This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH, rs6000] PR target/57150, do not use VSX instructions for long double caller saves
- From: David Edelsohn <dje dot gcc at gmail dot com>
- To: "Joseph S. Myers" <joseph at codesourcery dot com>
- Cc: Michael Meissner <meissner at linux dot vnet dot ibm dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Tue, 9 Jul 2013 18:00:01 -0400
- Subject: Re: [PATCH, rs6000] PR target/57150, do not use VSX instructions for long double caller saves
- References: <20130503230523 dot GA15350 at ibm-tiger dot the-meissners dot org> <Pine dot LNX dot 4 dot 64 dot 1307031608490 dot 18167 at digraph dot polyomino dot org dot uk>
On Wed, Jul 3, 2013 at 12:09 PM, Joseph S. Myers
<joseph@codesourcery.com> wrote:
> On Fri, 3 May 2013, Michael Meissner wrote:
>
>> 2013-05-03 Michael Meissner <meissner@linux.vnet.ibm.com>
>>
>> PR target/57150
>> * config/rs6000/rs6000.h (HARD_REGNO_CALLER_SAVE_MODE): Use DFmode
>> to save TFmode registers and DImode to save TImode registers for
>> caller save operations.
>> (HARD_REGNO_CALL_PART_CLOBBERED): TFmode and TDmode do not need to
>> mark being partially clobbered since they only use the first
>> double word.
>>
>> * config/rs6000/rs6000.c (rs6000_init_hard_regno_mode_ok): TFmode
>> and TDmode only use the upper 64-bits of each VSX register.
>
> That change has the effect that reload thinks TFmode (and no doubt
> TDmode) only takes two registers even when in general registers,
> causing a segfault in glibc's test-ldouble built for soft float.
>
> I'm testing this patch (this diff is against 4.8 branch) to fix this;
> at least, it fixes the glibc testing issue. Since the original patch
> went on 4.7 and 4.8 branches as well as trunk, I propose this patch
> for the branches as well as trunk. You may wish to test it in your
> original VSX configuration.
>
> 2013-07-03 Joseph Myers <joseph@codesourcery.com>
>
> * config/rs6000/rs6000.c (rs6000_init_hard_regno_mode_ok): Only
> adjust register size for TDmode and TFmode for VSX registers.
I thought that you already were applying it, not asking for approval.
The patch is okay.
TFmode and TImode on VSX need some TLC.
- David