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Merge pull request #782 from dbabokin/mic_perf

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Fixing MIC performance issue (generate <2,2,2,2> as 2 in cpp).
This commit is contained in:
Dmitry Babokin
2014-04-17 21:24:40 +04:00
parent 94467fdb70 096546f888
commit fce4ba64a1
3 changed files with 39 additions and 14 deletions
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8
cbackend.cpp
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@@ -3286,11 +3286,17 @@ void CWriter::visitBinaryOperator(llvm::Instruction &I) {
if ((I.getOpcode() == llvm::Instruction::Shl || if ((I.getOpcode() == llvm::Instruction::Shl ||
I.getOpcode() == llvm::Instruction::LShr || I.getOpcode() == llvm::Instruction::LShr ||
I.getOpcode() == llvm::Instruction::AShr)) { I.getOpcode() == llvm::Instruction::AShr)) {
if (LLVMVectorValuesAllEqual(I.getOperand(1))) { llvm::Value *splat = NULL;
if (LLVMVectorValuesAllEqual(I.getOperand(1), &splat)) {
if (splat) {
// Avoid __extract_element(splat(value), 0), if possible.
writeOperand(splat);
} else {
Out << "__extract_element("; Out << "__extract_element(";
writeOperand(I.getOperand(1)); writeOperand(I.getOperand(1));
Out << ", 0) "; Out << ", 0) ";
} }
}
else else
writeOperand(I.getOperand(1)); writeOperand(I.getOperand(1));
} }

36
llvmutil.cpp
View File

@@ -818,7 +818,8 @@ LLVMExtractVectorInts(llvm::Value *v, int64_t ret[], int *nElts) {
static bool static bool
lVectorValuesAllEqual(llvm::Value *v, int vectorLength, lVectorValuesAllEqual(llvm::Value *v, int vectorLength,
std::vector<llvm::PHINode *> &seenPhis); std::vector<llvm::PHINode *> &seenPhis,
llvm::Value **splatValue = NULL);
/** This function checks to see if the given (scalar or vector) value is an /** This function checks to see if the given (scalar or vector) value is an
@@ -1068,20 +1069,37 @@ lVectorShiftRightAllEqual(llvm::Value *val, llvm::Value *shift,
static bool static bool
lVectorValuesAllEqual(llvm::Value *v, int vectorLength, lVectorValuesAllEqual(llvm::Value *v, int vectorLength,
std::vector<llvm::PHINode *> &seenPhis) { std::vector<llvm::PHINode *> &seenPhis,
llvm::Value **splatValue) {
if (vectorLength == 1) if (vectorLength == 1)
return true; return true;
if (llvm::isa<llvm::ConstantAggregateZero>(v)) if (llvm::isa<llvm::ConstantAggregateZero>(v)) {
if (splatValue) {
llvm::ConstantAggregateZero *caz =
llvm::dyn_cast<llvm::ConstantAggregateZero>(v);
*splatValue = caz->getSequentialElement();
}
return true; return true;
}
llvm::ConstantVector *cv = llvm::dyn_cast<llvm::ConstantVector>(v); llvm::ConstantVector *cv = llvm::dyn_cast<llvm::ConstantVector>(v);
if (cv != NULL) if (cv != NULL) {
return (cv->getSplatValue() != NULL); llvm::Value* splat = cv->getSplatValue();
if (splat != NULL && splatValue) {
*splatValue = splat;
}
return (splat != NULL);
}
llvm::ConstantDataVector *cdv = llvm::dyn_cast<llvm::ConstantDataVector>(v); llvm::ConstantDataVector *cdv = llvm::dyn_cast<llvm::ConstantDataVector>(v);
if (cdv != NULL) if (cdv != NULL) {
return (cdv->getSplatValue() != NULL); llvm::Value* splat = cdv->getSplatValue();
if (splat != NULL && splatValue) {
*splatValue = splat;
}
return (splat != NULL);
}
llvm::BinaryOperator *bop = llvm::dyn_cast<llvm::BinaryOperator>(v); llvm::BinaryOperator *bop = llvm::dyn_cast<llvm::BinaryOperator>(v);
if (bop != NULL) { if (bop != NULL) {
@@ -1178,14 +1196,14 @@ lVectorValuesAllEqual(llvm::Value *v, int vectorLength,
where the values are actually all equal. where the values are actually all equal.
*/ */
bool bool
LLVMVectorValuesAllEqual(llvm::Value *v) { LLVMVectorValuesAllEqual(llvm::Value *v, llvm::Value **splat) {
llvm::VectorType *vt = llvm::VectorType *vt =
llvm::dyn_cast<llvm::VectorType>(v->getType()); llvm::dyn_cast<llvm::VectorType>(v->getType());
Assert(vt != NULL); Assert(vt != NULL);
int vectorLength = vt->getNumElements(); int vectorLength = vt->getNumElements();
std::vector<llvm::PHINode *> seenPhis; std::vector<llvm::PHINode *> seenPhis;
bool equal = lVectorValuesAllEqual(v, vectorLength, seenPhis); bool equal = lVectorValuesAllEqual(v, vectorLength, seenPhis, splat);
Debug(SourcePos(), "LLVMVectorValuesAllEqual(%s) -> %s.", Debug(SourcePos(), "LLVMVectorValuesAllEqual(%s) -> %s.",
v->getName().str().c_str(), equal ? "true" : "false"); v->getName().str().c_str(), equal ? "true" : "false");

3
llvmutil.h
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@@ -228,7 +228,8 @@ extern llvm::Constant *LLVMMaskAllOff;
/** Tests to see if all of the elements of the vector in the 'v' parameter /** Tests to see if all of the elements of the vector in the 'v' parameter
are equal. Like lValuesAreEqual(), this is a conservative test and may are equal. Like lValuesAreEqual(), this is a conservative test and may
return false for arrays where the values are actually all equal. */ return false for arrays where the values are actually all equal. */
extern bool LLVMVectorValuesAllEqual(llvm::Value *v); extern bool LLVMVectorValuesAllEqual(llvm::Value *v,
llvm::Value **splat = NULL);
/** Given vector of integer-typed values, this function returns true if it /** Given vector of integer-typed values, this function returns true if it
can determine that the elements of the vector have a step of 'stride' can determine that the elements of the vector have a step of 'stride'