add test; address comments

Author: knwng

llvm/lib/Transforms/Vectorize/VectorCombine.cpp

@@ -1805,10 +1805,6 @@ bool VectorCombine::scalarizeLoadExtract(Instruction &I) {
   // erased in the correct order.
   Worklist.push(LI);
 
-  LLVMContext &ctx = LI->getContext();
-  unsigned aliasScopeKind = ctx.getMDKindID("alias.scope");
-  unsigned noAliasKind = ctx.getMDKindID("noalias");
-
   // Replace extracts with narrow scalar loads.
   for (User *U : LI->users()) {
     auto *EI = cast<ExtractElementInst>(U);
@@ -1829,12 +1825,12 @@ bool VectorCombine::scalarizeLoadExtract(Instruction &I) {
         LI->getAlign(), VecTy->getElementType(), Idx, *DL);
     NewLoad->setAlignment(ScalarOpAlignment);
 
-    if (MDNode *aliasScope = LI->getMetadata(aliasScopeKind)) {
-      NewLoad->setMetadata(aliasScopeKind, aliasScope);
+    if (MDNode *aliasScope = LI->getMetadata(LLVMContext::MD_alias_scope)) {
+      NewLoad->setMetadata(LLVMContext::MD_alias_scope, aliasScope);
     }
 
-    if (MDNode *noAlias = LI->getMetadata(noAliasKind)) {
-      NewLoad->setMetadata(noAliasKind, noAlias);
+    if (MDNode *noAlias = LI->getMetadata(LLVMContext::MD_noalias)) {
+      NewLoad->setMetadata(LLVMContext::MD_noalias, noAlias);
     }
 
     replaceValue(*EI, *NewLoad);

llvm/test/Transforms/VectorCombine/alias.ll

@@ -0,0 +1,49 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=vector-combine -S | FileCheck %s --check-prefixes=CHECK
+
+define <4 x i32> @quux(ptr addrspace(3) %arg) {
+; CHECK-LABEL: define <4 x i32> @quux(
+; CHECK-SAME: ptr addrspace(3) [[ARG:%.*]]) {
+; CHECK-NEXT:  [[BB:.*:]]
+; CHECK-NEXT:    [[EXTRACTELEMENT:%.*]] = load i8, ptr addrspace(3) [[ARG]], align 4, !alias.scope [[META0:![0-9]+]], !noalias [[META0]]
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds <4 x i8>, ptr addrspace(3) [[ARG]], i32 0, i64 1
+; CHECK-NEXT:    [[EXTRACTELEMENT1:%.*]] = load i8, ptr addrspace(3) [[TMP0]], align 1, !alias.scope [[META0]], !noalias [[META0]]
+; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds <4 x i8>, ptr addrspace(3) [[ARG]], i32 0, i64 2
+; CHECK-NEXT:    [[EXTRACTELEMENT2:%.*]] = load i8, ptr addrspace(3) [[TMP1]], align 2, !alias.scope [[META0]], !noalias [[META0]]
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds <4 x i8>, ptr addrspace(3) [[ARG]], i32 0, i64 3
+; CHECK-NEXT:    [[EXTRACTELEMENT3:%.*]] = load i8, ptr addrspace(3) [[TMP2]], align 1, !alias.scope [[META0]], !noalias [[META0]]
+; CHECK-NEXT:    [[ZEXT:%.*]] = zext i8 [[EXTRACTELEMENT]] to i32
+; CHECK-NEXT:    [[ZEXT4:%.*]] = zext i8 [[EXTRACTELEMENT1]] to i32
+; CHECK-NEXT:    [[ZEXT5:%.*]] = zext i8 [[EXTRACTELEMENT2]] to i32
+; CHECK-NEXT:    [[ZEXT6:%.*]] = zext i8 [[EXTRACTELEMENT3]] to i32
+; CHECK-NEXT:    [[INSERTELEMENT:%.*]] = insertelement <4 x i32> poison, i32 [[ZEXT]], i64 0
+; CHECK-NEXT:    [[INSERTELEMENT7:%.*]] = insertelement <4 x i32> [[INSERTELEMENT]], i32 [[ZEXT4]], i64 1
+; CHECK-NEXT:    [[INSERTELEMENT8:%.*]] = insertelement <4 x i32> [[INSERTELEMENT7]], i32 [[ZEXT5]], i64 2
+; CHECK-NEXT:    [[INSERTELEMENT9:%.*]] = insertelement <4 x i32> [[INSERTELEMENT8]], i32 [[ZEXT6]], i64 3
+; CHECK-NEXT:    ret <4 x i32> [[INSERTELEMENT9]]
+;
+bb:
+  %load = load <4 x i8>, ptr addrspace(3) %arg, align 4, !alias.scope !0, !noalias !0
+  %extractelement = extractelement <4 x i8> %load, i64 0
+  %extractelement1 = extractelement <4 x i8> %load, i64 1
+  %extractelement2 = extractelement <4 x i8> %load, i64 2
+  %extractelement3 = extractelement <4 x i8> %load, i64 3
+  %zext = zext i8 %extractelement to i32
+  %zext4 = zext i8 %extractelement1 to i32
+  %zext5 = zext i8 %extractelement2 to i32
+  %zext6 = zext i8 %extractelement3 to i32
+  %insertelement = insertelement <4 x i32> poison, i32 %zext, i64 0
+  %insertelement7 = insertelement <4 x i32> %insertelement, i32 %zext4, i64 1
+  %insertelement8 = insertelement <4 x i32> %insertelement7, i32 %zext5, i64 2
+  %insertelement9 = insertelement <4 x i32> %insertelement8, i32 %zext6, i64 3
+  ret <4 x i32> %insertelement9
+}
+
+!0 = !{!1}
+!1 = distinct !{!1, !2}
+!2 = distinct !{!2}
+;.
+; CHECK: [[META0]] = !{[[META1:![0-9]+]]}
+; CHECK: [[META1]] = distinct !{[[META1]], [[META2:![0-9]+]]}
+; CHECK: [[META2]] = distinct !{[[META2]]}
+;.