1 files changed, 88 insertions, 85 deletions

diff --git a/lib/Transforms/Scalar/LowerAtomic.cpp b/lib/Transforms/Scalar/LowerAtomic.cpp
index 9087b46..689bbe9 100644
--- a/lib/Transforms/Scalar/LowerAtomic.cpp
+++ b/lib/Transforms/Scalar/LowerAtomic.cpp
@@ -20,98 +20,88 @@
 #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;
+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;
+}
 
-  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);
+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;
-    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);
+  LoadInst *Orig = Builder.CreateLoad(Ptr);
+  Value *Res = NULL;
 
-    II->replaceAllUsesWith(Orig);
+  switch (RMWI->getOperation()) {
+  default: llvm_unreachable("Unexpected RMW operation");
+  case AtomicRMWInst::Xchg:
+    Res = Val;
     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);
+  case AtomicRMWInst::Add:
+    Res = Builder.CreateAdd(Orig, Val);
     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);
+  case AtomicRMWInst::Sub:
+    Res = Builder.CreateSub(Orig, Val);
+    break;
+  case AtomicRMWInst::And:
+    Res = Builder.CreateAnd(Orig, Val);
+    break;
+  case AtomicRMWInst::Nand:
+    Res = Builder.CreateNot(Builder.CreateAnd(Orig, Val));
+    break;
+  case AtomicRMWInst::Or:
+    Res = Builder.CreateOr(Orig, Val);
+    break;
+  case AtomicRMWInst::Xor:
+    Res = Builder.CreateXor(Orig, Val);
+    break;
+  case AtomicRMWInst::Max:
+    Res = Builder.CreateSelect(Builder.CreateICmpSLT(Orig, Val),
+                               Val, Orig);
+    break;
+  case AtomicRMWInst::Min:
+    Res = Builder.CreateSelect(Builder.CreateICmpSLT(Orig, Val),
+                               Orig, Val);
+    break;
+  case AtomicRMWInst::UMax:
+    Res = Builder.CreateSelect(Builder.CreateICmpULT(Orig, Val),
+                               Val, Orig);
+    break;
+  case AtomicRMWInst::UMin:
+    Res = Builder.CreateSelect(Builder.CreateICmpULT(Orig, Val),
+                               Orig, Val);
     break;
   }
+  Builder.CreateStore(Res, Ptr);
+  RMWI->replaceAllUsesWith(Orig);
+  RMWI->eraseFromParent();
+  return true;
+}
 
-  default:
-    return false;
-  }
+static bool LowerFenceInst(FenceInst *FI) {
+  FI->eraseFromParent();
+  return true;
+}
 
-  assert(II->use_empty() &&
-         "Lowering should have eliminated any uses of the intrinsic call!");
-  II->eraseFromParent();
+static bool LowerLoadInst(LoadInst *LI) {
+  LI->setAtomic(NotAtomic);
+  return true;
+}
 
+static bool LowerStoreInst(StoreInst *SI) {
+  SI->setAtomic(NotAtomic);
   return true;
 }
 
@@ -123,9 +113,22 @@ namespace {
     }
     bool runOnBasicBlock(BasicBlock &BB) {
       bool Changed = false;
-      for (BasicBlock::iterator DI = BB.begin(), DE = BB.end(); DI != DE; )
-        if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(DI++))
-          Changed |= LowerAtomicIntrinsic(II);
+      for (BasicBlock::iterator DI = BB.begin(), DE = BB.end(); DI != DE; ) {
+        Instruction *Inst = DI++;
+        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;
     }
   };