[PATCH] D145403: [Pipeline] Don't run EarlyFPM in LTO post link

[Arthur Eubanks via Phabricator via llvm-commits]

aeubanks created this revision.
aeubanks added a reviewer: tejohnson.
Herald added subscribers: hiraditya, inglorion.
Herald added a reviewer: ctetreau.
Herald added a reviewer: ctetreau.
Herald added a project: All.
aeubanks requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

EarlyFPM cleans up the output of the frontend. This isn't necessary in post link pipelines as the pre link pipeline already ran this.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D145403

Files:
  llvm/lib/Passes/PassBuilderPipelines.cpp


Index: llvm/lib/Passes/PassBuilderPipelines.cpp
===================================================================
--- llvm/lib/Passes/PassBuilderPipelines.cpp
+++ llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -951,22 +951,26 @@
   if (Phase == ThinOrFullLTOPhase::ThinLTOPostLink && !LoadSampleProfile)
     MPM.addPass(PGOIndirectCallPromotion(true /* InLTO */, HasSampleProfile));
 
-  // Do basic inference of function attributes from known properties of system
-  // libraries and other oracles.
-  MPM.addPass(InferFunctionAttrsPass());
-  MPM.addPass(CoroEarlyPass());
-
   // Create an early function pass manager to cleanup the output of the
-  // frontend.
+  // frontend. Not necessary with LTO post link pipelines since the pre link
+  // pipeline already cleaned up the frontend output.
   FunctionPassManager EarlyFPM;
-  // Lower llvm.expect to metadata before attempting transforms.
-  // Compare/branch metadata may alter the behavior of passes like SimplifyCFG.
-  EarlyFPM.addPass(LowerExpectIntrinsicPass());
-  EarlyFPM.addPass(SimplifyCFGPass());
-  EarlyFPM.addPass(SROAPass(SROAOptions::ModifyCFG));
-  EarlyFPM.addPass(EarlyCSEPass());
-  if (Level == OptimizationLevel::O3)
-    EarlyFPM.addPass(CallSiteSplittingPass());
+  if (Phase != ThinOrFullLTOPhase::ThinLTOPostLink) {
+    // Do basic inference of function attributes from known properties of system
+    // libraries and other oracles.
+    MPM.addPass(InferFunctionAttrsPass());
+    MPM.addPass(CoroEarlyPass());
+
+    // Lower llvm.expect to metadata before attempting transforms.
+    // Compare/branch metadata may alter the behavior of passes like
+    // SimplifyCFG.
+    EarlyFPM.addPass(LowerExpectIntrinsicPass());
+    EarlyFPM.addPass(SimplifyCFGPass());
+    EarlyFPM.addPass(SROAPass(SROAOptions::ModifyCFG));
+    EarlyFPM.addPass(EarlyCSEPass());
+    if (Level == OptimizationLevel::O3)
+      EarlyFPM.addPass(CallSiteSplittingPass());
+  }
 
   // In SamplePGO ThinLTO backend, we need instcombine before profile annotation
   // to convert bitcast to direct calls so that they can be inlined during the
@@ -976,8 +980,10 @@
   // FIXME: revisit how SampleProfileLoad/Inliner/ICP is structured.
   if (LoadSampleProfile)
     EarlyFPM.addPass(InstCombinePass());
-  MPM.addPass(createModuleToFunctionPassAdaptor(std::move(EarlyFPM),
-                                                PTO.EagerlyInvalidateAnalyses));
+
+  if (!EarlyFPM.isEmpty())
+    MPM.addPass(createModuleToFunctionPassAdaptor(
+        std::move(EarlyFPM), PTO.EagerlyInvalidateAnalyses));
 
   if (LoadSampleProfile) {
     // Annotate sample profile right after early FPM to ensure freshness of


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D145403.502715.patch
Type: text/x-patch
Size: 2673 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230306/ce963a7d/attachment.bin>