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[Bug target/49583] Reloading stack operands in the wrong order, so needs to insert fxch
- From: "ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sun, 3 Jul 2011 14:39:33 +0000
- Subject: [Bug target/49583] Reloading stack operands in the wrong order, so needs to insert fxch
- Auto-submitted: auto-generated
- References: <bug-49583-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49583
Uros Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |WONTFIX
--- Comment #2 from Uros Bizjak <ubizjak at gmail dot com> 2011-07-03 14:38:54 UTC ---
You should use powf instead of pow. Many of these moves are actually
double->float and float->double x87 conversion instructions.
You can use -ffast-math to avoid these conversions, but using powf on float
values is probably what you want.
Other moves are necessary to pass arguments to the function via stack and to
save live values from registers around the call.
Also, don't worry about fxch or two, these are extremely fast instructions.