RE: rfa (x86): 387<=>sse moves

["Linthicum, Tony" <tony dot linthicum at amd dot com>]

Hello All,

I applied the recent patches to the 7/23 snapshot, and am still seeing
some 387 to sse moves.  In particular, in SpecFP's 177.mesa (matrix.c),
I'm seeing fld1's feeding moves to sse registers.  

Compiled via: gcc -O3 -march=k8 -mfpmath=sse matrix.c

Thanks.

Tony


-----Original Message-----
From: gcc-owner@gcc.gnu.org [mailto:gcc-owner@gcc.gnu.org] On Behalf Of
Dale Johannesen
Sent: Monday, August 01, 2005 1:53 PM
To: ubizjak@gmail.com
Cc: paolo.bonzini@lu.unisi.ch; gcc@gcc.gnu.org
Subject: Re: rfa (x86): 387<=>sse moves


On Jul 31, 2005, at 9:51 AM, Uros Bizjak wrote:

> Hello!
>
>> With -march=pentium4 -mfpmath=sse -O2, we get an extra move for code 
>> like
>>
>>    double d = atof(foo);
>>    int i = d;
>>
>>
>>        call    atof
>>        fstpl   -8(%ebp)
>>        movsd   -8(%ebp), %xmm0
>>        cvttsd2si       %xmm0, %eax
>>
>>
>> (This is Linux, Darwin is similar.) I think the difficulty is that
for
>
> This problem is similar to the problem, described in PR target/19398. 
> There is another testcase and a small analysis in the PR that might 
> help with this problem.

Thanks, that does seem relevant.  The patches so far don't fix this 
case;
I've commented the PR explaining why.