[InstCombine] Preserve GEP no-wrap flags

Author: artagnon

llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp

@@ -537,7 +537,7 @@ Instruction *InstCombinerImpl::visitExtractElementInst(ExtractElementInst &EI) {
 
           GetElementPtrInst *NewGEP = GetElementPtrInst::Create(
               GEP->getSourceElementType(), NewPtr, NewOps);
-          NewGEP->setIsInBounds(GEP->isInBounds());
+          NewGEP->setNoWrapFlags(GEP->getNoWrapFlags());
           return NewGEP;
         }
       }
@@ -1982,7 +1982,7 @@ static Value *buildNew(Instruction *I, ArrayRef<Value*> NewOps,
       ArrayRef<Value*> Idx = NewOps.slice(1);
       return Builder.CreateGEP(cast<GEPOperator>(I)->getSourceElementType(),
                                Ptr, Idx, "",
-                               cast<GEPOperator>(I)->isInBounds());
+                               cast<GEPOperator>(I)->getNoWrapFlags());
     }
   }
   llvm_unreachable("failed to rebuild vector instructions");

llvm/test/Transforms/InstCombine/gep-vector-indices.ll

@@ -26,7 +26,7 @@ define ptr @vector_splat_indices_nxv2i64_ext0_inbounds(ptr %a) {
 
 define ptr @vector_splat_indices_nxv2i64_ext0_nuw(ptr %a) {
 ; CHECK-LABEL: @vector_splat_indices_nxv2i64_ext0_nuw(
-; CHECK-NEXT:    [[RES:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 16
+; CHECK-NEXT:    [[RES:%.*]] = getelementptr nuw i8, ptr [[A:%.*]], i64 16
 ; CHECK-NEXT:    ret ptr [[RES]]
 ;
   %tmp = insertelement <vscale x 2 x i64> poison, i64 4, i32 0
@@ -38,7 +38,7 @@ define ptr @vector_splat_indices_nxv2i64_ext0_nuw(ptr %a) {
 
 define ptr @vector_splat_indices_nxv2i64_ext0_nusw(ptr %a) {
 ; CHECK-LABEL: @vector_splat_indices_nxv2i64_ext0_nusw(
-; CHECK-NEXT:    [[RES:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 16
+; CHECK-NEXT:    [[RES:%.*]] = getelementptr nusw nuw i8, ptr [[A:%.*]], i64 16
 ; CHECK-NEXT:    ret ptr [[RES]]
 ;
   %tmp = insertelement <vscale x 2 x i64> poison, i64 4, i32 0

llvm/test/Transforms/InstCombine/vec_shuffle.ll

@@ -277,7 +277,7 @@ define <1 x ptr> @shuffle_gep_inbounds(ptr %x1, ptr %x2) {
 define <1 x ptr> @shuffle_gep_nuw(ptr %x1, ptr %x2) {
 ; CHECK-LABEL: @shuffle_gep_nuw(
 ; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <1 x ptr> poison, ptr [[X2:%.*]], i64 0
-; CHECK-NEXT:    [[RET:%.*]] = getelementptr i8, <1 x ptr> [[TMP1]], i64 5
+; CHECK-NEXT:    [[RET:%.*]] = getelementptr nuw i8, <1 x ptr> [[TMP1]], i64 5
 ; CHECK-NEXT:    ret <1 x ptr> [[RET]]
 ;
   %ins.1 = insertelement <2 x ptr> poison, ptr %x1, i32 0
@@ -290,7 +290,7 @@ define <1 x ptr> @shuffle_gep_nuw(ptr %x1, ptr %x2) {
 define <1 x ptr> @shuffle_gep_nusw(ptr %x1, ptr %x2) {
 ; CHECK-LABEL: @shuffle_gep_nusw(
 ; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <1 x ptr> poison, ptr [[X2:%.*]], i64 0
-; CHECK-NEXT:    [[RET:%.*]] = getelementptr i8, <1 x ptr> [[TMP1]], i64 5
+; CHECK-NEXT:    [[RET:%.*]] = getelementptr nusw i8, <1 x ptr> [[TMP1]], i64 5
 ; CHECK-NEXT:    ret <1 x ptr> [[RET]]
 ;
   %ins.1 = insertelement <2 x ptr> poison, ptr %x1, i32 0