public void EmitMoveVar(CompilerVar var, RegIndex regIndex, VariableAlloc vflags)
{
Contract.Requires(var != null);
if (var.RegisterIndex == RegIndex.Invalid)
throw new ArgumentException("Caller must ensure that variable is allocated.");
if ((vflags & VariableAlloc.Read) == 0)
return;
switch (var.Type)
{
case VariableType.GPD:
_compiler.Emit(InstructionCode.Mov, Register.gpd(regIndex), Register.gpd(var.RegisterIndex));
break;
case VariableType.GPQ:
if (!Util.IsX64)
throw new NotSupportedException();
_compiler.Emit(InstructionCode.Mov, Register.gpq(regIndex), Register.gpq(var.RegisterIndex));
break;
case VariableType.X87:
case VariableType.X87_1F:
case VariableType.X87_1D:
// TODO: X87 VARIABLES NOT IMPLEMENTED.
throw new NotImplementedException("X87 variables are not yet implemented.");
case VariableType.MM:
_compiler.Emit(InstructionCode.Movq, Register.mm(regIndex), Register.mm(var.RegisterIndex));
break;
case VariableType.XMM:
_compiler.Emit(InstructionCode.Movdqa, Register.xmm(regIndex), Register.xmm(var.RegisterIndex));
break;
case VariableType.XMM_1F:
_compiler.Emit(InstructionCode.Movss, Register.xmm(regIndex), Register.xmm(var.RegisterIndex));
break;
case VariableType.XMM_1D:
_compiler.Emit(InstructionCode.Movsd, Register.xmm(regIndex), Register.xmm(var.RegisterIndex));
break;
case VariableType.XMM_4F:
_compiler.Emit(InstructionCode.Movaps, Register.xmm(regIndex), Register.xmm(var.RegisterIndex));
break;
case VariableType.XMM_2D:
_compiler.Emit(InstructionCode.Movapd, Register.xmm(regIndex), Register.xmm(var.RegisterIndex));
break;
default:
throw new CompilerException("Invalid variable type.");
}
}
public void EmitExchangeVar(CompilerVar var, RegIndex regIndex, VariableAlloc vflags, CompilerVar other)
{
Contract.Requires(var != null);
Contract.Requires(other != null);
if (var.RegisterIndex == RegIndex.Invalid)
throw new CompilerException("Caller must ensure that variable is allocated.");
// If other is not valid then we can just emit MOV (or other similar instruction).
if (other == null)
{
EmitMoveVar(var, regIndex, vflags);
return;
}
// If we need to alloc for write-only operation then we can move other
// variable away instead of exchanging them.
if ((vflags & VariableAlloc.Read) == 0)
{
EmitMoveVar(other, var.RegisterIndex, VariableAlloc.Read);
return;
}
switch (var.Type)
{
case VariableType.GPD:
_compiler.Emit(InstructionCode.Xchg, Register.gpd(regIndex), Register.gpd(var.RegisterIndex));
break;
case VariableType.GPQ:
if (!Util.IsX64)
throw new NotSupportedException();
_compiler.Emit(InstructionCode.Xchg, Register.gpq(regIndex), Register.gpq(var.RegisterIndex));
break;
case VariableType.X87:
case VariableType.X87_1F:
case VariableType.X87_1D:
// TODO: X87 VARIABLES NOT IMPLEMENTED.
break;
// NOTE: MM and XMM registers shoudln't be exchanged using this way, it's
// correct, but it sucks.
