skeleton of a lowerCall implementation for ARM
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29159 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index 2b75b42..2eb89b7 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -13,6 +13,7 @@
#include "ARM.h"
#include "ARMTargetMachine.h"
+#include "llvm/CallingConv.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/Intrinsics.h"
@@ -33,6 +34,7 @@
public:
ARMTargetLowering(TargetMachine &TM);
virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
+ virtual const char *getTargetNodeName(unsigned Opcode) const;
};
}
@@ -42,9 +44,73 @@
setOperationAction(ISD::RET, MVT::Other, Custom);
}
+namespace llvm {
+ namespace ARMISD {
+ enum NodeType {
+ // Start the numbering where the builting ops and target ops leave off.
+ FIRST_NUMBER = ISD::BUILTIN_OP_END+ARM::INSTRUCTION_LIST_END,
+ /// CALL - A direct function call.
+ CALL
+ };
+ }
+}
+
+const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
+ switch (Opcode) {
+ default: return 0;
+ case ARMISD::CALL: return "ARMISD::CALL";
+ }
+}
+
+// This transforms a ISD::CALL node into a
+// callseq_star <- ARMISD:CALL <- callseq_end
+// chain
static SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG) {
- assert(0 && "Not implemented");
- abort();
+ SDOperand Chain = Op.getOperand(0);
+ unsigned CallConv = cast<ConstantSDNode>(Op.getOperand(1))->getValue();
+ assert(CallConv == CallingConv::C && "unknown calling convention");
+ bool isVarArg = cast<ConstantSDNode>(Op.getOperand(2))->getValue() != 0;
+ assert(isVarArg == false && "VarArg not supported");
+ bool isTailCall = cast<ConstantSDNode>(Op.getOperand(3))->getValue() != 0;
+ assert(isTailCall == false && "tail call not supported");
+ SDOperand Callee = Op.getOperand(4);
+ unsigned NumOps = (Op.getNumOperands() - 5) / 2;
+ assert(NumOps == 0);
+
+ // Count how many bytes are to be pushed on the stack. Initially
+ // only the link register.
+ unsigned NumBytes = 4;
+
+ // Adjust the stack pointer for the new arguments...
+ // These operations are automatically eliminated by the prolog/epilog pass
+ Chain = DAG.getCALLSEQ_START(Chain,
+ DAG.getConstant(NumBytes, MVT::i32));
+
+ std::vector<MVT::ValueType> NodeTys;
+ NodeTys.push_back(MVT::Other); // Returns a chain
+ NodeTys.push_back(MVT::Flag); // Returns a flag for retval copy to use.
+
+ // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
+ // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
+ // node so that legalize doesn't hack it.
+ if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
+ Callee = DAG.getTargetGlobalAddress(G->getGlobal(), Callee.getValueType());
+
+ // If this is a direct call, pass the chain and the callee.
+ assert (Callee.Val);
+ std::vector<SDOperand> Ops;
+ Ops.push_back(Chain);
+ Ops.push_back(Callee);
+
+ unsigned CallOpc = ARMISD::CALL;
+ Chain = DAG.getNode(CallOpc, NodeTys, Ops);
+
+ assert(Op.Val->getValueType(0) == MVT::Other);
+
+ Chain = DAG.getNode(ISD::CALLSEQ_END, MVT::Other, Chain,
+ DAG.getConstant(NumBytes, MVT::i32));
+
+ return Chain;
}
static SDOperand LowerRET(SDOperand Op, SelectionDAG &DAG) {