/43137] " ramana at gcc dot gnu dot org
2010-09-06 22:32 ` bernds at gcc dot gnu dot org
@ 2010-09-07 11:17 ` bernds at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: bernds at gcc dot gnu dot org @ 2010-09-07 11:17 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from bernds at gcc dot gnu dot org 2010-09-07 11:16 -------
Fixed.
--
bernds at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43137
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2010-09-07 11:17 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2010-02-22 9:39 [Bug target/43137] New: redundant register move for sign extending carrot at google dot com
2010-02-22 14:33 ` [Bug target/43137] " ramana at gcc dot gnu dot org
2010-09-06 22:32 ` bernds at gcc dot gnu dot org
2010-09-07 11:17 ` bernds at gcc dot gnu dot org
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