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| author | Hal Finkel <hfinkel@anl.gov> | 2015-02-12 01:02:52 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2015-02-12 01:02:52 +0000 |
| commit | 7a0516ea668b3ee511b3e5a4f16438189d1a78ae (patch) | |
| tree | c306ebb3f71f63a32633d3e38a331dc064d012fb /llvm/lib/Target | |
| parent | 1225816a2d24787dbd845fdfe31e7f23fd8ef8fb (diff) | |
| download | bcm5719-llvm-7a0516ea668b3ee511b3e5a4f16438189d1a78ae.tar.gz bcm5719-llvm-7a0516ea668b3ee511b3e5a4f16438189d1a78ae.zip | |
[PowerPC] Mark jumps as expensive (using using CR bits)
On PowerPC, which has a full set of logical operations on (its multiple sets
of) condition-register bits, it is not profitable to break of complex
conditions feeding a jump into multiple jumps. We can turn off this feature of
CGP/SDAGBuilder by marking jumps as "expensive".
P7 test-suite speedups (no regressions):
MultiSource/Benchmarks/FreeBench/pcompress2/pcompress2
-0.626647% +/- 0.323583%
MultiSource/Benchmarks/Olden/power/power
-18.2821% +/- 8.06481%
llvm-svn: 228895
Diffstat (limited to 'llvm/lib/Target')
| -rw-r--r-- | llvm/lib/Target/PowerPC/PPCISelLowering.cpp | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp index 7ecfac66b49..15a0818c816 100644 --- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp +++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp @@ -687,8 +687,10 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM, // With 32 condition bits, we don't need to sink (and duplicate) compares // aggressively in CodeGenPrep. - if (Subtarget.useCRBits()) + if (Subtarget.useCRBits()) { setHasMultipleConditionRegisters(); + setJumpIsExpensive(); + } setMinFunctionAlignment(2); if (Subtarget.isDarwin()) |
