Add support for variable argument functions!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@6046 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2003-05-08 19:44:13 +00:00
parent 18ac3c8914
commit eca195e7b4
2 changed files with 168 additions and 4 deletions

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@ -17,6 +17,7 @@
#include "llvm/DerivedTypes.h"
#include "llvm/Constants.h"
#include "llvm/Pass.h"
#include "llvm/Intrinsics.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/SSARegMap.h"
@ -57,8 +58,9 @@ inline static MachineInstrBuilder BMI(MachineBasicBlock *MBB,
namespace {
struct ISel : public FunctionPass, InstVisitor<ISel> {
TargetMachine &TM;
MachineFunction *F; // The function we are compiling into
MachineBasicBlock *BB; // The current MBB we are compiling
MachineFunction *F; // The function we are compiling into
MachineBasicBlock *BB; // The current MBB we are compiling
int VarArgsFrameIndex; // FrameIndex for start of varargs area
std::map<Value*, unsigned> RegMap; // Mapping between Val's and SSA Regs
@ -134,6 +136,7 @@ namespace {
void doCall(const ValueRecord &Ret, MachineInstr *CallMI,
const std::vector<ValueRecord> &Args);
void visitCallInst(CallInst &I);
void visitIntrinsicCall(LLVMIntrinsic::ID ID, CallInst &I);
// Arithmetic operators
void visitSimpleBinary(BinaryOperator &B, unsigned OpcodeClass);
@ -173,6 +176,7 @@ namespace {
void visitShiftInst(ShiftInst &I);
void visitPHINode(PHINode &I) {} // PHI nodes handled by second pass
void visitCastInst(CastInst &I);
void visitVarArgInst(VarArgInst &I);
void visitInstruction(Instruction &I) {
std::cerr << "Cannot instruction select: " << I;
@ -434,6 +438,12 @@ void ISel::LoadArgumentsToVirtualRegs(Function &Fn) {
}
ArgOffset += 4; // Each argument takes at least 4 bytes on the stack...
}
// If the function takes variable number of arguments, add a frame offset for
// the start of the first vararg value... this is used to expand
// llvm.va_start.
if (Fn.getFunctionType()->isVarArg())
VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset);
}
@ -876,6 +886,12 @@ void ISel::doCall(const ValueRecord &Ret, MachineInstr *CallMI,
void ISel::visitCallInst(CallInst &CI) {
MachineInstr *TheCall;
if (Function *F = CI.getCalledFunction()) {
// Is it an intrinsic function call?
if (LLVMIntrinsic::ID ID = (LLVMIntrinsic::ID)F->getIntrinsicID()) {
visitIntrinsicCall(ID, CI); // Special intrinsics are not handled here
return;
}
// Emit a CALL instruction with PC-relative displacement.
TheCall = BuildMI(X86::CALLpcrel32, 1).addGlobalAddress(F, true);
} else { // Emit an indirect call...
@ -892,6 +908,29 @@ void ISel::visitCallInst(CallInst &CI) {
doCall(ValueRecord(DestReg, CI.getType()), TheCall, Args);
}
void ISel::visitIntrinsicCall(LLVMIntrinsic::ID ID, CallInst &CI) {
unsigned TmpReg1, TmpReg2;
switch (ID) {
case LLVMIntrinsic::va_start:
// Get the address of the first vararg value...
TmpReg1 = makeAnotherReg(Type::UIntTy);
addFrameReference(BuildMI(BB, X86::LEAr32, 5, TmpReg1), VarArgsFrameIndex);
TmpReg2 = getReg(CI.getOperand(1));
addDirectMem(BuildMI(BB, X86::MOVrm32, 5), TmpReg2).addReg(TmpReg1);
return;
case LLVMIntrinsic::va_end: return; // Noop on X86
case LLVMIntrinsic::va_copy:
TmpReg1 = getReg(CI.getOperand(2)); // Get existing va_list
TmpReg2 = getReg(CI.getOperand(1)); // Get va_list* to store into
addDirectMem(BuildMI(BB, X86::MOVrm32, 5), TmpReg2).addReg(TmpReg1);
return;
default: assert(0 && "Unknown intrinsic for X86!");
}
}
/// visitSimpleBinary - Implement simple binary operators for integral types...
