InstCombine: Disable umul.with.overflow recognition for vectors.

It doesn't make a lot on most targets and the code isn't ready for it. PR20113.

llvm-svn: 211583

2 files changed, 16 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 639d8319e0d..f204eeb548c 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -2042,9 +2042,13 @@ static Instruction *ProcessUAddIdiom(Instruction &I, Value *OrigAddV,
 ///          replacement required.
 static Instruction *ProcessUMulZExtIdiom(ICmpInst &I, Value *MulVal,
                                          Value *OtherVal, InstCombiner &IC) {
+  // Don't bother doing this transformation for pointers, don't do it for
+  // vectors.
+  if (!isa<IntegerType>(MulVal->getType()))
+    return nullptr;
+
   assert(I.getOperand(0) == MulVal || I.getOperand(1) == MulVal);
   assert(I.getOperand(0) == OtherVal || I.getOperand(1) == OtherVal);
-  assert(isa<IntegerType>(MulVal->getType()));
   Instruction *MulInstr = cast<Instruction>(MulVal);
   assert(MulInstr->getOpcode() == Instruction::Mul);
 
diff --git a/llvm/test/Transforms/InstCombine/overflow-mul.ll b/llvm/test/Transforms/InstCombine/overflow-mul.ll
index 04019ae7bc1..cbb2f5f9500 100644
--- a/llvm/test/Transforms/InstCombine/overflow-mul.ll
+++ b/llvm/test/Transforms/InstCombine/overflow-mul.ll
@@ -162,3 +162,14 @@ entry:
   ret i32 %retval
 }
 
+define <4 x i32> @pr20113(<4 x i16> %a, <4 x i16> %b) {
+; CHECK-LABEL: @pr20113
+; CHECK-NOT: mul.with.overflow
+; CHECK: ret
+  %vmovl.i.i726 = zext <4 x i16> %a to <4 x i32>
+  %vmovl.i.i712 = zext <4 x i16> %b to <4 x i32>
+  %mul.i703 = mul <4 x i32> %vmovl.i.i712, %vmovl.i.i726
+  %tmp = icmp sge <4 x i32> %mul.i703, zeroinitializer
+  %vcgez.i = sext <4 x i1> %tmp to <4 x i32>
+  ret <4 x i32> %vcgez.i
+}