[InstCombine] fix crash while trying to narrow a binop of shuffles (PR40734)
https://bugs.llvm.org/show_bug.cgi?id=40734
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354144 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp
index 8cbf57a..723bb4c 100644
--- a/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1375,7 +1375,8 @@
if (match(LHS, m_ShuffleVector(m_Value(L0), m_Value(L1), m_Constant(Mask))) &&
match(RHS, m_ShuffleVector(m_Value(R0), m_Value(R1), m_Specific(Mask))) &&
LHS->hasOneUse() && RHS->hasOneUse() &&
- cast<ShuffleVectorInst>(LHS)->isConcat()) {
+ cast<ShuffleVectorInst>(LHS)->isConcat() &&
+ cast<ShuffleVectorInst>(RHS)->isConcat()) {
// This transform does not have the speculative execution constraint as
// below because the shuffle is a concatenation. The new binops are
// operating on exactly the same elements as the existing binop.
diff --git a/test/Transforms/InstCombine/vec_shuffle.ll b/test/Transforms/InstCombine/vec_shuffle.ll
index aae337d..354256a 100644
--- a/test/Transforms/InstCombine/vec_shuffle.ll
+++ b/test/Transforms/InstCombine/vec_shuffle.ll
@@ -1125,3 +1125,18 @@
ret <2 x float> %r
}
+; Equivalent shuffle masks, but only one is a narrowing op.
+
+define <2 x i1> @PR40734(<1 x i1> %x, <4 x i1> %y) {
+; CHECK-LABEL: @PR40734(
+; CHECK-NEXT: [[WIDEN:%.*]] = shufflevector <1 x i1> zeroinitializer, <1 x i1> [[X:%.*]], <2 x i32> <i32 0, i32 1>
+; CHECK-NEXT: [[NARROW:%.*]] = shufflevector <4 x i1> [[Y:%.*]], <4 x i1> undef, <2 x i32> <i32 0, i32 1>
+; CHECK-NEXT: [[R:%.*]] = and <2 x i1> [[WIDEN]], [[NARROW]]
+; CHECK-NEXT: ret <2 x i1> [[R]]
+;
+ %widen = shufflevector <1 x i1> zeroinitializer, <1 x i1> %x, <2 x i32> <i32 0, i32 1>
+ %narrow = shufflevector <4 x i1> %y, <4 x i1> undef, <2 x i32> <i32 0, i32 1>
+ %r = and <2 x i1> %widen, %narrow
+ ret <2 x i1> %r
+}
+
