[Bug target/54830] New: [SH] Unnecessary exts.w before extu.b

[olegendo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54830



             Bug #: 54830

           Summary: [SH] Unnecessary exts.w before extu.b

    Classification: Unclassified

           Product: gcc

           Version: 4.8.0

            Status: UNCONFIRMED

          Severity: enhancement

          Priority: P3

         Component: target

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: olege...@gcc.gnu.org

            Target: sh*-*-*





While working on another issue, I've spotted the following sequence



        swap.w    r11,r1

        exts.w    r1,r1

        extu.b    r1,r2

        mov.l    @(16,r12),r1



in CSiBE/jpeg-6b/jcphuff.c, function _emit_eobrun, when compiling with

-m4-single -ml -O2 -mpretend-cmove.



I will try to investigate that later.