[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: unassigned@gcc.gnu.org
        ReportedBy: olegendo@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.