[Bug rtl-optimization/20969] New: unrolling does not take target register pressure into account.

[amylaar at gcc dot gnu dot org]

When a loop contains multiple labels inside, unrolling it increases the
target register pressure on targets that need target registers to do
branches.  This gets quickly so bad that the unrolled loop performs worse
than a non-unrolled loop, because of the number of target register spills.

-- 
           Summary: unrolling does not take target register pressure into
                    account.
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: amylaar at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: sh64-elf
OtherBugsDependingO 17652
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20969