[SandboxVectorizer] Use sbvec-passes flag to create a pipeline of Region passes after BottomUpVec.

llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.h

@@ -19,14 +19,19 @@
 
 namespace llvm::sandboxir {
 
+class RegionPassManager;
+
 class BottomUpVec final : public FunctionPass {
   bool Change = false;
   LegalityAnalysis Legality;
   void vectorizeRec(ArrayRef<Value *> Bndl);
   void tryVectorize(ArrayRef<Value *> Seeds);
 
+  [[maybe_unused]] RegionPassManager *RPM;
+
 public:
-  BottomUpVec() : FunctionPass("bottom-up-vec") {}
+  BottomUpVec(RegionPassManager *RPM)
+      : FunctionPass("bottom-up-vec"), RPM(RPM) {}
   bool runOnFunction(Function &F) final;
 };
 

llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/Passes/NullPass.h

@@ -0,0 +1,19 @@
+#ifndef LLVM_TRANSFORMS_VECTORIZE_SANDBOXVECTORIZER_PASSES_NULLPASS_H
+#define LLVM_TRANSFORMS_VECTORIZE_SANDBOXVECTORIZER_PASSES_NULLPASS_H
+
+#include "llvm/SandboxIR/Pass.h"
+
+namespace llvm::sandboxir {
+
+class Region;
+
+/// A Region pass that does nothing, for use as a placeholder in tests.
+class NullPass final : public RegionPass {
+public:
+  NullPass() : RegionPass("null") {}
+  bool runOnRegion(Region &R) final { return false; }
+};
+
+} // namespace llvm::sandboxir
+
+#endif // LLVM_TRANSFORMS_VECTORIZE_SANDBOXVECTORIZER_PASSES_NULLPASS_H

llvm/include/llvm/Transforms/Vectorize/SandboxVectorizer/SandboxVectorizer.h

@@ -8,7 +8,11 @@
 #ifndef LLVM_TRANSFORMS_VECTORIZE_SANDBOXVECTORIZER_SANDBOXVECTORIZER_H
 #define LLVM_TRANSFORMS_VECTORIZE_SANDBOXVECTORIZER_SANDBOXVECTORIZER_H
 
+#include <memory>
+
 #include "llvm/IR/PassManager.h"
+#include "llvm/SandboxIR/PassManager.h"
+#include "llvm/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.h"
 
 namespace llvm {
 
@@ -17,10 +21,22 @@ class TargetTransformInfo;
 class SandboxVectorizerPass : public PassInfoMixin<SandboxVectorizerPass> {
   TargetTransformInfo *TTI = nullptr;
 
-public:
-  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+  // Used to build a RegionPass pipeline to be run on Regions created by the
+  // bottom-up vectorization pass.
+  sandboxir::PassRegistry PR;
+
+  // The main vectorizer pass.
+  std::unique_ptr<sandboxir::BottomUpVec> BottomUpVecPass;
+
+  // The PM containing the pipeline of region passes. It's owned by the pass
+  // registry.
+  sandboxir::RegionPassManager *RPM;
 
   bool runImpl(Function &F);
+
+public:
+  SandboxVectorizerPass();
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
 };
 
 } // namespace llvm

llvm/lib/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.cpp

@@ -59,6 +59,8 @@ bool BottomUpVec::runOnFunction(Function &F) {
     // TODO: Replace with proper SeedCollector function.
     auto Seeds = collectSeeds(BB);
     // TODO: Slice Seeds into smaller chunks.
+    // TODO: If vectorization succeeds, run the RegionPassManager on the
+    // resulting region.
     if (Seeds.size() >= 2)
       tryVectorize(Seeds);
   }

llvm/lib/Transforms/Vectorize/SandboxVectorizer/SandboxVectorizer.cpp

@@ -12,6 +12,7 @@
 #include "llvm/SandboxIR/PassManager.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Transforms/Vectorize/SandboxVectorizer/Passes/BottomUpVec.h"
+#include "llvm/Transforms/Vectorize/SandboxVectorizer/Passes/NullPass.h"
 
 using namespace llvm;
 
@@ -30,6 +31,57 @@ cl::opt<std::string> UserDefinedPassPipeline(
     cl::desc("Comma-separated list of vectorizer passes. If not set "
              "we run the predefined pipeline."));
 
