public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug target/46631] New: Change operands order so we can use 16bit and instead of 32bit in thumb2
@ 2010-11-24 2:57 carrot at google dot com
2010-11-24 12:09 ` [Bug target/46631] " rguenth at gcc dot gnu.org
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: carrot at google dot com @ 2010-11-24 2:57 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46631
Summary: Change operands order so we can use 16bit and instead
of 32bit in thumb2
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: carrot@google.com
CC: carrot@google.com
Compile the following code with options -march=armv7-a -mthumb -Os
struct S {
int bi_buf;
int bi_valid;
};
int tz (struct S* p, int bits, int value)
{
if (p == 0) return 1;
p->bi_valid = bits;
p->bi_buf = value & ((1 << bits) - 1);
return 0;
}
GCC 4.6 generates:
00000000 <tz>:
0: 2301 movs r3, #1
2: b138 cbz r0, 14 <tz+0x14>
4: 408b lsls r3, r1
6: 6041 str r1, [r0, #4]
8: 3b01 subs r3, #1
a: ea03 0202 and.w r2, r3, r2 // A
e: 6002 str r2, [r0, #0]
10: 2000 movs r0, #0
12: 4770 bx lr
14: 4618 mov r0, r3
16: 4770 bx lr
Notice instruction A is 32 bit, if we change it to
and r2, r2, r3
then we can encode it as 16bit.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/46631] Change operands order so we can use 16bit and instead of 32bit in thumb2
2010-11-24 2:57 [Bug target/46631] New: Change operands order so we can use 16bit and instead of 32bit in thumb2 carrot at google dot com
@ 2010-11-24 12:09 ` rguenth at gcc dot gnu.org
2010-12-03 9:55 ` ramana at gcc dot gnu.org
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: rguenth at gcc dot gnu.org @ 2010-11-24 12:09 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46631
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/46631] Change operands order so we can use 16bit and instead of 32bit in thumb2
2010-11-24 2:57 [Bug target/46631] New: Change operands order so we can use 16bit and instead of 32bit in thumb2 carrot at google dot com
2010-11-24 12:09 ` [Bug target/46631] " rguenth at gcc dot gnu.org
@ 2010-12-03 9:55 ` ramana at gcc dot gnu.org
2010-12-08 16:38 ` rearnsha at gcc dot gnu.org
2010-12-08 16:49 ` rearnsha at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: ramana at gcc dot gnu.org @ 2010-12-03 9:55 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46631
Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Status|UNCONFIRMED |NEW
Last reconfirmed| |2010.12.03 09:55:09
CC| |ramana at gcc dot gnu.org
Ever Confirmed|0 |1
--- Comment #1 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> 2010-12-03 09:55:09 UTC ---
Confirmed.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/46631] Change operands order so we can use 16bit and instead of 32bit in thumb2
2010-11-24 2:57 [Bug target/46631] New: Change operands order so we can use 16bit and instead of 32bit in thumb2 carrot at google dot com
2010-11-24 12:09 ` [Bug target/46631] " rguenth at gcc dot gnu.org
2010-12-03 9:55 ` ramana at gcc dot gnu.org
@ 2010-12-08 16:38 ` rearnsha at gcc dot gnu.org
2010-12-08 16:49 ` rearnsha at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: rearnsha at gcc dot gnu.org @ 2010-12-08 16:38 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46631
--- Comment #2 from Richard Earnshaw <rearnsha at gcc dot gnu.org> 2010-12-08 16:38:14 UTC ---
Author: rearnsha
Date: Wed Dec 8 16:38:10 2010
New Revision: 167595
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=167595
Log:
2010-12-08 Richard Earnshaw <rearnsha@arm.com>
PR target/46631
* arm.c (thumb2_reorg): Also try to reduce <commutative_op> Rd, Rn, Rd
into a 16-bit instruction.
2010-12-08 Wei Guozhi <carrot@google.com>
PR target/46631
* gcc.target/arm/pr46631: New testcase.
Added:
trunk/gcc/testsuite/gcc.target/arm/pr46631.c (with props)
Modified:
trunk/gcc/ChangeLog
trunk/gcc/config/arm/arm.c
trunk/gcc/testsuite/ChangeLog
Propchange: trunk/gcc/testsuite/gcc.target/arm/pr46631.c
('svn:eol-style' added)
Propchange: trunk/gcc/testsuite/gcc.target/arm/pr46631.c
('svn:keywords' added)
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/46631] Change operands order so we can use 16bit and instead of 32bit in thumb2
2010-11-24 2:57 [Bug target/46631] New: Change operands order so we can use 16bit and instead of 32bit in thumb2 carrot at google dot com
` (2 preceding siblings ...)
2010-12-08 16:38 ` rearnsha at gcc dot gnu.org
@ 2010-12-08 16:49 ` rearnsha at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: rearnsha at gcc dot gnu.org @ 2010-12-08 16:49 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46631
Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
Target Milestone|--- |4.6.0
--- Comment #3 from Richard Earnshaw <rearnsha at gcc dot gnu.org> 2010-12-08 16:48:46 UTC ---
Fixed in trunk
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2010-12-08 16:49 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2010-11-24 2:57 [Bug target/46631] New: Change operands order so we can use 16bit and instead of 32bit in thumb2 carrot at google dot com
2010-11-24 12:09 ` [Bug target/46631] " rguenth at gcc dot gnu.org
2010-12-03 9:55 ` ramana at gcc dot gnu.org
2010-12-08 16:38 ` rearnsha at gcc dot gnu.org
2010-12-08 16:49 ` rearnsha at gcc dot gnu.org
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).