Use unary CreateShuffleVector if possible
As mentioned in D93793, there are quite a few places where unary `IRBuilder::CreateShuffleVector(X, Mask)` can be used
instead of `IRBuilder::CreateShuffleVector(X, Undef, Mask)`.
Let's update them.
Actually, it would have been more natural if the patches were made in this order:
(1) let them use unary CreateShuffleVector first
(2) update IRBuilder::CreateShuffleVector to use poison as a placeholder value (D93793)
The order is swapped, but in terms of correctness it is still fine.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D93923
diff --git a/llvm/lib/Analysis/VectorUtils.cpp b/llvm/lib/Analysis/VectorUtils.cpp
index 9072697..1de17aa 100644
--- a/llvm/lib/Analysis/VectorUtils.cpp
+++ b/llvm/lib/Analysis/VectorUtils.cpp
@@ -829,8 +829,7 @@
if (NumElts1 > NumElts2) {
// Extend with UNDEFs.
V2 = Builder.CreateShuffleVector(
- V2, UndefValue::get(VecTy2),
- createSequentialMask(0, NumElts2, NumElts1 - NumElts2));
+ V2, createSequentialMask(0, NumElts2, NumElts1 - NumElts2));
}
return Builder.CreateShuffleVector(