+static void registerAllRegionPasses(sandboxir::PassRegistry &PR) {
+  PR.registerPass(std::make_unique<sandboxir::NullPass>());
+}
+
+static sandboxir::RegionPassManager &
+parseAndCreatePassPipeline(sandboxir::PassRegistry &PR, StringRef Pipeline) {
+  static constexpr const char EndToken = '\0';
+  // Add EndToken to the end to ease parsing.
+  std::string PipelineStr = std::string(Pipeline) + EndToken;
+  int FlagBeginIdx = 0;
+  auto &RPM = static_cast<sandboxir::RegionPassManager &>(
+      PR.registerPass(std::make_unique<sandboxir::RegionPassManager>("rpm")));
+
+  for (auto [Idx, C] : enumerate(PipelineStr)) {
+    // Keep moving Idx until we find the end of the pass name.
+    bool FoundDelim = C == EndToken || C == PR.PassDelimToken;
+    if (!FoundDelim)
+      continue;
+    unsigned Sz = Idx - FlagBeginIdx;
+    std::string PassName(&PipelineStr[FlagBeginIdx], Sz);
+    FlagBeginIdx = Idx + 1;
+
+    // Get the pass that corresponds to PassName and add it to the pass manager.
+    auto *Pass = PR.getPassByName(PassName);
+    if (Pass == nullptr) {
+      errs() << "Pass '" << PassName << "' not registered!\n";
+      exit(1);
+    }
+    // TODO: Add a type check here. The downcast is correct as long as
+    // registerAllRegionPasses only registers regions passes.
+    RPM.addPass(static_cast<sandboxir::RegionPass *>(Pass));
+  }
+  return RPM;
+}
+
+SandboxVectorizerPass::SandboxVectorizerPass() {
+  registerAllRegionPasses(PR);
+
+  // Create a pipeline to be run on each Region created by BottomUpVec.
+  if (UserDefinedPassPipeline == DefaultPipelineMagicStr) {
+    // Create the default pass pipeline.
+    RPM = &static_cast<sandboxir::RegionPassManager &>(PR.registerPass(
+        std::make_unique<sandboxir::FunctionPassManager>("rpm")));
+    // TODO: Add passes to the default pipeline.
+  } else {
+    // Create the user-defined pipeline.
+    RPM = &parseAndCreatePassPipeline(PR, UserDefinedPassPipeline);
+  }
+  BottomUpVecPass = std::make_unique<sandboxir::BottomUpVec>(RPM);
+}
+
 PreservedAnalyses SandboxVectorizerPass::run(Function &F,
                                              FunctionAnalysisManager &AM) {
   TTI = &AM.getResult<TargetIRAnalysis>(F);
@@ -56,31 +108,13 @@ bool SandboxVectorizerPass::runImpl(Function &LLVMF) {
     return false;
   }
 
-  sandboxir::Context Ctx(LLVMF.getContext());
-  // Create SandboxIR for `LLVMF`.
-  sandboxir::Function &F = *Ctx.createFunction(&LLVMF);
-  // Create the passes and register them with the PassRegistry.
-  sandboxir::PassRegistry PR;
-  auto &BottomUpVecPass = static_cast<sandboxir::FunctionPass &>(
-      PR.registerPass(std::make_unique<sandboxir::BottomUpVec>()));
-
-  sandboxir::FunctionPassManager *PM = nullptr;
-  if (UserDefinedPassPipeline == DefaultPipelineMagicStr) {
-    // Create the default pass pipeline.
-    PM = &static_cast<sandboxir::FunctionPassManager &>(PR.registerPass(
-        std::make_unique<sandboxir::FunctionPassManager>("pm")));
-    PM->addPass(&BottomUpVecPass);
-  } else {
-    // Create the user-defined pipeline.
-    PM = &PR.parseAndCreatePassPipeline(UserDefinedPassPipeline);
-  }
-
   if (PrintPassPipeline) {
-    PM->printPipeline(outs());
+    RPM->printPipeline(outs());
     return false;
   }
 
-  // Run the pass pipeline.
-  bool Change = PM->runOnFunction(F);
-  return Change;
+  // Create SandboxIR for LLVMF and run BottomUpVec on it.
+  sandboxir::Context Ctx(LLVMF.getContext());
+  sandboxir::Function &F = *Ctx.createFunction(&LLVMF);
+  return BottomUpVecPass->runOnFunction(F);
 }

llvm/test/Transforms/SandboxVectorizer/default_pass_pipeline.ll

@@ -4,8 +4,7 @@
 
 ; This checks the default pass pipeline for the sandbox vectorizer.
 define void @pipeline() {
-; CHECK: pm
-; CHECK: bottom-up-vec
+; CHECK: rpm
 ; CHECK-EMPTY:
   ret void
 }

llvm/test/Transforms/SandboxVectorizer/user_pass_pipeline.ll

@@ -1,12 +1,12 @@
-; RUN: opt -passes=sandbox-vectorizer -sbvec-print-pass-pipeline -sbvec-passes=bottom-up-vec,bottom-up-vec %s -disable-output | FileCheck %s
+; RUN: opt -passes=sandbox-vectorizer -sbvec-print-pass-pipeline -sbvec-passes=null,null %s -disable-output | FileCheck %s
 
 ; !!!WARNING!!! This won't get updated by update_test_checks.py !
 
 ; This checks the user defined pass pipeline.
 define void @pipeline() {
-; CHECK: pm
-; CHECK: bottom-up-vec
-; CHECK: bottom-up-vec
+; CHECK: rpm
+; CHECK: null
+; CHECK: null
 ; CHECK-EMPTY:
   ret void
 }