[Bug target/36224] New: vec_widen_smult_{hi,lo}_v4si generates pmuludq instruction

[gnu at the-meissners dot org]

The vec_widen_smult_{hi,lo}_v4si functions are incorrect, in that they generate
the pmuludq instruction, which does a 32x32->64 unsigned multiply.  For
example, multiplying -13 * 15 = gives 64424509245 with the current code, when
it should give -195.

The sse5 instructions pmacsdqh and pmacsdql could do this instruction, but not
anything in the standard sse2 set.


-- 
           Summary: vec_widen_smult_{hi,lo}_v4si generates pmuludq
                    instruction
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: gnu at the-meissners dot org
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36224