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From cf00b30288c4c81b2c6a5af01c38f236148777a0 Mon Sep 17 00:00:00 2001
From: Mike Hommey <mh@glandium.org>
Date: Tue, 28 Mar 2023 06:13:36 +0900
Subject: [PATCH] Revert "[Passes][VectorCombine] enable early run generally
and try load folds"
This reverts commit 163bb6d64e5f1220777c3ec2a8b58c0666a74d91.
It causes various reftest regressions.
---
llvm/lib/Passes/PassBuilderPipelines.cpp | 7 ++++---
llvm/lib/Transforms/Vectorize/VectorCombine.cpp | 8 ++------
9 files changed, 18 insertions(+), 19 deletions(-)
diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index 256cf9d4cd1c..6817ba63e215 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -722,9 +722,10 @@ PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
// Delete small array after loop unroll.
FPM.addPass(SROAPass(SROAOptions::ModifyCFG));
- // Try vectorization/scalarization transforms that are both improvements
- // themselves and can allow further folds with GVN and InstCombine.
- FPM.addPass(VectorCombinePass(/*TryEarlyFoldsOnly=*/true));
+ // The matrix extension can introduce large vector operations early, which can
+ // benefit from running vector-combine early on.
+ if (EnableMatrix)
+ FPM.addPass(VectorCombinePass(/*TryEarlyFoldsOnly=*/true));
// Eliminate redundancies.
FPM.addPass(MergedLoadStoreMotionPass());
diff --git a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
index 0ef933f59660..44bafd83bc88 100644
--- a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
+++ b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
@@ -4497,25 +4497,6 @@ bool VectorCombine::run() {
LLVM_DEBUG(dbgs() << "VC: Visiting: " << I << '\n');
- // These folds should be beneficial regardless of when this pass is run
- // in the optimization pipeline.
- // The type checking is for run-time efficiency. We can avoid wasting time
- // dispatching to folding functions if there's no chance of matching.
- if (IsFixedVectorType) {
- switch (Opcode) {
- case Instruction::InsertElement:
- if (vectorizeLoadInsert(I))
- return true;
- break;
- case Instruction::ShuffleVector:
- if (widenSubvectorLoad(I))
- return true;
- break;
- default:
- break;
- }
- }
-
// This transform works with scalable and fixed vectors
// TODO: Identify and allow other scalable transforms
if (IsVectorType) {
@@ -4546,6 +4527,8 @@ bool VectorCombine::run() {
if (IsFixedVectorType) {
switch (Opcode) {
case Instruction::InsertElement:
+ if (vectorizeLoadInsert(I))
+ return true;
if (foldInsExtFNeg(I))
return true;
if (foldInsExtBinop(I))
@@ -4554,6 +4537,8 @@ bool VectorCombine::run() {
return true;
break;
case Instruction::ShuffleVector:
+ if (widenSubvectorLoad(I))
+ return true;
if (foldPermuteOfBinops(I))
return true;
if (foldShuffleOfBinops(I))