[LV] Preserve LAA in LoopVectorize (NFCI).

LoopVectorize already always preserves DT, LI and SCEV. If any changes get made to the CFG, cached LAA info for loops are cleared. LoopAccessAnalysis also implements ::invalidate to clear the analysis if SE, DT or LI gets invalidated. Hence it should be safe to preserve LAA and save a small amount of compile-time.
llvm · Jul 5, 2024 · ac03ae3 · ac03ae3
1 parent c2fbc70
commit ac03ae3
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diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -10258,6 +10258,7 @@ PreservedAnalyses LoopVectorizePass::run(Function &F,
     PA.preserve<LoopAnalysis>();
     PA.preserve<DominatorTreeAnalysis>();
     PA.preserve<ScalarEvolutionAnalysis>();
+    PA.preserve<LoopAccessAnalysis>();
 
     if (Result.MadeCFGChange) {
       // Making CFG changes likely means a loop got vectorized. Indicate that

diff --git a/llvm/test/Transforms/LoopVectorize/novect-lcssa-cfg-invalidation.ll b/llvm/test/Transforms/LoopVectorize/novect-lcssa-cfg-invalidation.ll
@@ -12,7 +12,7 @@ define i32 @novect(ptr %p) {
 ; CHECK-NOT:       Invalidating analysis: BranchProbabilityAnalysis on novect
 ; CHECK-NOT:       Invalidating analysis: BlockFrequencyAnalysis on novect
 ; CHECK:           Invalidating analysis: DemandedBitsAnalysis on novect
-; CHECK:           Invalidating analysis: LoopAccessAnalysis on novect
+; CHECK-NOT:       Invalidating analysis: LoopAccessAnalysis on novect
 ; CHECK:           Running pass: JumpThreadingPass on novect
 
 ; CHECK:           entry: