[Bug c/53071] New: Wrong instruction replacement when compiling for xop

[agner at agner dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53071

             Bug #: 53071
           Summary: Wrong instruction replacement when compiling for xop
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: agner@agner.org


Created attachment 27216
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27216
source code and asm output

An intrinsic vector multiply function is replaced by xop instructions when the
attached file is compiled with -mxop. Perhaps the compiler is trying to combine
a shift instruction and a multiply instruction into a single xop instruction,
but it ends up with something wrong.

This is perhaps related to bugs # 52908 and 52910.