func (v *allocator) addValue(val ir.Value) {
if _, ok := v.locs[val]; ok {
panic("allocating value twice")
}
v.stackSize += v.target.TypeSize(val.Type())
v.locs[val] = &location{
stackPos: -v.stackSize,
}
}
func (v *allocator) valToReg(gen *gen, reg string, val ir.Value) string {
bits := v.target.TypeSizeInBits(val.Type())
bytes := v.target.TypeSize(val.Type())
bitmask := uint64((1 << uint(bits)) - 1)
if val.IsLit() {
switch val.(type) {
case *ir.IntLit:
il := val.(*ir.IntLit)
gen.emitOp("movl $%d, %s", il.Value()&bitmask, reg)
}
} else {
if bits != 32 {
gen.emitOp("xorl %s, %s", reg, reg)
}
gen.emitOp("mov%s %s, %s", sizeSuffix(bytes), v.get(val).String(), regToSize(reg, bytes))
if bits%8 != 0 {
gen.emitOp("andl $0x%x, %s", bitmask, reg)
}
}
return regToSize(reg, v.target.TypeSize(val.Type()))
}
func (v *allocator) regToVal(gen *gen, val ir.Value, reg string) ir.Value {
if val.IsLit() {
panic("can't move reg to literal value")
}
bits := v.target.TypeSizeInBits(val.Type())
bytes := v.target.TypeSize(val.Type())
bitmask := uint64((1 << uint(bits)) - 1)
if bits == 32 {
gen.emitOp("movl %s, %s", reg, v.get(val).String())
} else {
if bits%8 != 0 {
gen.emitOp("and%s $0x%x, %s", sizeSuffix(bytes), bitmask, regToSize(reg, bytes))
}
gen.emitOp("mov%s %s, %s", sizeSuffix(bytes), regToSize(reg, bytes), v.get(val).String())
}
return val
}
func (v *allocator) pushVal(gen *gen, val ir.Value) {
bits := v.target.TypeSizeInBits(val.Type())
bytes := v.target.TypeSize(val.Type())
if bytes%2 == 1 {
bytes++
}
bitmask := uint64((1 << uint(bits)) - 1)
if val.IsLit() {
switch val.(type) {
case *ir.IntLit:
il := val.(*ir.IntLit)
gen.emitOp("push%s $%d", sizeSuffix(bytes), il.Value()&bitmask)
}
} else {
gen.emitOp("push%s %s", sizeSuffix(bytes), v.get(val).String())
if bits%8 != 0 {
gen.emitOp("and%s $0x%x, (@esp)", sizeSuffix(bytes), bitmask)
}
}
}