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| author | Alexey Volkov <avolkov.intel@gmail.com> | 2014-05-20 08:55:50 +0000 |
|---|---|---|
| committer | Alexey Volkov <avolkov.intel@gmail.com> | 2014-05-20 08:55:50 +0000 |
| commit | 6226de67210755a56d15dca7f1891fe7fddda3ca (patch) | |
| tree | 49e5679bb8c10b7fed4057f8b74aecbf2b818d01 /llvm/lib/Target/X86/X86.td | |
| parent | abdf44e7f38d392fed85692b2a31bf1578f3ee3b (diff) | |
| download | bcm5719-llvm-6226de67210755a56d15dca7f1891fe7fddda3ca.tar.gz bcm5719-llvm-6226de67210755a56d15dca7f1891fe7fddda3ca.zip | |
[X86] Tune LEA usage for Silvermont
According to Intel Software Optimization Manual on Silvermont in some cases LEA
is better to be replaced with ADD instructions:
"The rule of thumb for ADDs and LEAs is that it is justified to use LEA
with a valid index and/or displacement for non-destructive destination purposes
(especially useful for stack offset cases), or to use a SCALE.
Otherwise, ADD(s) are preferable."
Differential Revision: http://reviews.llvm.org/D3826
llvm-svn: 209198
Diffstat (limited to 'llvm/lib/Target/X86/X86.td')
| -rw-r--r-- | llvm/lib/Target/X86/X86.td | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86.td b/llvm/lib/Target/X86/X86.td index d01e4621616..6912b579b12 100644 --- a/llvm/lib/Target/X86/X86.td +++ b/llvm/lib/Target/X86/X86.td @@ -166,6 +166,8 @@ def FeatureCallRegIndirect : SubtargetFeature<"call-reg-indirect", "Call register indirect">; def FeatureLEAUsesAG : SubtargetFeature<"lea-uses-ag", "LEAUsesAG", "true", "LEA instruction needs inputs at AG stage">; +def FeatureSlowLEA : SubtargetFeature<"slow-lea", "SlowLEA", "true", + "LEA instruction with certain arguments is slow">; //===----------------------------------------------------------------------===// // X86 processors supported. @@ -226,6 +228,7 @@ def : ProcessorModel<"slm", SLMModel, [ProcIntelSLM, FeaturePCLMUL, FeatureAES, FeatureCallRegIndirect, FeaturePRFCHW, + FeatureSlowLEA, FeatureSlowBTMem, FeatureFastUAMem]>; // "Arrandale" along with corei3 and corei5 def : ProcessorModel<"corei7", SandyBridgeModel, |
