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[Bug target/19150] New: [3.3/3.4/4.0 Regression] suboptimal fp division with -ffast-math
- From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 24 Dec 2004 19:23:37 -0000
- Subject: [Bug target/19150] New: [3.3/3.4/4.0 Regression] suboptimal fp division with -ffast-math
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
Take the following code:
double test (double x) {
return 1.1 / x;
}
With -O2 -ffast-math with 2.95.3, we get:
fldl .LC0
pushl %ebp
movl %esp, %ebp
fdivl 8(%ebp)
popl %ebp
ret
But with 3.3, and 4.0:
pushl %ebp
movl %esp, %ebp
fld1
fdivl 8(%ebp)
fmull .LC1
leave
ret
--
Summary: [3.3/3.4/4.0 Regression] suboptimal fp division with -
ffast-math
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P2
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: pinskia at gcc dot gnu dot org
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19150