[Passes] Use MemorySSA for LICM during LTO.

Split off from D102345 to commit this separately from other changes in
the patch. This aligns the behavior of the new PM with the legacy PM
for LTO, with respect to running LICM.

Together with the remaining changes in D102345, this fixes new PM
regressions where we fail to vectorize loops that are vectorized with
the legacy PM.

diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 6c2315c..0684d6f 100644 (file)
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -1826,7 +1826,8 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level,
   FunctionPassManager MainFPM;
 
   MainFPM.addPass(createFunctionToLoopPassAdaptor(
-      LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap)));
+      LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap),
+      EnableMSSALoopDependency, /*UseBlockFrequencyInfo=*/true));
 
   if (RunNewGVN)
     MainFPM.addPass(NewGVNPass());

diff --git a/llvm/test/Other/new-pm-lto-defaults.ll b/llvm/test/Other/new-pm-lto-defaults.ll
index ddfe904..21e4bca 100644 (file)
--- a/llvm/test/Other/new-pm-lto-defaults.ll
+++ b/llvm/test/Other/new-pm-lto-defaults.ll
@@ -82,6 +82,7 @@
 ; CHECK-O23SZ-NEXT: Running pass: LoopSimplifyPass on foo
 ; CHECK-O23SZ-NEXT: Running analysis: LoopAnalysis on foo
 ; CHECK-O23SZ-NEXT: Running pass: LCSSAPass on foo
+; CHECK-O23SZ-NEXT: Running analysis: MemorySSAAnalysis on foo
 ; CHECK-O23SZ-NEXT: Running analysis: ScalarEvolutionAnalysis on foo
 ; CHECK-O23SZ-NEXT: Running analysis: InnerAnalysisManagerProxy
 ; CHECK-O23SZ-NEXT: Running pass: LICMPass on Loop
@@ -89,7 +90,6 @@
 ; CHECK-O23SZ-NEXT: Running analysis: MemoryDependenceAnalysis on foo
 ; CHECK-O23SZ-NEXT: Running analysis: PhiValuesAnalysis on foo
 ; CHECK-O23SZ-NEXT: Running pass: MemCpyOptPass on foo
-; CHECK-O23SZ-NEXT: Running analysis: MemorySSAAnalysis on foo
 ; CHECK-O23SZ-NEXT: Running pass: DSEPass on foo
 ; CHECK-O23SZ-NEXT: Running analysis: PostDominatorTreeAnalysis on foo
 ; CHECK-O23SZ-NEXT: Running pass: MergedLoadStoreMotionPass on foo