[Bug optimization/11708] New: Non-Optimal jump code generation.

[naveens at noida dot hcltech dot com]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11708

           Summary: Non-Optimal jump code generation.
           Product: gcc
           Version: 3.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: naveens at noida dot hcltech dot com
                CC: gcc-bugs at gcc dot gnu dot org,joern dot rennecke at
                    superh dot com
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: sh-unknown-elf

I am seeing some redundant jumps in code generated by GCC3.3 and 
the mainline. e.g. I see this assembly generated for 
one of my benchmark (sh-elf target, options: -ml -m4 -O2)

        ! basic block 1
        cmp/pl  r3
        mov.w   .L147,r1
        bt      .L3     <--- conditional branch C1
        mov     #0,r1
        bra     .L208   <--- Branch B1
        mov     r1,r3   <--- delay slot
.L3:
        ! basic block 2
        mov     r1,r3
.L208:
        mov.w   .L149,r2
        mov.w   .L150,r1
        cmp/gt  r1,r3
        bt      .L7

It seems it should be better generated as:

        ! basic block 1
        cmp/pl  r3
        mov.w   .L147,r1
        bt      .L208    <--- conditional branch C1
        mov     #0,r1
.L208:
       ! basic block 2
        mov     r1,r3
        mov.w   .L149,r2
        mov.w   .L150,r1
        cmp/gt  r1,r3
        bt      .L7

So, a jump(bra) instruction could be eliminated.