[PM] Port LowerExpectIntrinsic to the new pass manager.

This just lifts the logic into a static helper function, sinks the
legacy pass to be a trivial wrapper of that helper fuction, and adds
a trivial wrapper for the new PM as well. Not much to see here.

I switched a test case to run in both modes, but we have to strip the
dead prototypes separately as that pass isn't in the new pass manager
(yet).

llvm-svn: 226999

1 files changed, 28 insertions, 20 deletions

diff --git a/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp b/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
index 0cea5c5bc59..0c47cbd5bfd 100644
--- a/llvm/lib/Transforms/Scalar/LowerExpectIntrinsic.cpp
+++ b/llvm/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"
@@ -25,6 +25,7 @@
 #include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Transforms/Scalar.h"
 
 using namespace llvm;
 
@@ -40,24 +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)
@@ -143,7 +126,7 @@ static bool handleBranchExpect(BranchInst &BI) {
   return true;
 }
 
-bool LowerExpectIntrinsic::runOnFunction(Function &F) {
+static bool lowerExpectIntrinsic(Function &F) {
   bool Changed = false;
 
   for (BasicBlock &BB : F) {
@@ -175,6 +158,31 @@ bool LowerExpectIntrinsic::runOnFunction(Function &F) {
   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;
 INITIALIZE_PASS(LowerExpectIntrinsic, "lower-expect",
                 "Lower 'expect' Intrinsics", false, false)