Fix hasOneUse check to only consider shuffles

Author: lukel97

llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp

@@ -1424,8 +1424,11 @@ InstCombinerImpl::foldShuffledIntrinsicOperands(IntrinsicInst *II) {
       !match(NonConstArg, m_Shuffle(m_Value(X), m_Poison(), m_Mask(Mask))))
     return nullptr;
 
-  // At least 1 operand must have 1 use because we are creating 2 instructions.
-  if (none_of(II->args(), [](Value *V) { return V->hasOneUse(); }))
+  // At least 1 operand must be a shuffle with 1 use because we are creating 2
+  // instructions.
+  if (none_of(II->args(), [](Value *V) {
+        return isa<ShuffleVectorInst>(V) && V->hasOneUse();
+      }))
     return nullptr;
 
   // See if all arguments are shuffled with the same mask.

llvm/test/Transforms/InstCombine/minmax-intrinsics.ll

@@ -2511,6 +2511,21 @@ define <3 x i8> @smin_unary_shuffle_ops_uses(<3 x i8> %x, <3 x i8> %y) {
   ret <3 x i8> %r
 }
 
+; negative test - too many uses
+
+define <3 x i8> @smin_unary_shuffle_ops_uses_const(<3 x i8> %x, <3 x i8> %y) {
+; CHECK-LABEL: @smin_unary_shuffle_ops_uses_const(
+; CHECK-NEXT:    [[SX:%.*]] = shufflevector <3 x i8> [[X:%.*]], <3 x i8> poison, <3 x i32> <i32 1, i32 0, i32 2>
+; CHECK-NEXT:    call void @use_vec(<3 x i8> [[SX]])
+; CHECK-NEXT:    [[R:%.*]] = call <3 x i8> @llvm.smin.v3i8(<3 x i8> [[SX]], <3 x i8> <i8 1, i8 2, i8 3>)
+; CHECK-NEXT:    ret <3 x i8> [[R]]
+;
+  %sx = shufflevector <3 x i8> %x, <3 x i8> poison, <3 x i32> <i32 1, i32 0, i32 2>
+  call void @use_vec(<3 x i8> %sx)
+  %r = call <3 x i8> @llvm.smin.v3i8(<3 x i8> %sx, <3 x i8> <i8 1, i8 2, i8 3>)
+  ret <3 x i8> %r
+}
+
 ; This would assert/crash because we tried to zext to i1.
 
 @g = external dso_local global i32, align 4

llvm/test/Transforms/InstCombine/powi.ll

@@ -582,8 +582,7 @@ define <3 x float> @powi_unary_shuffle_ops_use(<3 x float> %x, i32 %power, ptr %
 ; CHECK-LABEL: @powi_unary_shuffle_ops_use(
 ; CHECK-NEXT:    [[SX:%.*]] = shufflevector <3 x float> [[X:%.*]], <3 x float> poison, <3 x i32> <i32 1, i32 0, i32 2>
 ; CHECK-NEXT:    store <3 x float> [[SX]], ptr [[P:%.*]], align 16
-; CHECK-NEXT:    [[TMP1:%.*]] = call <3 x float> @llvm.powi.v3f32.i32(<3 x float> [[X]], i32 [[POWER:%.*]])
-; CHECK-NEXT:    [[R:%.*]] = shufflevector <3 x float> [[TMP1]], <3 x float> poison, <3 x i32> <i32 1, i32 0, i32 2>
+; CHECK-NEXT:    [[R:%.*]] = call <3 x float> @llvm.powi.v3f32.i32(<3 x float> [[SX]], i32 [[POWER:%.*]])
 ; CHECK-NEXT:    ret <3 x float> [[R]]
 ;
   %sx = shufflevector <3 x float> %x, <3 x float> poison, <3 x i32> <i32 1, i32 0, i32 2>