/// OperatorClass is one of: 0 for Add, 1 for Sub, 2 for And, 3 for Or,
@ -1597,6 +1636,49 @@ void ISel::emitCastOperation(MachineBasicBlock *BB,
abort();
}
/// visitVarArgInst - Implement the va_arg instruction...
///
void ISel::visitVarArgInst(VarArgInst &I) {
unsigned SrcReg = getReg(I.getOperand(0));
unsigned DestReg = getReg(I);
// Load the va_list into a register...
unsigned VAList = makeAnotherReg(Type::UIntTy);
addDirectMem(BuildMI(BB, X86::MOVmr32, 4, VAList), SrcReg);
unsigned Size;
switch (I.getType()->getPrimitiveID()) {
default:
std::cerr << I;
assert(0 && "Error: bad type for va_arg instruction!");
return;
case Type::PointerTyID:
case Type::UIntTyID:
case Type::IntTyID:
Size = 4;
addDirectMem(BuildMI(BB, X86::MOVmr32, 4, DestReg), VAList);
break;
case Type::ULongTyID:
case Type::LongTyID:
Size = 8;
addDirectMem(BuildMI(BB, X86::MOVmr32, 4, DestReg), VAList);
addRegOffset(BuildMI(BB, X86::MOVmr32, 4, DestReg+1), VAList, 4);
break;
case Type::DoubleTyID:
Size = 8;
addDirectMem(BuildMI(BB, X86::FLDr64, 4, DestReg), VAList);
break;
}
// Increment the VAList pointer...
unsigned NextVAList = makeAnotherReg(Type::UIntTy);
BuildMI(BB, X86::ADDri32, 2, NextVAList).addReg(VAList).addZImm(Size);
// Update the VAList in memory...
addDirectMem(BuildMI(BB, X86::MOVrm32, 5), SrcReg).addReg(NextVAList);
}
// ExactLog2 - This function solves for (Val == 1 << (N-1)) and returns N. It
// returns zero when the input is not exactly a power of two.
static unsigned ExactLog2(unsigned Val) {

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@ -17,6 +17,7 @@
#include "llvm/DerivedTypes.h"
#include "llvm/Constants.h"
#include "llvm/Pass.h"
#include "llvm/Intrinsics.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/SSARegMap.h"
@ -57,8 +58,9 @@ inline static MachineInstrBuilder BMI(MachineBasicBlock *MBB,
namespace {
struct ISel : public FunctionPass, InstVisitor<ISel> {
TargetMachine &TM;
MachineFunction *F; // The function we are compiling into
MachineBasicBlock *BB; // The current MBB we are compiling
MachineFunction *F; // The function we are compiling into
MachineBasicBlock *BB; // The current MBB we are compiling
int VarArgsFrameIndex; // FrameIndex for start of varargs area
std::map<Value*, unsigned> RegMap; // Mapping between Val's and SSA Regs
@ -134,6 +136,7 @@ namespace {
void doCall(const ValueRecord &Ret, MachineInstr *CallMI,
const std::vector<ValueRecord> &Args);
void visitCallInst(CallInst &I);
void visitIntrinsicCall(LLVMIntrinsic::ID ID, CallInst &I);
// Arithmetic operators
void visitSimpleBinary(BinaryOperator &B, unsigned OpcodeClass);
@ -173,6 +176,7 @@ namespace {
void visitShiftInst(ShiftInst &I);
void visitPHINode(PHINode &I) {} // PHI nodes handled by second pass
void visitCastInst(CastInst &I);
void visitVarArgInst(VarArgInst &I);
void visitInstruction(Instruction &I) {
std::cerr << "Cannot instruction select: " << I;
@ -434,6 +438,12 @@ void ISel::LoadArgumentsToVirtualRegs(Function &Fn) {
}
ArgOffset += 4; // Each argument takes at least 4 bytes on the stack...
