This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] PR opt/10764: ICE using x86 logdf2

On May 14, 2003, Richard Henderson <> wrote:

> On Wed, May 14, 2003 at 01:47:42PM -0600, Roger Sayle wrote:
>> PR optimization/10764
>> * config/i386/ (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
Red Hat GCC Developer                 aoliva@{,}
CS PhD student at IC-Unicamp        oliva@{,}
Free Software Evangelist                Professional serial bug killer

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]