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[Bug target/19653] x87 reg allocated for constants for -mfpmath=sse
- From: "bonzini at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 13 Jul 2005 11:51:16 -0000
- Subject: [Bug target/19653] x87 reg allocated for constants for -mfpmath=sse
- References: <20050127083359.19653.uros@kss-loka.si>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From bonzini at gcc dot gnu dot org 2005-07-13 11:51 -------
Smaller testcase from PR22453:
extern double f(double, double);
void g (double x)
{
double z, y;
z = 0.0;
y = 1.0 - x;
again:
z = y - z;
f(z, 1.0);
if (z == 0.0)
goto again;
}
has a fld1 instruction when compiled with "-mfpmath=sse -msse2 -msseregparm
-mtune=pentiumpro -O2".
This instruction is caused by a reload into a FLOAT_REGS register, and moving
the value to a SSE register needs secondary memory.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19653