Fix trivial todo in instcombine.

llvm-svn: 75586

llvm/lib/Transforms/Scalar/InstructionCombining.cpp

@@ -2702,7 +2702,8 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) {
                  Context->getConstantInt(Op0->getType(), Val.logBase2()));
       }
     } else if (isa<VectorType>(Op1->getType())) {
-      // TODO: If Op1 is all zeros and Op0 is all finite, return all zeros.
+      if (Op1->isNullValue())
+        return ReplaceInstUsesWith(I, Op1);
 
       if (ConstantVector *Op1V = dyn_cast<ConstantVector>(Op1)) {
         if (Op1V->isAllOnesValue())              // X * -1 == 0 - X

llvm/test/Transforms/InstCombine/mul.ll

@@ -83,3 +83,8 @@ define internal void @test13(<4 x float>*) {
 	store <4 x float> %3, <4 x float>* %0, align 1
 	ret void
 }
+
+define <16 x i8> @test14(<16 x i8> %a) {
+        %b = mul <16 x i8> %a, zeroinitializer
+        ret <16 x i8> %b
+}