[SystemZ] Use SRST to implement strlen and strnlen
It would also make sense to use it for memchr; I'm working on that now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188547 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 9bb7897..3b9f358 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5616,6 +5616,59 @@
return false;
}
+/// visitStrLenCall -- See if we can lower a strlen call into an optimized
+/// form. If so, return true and lower it, otherwise return false and it
+/// will be lowered like a normal call.
+bool SelectionDAGBuilder::visitStrLenCall(const CallInst &I) {
+ // Verify that the prototype makes sense. size_t strlen(char *)
+ if (I.getNumArgOperands() != 1)
+ return false;
+
+ const Value *Arg0 = I.getArgOperand(0);
+ if (!Arg0->getType()->isPointerTy() || !I.getType()->isIntegerTy())
+ return false;
+
+ const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
+ std::pair<SDValue, SDValue> Res =
+ TSI.EmitTargetCodeForStrlen(DAG, getCurSDLoc(), DAG.getRoot(),
+ getValue(Arg0), MachinePointerInfo(Arg0));
+ if (Res.first.getNode()) {
+ processIntegerCallValue(I, Res.first, false);
+ PendingLoads.push_back(Res.second);
+ return true;
+ }
+
+ return false;
+}
+
+/// visitStrNLenCall -- See if we can lower a strnlen call into an optimized
+/// form. If so, return true and lower it, otherwise return false and it
+/// will be lowered like a normal call.
+bool SelectionDAGBuilder::visitStrNLenCall(const CallInst &I) {
+ // Verify that the prototype makes sense. size_t strnlen(char *, size_t)
+ if (I.getNumArgOperands() != 2)
+ return false;
+
+ const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1);
+ if (!Arg0->getType()->isPointerTy() ||
+ !Arg1->getType()->isIntegerTy() ||
+ !I.getType()->isIntegerTy())
+ return false;
+
+ const TargetSelectionDAGInfo &TSI = DAG.getSelectionDAGInfo();
+ std::pair<SDValue, SDValue> Res =
+ TSI.EmitTargetCodeForStrnlen(DAG, getCurSDLoc(), DAG.getRoot(),
+ getValue(Arg0), getValue(Arg1),
+ MachinePointerInfo(Arg0));
+ if (Res.first.getNode()) {
+ processIntegerCallValue(I, Res.first, false);
+ 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.
@@ -5774,6 +5827,14 @@
if (visitStrCmpCall(I))
return;
break;
+ case LibFunc::strlen:
+ if (visitStrLenCall(I))
+ return;
+ break;
+ case LibFunc::strnlen:
+ if (visitStrNLenCall(I))
+ return;
+ break;
}
}
}