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Re: [PATCH] PR opt/10764: ICE using x86 logdf2
- From: Alexandre Oliva <aoliva at redhat dot com>
- To: Richard Henderson <rth at redhat dot com>
- Cc: Roger Sayle <roger at www dot eyesopen dot com>, gcc-patches at gcc dot gnu dot org, Toon Moene <toon at moene dot indiv dot nluug dot nl>
- Date: 14 May 2003 22:30:53 -0300
- Subject: Re: [PATCH] PR opt/10764: ICE using x86 logdf2
- Organization: GCC Team, Red Hat
- References: <Pine.LNX.4.44.0305141326520.6537-100000@www.eyesopen.com><20030514204839.GA9350@redhat.com>
On May 14, 2003, Richard Henderson <rth@redhat.com> wrote:
> On Wed, May 14, 2003 at 01:47:42PM -0600, Roger Sayle wrote:
>> PR optimization/10764
>> * config/i386/i386.md (atan2df3, atan2sf3, atan2xf3, atan2tf3):
>> Add an explicit clobber to show that UNSPEC_FPATAN clobbers st(1).
>> (*fyl2x_sfxf3, *fyl2x_dfxf3, *fyl2x_xf3, *fyl2x_tfxf3): Likewise,
>> add an explicit clobber to show that UNSPEC_FYL2X clobbers st(1).
>> (logsf2, logdf2, logxf2, logtf2): Update expander patterns to match
>> the corresponding *fyl2x_?fxf3 instructions.
>>
>> * gcc.dg/builtins-15.c: New test case.
> Ok.
I think I learned a long time ago that a CLOBBER of an input operand
in PARALLEL with an input operand was not quite the right way to do
it. I don't recall whether it was for efficiency or correctness
(clobber in parallel with input might be considered confusing by some
passes). Wouldn't it be better to just mark the match_operand as
in/out with + instead?
--
Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer aoliva@{redhat.com, gcc.gnu.org}
CS PhD student at IC-Unicamp oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist Professional serial bug killer