--- Comment #19 from ubizjak at gmail dot com 2008-09-06 16:18 ---
Exact duplicate of PR 17236. Mainline gcc (4.4.0 20080906, IRA) generates:
pushl %ebx
movl8(%esp), %eax
movl16(%esp), %edx
movl20(%esp), %ecx
movl12(%esp), %ebx
--- Comment #18 from rask at gcc dot gnu dot org 2007-12-19 14:15 ---
Created an attachment (id=14795)
-- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=14795action=view)
(u)mulsidi3 patch
This patch (in testing) improves the register allocation, removing the last
redundant movl
--- Comment #16 from rask at gcc dot gnu dot org 2007-11-23 20:43 ---
(In reply to comment #
I think the bug can be closed as fixed now.
I'm not so convinced. This part
leal(%ecx,%edx), %esi
movl%esi, %edx
movl4(%esp), %esi
should have been
--- Comment #17 from steven at gcc dot gnu dot org 2007-11-23 20:48 ---
And we're not going to keep every ra bug open. This just spoils bugzilla
search results.
*** This bug has been marked as a duplicate of 17236 ***
--
steven at gcc dot gnu dot org changed:
What
--- Comment #15 from ubizjak at gmail dot com 2007-11-23 07:43 ---
(In reply to comment #13)
I think the bug can be closed as fixed now.
The problem of redundant stores has been fixed, but the code is far from
optimal. As evident from PR 17236, icc generates:
movl
--- Comment #14 from steven at gcc dot gnu dot org 2007-11-23 07:36 ---
.
--
steven at gcc dot gnu dot org changed:
What|Removed |Added
Status|NEW
--- Comment #13 from ismail at pardus dot org dot tr 2007-11-23 06:02
---
Mainline now looks like :
[~] cat mul.s
.file mul.c
.text
.p2align 4,,15
.globl mul
.type mul, @function
mul:
subl$8, %esp
movl%ebx, (%esp)
--- Additional Comments From bruno at clisp dot org 2005-06-27 11:50
---
Indeed, the result is much better now, nearly optimal.
As you say, the only further optimization possible is that a better
register allocation could get rid of the
movl%edx, %esi
and
movl
--- Additional Comments From steven at gcc dot gnu dot org 2005-06-26
13:35 ---
Today's results (-O2 -m32 -march=i686 -mtune=i686 -fomit-frame-pointer):
.file t.c
.text
.p2align 4,,15
.globl mul
.type mul, @function
mul:
subl$12,
--- Additional Comments From bruno at clisp dot org 2004-10-11 11:55 ---
This result is even better: shorter than the previous ones, and there are
no useless moves between registers any more.
However, there are more useless moves from register to stack slot and back
from stack slot
--- Additional Comments From pinskia at gcc dot gnu dot org 2004-10-11 02:57
---
Here is the latest asm from the mainline:
mul:
subl$20, %esp
movl32(%esp), %ecx
movl24(%esp), %eax
movl%ebx, 8(%esp)
movl36(%esp), %ebx
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