case VariableType.MM:
{
MMReg a = Register.mm(regIndex);
MMReg b = Register.mm(var.RegisterIndex);
_compiler.Emit(InstructionCode.Pxor, a, b);
_compiler.Emit(InstructionCode.Pxor, b, a);
_compiler.Emit(InstructionCode.Pxor, a, b);
break;
}
case VariableType.XMM_1F:
case VariableType.XMM_4F:
{
XMMReg a = Register.xmm(regIndex);
XMMReg b = Register.xmm(var.RegisterIndex);
_compiler.Emit(InstructionCode.Xorps, a, b);
_compiler.Emit(InstructionCode.Xorps, b, a);
_compiler.Emit(InstructionCode.Xorps, a, b);
break;
}
case VariableType.XMM_1D:
case VariableType.XMM_2D:
{
XMMReg a = Register.xmm(regIndex);
XMMReg b = Register.xmm(var.RegisterIndex);
_compiler.Emit(InstructionCode.Xorpd, a, b);
_compiler.Emit(InstructionCode.Xorpd, b, a);
_compiler.Emit(InstructionCode.Xorpd, a, b);
break;
}
case VariableType.XMM:
{
XMMReg a = Register.xmm(regIndex);
XMMReg b = Register.xmm(var.RegisterIndex);
_compiler.Emit(InstructionCode.Pxor, a, b);
_compiler.Emit(InstructionCode.Pxor, b, a);
_compiler.Emit(InstructionCode.Pxor, a, b);
break;
}
}
}
public void AllocVar(CompilerVar var, RegisterMask regMask, VariableAlloc variableAlloc)
{
Contract.Requires(var != null);
switch (var.Type)
{
case VariableType.GPD:
case VariableType.GPQ:
if (var.Type == VariableType.GPQ && !Util.IsX64)
throw new NotSupportedException();
AllocGPVar(var, regMask, variableAlloc);
break;
case VariableType.X87:
case VariableType.X87_1F:
case VariableType.X87_1D:
// TODO: X87 VARIABLES NOT IMPLEMENTED.
break;
case VariableType.MM:
AllocMMVar(var, regMask, variableAlloc);
break;
case VariableType.XMM:
case VariableType.XMM_1F:
case VariableType.XMM_4F:
case VariableType.XMM_1D:
case VariableType.XMM_2D:
AllocXMMVar(var, regMask, variableAlloc);
break;
}
PostAlloc(var, variableAlloc);
}
public void AllocXMMVar(CompilerVar var, RegisterMask regMask, VariableAlloc vflags)
{
Contract.Requires(var != null);
Contract.Requires(Function != null);
AllocNonGPVar(var, regMask, vflags, RegNum.XMM, var.Scope.Declaration.PreservedXMM, _state.UsedXMM, _state.XMM, AllocatedXMMRegister, SpillXMMVar, FreedXMMRegister);
}
public void AllocGPVar(CompilerVar var, RegisterMask regMask, VariableAlloc variableAlloc)
{
Contract.Requires(var != null);
Contract.Requires(Function != null);
RegisterMask fullMask = RegisterMask.MaskToIndex(RegNum.GP) & ~RegisterMask.FromIndex(RegIndex.Esp);
if (!_allocableEBP)
fullMask &= ~RegisterMask.FromIndex(RegIndex.Ebp);
// Fix the regMask (0 or full bit-array means that any register may be used).
if (regMask == RegisterMask.Zero)
regMask = RegisterMask.MaskToIndex(RegNum.GP);
regMask &= fullMask;
int i;
RegisterMask mask;
// Last register code (aka home).
RegIndex home = var.HomeRegisterIndex;
// New register code.
RegIndex idx = RegIndex.Invalid;
// Preserved GP variables.
RegisterMask preservedGP = var.Scope.Declaration.PreservedGP;
// Spill candidate.
CompilerVar spillCandidate = null;
// spill caused by direct jump to L_Spill
bool doSpill = false;
// Whether to alloc the non-preserved variables first.
bool nonPreservedFirst = true;
if (Function.IsCaller)
{
nonPreservedFirst = var.FirstCallable == null ||
var.FirstCallable.Offset >= var.LastItem.Offset;
}
// --------------------------------------------------------------------------
// [Already Allocated]
// --------------------------------------------------------------------------
// Go away if variable is already allocated.
if (var.State == VariableState.Register)
{
RegIndex oldIndex = var.RegisterIndex;
// Already allocated in the right register.
if ((RegisterMask.FromIndex(oldIndex) & regMask) != RegisterMask.Zero)
return;
// Try to find unallocated register first.
mask = regMask & ~_state.UsedGP;
if (mask != RegisterMask.Zero)
{
idx = ((nonPreservedFirst && (mask & ~preservedGP) != RegisterMask.Zero) ? mask & ~preservedGP : mask).FirstRegister;
}
// Then find the allocated and exchange later.
else
{
idx = (regMask & _state.UsedGP).FirstRegister;
}
Contract.Assert(idx != RegIndex.Invalid);
CompilerVar other = _state.GP[(int)idx];
EmitExchangeVar(var, idx, variableAlloc, other);
_state.GP[(int)oldIndex] = other;
_state.GP[(int)idx] = var;
if (other != null)
other.RegisterIndex = oldIndex;
else
FreedGPRegister(oldIndex);
// Update VarData.
