[Bug lto/50494] gcc.dg/vect/vect-reduc-2char.c fails spuriously on ppc with -flto

[meissner at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50494

Michael Meissner <meissner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|target                      |lto

--- Comment #7 from Michael Meissner <meissner at gcc dot gnu.org> 2013-02-12 18:25:38 UTC ---
I am switching this to LTO instead of target, as it appears to be an LTO bug. 
Before LTO is run, the alignment of the .rodata section is 16 byte alignment
since the array used to initialize the auto array is copied with altivec
instructions.  After LTO, the alignment of the .rodata section is 4 bytes.  The
powerpc Altivec instructions ignore the bottom 4 bits of the address, and so
depending on what else is linked, the test will randomly fail or succeed.

I added attachments from compiling slp-perm-1.c with -O3 -mcpu=power6 -maltivec
-save-temps to give the asm files.