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[Bug target/49600] Bad SSE2 int->float split in i386.md
- From: "hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Mon, 4 Jul 2011 13:42:02 +0000
- Subject: [Bug target/49600] Bad SSE2 int->float split in i386.md
- Auto-submitted: auto-generated
- References: <bug-49600-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49600
--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> 2011-07-04 13:42:00 UTC ---
Here is the testcase:
---
long int seedi;
long lo;
double ran() {
long hi;
long test;
hi = seedi / 127773L;
test = 16807L * lo - 2836L * hi;
if (test > 0) {
seedi = test;
}
return ( (float) seedi / 2147483647L);
}
---
It failed at -O3 -funroll-loops -msse2 -mfpmath=sse -ffast-math -mtune=XXX,
where XXX is a new x86 optimization we are working on.