[llvm] f3c417f - [Passes] Add option for LoopVersioningLICM pass. (#67107)

[via llvm-commits]

Author: lcvon007
Date: 2023-09-27T07:38:37-05:00
New Revision: f3c417f341135ff357f2d454866d7d05262ebfca

URL: https://github.com/llvm/llvm-project/commit/f3c417f341135ff357f2d454866d7d05262ebfca
DIFF: https://github.com/llvm/llvm-project/commit/f3c417f341135ff357f2d454866d7d05262ebfca.diff

LOG: [Passes] Add option for LoopVersioningLICM pass. (#67107)

User only can use opt to test LoopVersioningLICM pass, and this PR add
the option back(deleted in https://reviews.llvm.org/D137915) so that
it's easy for verifying if it is useful for some benchmarks.

Added: 
    

Modified: 
    llvm/lib/Passes/PassBuilderPipelines.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index 2cc7d43cfcc71fa..78e0e6353056343 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -105,6 +105,7 @@
 #include "llvm/Transforms/Scalar/LoopSink.h"
 #include "llvm/Transforms/Scalar/LoopUnrollAndJamPass.h"
 #include "llvm/Transforms/Scalar/LoopUnrollPass.h"
+#include "llvm/Transforms/Scalar/LoopVersioningLICM.h"
 #include "llvm/Transforms/Scalar/LowerConstantIntrinsics.h"
 #include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
 #include "llvm/Transforms/Scalar/LowerMatrixIntrinsics.h"
@@ -271,6 +272,10 @@ static cl::opt<AttributorRunOption> AttributorRun(
                clEnumValN(AttributorRunOption::NONE, "none",
                           "disable attributor runs")));
 
+static cl::opt<bool> UseLoopVersioningLICM(
+    "enable-loop-versioning-licm", cl::init(false), cl::Hidden,
+    cl::desc("Enable the experimental Loop Versioning LICM pass"));
+
 cl::opt<bool> EnableMemProfContextDisambiguation(
     "enable-memprof-context-disambiguation", cl::init(false), cl::Hidden,
     cl::ZeroOrMore, cl::desc("Enable MemProf context disambiguation"));
@@ -1343,6 +1348,21 @@ PassBuilder::buildModuleOptimizationPipeline(OptimizationLevel Level,
   invokeOptimizerEarlyEPCallbacks(MPM, Level);
 
   FunctionPassManager OptimizePM;
+  // Scheduling LoopVersioningLICM when inlining is over, because after that
+  // we may see more accurate aliasing. Reason to run this late is that too
+  // early versioning may prevent further inlining due to increase of code
+  // size. Other optimizations which runs later might get benefit of no-alias
+  // assumption in clone loop.
+  if (UseLoopVersioningLICM) {
+    OptimizePM.addPass(
+        createFunctionToLoopPassAdaptor(LoopVersioningLICMPass()));
+    // LoopVersioningLICM pass might increase new LICM opportunities.
+    OptimizePM.addPass(createFunctionToLoopPassAdaptor(
+        LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap,
+                 /*AllowSpeculation=*/true),
+        /*USeMemorySSA=*/true, /*UseBlockFrequencyInfo=*/false));
+  }
+
   OptimizePM.addPass(Float2IntPass());
   OptimizePM.addPass(LowerConstantIntrinsicsPass());