[LIR] Move all the helpers to be private and re-order the methods in

[oota-llvm.git] / lib / Transforms / Scalar / LowerExpectIntrinsic.cpp

diff --git a/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp b/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
index aa991faafea48c141b0109b6c27fb4dc7937d911..0c47cbd5bfda6da1a891432ac82a2cd8dd2c4783 100644 (file)
--- a/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
+++ b/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
@@ -11,7 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/IR/BasicBlock.h"
@@ -25,12 +25,14 @@
 #include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Transforms/Scalar.h"
 
 using namespace llvm;
 
 #define DEBUG_TYPE "lower-expect-intrinsic"
 
-STATISTIC(IfHandled, "Number of 'expect' intrinsic instructions handled");
+STATISTIC(ExpectIntrinsicsHandled,
+          "Number of 'expect' intrinsic instructions handled");
 
 static cl::opt<uint32_t>
 LikelyBranchWeight("likely-branch-weight", cl::Hidden, cl::init(64),
@@ -39,24 +41,6 @@ static cl::opt<uint32_t>
 UnlikelyBranchWeight("unlikely-branch-weight", cl::Hidden, cl::init(4),
                    cl::desc("Weight of the branch unlikely to be taken (default = 4)"));
 
-namespace {
-/// \brief Legacy pass for lowering expect intrinsics out of the IR.
-///
-/// When this pass is run over a function it uses expect intrinsics which feed
-/// branches and switches to provide branch weight metadata for those
-/// terminators. It then removes the expect intrinsics from the IR so the rest
-/// of the optimizer can ignore them.
-class LowerExpectIntrinsic : public FunctionPass {
-public:
-  static char ID;
-  LowerExpectIntrinsic() : FunctionPass(ID) {
-    initializeLowerExpectIntrinsicPass(*PassRegistry::getPassRegistry());
-  }
-
-  bool runOnFunction(Function &F) override;
-};
-}
-
 static bool handleSwitchExpect(SwitchInst &SI) {
   CallInst *CI = dyn_cast<CallInst>(SI.getCondition());
   if (!CI)
@@ -142,21 +126,21 @@ static bool handleBranchExpect(BranchInst &BI) {
   return true;
 }
 
-bool LowerExpectIntrinsic::runOnFunction(Function &F) {
-  for (Function::iterator I = F.begin(), E = F.end(); I != E;) {
-    BasicBlock *BB = I++;
+static bool lowerExpectIntrinsic(Function &F) {
+  bool Changed = false;
 
+  for (BasicBlock &BB : F) {
     // Create "block_weights" metadata.
-    if (BranchInst *BI = dyn_cast<BranchInst>(BB->getTerminator())) {
+    if (BranchInst *BI = dyn_cast<BranchInst>(BB.getTerminator())) {
       if (handleBranchExpect(*BI))
-        IfHandled++;
-    } else if (SwitchInst *SI = dyn_cast<SwitchInst>(BB->getTerminator())) {
+        ExpectIntrinsicsHandled++;
+    } else if (SwitchInst *SI = dyn_cast<SwitchInst>(BB.getTerminator())) {
       if (handleSwitchExpect(*SI))
-        IfHandled++;
+        ExpectIntrinsicsHandled++;
     }
 
     // remove llvm.expect intrinsics.
-    for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE;) {
+    for (BasicBlock::iterator BI = BB.begin(), BE = BB.end(); BI != BE;) {
       CallInst *CI = dyn_cast<CallInst>(BI++);
       if (!CI)
         continue;
@@ -166,11 +150,37 @@ bool LowerExpectIntrinsic::runOnFunction(Function &F) {
         Value *Exp = CI->getArgOperand(0);
         CI->replaceAllUsesWith(Exp);
         CI->eraseFromParent();
+        Changed = true;
       }
     }
   }
 
-  return false;
+  return Changed;
+}
+
+PreservedAnalyses LowerExpectIntrinsicPass::run(Function &F) {
+  if (lowerExpectIntrinsic(F))
+    return PreservedAnalyses::none();
+
+  return PreservedAnalyses::all();
+}
+
+namespace {
+/// \brief Legacy pass for lowering expect intrinsics out of the IR.
+///
+/// When this pass is run over a function it uses expect intrinsics which feed
+/// branches and switches to provide branch weight metadata for those
+/// terminators. It then removes the expect intrinsics from the IR so the rest
+/// of the optimizer can ignore them.
+class LowerExpectIntrinsic : public FunctionPass {
+public:
+  static char ID;
+  LowerExpectIntrinsic() : FunctionPass(ID) {
+    initializeLowerExpectIntrinsicPass(*PassRegistry::getPassRegistry());
+  }
+
+  bool runOnFunction(Function &F) override { return lowerExpectIntrinsic(F); }
+};
 }
 
 char LowerExpectIntrinsic::ID = 0;