/*
产生滙编指令
@ EmitMove
@ EmitAssign
@ EmitBranch
@ EmitJump
@ EmitCall
@ EmitReturn
*/
void Compiler::EmitMove(IRInst inst)
{
if (SRC1->kind == SK_Constant)
{
Move(DST, SRC1);
}
else
{
AllocateReg(inst, 1);
AllocateReg(inst, 0);
if (SRC1->reg == NULL && DST->reg == NULL)
{
Symbol reg;
reg = GetRegInternal();
Move(reg, SRC1);
Move(DST, reg);
}
else
{
Move(DST, SRC1);
}
}
if (DST) DST->ref--;
if (SRC1) SRC1->ref--;
}
Symbol Compiler::PutInReg(Symbol p)
{
Symbol reg;
if (p->reg != NULL)
{
return p->reg;
}
reg = GetRegInternal();
Move(reg, p);
return reg;
}
void Compiler::AllocateReg(IRInst inst, int index)
{
Symbol reg;
Symbol p;
p = inst->opds[index];
// 只分配给临时变量
if (p->kind != SK_Temp)
return;
// if it is already in a register, mark the register as used by current uil
if (p->reg != NULL)
{
UsedRegs |= 1 << p->reg->val;
return;
}
if (index == 0 && SRC1->ref == 1 && SRC1->reg != NULL)
{
reg = SRC1->reg;
reg->link = NULL;
//Add Var To Reg
p->link = reg->link;
reg->link = p;
p->reg = reg;
return;
}
reg = GetRegInternal();
if (index != 0)
{
Move(reg, p);
}
//Add Var To Reg
p->link = reg->link;
reg->link = p;
p->reg = reg;
}
void Compiler::EmitAssign(IRInst inst)
{
switch (OP)
{
case $ADD:
case $SUB:
AllocateReg(inst, 1);
AllocateReg(inst, 2);
AllocateReg(inst, 0);
//char name[40];
//sprintf(name, "%s", SRC1->reg->name.c_str());
//PutString(name);
if (DST->reg != SRC1->reg)
{
Move(DST, SRC1);
}
if (OP == $ADD) PutASMCode(X86_ADDI4, inst->opds);
if (OP == $SUB) PutASMCode(X86_SUBI4, inst->opds);
break;
case $MUL:
case $DIV:
if (SRC1->reg == Regs[EAX])
{
SpillReg(Regs[EAX]);
}
else
{
Symbol sym = Regs[EAX]->link;
if (sym != NULL && sym->ref > 0) {
Symbol reg = GetRegInternal();
SpillReg(Regs[EAX]);
Move(reg, Regs[EAX]);
sym->reg = reg;
reg->link = sym;
}
else {
SpillReg(Regs[EAX]);
}
Move(Regs[EAX], SRC1);
}
// SpillReg(Regs[EDX]);
// 将SRC1扩展后放在EAX与EDX
UsedRegs = 1 << EAX ;
if (SRC2->kind == SK_Constant)
{
Symbol reg = GetRegInternal();
Move(reg, SRC2);
SRC2 = reg;
}
else
{
AllocateReg(inst, 2);
}
if (OP == $MUL) PutASMCode(X86_MULI4, inst->opds);
if (OP == $DIV) PutASMCode(X86_DIVI4, inst->opds);
DST->link = Regs[EAX]->link;
Regs[EAX]->link = DST;
DST->reg = Regs[EAX];
break;
default:
break;
}
if (DST) DST->ref--;
if (SRC1) SRC1->ref--;
if (SRC2) SRC2->ref--;
}
Symbol GetReg(void)
{
return GetRegInternal(4);
}
Symbol GetWordReg(void)
{
return GetRegInternal(2);
}
Symbol GetByteReg(void)
{
return GetRegInternal(1);
}