[Vectorizer] Add a new 'OperandValueKind' in TargetTransformInfo called

'OK_NonUniformConstValue' to identify operands which are constants but
not constant splats.

The cost model now allows returning 'OK_NonUniformConstValue'
for non splat operands that are instances of ConstantVector or
ConstantDataVector.

With this change, targets are now able to compute different costs
for instructions with non-uniform constant operands.
For example, On X86 the cost of a vector shift may vary depending on whether
the second operand is a uniform or non-uniform constant.

This patch applies the following changes:
 - The cost model computation now takes into account non-uniform constants;
 - The cost of vector shift instructions has been improved in
   X86TargetTransformInfo analysis pass;
 - BBVectorize, SLPVectorizer and LoopVectorize now know how to distinguish
   between non-uniform and uniform constant operands.

Added a new test to verify that the output of opt
'-cost-model -analyze' is valid in the following configurations: SSE2,
SSE4.1, AVX, AVX2.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201272 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrea Di Biagio
2014-02-12 23:43:47 +00:00
parent 8887371782
commit 029a76b0a2
7 changed files with 293 additions and 15 deletions

View File

@ -1044,12 +1044,26 @@ int BoUpSLP::getEntryCost(TreeEntry *E) {
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))) {
// If all operands are exactly the same ConstantInt then set the
// operand kind to OK_UniformConstantValue.
// If instead not all operands are constants, then set the operand kind
// to OK_AnyValue. If all operands are constants but not the same,
// then set the operand kind to OK_NonUniformConstantValue.
ConstantInt *CInt = NULL;
for (unsigned i = 0; i < VL.size(); ++i) {
const Instruction *I = cast<Instruction>(VL[i]);
if (!isa<ConstantInt>(I->getOperand(1))) {
Op2VK = TargetTransformInfo::OK_AnyValue;
break;
}
if (i == 0) {
CInt = cast<ConstantInt>(I->getOperand(1));
continue;
}
if (Op2VK == TargetTransformInfo::OK_UniformConstantValue &&
CInt != cast<ConstantInt>(I->getOperand(1)))
Op2VK = TargetTransformInfo::OK_NonUniformConstantValue;
}
ScalarCost =
VecTy->getNumElements() *