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authorArnold Schwaighofer <aschwaighofer@apple.com>2013-10-29 01:33:53 +0000
committerArnold Schwaighofer <aschwaighofer@apple.com>2013-10-29 01:33:53 +0000
commit7e8cebf22d170769b0bf0c2a69309faa0e36ac4c (patch)
tree64fe80f53f2b6d754f1f418ac3be688165263ee6 /lib/Transforms
parent4a6b3a9a770ec2064fb5975ff2d57419c1339a21 (diff)
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ARM cost model: Account for zero cost scalar SROA instructions
By vectorizing a series of srl, or, ... instructions we have obfuscated the intention so much that the backend does not know how to fold this code away. radar://15336950 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193573 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
-rw-r--r--lib/Transforms/Vectorize/SLPVectorizer.cpp21
1 files changed, 18 insertions, 3 deletions
diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 012521a..2797a21 100644
--- a/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -1013,9 +1013,24 @@ int BoUpSLP::getEntryCost(TreeEntry *E) {
TTI->getCmpSelInstrCost(Opcode, ScalarTy, Builder.getInt1Ty());
VecCost = TTI->getCmpSelInstrCost(Opcode, VecTy, MaskTy);
} else {
- ScalarCost = VecTy->getNumElements() *
- TTI->getArithmeticInstrCost(Opcode, ScalarTy);
- VecCost = TTI->getArithmeticInstrCost(Opcode, VecTy);
+ // Certain instructions can be cheaper to vectorize if they have a
+ // constant second vector operand.
+ TargetTransformInfo::OperandValueKind Op1VK =
+ TargetTransformInfo::OK_AnyValue;
+ TargetTransformInfo::OperandValueKind Op2VK =
+ TargetTransformInfo::OK_UniformConstantValue;
+
+ // Check whether all second operands are constant.
+ for (unsigned i = 0; i < VL.size(); ++i)
+ if (!isa<ConstantInt>(cast<Instruction>(VL[i])->getOperand(1))) {
+ Op2VK = TargetTransformInfo::OK_AnyValue;
+ break;
+ }
+
+ ScalarCost =
+ VecTy->getNumElements() *
+ TTI->getArithmeticInstrCost(Opcode, ScalarTy, Op1VK, Op2VK);
+ VecCost = TTI->getArithmeticInstrCost(Opcode, VecTy, Op1VK, Op2VK);
}
return VecCost - ScalarCost;
}