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| author | Hal Finkel <hfinkel@anl.gov> | 2013-11-01 10:58:22 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2013-11-01 10:58:22 +0000 |
| commit | e14fb073574dcb74de05bdeedbfb3fcffbfa1bf6 (patch) | |
| tree | 10a5655b64112d33790b371fde46bb0be6693316 /LICENSE.TXT | |
| parent | 0097e155025767c11790912dcf780f82dffaffb1 (diff) | |
| download | llvm-e14fb073574dcb74de05bdeedbfb3fcffbfa1bf6.tar.gz llvm-e14fb073574dcb74de05bdeedbfb3fcffbfa1bf6.tar.bz2 llvm-e14fb073574dcb74de05bdeedbfb3fcffbfa1bf6.tar.xz | |
Consider (x == -1) unlikely in BranchProbabilityInfo
This adds another heuristic to BPI, similar to the existing heuristic that
considers (x == 0) unlikely to be true. As suggested in the PACT'98 paper by
Deitrich, Cheng, and Hwu, -1 is often used to indicate an invalid index, and
equality comparisons with -1 are also unlikely to succeed. Local
experimentation supports this hypothesis: This yields a 1-2% speedup in the
test-suite sqlite benchmark on the PPC A2 core, with no significant
regressions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193855 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'LICENSE.TXT')
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