From 84b19be6ab9544f72eafb11048a1121f5ea77c95 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Sun, 16 Jul 2006 01:02:57 +0000
Subject: [PATCH] skeleton of a lowerCall implementation for ARM

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29159 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMAsmPrinter.cpp   |  8 ++--
 lib/Target/ARM/ARMISelDAGToDAG.cpp | 70 +++++++++++++++++++++++++++++-
 lib/Target/ARM/ARMInstrInfo.td     |  6 +++
 3 files changed, 79 insertions(+), 5 deletions(-)

diff --git a/lib/Target/ARM/ARMAsmPrinter.cpp b/lib/Target/ARM/ARMAsmPrinter.cpp
index 9172c53b3b1..efb20d150ed 100644
--- a/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -156,9 +156,11 @@ void ARMAsmPrinter::printOperand(const MachineInstr *MI, int opNum) {
     assert(0 && "not implemented");
     abort();
     return;
-  case MachineOperand::MO_GlobalAddress:
-    assert(0 && "not implemented");
-    abort();
+  case MachineOperand::MO_GlobalAddress: {
+    GlobalValue *GV = MO.getGlobal();
+    std::string Name = Mang->getValueName(GV);
+    O << Name;
+  }
     break;
   case MachineOperand::MO_ExternalSymbol:
     assert(0 && "not implemented");
diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index 2b75b42aa4e..2eb89b79972 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 @@ namespace {
   public:
     ARMTargetLowering(TargetMachine &TM);
     virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
+    virtual const char *getTargetNodeName(unsigned Opcode) const;
   };
 
 }
@@ -42,9 +44,73 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
   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) {
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index 2f3196f1891..15a57c5a83d 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -41,6 +41,10 @@ def SDT_ARMCallSeq : SDTypeProfile<0, 1, [ SDTCisVT<0, i32> ]>;
 def callseq_start  : SDNode<"ISD::CALLSEQ_START", SDT_ARMCallSeq, [SDNPHasChain]>;
 def callseq_end    : SDNode<"ISD::CALLSEQ_END",   SDT_ARMCallSeq, [SDNPHasChain]>;
 
+def SDT_ARMcall    : SDTypeProfile<0, -1, [SDTCisInt<0>]>;
+def ARMcall        : SDNode<"ARMISD::CALL", SDT_ARMcall,
+                           [SDNPHasChain, SDNPOptInFlag, SDNPOutFlag]>;
+
 def ADJCALLSTACKUP : InstARM<(ops i32imm:$amt),
                             "!ADJCALLSTACKUP $amt",
                             [(callseq_end imm:$amt)]>;
@@ -51,6 +55,8 @@ def ADJCALLSTACKDOWN : InstARM<(ops i32imm:$amt),
 
 def bxr: InstARM<(ops IntRegs:$dst), "bx $dst", [(brind IntRegs:$dst)]>;
 
+def bl: InstARM<(ops i32imm:$func, variable_ops), "bl $func", [(ARMcall tglobaladdr:$func)]>;
+
 def ldr   : InstARM<(ops IntRegs:$dst, memri:$addr),
                      "ldr $dst, [$addr]",
                      [(set IntRegs:$dst, (load iaddr:$addr))]>;
-- 
2.34.1