[Bug target/68837] New: PowerPC switch statement performance

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68837

            Bug ID: 68837
           Summary: PowerPC switch statement performance
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dje at gcc dot gnu.org
  Target Milestone: ---
            Target: powerpc*-*-*

Improve performance of switch statements:

1) Heuristics for decision tree vs tablejump

2) Avoid sign extended lwa for offset