var.State = VariableState.Register;
var.RegisterIndex = idx;
var.HomeRegisterIndex = idx;
AllocatedGPRegister(idx);
return;
}
// --------------------------------------------------------------------------
// [Find Unused GP]
// --------------------------------------------------------------------------
// Home register code.
if (idx == RegIndex.Invalid
&& home != RegIndex.Invalid
&& (regMask & RegisterMask.FromIndex(home)) != RegisterMask.Zero
&& (State.UsedGP & RegisterMask.FromIndex(home)) == RegisterMask.Zero)
{
idx = home;
goto _Alloc;
}
// We start from 1, because EAX/RAX register is sometimes explicitly
// needed. So we trying to prevent reallocation in near future.
if (idx == RegIndex.Invalid)
{
for (i = 1, mask = RegisterMask.FromIndex((RegIndex)i); i < (int)RegNum.GP; i++, mask = RegisterMask.FromIndex((RegIndex)i))
{
if ((regMask & mask) != RegisterMask.Zero && (_state.UsedGP & mask) == RegisterMask.Zero)
{
// Convenience to alloc non-preserved first or non-preserved last.
if (nonPreservedFirst)
{
if (idx != RegIndex.Invalid && (preservedGP & mask) != RegisterMask.Zero)
continue;
idx = (RegIndex)i;
// If current register is preserved, we should try to find different
// one that is not. This can save one push / pop in prolog / epilog.
if ((preservedGP & mask) == RegisterMask.Zero)
break;
}
else
{
if (idx != RegIndex.Invalid && (preservedGP & mask) == RegisterMask.Zero)
continue;
idx = (RegIndex)i;
// The opposite.
if ((preservedGP & mask) != RegisterMask.Zero)
break;
}
}
}
}
// If not found, try EAX/RAX.
if (idx == RegIndex.Invalid
&& (regMask & RegisterMask.FromIndex(RegIndex.Eax)) != RegisterMask.Zero
&& (_state.UsedGP & RegisterMask.FromIndex(RegIndex.Eax)) == RegisterMask.Zero)
{
idx = RegIndex.Eax;
goto _Alloc;
}
// If regMask contains restricted registers which may be used then everything
// is handled inside this block.
if (idx == RegIndex.Invalid && regMask != fullMask)
{
// Try to find unallocated register first.
mask = regMask & ~_state.UsedGP;
if (mask != RegisterMask.Zero)
{
idx = ((nonPreservedFirst && (mask & ~preservedGP) != RegisterMask.Zero) ? (mask & ~preservedGP) : mask).FirstRegister;
Contract.Assert(idx != RegIndex.Invalid);
}
// Then find the allocated and spill later.
else
{
idx = (regMask & _state.UsedGP).FirstRegister;
Contract.Assert(idx != RegIndex.Invalid);
// Spill register we need.
spillCandidate = _state.GP[(int)idx];
// Jump to spill part of allocation.
doSpill = true;
goto L_Spill;
}
}
// --------------------------------------------------------------------------
// [Spill]
// --------------------------------------------------------------------------
// If register is still not found, spill other variable.
if (idx == RegIndex.Invalid)
{
if (spillCandidate == null)
{
spillCandidate = GetSpillCandidateGP();
}
// Spill candidate not found?
if (spillCandidate == null)
{
throw new CompilerException("Not enough registers.");
}
}
L_Spill:
if (idx == RegIndex.Invalid || doSpill)
{
// Prevented variables can't be spilled. _getSpillCandidate() never returns
// prevented variables, but when jumping to L_Spill it can happen.
if (spillCandidate.WorkOffset == _currentOffset)
{
throw new CompilerException("Registers overlap.");
}
idx = spillCandidate.RegisterIndex;
SpillGPVar(spillCandidate);
}
// --------------------------------------------------------------------------
// [Alloc]
// --------------------------------------------------------------------------
_Alloc:
if (var.State == VariableState.Memory && (variableAlloc & VariableAlloc.Read) != 0)
{
EmitLoadVar(var, idx);
}
// Update VarData.
var.State = VariableState.Register;
var.RegisterIndex = idx;
var.HomeRegisterIndex = idx;
// Update StateData.
AllocatedVariable(var);
}