[SystemZ] Use CLST to implement strcmp

llvm-svn: 188544

2 files changed, 34 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 7a9a4d77d2d..b1812f2cda9 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5558,6 +5558,35 @@ bool SelectionDAGBuilder::visitMemCmpCall(const CallInst &I) {
   return false;
 }
 
+/// visitStrCmpCall - See if we can lower a call to strcmp in an optimized form.
+/// If so, return true and lower it, otherwise return false and it will be
+/// lowered like a normal call.
+bool SelectionDAGBuilder::visitStrCmpCall(const CallInst &I) {
+  // Verify that the prototype makes sense.  int strcmp(void*,void*)
+  if (I.getNumArgOperands() != 2)
+    return false;
+
+  const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1);
+  if (!Arg0->getType()->isPointerTy() ||
+      !Arg1->getType()->isPointerTy() ||
+      !I.getType()->isIntegerTy())
+    return false;
+
+  const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
+  std::pair<SDValue, SDValue> Res =
+    TSI.EmitTargetCodeForStrcmp(DAG, getCurSDLoc(), DAG.getRoot(),
+                                getValue(Arg0), getValue(Arg1),
+                                MachinePointerInfo(Arg0),
+                                MachinePointerInfo(Arg1));
+  if (Res.first.getNode()) {
+    processIntegerCallValue(I, Res.first, true);
+    PendingLoads.push_back(Res.second);
+    return true;
+  }
+
+  return false;
+}
+
 /// visitUnaryFloatCall - If a call instruction is a unary floating-point
 /// operation (as expected), translate it to an SDNode with the specified opcode
 /// and return true.
@@ -5704,6 +5733,10 @@ void SelectionDAGBuilder::visitCall(const CallInst &I) {
         if (visitMemCmpCall(I))
           return;
         break;
+      case LibFunc::strcmp:
+        if (visitStrCmpCall(I))
+          return;
+        break;
       }
     }
   }
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
index 217d2f9e6ac..ff15347aae5 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -523,6 +523,7 @@ private:
   void visitPHI(const PHINode &I);
   void visitCall(const CallInst &I);
   bool visitMemCmpCall(const CallInst &I);
+  bool visitStrCmpCall(const CallInst &I);
   bool visitUnaryFloatCall(const CallInst &I, unsigned Opcode);
   void visitAtomicLoad(const LoadInst &I);
   void visitAtomicStore(const StoreInst &I);