Merge "Update prebuilt Clang to r353983." into p9.0HEADp9.0-backupp9.0

1 files changed, 68 insertions, 0 deletions

diff --git a/clang-r353983/include/llvm/Analysis/LegacyDivergenceAnalysis.h b/clang-r353983/include/llvm/Analysis/LegacyDivergenceAnalysis.h
new file mode 100644
index 00000000..0a338b81
--- /dev/null
+++ b/clang-r353983/include/llvm/Analysis/LegacyDivergenceAnalysis.h
@@ -0,0 +1,68 @@
+//===- llvm/Analysis/LegacyDivergenceAnalysis.h - KernelDivergence Analysis -*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// The kernel divergence analysis is an LLVM pass which can be used to find out
+// if a branch instruction in a GPU program (kernel) is divergent or not. It can help
+// branch optimizations such as jump threading and loop unswitching to make
+// better decisions.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_ANALYSIS_LEGACY_DIVERGENCE_ANALYSIS_H
+#define LLVM_ANALYSIS_LEGACY_DIVERGENCE_ANALYSIS_H
+
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Pass.h"
+#include "llvm/Analysis/DivergenceAnalysis.h"
+
+namespace llvm {
+class Value;
+class GPUDivergenceAnalysis;
+class LegacyDivergenceAnalysis : public FunctionPass {
+public:
+  static char ID;
+
+  LegacyDivergenceAnalysis() : FunctionPass(ID) {
+    initializeLegacyDivergenceAnalysisPass(*PassRegistry::getPassRegistry());
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+  bool runOnFunction(Function &F) override;
+
+  // Print all divergent branches in the function.
+  void print(raw_ostream &OS, const Module *) const override;
+
+  // Returns true if V is divergent at its definition.
+  //
+  // Even if this function returns false, V may still be divergent when used
+  // in a different basic block.
+  bool isDivergent(const Value *V) const;
+
+  // Returns true if V is uniform/non-divergent.
+  //
+  // Even if this function returns true, V may still be divergent when used
+  // in a different basic block.
+  bool isUniform(const Value *V) const { return !isDivergent(V); }
+
+  // Keep the analysis results uptodate by removing an erased value.
+  void removeValue(const Value *V) { DivergentValues.erase(V); }
+
+private:
+  // Whether analysis should be performed by GPUDivergenceAnalysis.
+  bool shouldUseGPUDivergenceAnalysis(const Function &F) const;
+
+  // (optional) handle to new DivergenceAnalysis
+  std::unique_ptr<GPUDivergenceAnalysis> gpuDA;
+
+  // Stores all divergent values.
+  DenseSet<const Value *> DivergentValues;
+};
+} // End llvm namespace
+
+#endif //LLVM_ANALYSIS_LEGACY_DIVERGENCE_ANALYSIS_H