[C++] Use 'nullptr'. Transforms edition.
[oota-llvm.git] / lib / Transforms / Scalar / LowerAtomic.cpp
index 5f5ed03bd821c51bad3d5fb9e28aba7c0bbe654b..4251ac47ed51b3ba2e46b7318525aace4fe1a444 100644 (file)
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "loweratomic"
 #include "llvm/Transforms/Scalar.h"
-#include "llvm/Function.h"
-#include "llvm/IntrinsicInst.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/Pass.h"
-#include "llvm/Support/IRBuilder.h"
 using namespace llvm;
 
-static bool LowerAtomicIntrinsic(IntrinsicInst *II) {
-  IRBuilder<> Builder(II->getParent(), II);
-  unsigned IID = II->getIntrinsicID();
-  switch (IID) {
-  case Intrinsic::memory_barrier:
-    break;
-
-  case Intrinsic::atomic_load_add:
-  case Intrinsic::atomic_load_sub:
-  case Intrinsic::atomic_load_and:
-  case Intrinsic::atomic_load_nand:
-  case Intrinsic::atomic_load_or:
-  case Intrinsic::atomic_load_xor:
-  case Intrinsic::atomic_load_max:
-  case Intrinsic::atomic_load_min:
-  case Intrinsic::atomic_load_umax:
-  case Intrinsic::atomic_load_umin: {
-    Value *Ptr = II->getArgOperand(0), *Delta = II->getArgOperand(1);
-
-    LoadInst *Orig = Builder.CreateLoad(Ptr);
-    Value *Res = NULL;
-    switch (IID) {
-    default: assert(0 && "Unrecognized atomic modify operation");
-    case Intrinsic::atomic_load_add:
-      Res = Builder.CreateAdd(Orig, Delta);
-      break;
-    case Intrinsic::atomic_load_sub:
-      Res = Builder.CreateSub(Orig, Delta);
-      break;
-    case Intrinsic::atomic_load_and:
-      Res = Builder.CreateAnd(Orig, Delta);
-      break;
-    case Intrinsic::atomic_load_nand:
-      Res = Builder.CreateNot(Builder.CreateAnd(Orig, Delta));
-      break;
-    case Intrinsic::atomic_load_or:
-      Res = Builder.CreateOr(Orig, Delta);
-      break;
-    case Intrinsic::atomic_load_xor:
-      Res = Builder.CreateXor(Orig, Delta);
-      break;
-    case Intrinsic::atomic_load_max:
-      Res = Builder.CreateSelect(Builder.CreateICmpSLT(Orig, Delta),
-                                 Delta, Orig);
-      break;
-    case Intrinsic::atomic_load_min:
-      Res = Builder.CreateSelect(Builder.CreateICmpSLT(Orig, Delta),
-                                 Orig, Delta);
-      break;
-    case Intrinsic::atomic_load_umax:
-      Res = Builder.CreateSelect(Builder.CreateICmpULT(Orig, Delta),
-                                 Delta, Orig);
-      break;
-    case Intrinsic::atomic_load_umin:
-      Res = Builder.CreateSelect(Builder.CreateICmpULT(Orig, Delta),
-                                 Orig, Delta);
-      break;
-    }
-    Builder.CreateStore(Res, Ptr);
-
-    II->replaceAllUsesWith(Orig);
-    break;
-  }
-
-  case Intrinsic::atomic_swap: {
-    Value *Ptr = II->getArgOperand(0), *Val = II->getArgOperand(1);
-    LoadInst *Orig = Builder.CreateLoad(Ptr);
-    Builder.CreateStore(Val, Ptr);
-    II->replaceAllUsesWith(Orig);
-    break;
-  }
-
-  case Intrinsic::atomic_cmp_swap: {
-    Value *Ptr = II->getArgOperand(0), *Cmp = II->getArgOperand(1);
-    Value *Val = II->getArgOperand(2);
-
-    LoadInst *Orig = Builder.CreateLoad(Ptr);
-    Value *Equal = Builder.CreateICmpEQ(Orig, Cmp);
-    Value *Res = Builder.CreateSelect(Equal, Val, Orig);
-    Builder.CreateStore(Res, Ptr);
-    II->replaceAllUsesWith(Orig);
-    break;
-  }
-
-  default:
-    return false;
-  }
-
-  assert(II->use_empty() &&
-         "Lowering should have eliminated any uses of the intrinsic call!");
-  II->eraseFromParent();
-
-  return true;
-}
+#define DEBUG_TYPE "loweratomic"
 
-bool LowerAtomicCmpXchgInst(AtomicCmpXchgInst *CXI) {
+static bool LowerAtomicCmpXchgInst(AtomicCmpXchgInst *CXI) {
   IRBuilder<> Builder(CXI->getParent(), CXI);
   Value *Ptr = CXI->getPointerOperand();
   Value *Cmp = CXI->getCompareOperand();
   Value *Val = CXI->getNewValOperand();
+
   LoadInst *Orig = Builder.CreateLoad(Ptr);
   Value *Equal = Builder.CreateICmpEQ(Orig, Cmp);
   Value *Res = Builder.CreateSelect(Equal, Val, Orig);
   Builder.CreateStore(Res, Ptr);
+
   CXI->replaceAllUsesWith(Orig);
   CXI->eraseFromParent();
   return true;
 }
 
-bool LowerAtomicRMWInst(AtomicRMWInst *RMWI) {
+static bool LowerAtomicRMWInst(AtomicRMWInst *RMWI) {
   IRBuilder<> Builder(RMWI->getParent(), RMWI);
   Value *Ptr = RMWI->getPointerOperand();
   Value *Val = RMWI->getValOperand();
 
   LoadInst *Orig = Builder.CreateLoad(Ptr);
-  Value *Res = NULL;
+  Value *Res = nullptr;
 
   switch (RMWI->getOperation()) {
   default: llvm_unreachable("Unexpected RMW operation");
@@ -190,24 +96,41 @@ static bool LowerFenceInst(FenceInst *FI) {
   return true;
 }
 
+static bool LowerLoadInst(LoadInst *LI) {
+  LI->setAtomic(NotAtomic);
+  return true;
+}
+
+static bool LowerStoreInst(StoreInst *SI) {
+  SI->setAtomic(NotAtomic);
+  return true;
+}
+
 namespace {
   struct LowerAtomic : public BasicBlockPass {
     static char ID;
     LowerAtomic() : BasicBlockPass(ID) {
       initializeLowerAtomicPass(*PassRegistry::getPassRegistry());
     }
-    bool runOnBasicBlock(BasicBlock &BB) {
+    bool runOnBasicBlock(BasicBlock &BB) override {
+      if (skipOptnoneFunction(BB))
+        return false;
       bool Changed = false;
       for (BasicBlock::iterator DI = BB.begin(), DE = BB.end(); DI != DE; ) {
         Instruction *Inst = DI++;
-        if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst))
-          Changed |= LowerAtomicIntrinsic(II);
-        else if (FenceInst *FI = dyn_cast<FenceInst>(Inst))
+        if (FenceInst *FI = dyn_cast<FenceInst>(Inst))
           Changed |= LowerFenceInst(FI);
         else if (AtomicCmpXchgInst *CXI = dyn_cast<AtomicCmpXchgInst>(Inst))
           Changed |= LowerAtomicCmpXchgInst(CXI);
         else if (AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(Inst))
           Changed |= LowerAtomicRMWInst(RMWI);
+        else if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
+          if (LI->isAtomic())
+            LowerLoadInst(LI);
+        } else if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
+          if (SI->isAtomic())
+            LowerStoreInst(SI);
+        }
       }
       return Changed;
     }