[CostModel] Add SK_ExtractSubvector handling to getInstructionThroughput (PR39368)
Add ShuffleVectorInst::isExtractSubvectorMask helper to match shuffle masks.
llvm-svn: 346510
diff --git a/llvm/lib/IR/Instructions.cpp b/llvm/lib/IR/Instructions.cpp
index 7d4b6df..66fdb46 100644
--- a/llvm/lib/IR/Instructions.cpp
+++ b/llvm/lib/IR/Instructions.cpp
@@ -1798,6 +1798,35 @@
return true;
}
+bool ShuffleVectorInst::isExtractSubvectorMask(ArrayRef<int> Mask,
+ int NumSrcElts, int &Index) {
+ // Must extract from a single source.
+ if (!isSingleSourceMaskImpl(Mask, NumSrcElts))
+ return false;
+
+ // Must be smaller (else this is an Identity shuffle).
+ if (NumSrcElts <= Mask.size())
+ return false;
+
+ // Find start of extraction, accounting that we may start with an UNDEF.
+ int SubIndex = -1;
+ for (int i = 0, e = Mask.size(); i != e; ++i) {
+ int M = Mask[i];
+ if (M < 0)
+ continue;
+ int Offset = (M % NumSrcElts) - i;
+ if (0 <= SubIndex && SubIndex != Offset)
+ return false;
+ SubIndex = Offset;
+ }
+
+ if (0 <= SubIndex) {
+ Index = SubIndex;
+ return true;
+ }
+ return false;
+}
+
bool ShuffleVectorInst::isIdentityWithPadding() const {
int NumOpElts = Op<0>()->getType()->getVectorNumElements();
int NumMaskElts = getType()->getVectorNumElements();