InstCombine: Don't try to reorder shuffles where the mask is a ConstantExpr.

We can't analyze the individual values of a vector expression. PR20114.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211581 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 12 insertions, 1 deletions

diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp
index 88d7a0d59e..88d461e1b2 100644
--- a/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1227,7 +1227,9 @@ Value *InstCombiner::SimplifyVectorOp(BinaryOperator &Inst) {
   if (isa<ShuffleVectorInst>(RHS)) Shuffle = cast<ShuffleVectorInst>(RHS);
   if (isa<Constant>(LHS)) C1 = cast<Constant>(LHS);
   if (isa<Constant>(RHS)) C1 = cast<Constant>(RHS);
-  if (Shuffle && C1 && isa<UndefValue>(Shuffle->getOperand(1)) &&
+  if (Shuffle && C1 &&
+      (isa<ConstantVector>(C1) || isa<ConstantDataVector>(C1)) &&
+      isa<UndefValue>(Shuffle->getOperand(1)) &&
       Shuffle->getType() == Shuffle->getOperand(0)->getType()) {
     SmallVector<int, 16> ShMask = Shuffle->getShuffleMask();
     // Find constant C2 that has property:
diff --git a/test/Transforms/InstCombine/vec_shuffle.ll b/test/Transforms/InstCombine/vec_shuffle.ll
index fc0f8bd0aa..eb4e9d6f8c 100644
--- a/test/Transforms/InstCombine/vec_shuffle.ll
+++ b/test/Transforms/InstCombine/vec_shuffle.ll
@@ -405,3 +405,12 @@ define i32 @pr19737(<4 x i32> %in0) {
   %rv = extractelement <4 x i32> %and.i, i32 0
   ret i32 %rv
 }
+
+define <4 x i32> @pr20114(<4 x i32> %__mask) {
+; CHECK-LABEL: @pr20114
+; CHECK: shufflevector
+; CHECK: and
+  %mask01.i = shufflevector <4 x i32> %__mask, <4 x i32> undef, <4 x i32> <i32 0, i32 0, i32 1, i32 1>
+  %masked_new.i.i.i = and <4 x i32> bitcast (<2 x i64> <i64 ptrtoint (<4 x i32> (<4 x i32>)* @pr20114 to i64), i64 ptrtoint (<4 x i32> (<4 x i32>)* @pr20114 to i64)> to <4 x i32>), %mask01.i
+  ret <4 x i32> %masked_new.i.i.i
+}