Change lower atomic pass to use IntrinsicInst to simplify it a bit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113114 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 27 insertions, 37 deletions

diff --git a/lib/Transforms/Scalar/LowerAtomic.cpp b/lib/Transforms/Scalar/LowerAtomic.cpp
index 973ffe7e6a..db2dc46da9 100644
--- a/lib/Transforms/Scalar/LowerAtomic.cpp
+++ b/lib/Transforms/Scalar/LowerAtomic.cpp
@@ -18,22 +18,15 @@
 #include "llvm/Function.h"
 #include "llvm/Instruction.h"
 #include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
 #include "llvm/Intrinsics.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/IRBuilder.h"
-
 using namespace llvm;
 
-namespace {
-
-bool LowerAtomicIntrinsic(CallInst *CI) {
-  IRBuilder<> Builder(CI->getParent(), CI);
-
-  Function *Callee = CI->getCalledFunction();
-  if (!Callee)
-    return false;
-
-  unsigned IID = Callee->getIntrinsicID();
+static bool LowerAtomicIntrinsic(IntrinsicInst *II) {
+  IRBuilder<> Builder(II->getParent(), II);
+  unsigned IID = II->getIntrinsicID();
   switch (IID) {
   case Intrinsic::memory_barrier:
     break;
@@ -48,8 +41,8 @@ bool LowerAtomicIntrinsic(CallInst *CI) {
   case Intrinsic::atomic_load_min:
   case Intrinsic::atomic_load_umax:
   case Intrinsic::atomic_load_umin: {
-    Value *Ptr = CI->getArgOperand(0);
-    Value *Delta = CI->getArgOperand(1);
+    Value *Ptr = II->getArgOperand(0);
+    Value *Delta = II->getArgOperand(1);
 
     LoadInst *Orig = Builder.CreateLoad(Ptr);
     Value *Res = NULL;
@@ -96,32 +89,32 @@ bool LowerAtomicIntrinsic(CallInst *CI) {
     }
     Builder.CreateStore(Res, Ptr);
 
-    CI->replaceAllUsesWith(Orig);
+    II->replaceAllUsesWith(Orig);
     break;
   }
 
   case Intrinsic::atomic_swap: {
-    Value *Ptr = CI->getArgOperand(0);
-    Value *Val = CI->getArgOperand(1);
+    Value *Ptr = II->getArgOperand(0);
+    Value *Val = II->getArgOperand(1);
 
     LoadInst *Orig = Builder.CreateLoad(Ptr);
     Builder.CreateStore(Val, Ptr);
 
-    CI->replaceAllUsesWith(Orig);
+    II->replaceAllUsesWith(Orig);
     break;
   }
 
   case Intrinsic::atomic_cmp_swap: {
-    Value *Ptr = CI->getArgOperand(0);
-    Value *Cmp = CI->getArgOperand(1);
-    Value *Val = CI->getArgOperand(2);
+    Value *Ptr = II->getArgOperand(0);
+    Value *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);
 
-    CI->replaceAllUsesWith(Orig);
+    II->replaceAllUsesWith(Orig);
     break;
   }
 
@@ -129,28 +122,25 @@ bool LowerAtomicIntrinsic(CallInst *CI) {
     return false;
   }
 
-  assert(CI->use_empty() &&
+  assert(II->use_empty() &&
          "Lowering should have eliminated any uses of the intrinsic call!");
-  CI->eraseFromParent();
+  II->eraseFromParent();
 
   return true;
 }
 
-struct LowerAtomic : public BasicBlockPass {
-  static char ID;
-  LowerAtomic() : BasicBlockPass(ID) {}
-  bool runOnBasicBlock(BasicBlock &BB) {
-    bool Changed = false;
-    for (BasicBlock::iterator DI = BB.begin(), DE = BB.end(); DI != DE; ) {
-      Instruction *Inst = DI++;
-      if (CallInst *CI = dyn_cast<CallInst>(Inst))
-        Changed |= LowerAtomicIntrinsic(CI);
+namespace {
+  struct LowerAtomic : public BasicBlockPass {
+    static char ID;
+    LowerAtomic() : BasicBlockPass(ID) {}
+    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);
+      return Changed;
     }
-    return Changed;
-  }
-
-};
-
+  };
 }
 
 char LowerAtomic::ID = 0;