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| author | Tom Stellard <thomas.stellard@amd.com> | 2013-07-27 00:01:07 +0000 |
|---|---|---|
| committer | Tom Stellard <thomas.stellard@amd.com> | 2013-07-27 00:01:07 +0000 |
| commit | 57e6b2d1f3de0bf459e96f7038e692d624f7e580 (patch) | |
| tree | 42204d51445bcb178a24fa07fe9da2d1d22818ff /include/llvm/Analysis/TargetTransformInfo.h | |
| parent | 018696db4587dc6a0d8081d0627543f5c08b6c97 (diff) | |
| download | external_llvm-57e6b2d1f3de0bf459e96f7038e692d624f7e580.tar.gz external_llvm-57e6b2d1f3de0bf459e96f7038e692d624f7e580.tar.bz2 external_llvm-57e6b2d1f3de0bf459e96f7038e692d624f7e580.zip | |
SimplifyCFG: Use parallel-and and parallel-or mode to consolidate branch conditions
Merge consecutive if-regions if they contain identical statements.
Both transformations reduce number of branches. The transformation
is guarded by a target-hook, and is currently enabled only for +R600,
but the correctness has been tested on X86 target using a variety of
CPU benchmarks.
Patch by: Mei Ye
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187278 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include/llvm/Analysis/TargetTransformInfo.h')
| -rw-r--r-- | include/llvm/Analysis/TargetTransformInfo.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/llvm/Analysis/TargetTransformInfo.h b/include/llvm/Analysis/TargetTransformInfo.h index b8a44b5b66..21a3a12ebb 100644 --- a/include/llvm/Analysis/TargetTransformInfo.h +++ b/include/llvm/Analysis/TargetTransformInfo.h @@ -171,6 +171,12 @@ public: /// comments for a detailed explanation of the cost values. virtual unsigned getUserCost(const User *U) const; + /// \brief hasBranchDivergence - Return true if branch divergence exists. + /// Branch divergence has a significantly negative impact on GPU performance + /// when threads in the same wavefront take different paths due to conditional + /// branches. + virtual bool hasBranchDivergence() const; + /// \brief Test whether calls to a function lower to actual program function /// calls. /// |