[BUG][INDVAR] Fix for PR21014: wrong SCEV operands commuting for non-commutative...

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

diff --git a/lib/Transforms/Utils/LowerExpectIntrinsic.cpp b/lib/Transforms/Utils/LowerExpectIntrinsic.cpp
index 61ab3f65330a2620644508cd326fee77c93408b5..ff89e7474402556f419c62dd534d4b320eae9303 100644 (file)
--- a/lib/Transforms/Utils/LowerExpectIntrinsic.cpp
+++ b/lib/Transforms/Utils/LowerExpectIntrinsic.cpp
@@ -1,21 +1,36 @@
-#define DEBUG_TYPE "lower-expect-intrinsic"
-#include "llvm/Constants.h"
-#include "llvm/Function.h"
-#include "llvm/BasicBlock.h"
-#include "llvm/LLVMContext.h"
-#include "llvm/Instructions.h"
-#include "llvm/Intrinsics.h"
-#include "llvm/Metadata.h"
-#include "llvm/Pass.h"
+//===- LowerExpectIntrinsic.cpp - Lower expect intrinsic ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass lowers the 'expect' intrinsic to LLVM metadata.
+//
+//===----------------------------------------------------------------------===//
+
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/MDBuilder.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
-#include "llvm/ADT/Statistic.h"
 #include <vector>
 
 using namespace llvm;
 
-STATISTIC(IfHandled, "Number of 'expect' intrinsic intructions handled");
+#define DEBUG_TYPE "lower-expect-intrinsic"
+
+STATISTIC(IfHandled, "Number of 'expect' intrinsic instructions handled");
 
 static cl::opt<uint32_t>
 LikelyBranchWeight("likely-branch-weight", cl::Hidden, cl::init(64),
@@ -38,7 +53,7 @@ namespace {
       initializeLowerExpectIntrinsicPass(*PassRegistry::getPassRegistry());
     }
 
-    bool runOnFunction(Function &F);
+    bool runOnFunction(Function &F) override;
   };
 }
 
@@ -57,21 +72,18 @@ bool LowerExpectIntrinsic::HandleSwitchExpect(SwitchInst *SI) {
   if (!ExpectedValue)
     return false;
 
-  LLVMContext &Context = CI->getContext();
-  Type *Int32Ty = Type::getInt32Ty(Context);
-
-  unsigned caseNo = SI->findCaseValue(ExpectedValue);
-  std::vector<Value *> Vec;
-  unsigned n = SI->getNumCases();
-  Vec.resize(n + 1); // +1 for MDString
+  SwitchInst::CaseIt Case = SI->findCaseValue(ExpectedValue);
+  unsigned n = SI->getNumCases(); // +1 for default case.
+  std::vector<uint32_t> Weights(n + 1);
 
-  Vec[0] = MDString::get(Context, "branch_weights");
-  for (unsigned i = 0; i < n; ++i) {
-    Vec[i + 1] = ConstantInt::get(Int32Ty, i == caseNo ? LikelyBranchWeight : UnlikelyBranchWeight);
-  }
+  Weights[0] = Case == SI->case_default() ? LikelyBranchWeight
+                                          : UnlikelyBranchWeight;
+  for (unsigned i = 0; i != n; ++i)
+    Weights[i + 1] = i == Case.getCaseIndex() ? LikelyBranchWeight
+                                              : UnlikelyBranchWeight;
 
-  MDNode *WeightsNode = llvm::MDNode::get(Context, Vec);
-  SI->setMetadata(LLVMContext::MD_prof, WeightsNode);
+  SI->setMetadata(LLVMContext::MD_prof,
+                  MDBuilder(CI->getContext()).createBranchWeights(Weights));
 
   SI->setCondition(ArgValue);
   return true;
@@ -83,15 +95,25 @@ bool LowerExpectIntrinsic::HandleIfExpect(BranchInst *BI) {
     return false;
 
   // Handle non-optimized IR code like:
-  //   %expval = call i64 @llvm.expect.i64.i64(i64 %conv1, i64 1)
+  //   %expval = call i64 @llvm.expect.i64(i64 %conv1, i64 1)
   //   %tobool = icmp ne i64 %expval, 0
   //   br i1 %tobool, label %if.then, label %if.end
+  //
+  // Or the following simpler case:
+  //   %expval = call i1 @llvm.expect.i1(i1 %cmp, i1 1)
+  //   br i1 %expval, label %if.then, label %if.end
+
+  CallInst *CI;
 
   ICmpInst *CmpI = dyn_cast<ICmpInst>(BI->getCondition());
-  if (!CmpI || CmpI->getPredicate() != CmpInst::ICMP_NE)
-    return false;
+  if (!CmpI) {
+    CI = dyn_cast<CallInst>(BI->getCondition());
+  } else {
+    if (CmpI->getPredicate() != CmpInst::ICMP_NE)
+      return false;
+    CI = dyn_cast<CallInst>(CmpI->getOperand(0));
+  }
 
-  CallInst *CI = dyn_cast<CallInst>(CmpI->getOperand(0));
   if (!CI)
     return false;
 
@@ -104,22 +126,22 @@ bool LowerExpectIntrinsic::HandleIfExpect(BranchInst *BI) {
   if (!ExpectedValue)
     return false;
 
-  LLVMContext &Context = CI->getContext();
-  Type *Int32Ty = Type::getInt32Ty(Context);
-  bool Likely = ExpectedValue->isOne();
+  MDBuilder MDB(CI->getContext());
+  MDNode *Node;
 
   // If expect value is equal to 1 it means that we are more likely to take
   // branch 0, in other case more likely is branch 1.
-  Value *Ops[] = {
-    MDString::get(Context, "branch_weights"),
-    ConstantInt::get(Int32Ty, Likely ? LikelyBranchWeight : UnlikelyBranchWeight),
-    ConstantInt::get(Int32Ty, Likely ? UnlikelyBranchWeight : LikelyBranchWeight)
-  };
+  if (ExpectedValue->isOne())
+    Node = MDB.createBranchWeights(LikelyBranchWeight, UnlikelyBranchWeight);
+  else
+    Node = MDB.createBranchWeights(UnlikelyBranchWeight, LikelyBranchWeight);
 
-  MDNode *WeightsNode = MDNode::get(Context, Ops);
-  BI->setMetadata(LLVMContext::MD_prof, WeightsNode);
+  BI->setMetadata(LLVMContext::MD_prof, Node);
 
-  CmpI->setOperand(0, ArgValue);
+  if (CmpI)
+    CmpI->setOperand(0, ArgValue);
+  else
+    BI->setCondition(ArgValue);
   return true;
 }