[PM] Port EarlyCSE to the new pass manager.

I've added RUN lines both to the basic test for EarlyCSE and the
target-specific test, as this serves as a nice test that the TTI layer
in the new pass manager is in fact working well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227725 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Transforms/Scalar/EarlyCSE.h

@@ -0,0 +1,45 @@
+//===- EarlyCSE.h - Simple and fast CSE pass --------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file provides the interface for a simple, fast CSE pass.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_SCALAR_EARLYCSE_H
+#define LLVM_TRANSFORMS_SCALAR_EARLYCSE_H
+
+#include "llvm/IR/Function.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+/// \brief A simple and fast domtree-based CSE pass.
+///
+/// This pass does a simple depth-first walk over the dominator tree,
+/// eliminating trivially redundant instructions and using instsimplify to
+/// canonicalize things as it goes. It is intended to be fast and catch obvious
+/// cases so that instcombine and other passes are more effective. It is
+/// expected that a later pass of GVN will catch the interesting/hard cases.
+class EarlyCSEPass {
+public:
+  static StringRef name() { return "EarlyCSEPass"; }
+
+  /// \brief Run the pass over the function.
+  ///
+  /// This will lower all of th expect intrinsic calls in this function into
+  /// branch weight metadata. That metadata will subsequently feed the analysis
+  /// of the probabilities and frequencies of the CFG. After running this pass,
+  /// no more expect intrinsics remain, allowing the rest of the optimizer to
+  /// ignore them.
+  PreservedAnalyses run(Function &F, AnalysisManager<Function> *AM);
+};
+
+}
+
+#endif

lib/Transforms/Scalar/EarlyCSE.cpp

@@ -12,7 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/EarlyCSE.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/ScopedHashTable.h"
 #include "llvm/ADT/Statistic.h"
@@ -28,6 +28,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/RecyclingAllocator.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include <deque>
 using namespace llvm;
@@ -689,6 +690,27 @@ bool EarlyCSE::run() {
   return Changed;
 }
 
+PreservedAnalyses EarlyCSEPass::run(Function &F,
+                                    AnalysisManager<Function> *AM) {
+  const DataLayout *DL = F.getParent()->getDataLayout();
+
+  auto &TLI = AM->getResult<TargetLibraryAnalysis>(F);
+  auto &TTI = AM->getResult<TargetIRAnalysis>(F);
+  auto &DT = AM->getResult<DominatorTreeAnalysis>(F);
+  auto &AC = AM->getResult<AssumptionAnalysis>(F);
+
+  EarlyCSE CSE(F, DL, TLI, TTI, DT, AC);
+
+  if (!CSE.run())
+    return PreservedAnalyses::all();
+
+  // CSE preserves the dominator tree because it doesn't mutate the CFG.
+  // FIXME: Bundle this with other CFG-preservation.
+  PreservedAnalyses PA;
+  PA.preserve<DominatorTreeAnalysis>();
+  return PA;
+}
+
 namespace {
 /// \brief A simple and fast domtree-based CSE pass.
 ///

test/Transforms/EarlyCSE/AArch64/intrinsics.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -S -mtriple=aarch64-none-linux-gnu -mattr=+neon -early-cse | FileCheck %s
+; RUN: opt < %s -S -mtriple=aarch64-none-linux-gnu -mattr=+neon -passes=early-cse | FileCheck %s
 
 define <4 x i32> @test_cse(i32* %a, [2 x <4 x i32>] %s.coerce, i32 %n) {
 entry:

test/Transforms/EarlyCSE/basic.ll

@@ -1,4 +1,5 @@
 ; RUN: opt < %s -S -early-cse | FileCheck %s
+; RUN: opt < %s -S -passes=early-cse | FileCheck %s
 
 declare void @llvm.assume(i1) nounwind
 

tools/opt/PassRegistry.def

@@ -62,6 +62,7 @@ FUNCTION_ANALYSIS("targetir",
 #ifndef FUNCTION_PASS
 #define FUNCTION_PASS(NAME, CREATE_PASS)
 #endif
+FUNCTION_PASS("early-cse", EarlyCSEPass())
 FUNCTION_PASS("instcombine", InstCombinePass())
 FUNCTION_PASS("invalidate<all>", InvalidateAllAnalysesPass())
 FUNCTION_PASS("no-op-function", NoOpFunctionPass())

tools/opt/Passes.cpp

@@ -28,6 +28,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Transforms/InstCombine/InstCombine.h"
+#include "llvm/Transforms/Scalar/EarlyCSE.h"
 #include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
 
 using namespace llvm;