func (v *gen) genIntDiv(instr ir.Instr, signed, remainder bool, alloc *allocator) {
numBytes := v.target.TypeSize(instr.Type())
if v.target.TypeSizeInBits(instr.Type())%8 != 0 {
panic("unsupported int size for div")
}
alloc.valToReg(v, "@eax", instr.Operands()[0])
if numBytes == 4 {
if signed {
v.emitOp("cdq")
} else {
v.emitOp("xorl @edx, @edx")
}
} else if numBytes == 2 {
if signed {
v.emitOp("cwd")
} else {
v.emitOp("xorw @dx, @dx")
}
} else if numBytes == 1 {
if signed {
v.emitOp("cbw")
} else {
v.emitOp("xorb @ah, @ah")
}
} else {
panic("unimplemented")
}
var prefix string
if signed {
prefix = "i"
}
v.emitOp("%sdiv%s %s", prefix, sizeSuffix(numBytes), alloc.valToReg(v, "@ebx", instr.Operands()[1]))
returnReg := "@eax"
if remainder {
returnReg = "@edx"
}
alloc.regToVal(v, instr, returnReg)
}
func (v *gen) genTwoOperandIntInstr(mnemonic string, instr ir.Instr, alloc *allocator) {
numBytes := v.target.TypeSize(instr.Type())
v.emitOp("%s%s %s, %s", mnemonic, sizeSuffix(numBytes), alloc.valToReg(v, "@ebx", instr.Operands()[1]), alloc.valToReg(v, "@eax", instr.Operands()[0]))
alloc.regToVal(v, instr, "@eax")
}