This is my simple test proggie.
test1 is always ok, but test2 fails with -O3 (produces output 1 0 0 0 for
test2), but -O2 makes it behave.
I am on x86_64. -m32 has interesting effects:
-O3 -Wall -m32 -msse2 -march=i486 is ok (output 1 0 3 0, as expected)
-O3 -Wall -m32 -msse2 -march=i586 is broken (output 0 2 3 4)
-O3 -Wall -m32 -msse2 -march=athlon is broken (output 1 0 0 0)
Is this the aliasing issues I read about with 4.1 compiler? Is there an easy
work-around? In fact I need to pass data as aligned buffer, so I need test2
to behave correctly. :-(
Do you need anything else?
--
Summary: SSE2 generation bug with 4.1.2 and -O3
Product: gcc
Version: 4.1.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: prakash at punnoor dot de
GCC build triplet: x86_64-pc-linux-gnu
GCC host triplet: x86_64-pc-linux-gnu
GCC target triplet: x86_64-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31245
