PR4340: Run SimplifyDemandedVectorElts on insertelement instructions;

sometimes it can find simplifications that won't be found otherwise.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73006 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 97bd34c771c206ed6e3ec04feb8fe4a59281709d..6d2ff0e3e53c5a5f5e7752fff595177d9f430374 100644 (file)
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -12579,6 +12579,12 @@ Instruction *InstCombiner::visitInsertElementInst(InsertElementInst &IE) {
     }
   }
 
+  unsigned VWidth = cast<VectorType>(VecOp->getType())->getNumElements();
+  APInt UndefElts(VWidth, 0);
+  APInt AllOnesEltMask(APInt::getAllOnesValue(VWidth));
+  if (SimplifyDemandedVectorElts(&IE, AllOnesEltMask, UndefElts))
+    return &IE;
+
   return 0;
 }
 

diff --git a/test/Transforms/InstCombine/vec_demanded_elts-3.ll b/test/Transforms/InstCombine/vec_demanded_elts-3.ll
new file mode 100644 (file)
index 0000000..eba3629
--- /dev/null
+++ b/test/Transforms/InstCombine/vec_demanded_elts-3.ll
@@ -0,0 +1,14 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep load
+; PR4340
+
+define void @vac(<4 x float>* nocapture %a) nounwind {
+entry:
+       %tmp1 = load <4 x float>* %a            ; <<4 x float>> [#uses=1]
+       %vecins = insertelement <4 x float> %tmp1, float 0.000000e+00, i32 0    ; <<4 x float>> [#uses=1]
+       %vecins4 = insertelement <4 x float> %vecins, float 0.000000e+00, i32 1; <<4 x float>> [#uses=1]
+       %vecins6 = insertelement <4 x float> %vecins4, float 0.000000e+00, i32 2; <<4 x float>> [#uses=1]
+       %vecins8 = insertelement <4 x float> %vecins6, float 0.000000e+00, i32 3; <<4 x float>> [#uses=1]
+       store <4 x float> %vecins8, <4 x float>* %a
+       ret void
+}
+