[SCEV] teach SCEV symbolical execution about overflow intrinsics folding.

Differential Revision: https://reviews.llvm.org/D64422

llvm-svn: 365726

2 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index a5128342a7a..20231ca78b4 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -1036,6 +1036,9 @@ Constant *ConstantFoldInstOperandsImpl(const Value *InstOrCE, unsigned Opcode,
     return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
   case Instruction::ExtractElement:
     return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
+  case Instruction::ExtractValue:
+    return ConstantExpr::getExtractValue(
+        Ops[0], dyn_cast<ExtractValueInst>(InstOrCE)->getIndices());
   case Instruction::InsertElement:
     return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
   case Instruction::ShuffleVector:
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 4a98fc537a5..95d6c20b692 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -7674,7 +7674,7 @@ ScalarEvolution::ExitLimit ScalarEvolution::computeShiftCompareExitLimit(
 static bool CanConstantFold(const Instruction *I) {
   if (isa<BinaryOperator>(I) || isa<CmpInst>(I) ||
       isa<SelectInst>(I) || isa<CastInst>(I) || isa<GetElementPtrInst>(I) ||
-      isa<LoadInst>(I))
+      isa<LoadInst>(I) || isa<ExtractValueInst>(I))
     return true;
 
   if (const CallInst *CI = dyn_cast<CallInst>(I))