Don't override LowerArguments in the SPARC backend. In addition to

being more consistent with other backends, this makes the SPARC backend 
deal with functions with arguments with illegal types correctly, which 
fixes some tests in test/CodeGen/Generic.

llvm-svn: 76375

1 files changed, 37 insertions, 28 deletions

diff --git a/llvm/lib/Target/Sparc/SparcISelLowering.cpp b/llvm/lib/Target/Sparc/SparcISelLowering.cpp
index 3705ecb41ec..7badf2faad8 100644
--- a/llvm/lib/Target/Sparc/SparcISelLowering.cpp
+++ b/llvm/lib/Target/Sparc/SparcISelLowering.cpp
@@ -78,36 +78,41 @@ static SDValue LowerRET(SDValue Op, SelectionDAG &DAG) {
 /// LowerArguments - V8 uses a very simple ABI, where all values are passed in
 /// either one or two GPRs, including FP values.  TODO: we should pass FP values
 /// in FP registers for fastcc functions.
-void
-SparcTargetLowering::LowerArguments(Function &F, SelectionDAG &DAG,
-                                    SmallVectorImpl<SDValue> &ArgValues,
-                                    DebugLoc dl) {
+SDValue
+SparcTargetLowering::LowerFORMAL_ARGUMENTS(SDValue Op,
+                                           SelectionDAG &DAG) {
   MachineFunction &MF = DAG.getMachineFunction();
   MachineRegisterInfo &RegInfo = MF.getRegInfo();
+  SDValue Root = Op.getOperand(0);
+  bool isVarArg = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue() != 0;
+  unsigned CC = MF.getFunction()->getCallingConv();
+  DebugLoc dl = Op.getDebugLoc();
+
+  // Assign locations to all of the incoming arguments.
+  SmallVector<CCValAssign, 16> ArgLocs;
+  CCState CCInfo(CC, isVarArg, getTargetMachine(), ArgLocs, DAG.getContext());
+  CCInfo.AnalyzeFormalArguments(Op.getNode(), CC_Sparc32);
 
   static const unsigned ArgRegs[] = {
     SP::I0, SP::I1, SP::I2, SP::I3, SP::I4, SP::I5
   };
-
   const unsigned *CurArgReg = ArgRegs, *ArgRegEnd = ArgRegs+6;
   unsigned ArgOffset = 68;
 
-  SDValue Root = DAG.getRoot();
-  std::vector<SDValue> OutChains;
-
-  for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I) {
-    MVT ObjectVT = getValueType(I->getType());
-
+  SmallVector<SDValue, 16> ArgValues;
+  for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
+    SDValue ArgValue;
+    CCValAssign &VA = ArgLocs[i];
+    // FIXME: We ignore the register assignments of AnalyzeFormalArguments
+    // because it doesn't know how to split a double into two i32 registers.
+    MVT ObjectVT = VA.getValVT();
     switch (ObjectVT.getSimpleVT()) {
     default: llvm_unreachable("Unhandled argument type!");
     case MVT::i1:
     case MVT::i8:
     case MVT::i16:
     case MVT::i32:
-      if (I->use_empty()) {                // Argument is dead.
-        if (CurArgReg < ArgRegEnd) ++CurArgReg;
-        ArgValues.push_back(DAG.getUNDEF(ObjectVT));
-      } else if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
+      if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
         unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
         MF.getRegInfo().addLiveIn(*CurArgReg++, VReg);
         SDValue Arg = DAG.getCopyFromReg(Root, dl, VReg, MVT::i32);
@@ -141,10 +146,7 @@ SparcTargetLowering::LowerArguments(Function &F, SelectionDAG &DAG,
       ArgOffset += 4;
       break;
     case MVT::f32:
-      if (I->use_empty()) {                // Argument is dead.
-        if (CurArgReg < ArgRegEnd) ++CurArgReg;
-        ArgValues.push_back(DAG.getUNDEF(ObjectVT));
-      } else if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
+      if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
         // FP value is passed in an integer register.
         unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
         MF.getRegInfo().addLiveIn(*CurArgReg++, VReg);
@@ -163,11 +165,7 @@ SparcTargetLowering::LowerArguments(Function &F, SelectionDAG &DAG,
 
     case MVT::i64:
     case MVT::f64:
-      if (I->use_empty()) {                // Argument is dead.
-        if (CurArgReg < ArgRegEnd) ++CurArgReg;
-        if (CurArgReg < ArgRegEnd) ++CurArgReg;
-        ArgValues.push_back(DAG.getUNDEF(ObjectVT));
-      } else {
+      {
         SDValue HiVal;
         if (CurArgReg < ArgRegEnd) {  // Lives in an incoming GPR
           unsigned VRegHi = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
@@ -206,10 +204,12 @@ SparcTargetLowering::LowerArguments(Function &F, SelectionDAG &DAG,
   }
 
   // Store remaining ArgRegs to the stack if this is a varargs function.
-  if (F.isVarArg()) {
+  if (isVarArg) {
     // Remember the vararg offset for the va_start implementation.
     VarArgsFrameOffset = ArgOffset;
 
+    std::vector<SDValue> OutChains;
+
     for (; CurArgReg != ArgRegEnd; ++CurArgReg) {
       unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
       MF.getRegInfo().addLiveIn(*CurArgReg, VReg);
@@ -221,11 +221,19 @@ SparcTargetLowering::LowerArguments(Function &F, SelectionDAG &DAG,
       OutChains.push_back(DAG.getStore(DAG.getRoot(), dl, Arg, FIPtr, NULL, 0));
       ArgOffset += 4;
     }
+
+    if (!OutChains.empty()) {
+      OutChains.push_back(Root);
+      Root = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
+                         &OutChains[0], OutChains.size());
+    }
   }
 
-  if (!OutChains.empty())
-    DAG.setRoot(DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
-                            &OutChains[0], OutChains.size()));
+  ArgValues.push_back(Root);
+
+  // Return the new list of results.
+  return DAG.getNode(ISD::MERGE_VALUES, dl, Op.getNode()->getVTList(),
+                     &ArgValues[0], ArgValues.size()).getValue(Op.getResNo());
 }
 
 static SDValue LowerCALL(SDValue Op, SelectionDAG &DAG) {
@@ -918,6 +926,7 @@ LowerOperation(SDValue Op, SelectionDAG &DAG) {
   case ISD::VAARG:              return LowerVAARG(Op, DAG);
   case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
   case ISD::CALL:               return LowerCALL(Op, DAG);
+  case ISD::FORMAL_ARGUMENTS:   return LowerFORMAL_ARGUMENTS(Op, DAG);
   case ISD::RET:                return LowerRET(Op, DAG);
   }
 }