}
// If the function takes variable number of arguments, add a frame offset for
// the start of the first vararg value... this is used to expand
// llvm.va_start.
if (Fn.getFunctionType()->isVarArg())
VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset);
}
@ -876,6 +886,12 @@ void ISel::doCall(const ValueRecord &Ret, MachineInstr *CallMI,
void ISel::visitCallInst(CallInst &CI) {
MachineInstr *TheCall;
if (Function *F = CI.getCalledFunction()) {
// Is it an intrinsic function call?
if (LLVMIntrinsic::ID ID = (LLVMIntrinsic::ID)F->getIntrinsicID()) {
visitIntrinsicCall(ID, CI); // Special intrinsics are not handled here
return;
}
// Emit a CALL instruction with PC-relative displacement.
TheCall = BuildMI(X86::CALLpcrel32, 1).addGlobalAddress(F, true);
} else { // Emit an indirect call...
@ -892,6 +908,29 @@ void ISel::visitCallInst(CallInst &CI) {
doCall(ValueRecord(DestReg, CI.getType()), TheCall, Args);
}
void ISel::visitIntrinsicCall(LLVMIntrinsic::ID ID, CallInst &CI) {
unsigned TmpReg1, TmpReg2;
switch (ID) {
case LLVMIntrinsic::va_start:
// Get the address of the first vararg value...
TmpReg1 = makeAnotherReg(Type::UIntTy);
addFrameReference(BuildMI(BB, X86::LEAr32, 5, TmpReg1), VarArgsFrameIndex);
TmpReg2 = getReg(CI.getOperand(1));
addDirectMem(BuildMI(BB, X86::MOVrm32, 5), TmpReg2).addReg(TmpReg1);
return;
case LLVMIntrinsic::va_end: return; // Noop on X86
case LLVMIntrinsic::va_copy:
TmpReg1 = getReg(CI.getOperand(2)); // Get existing va_list
TmpReg2 = getReg(CI.getOperand(1)); // Get va_list* to store into
addDirectMem(BuildMI(BB, X86::MOVrm32, 5), TmpReg2).addReg(TmpReg1);
return;
default: assert(0 && "Unknown intrinsic for X86!");
}
}
/// visitSimpleBinary - Implement simple binary operators for integral types...
/// OperatorClass is one of: 0 for Add, 1 for Sub, 2 for And, 3 for Or,
@ -1597,6 +1636,49 @@ void ISel::emitCastOperation(MachineBasicBlock *BB,
abort();
}
/// visitVarArgInst - Implement the va_arg instruction...
///
void ISel::visitVarArgInst(VarArgInst &I) {
unsigned SrcReg = getReg(I.getOperand(0));
unsigned DestReg = getReg(I);
// Load the va_list into a register...
unsigned VAList = makeAnotherReg(Type::UIntTy);
addDirectMem(BuildMI(BB, X86::MOVmr32, 4, VAList), SrcReg);
unsigned Size;
switch (I.getType()->getPrimitiveID()) {
default:
std::cerr << I;
assert(0 && "Error: bad type for va_arg instruction!");
return;
case Type::PointerTyID:
case Type::UIntTyID:
case Type::IntTyID:
Size = 4;
addDirectMem(BuildMI(BB, X86::MOVmr32, 4, DestReg), VAList);
break;
case Type::ULongTyID:
case Type::LongTyID:
Size = 8;
addDirectMem(BuildMI(BB, X86::MOVmr32, 4, DestReg), VAList);
addRegOffset(BuildMI(BB, X86::MOVmr32, 4, DestReg+1), VAList, 4);
break;
case Type::DoubleTyID:
Size = 8;
addDirectMem(BuildMI(BB, X86::FLDr64, 4, DestReg), VAList);
break;
}
// Increment the VAList pointer...
unsigned NextVAList = makeAnotherReg(Type::UIntTy);
BuildMI(BB, X86::ADDri32, 2, NextVAList).addReg(VAList).addZImm(Size);
// Update the VAList in memory...
addDirectMem(BuildMI(BB, X86::MOVrm32, 5), SrcReg).addReg(NextVAList);
}
// ExactLog2 - This function solves for (Val == 1 << (N-1)) and returns N. It
// returns zero when the input is not exactly a power of two.
static unsigned ExactLog2(unsigned Val) {