[PATCH] D100302: [VectorCombine] Run load/extract scalarization after scalarizing store.

[Florian Hahn via Phabricator via llvm-commits]

fhahn created this revision.
fhahn added reviewers: spatel, RKSimon, lebedev.ri.
Herald added a subscriber: hiraditya.
fhahn requested review of this revision.
Herald added a project: LLVM.

Remove the insertelement instruction (via D98240 <https://reviews.llvm.org/D98240>) can enable further
load/extract scalarization opportunities. Try it again.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D100302

Files:
  llvm/lib/Transforms/Vectorize/VectorCombine.cpp
  llvm/test/Transforms/VectorCombine/AArch64/load-extract-insert-store-scalarization.ll


Index: llvm/test/Transforms/VectorCombine/AArch64/load-extract-insert-store-scalarization.ll
===================================================================
--- llvm/test/Transforms/VectorCombine/AArch64/load-extract-insert-store-scalarization.ll
+++ llvm/test/Transforms/VectorCombine/AArch64/load-extract-insert-store-scalarization.ll
@@ -6,14 +6,15 @@
 define void @test(i64 %i, <225 x double>* %A) {
 ; CHECK-LABEL: @test(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[LV:%.*]] = load <225 x double>, <225 x double>* [[A:%.*]], align 8
 ; CHECK-NEXT:    [[IDX_0:%.*]] = add nuw nsw i64 2, [[I:%.*]]
-; CHECK-NEXT:    [[EXT_0:%.*]] = extractelement <225 x double> [[LV]], i64 [[IDX_0]]
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds <225 x double>, <225 x double>* [[A:%.*]], i32 0, i64 [[IDX_0]]
+; CHECK-NEXT:    [[EXT_0:%.*]] = load double, double* [[TMP0]], align 1
 ; CHECK-NEXT:    [[MUL:%.*]] = fmul double 2.000000e+01, [[EXT_0]]
-; CHECK-NEXT:    [[EXT_1:%.*]] = extractelement <225 x double> [[LV]], i64 [[I]]
+; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds <225 x double>, <225 x double>* [[A]], i32 0, i64 [[I]]
+; CHECK-NEXT:    [[EXT_1:%.*]] = load double, double* [[TMP1]], align 1
 ; CHECK-NEXT:    [[SUB:%.*]] = fsub double [[EXT_1]], [[MUL]]
-; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr inbounds <225 x double>, <225 x double>* [[A]], i64 0, i64 [[I]]
-; CHECK-NEXT:    store double [[SUB]], double* [[TMP0]], align 8
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds <225 x double>, <225 x double>* [[A]], i64 0, i64 [[I]]
+; CHECK-NEXT:    store double [[SUB]], double* [[TMP2]], align 8
 ; CHECK-NEXT:    ret void
 ;
 entry:
Index: llvm/lib/Transforms/Vectorize/VectorCombine.cpp
===================================================================
--- llvm/lib/Transforms/Vectorize/VectorCombine.cpp
+++ llvm/lib/Transforms/Vectorize/VectorCombine.cpp
@@ -811,8 +811,14 @@
     StoreInst *NSI = Builder.CreateStore(NewElement, GEP);
     NSI->copyMetadata(*SI);
     replaceValue(I, *NSI);
+    auto *IEI = cast<Instruction>(SI->getOperand(0));
     // Need erasing the store manually.
     I.eraseFromParent();
+    // Removing the insertelement instruction may unlock further load/extract
+    // scalarization opportunities.
+    if (IEI->use_empty())
+      IEI->eraseFromParent();
+    scalarizeLoadExtract(*Load);
     return true;
   }
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D100302.336818.patch
Type: text/x-patch
Size: 2395 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210412/a67f6d43/attachment.bin>