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Re: optimizations
- From: Andrew Pinski <pinskia at physics dot uc dot edu>
- To: Reza Roboubi <reza at linisoft dot com>
- Cc: Andrew Pinski <pinskia at physics dot uc dot edu>, gcc-help <gcc-help at gcc dot gnu dot org>, "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: Tue, 14 Jan 2003 21:09:29 -0800
- Subject: Re: optimizations
On Tuesday, Jan 14, 2003, at 16:49 US/Pacific, Reza Roboubi wrote:
Could you please also tell me if 3.3 and 3.4 remove the extra mov's in
and out
of %eax. Ideally, there should be no more than 4 instructions in the
critical
loop.
For some reason it is not (even with -fnew-ra), but on PPC there is no
extra load/store.
Thanks,
Andrew Pinski
PS here is the asm for the loop of i[3-6]686, pentium4:
.L2:
movl -4(%ebp), %eax <== still does the store
cmpl $16, %eax
je .L7
incl %eax
movl %eax, -4(%ebp) <== and load
jmp .L2
.L7:
I do not have access to the machine with 3.{3,4} on PPC right now.