Remove RunSLPAfterLoopVectorization option...

[echristo]

Summary

It's been on by default for 4 years now, we're probably pretty good and it cleans up the pass hierarchy.

Sound good?

[hfinkel]

LGTM

[hfinkel]

Do we need to adjust the new pass manager too?

[echristo]

In D60745#1468829, @hfinkel wrote:

Do we need to adjust the new pass manager too?

Nope. There's only a single instantiation of the SLP vectorizer in the new pass manager - it's in a fairly gratuitously different location and some loop passes have run before and after. I think that should be handled separately.

[hfinkel]

In D60745#1469622, @echristo wrote:

In D60745#1468829, @hfinkel wrote:

Do we need to adjust the new pass manager too?

Nope. There's only a single instantiation of the SLP vectorizer in the new pass manager - it's in a fairly gratuitously different location and some loop passes have run before and after. I think that should be handled separately.

Sounds good.

[echristo]

Committed thusly:

commit 0ebbf72a6346a81cd349a30392b9d5cd27069e3b
Author: Eric Christopher <[e-mail]>
Date: Wed Apr 17 02:26:27 2019 +0000

Remove the run-slp-after-loop-vectorization option.

It's been on by default for 4 years and cleans up the pass
hierarchy.

llvm-svn: 358548

Forgot to put the differential revision tag in.

llvm/lib/Transforms/IPO/PassManagerBuilder.cpp

 
 static cl::opt<bool>
 RunLoopRerolling("reroll-loops", cl::Hidden,
                  cl::desc("Run the loop rerolling pass"));
 
 static cl::opt<bool> RunNewGVN("enable-newgvn", cl::init(false), cl::Hidden,
                                cl::desc("Run the NewGVN pass"));
 
-static cl::opt<bool>
-RunSLPAfterLoopVectorization("run-slp-after-loop-vectorization",
-  cl::init(true), cl::Hidden,
-  cl::desc("Run the SLP vectorizer (and BB vectorizer) after the Loop "
-           "vectorizer instead of before"));
-
 // Experimental option to use CFL-AA
 enum class CFLAAType { None, Steensgaard, Andersen, Both };
 static cl::opt<CFLAAType>
     UseCFLAA("use-cfl-aa", cl::init(CFLAAType::None), cl::Hidden,
              cl::desc("Enable the new, experimental CFL alias analysis"),
              cl::values(clEnumValN(CFLAAType::None, "none", "Disable CFL-AA"),
                         clEnumValN(CFLAAType::Steensgaard, "steens",
                                    "Enable unification-based CFL-AA"),
void PassManagerBuilder::addFunctionSimplificationPasses(
   MPM.add(createCorrelatedValuePropagationPass());
   MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
   MPM.add(createLICMPass());
 
   addExtensionsToPM(EP_ScalarOptimizerLate, MPM);
 
   if (RerollLoops)
     MPM.add(createLoopRerollPass());
-  if (!RunSLPAfterLoopVectorization && SLPVectorize)
-    MPM.add(createSLPVectorizerPass()); // Vectorize parallel scalar chains.
 
   MPM.add(createAggressiveDCEPass());         // Delete dead instructions
   MPM.add(createCFGSimplificationPass()); // Merge & remove BBs
   // Clean up after everything.
   addInstructionCombiningPass(MPM);
   addExtensionsToPM(EP_Peephole, MPM);
 
   if (EnableCHR && OptLevel >= 3 &&
void PassManagerBuilder::populateModulePassManager(
 
   // Cleanup after loop vectorization, etc. Simplification passes like CVP and
   // GVN, loop transforms, and others have already run, so it's now better to
   // convert to more optimized IR using more aggressive simplify CFG options.
   // The extra sinking transform can create larger basic blocks, so do this
   // before SLP vectorization.
   MPM.add(createCFGSimplificationPass(1, true, true, false, true));
 
-  if (RunSLPAfterLoopVectorization && SLPVectorize) {
+  if (SLPVectorize) {
     MPM.add(createSLPVectorizerPass()); // Vectorize parallel scalar chains.
     if (OptLevel > 1 && ExtraVectorizerPasses) {
       MPM.add(createEarlyCSEPass());
     }
   }
 
   addExtensionsToPM(EP_Peephole, MPM);
   addInstructionCombiningPass(MPM);
void PassManagerBuilder::addLTOOptimizationPasses(legacy::PassManagerBase &PM) {
   // optimizer again at this point.
   addInstructionCombiningPass(PM); // Initial cleanup
   PM.add(createCFGSimplificationPass()); // if-convert
   PM.add(createSCCPPass()); // Propagate exposed constants
   addInstructionCombiningPass(PM); // Clean up again
   PM.add(createBitTrackingDCEPass());
 
   // More scalar chains could be vectorized due to more alias information
-  if (RunSLPAfterLoopVectorization)
-    if (SLPVectorize)
-      PM.add(createSLPVectorizerPass()); // Vectorize parallel scalar chains.
 
   // After vectorization, assume intrinsics may tell us more about pointer
   // alignments.
   PM.add(createAlignmentFromAssumptionsPass());
 
   // Cleanup and simplify the code after the scalar optimizations.
   addInstructionCombiningPass(PM);
   addExtensionsToPM(EP_Peephole, PM);