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implement function calling of functions with up to 4 arguments

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29274 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rafael Espindola 2006-07-25 20:17:20 +00:00
parent c152efda47
commit fac00a93a9
2 changed files with 53 additions and 3 deletions
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48
lib/Target/ARM/ARMISelDAGToDAG.cpp
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@ -75,17 +75,38 @@ static SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG) {
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;
assert(NumOps <= 4); //no args on the stack
// 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));
static const unsigned regs[] = {
ARM::R0, ARM::R1, ARM::R2, ARM::R3
};
std::vector<std::pair<unsigned, SDOperand> > RegsToPass;
for (unsigned i = 0; i != NumOps; ++i) {
SDOperand Arg = Op.getOperand(5+2*i);
RegsToPass.push_back(std::make_pair(regs[i], Arg));
}
// Build a sequence of copy-to-reg nodes chained together with token chain
// and flag operands which copy the outgoing args into the appropriate regs.
SDOperand InFlag;
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
Chain = DAG.getCopyToReg(Chain, RegsToPass[i].first, RegsToPass[i].second,
InFlag);
InFlag = Chain.getValue(1);
}
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.
@ -103,14 +124,35 @@ static SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG) {
Ops.push_back(Callee);
unsigned CallOpc = ARMISD::CALL;
if (InFlag.Val)
Ops.push_back(InFlag);
Chain = DAG.getNode(CallOpc, NodeTys, Ops);
InFlag = Chain.getValue(1);
assert(Op.Val->getValueType(0) == MVT::Other);
std::vector<SDOperand> ResultVals;
NodeTys.clear();
// If the call has results, copy the values out of the ret val registers.
switch (Op.Val->getValueType(0)) {
default: assert(0 && "Unexpected ret value!");
case MVT::Other:
break;
case MVT::i32:
Chain = DAG.getCopyFromReg(Chain, ARM::R0, MVT::i32, InFlag).getValue(1);
ResultVals.push_back(Chain.getValue(0));
NodeTys.push_back(MVT::i32);
}
Chain = DAG.getNode(ISD::CALLSEQ_END, MVT::Other, Chain,
DAG.getConstant(NumBytes, MVT::i32));
NodeTys.push_back(MVT::Other);
return Chain;
if (ResultVals.empty())
return Chain;
ResultVals.push_back(Chain);
SDOperand Res = DAG.getNode(ISD::MERGE_VALUES, NodeTys, ResultVals);
return Res.getValue(Op.ResNo);
}
static SDOperand LowerRET(SDOperand Op, SelectionDAG &DAG) {

8
test/CodeGen/ARM/call.ll Normal file
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@ -0,0 +1,8 @@
; RUN: llvm-as < %s | llc -march=arm
void %f() {
entry:
call void %g( int 1, int 2, int 3, int 4 )
ret void
}
declare void %g(int, int, int, int)