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codeGeneration.go
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codeGeneration.go
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package main
import (
"fmt"
)
type ASMFunction struct {
code [][3]string
inline bool
used bool
}
type ASM struct {
header []string
//constants [][2]string
// value -> name
constants map[string]string
sysConstants map[string]string
variables [][3]string
sectionText []string
//functions [][3]string
functions map[string]ASMFunction
program [][3]string
// Increasing number to generate unique const variable names
constName int
labelName int
funName int
}
func (asm *ASM) addConstant(value string) string {
if v, ok := asm.constants[value]; ok {
return v
}
asm.constName += 1
name := fmt.Sprintf("const_%v", asm.constName-1)
asm.constants[value] = name
return name
}
func (asm *ASM) addSysConstant(name, value string) {
if _, ok := asm.sysConstants[value]; ok {
panic(fmt.Sprintf("Code generation error. Name %v already registered in Constants", name))
}
asm.sysConstants[value] = name
}
func (asm *ASM) nextLabelName() string {
asm.labelName += 1
return fmt.Sprintf("label_%v", asm.labelName-1)
}
func (asm *ASM) nextFunctionName() string {
asm.funName += 1
return fmt.Sprintf("fun_%v", asm.funName-1)
}
func (asm *ASM) addLabel(label string) {
asm.program = append(asm.program, [3]string{"", label + ":", ""})
}
func (asm *ASM) addFun(name string, inline bool) {
asm.functions[name] = ASMFunction{make([][3]string, 0), inline, false}
}
func (asm *ASM) setFunIsUsed(name string, isUsed bool) {
if e, ok := asm.functions[name]; ok {
e.used = isUsed
asm.functions[name] = e
return
}
panic("Code generation error. setFunIsUsed - function not found to set flag to")
}
func (asm *ASM) addLine(command, args string) {
asm.program = append(asm.program, [3]string{" ", command, args})
}
func (asm *ASM) addLines(commands [][3]string) {
asm.program = append(asm.program, commands...)
}
func (asm *ASM) addRawLine(command string) {
asm.program = append(asm.program, [3]string{"", command, ""})
}
func (asm *ASM) getFunctionCode(asmName string) [][3]string {
f, ok := asm.functions[asmName]
if !ok {
panic("Code generation error. Unknown function to get code from")
}
return f.code
}
func getJumpType(op Operator) string {
switch op {
case OP_GE:
return "jge"
case OP_GREATER:
return "jg"
case OP_LESS:
return "jl"
case OP_LE:
return "jle"
case OP_EQ:
return "je"
case OP_NE:
return "jne"
}
return ""
}
func getCommandFloat(op Operator) string {
switch op {
case OP_PLUS:
return "addsd"
case OP_MINUS:
return "subsd"
case OP_MULT:
return "mulsd"
case OP_DIV:
return "divsd"
default:
panic("Code generation error. Unknown operator for float")
}
return ""
}
func getCommandInt(op Operator) string {
switch op {
case OP_PLUS:
return "add"
case OP_MINUS:
return "sub"
case OP_MULT:
return "imul"
case OP_DIV, OP_MOD:
return "idiv"
default:
panic("Code generation error. Unknown operator for int")
}
return ""
}
func getCommandChar(op Operator) string {
panic("Code generation error. Unknown operator for char")
return ""
}
func getCommandBool(op Operator) string {
switch op {
case OP_AND:
return "and"
case OP_OR:
return "or"
default:
panic("Code generation error. Unknown operator for bool")
}
return ""
}
func getRegister(t Type) (string, string) {
switch t {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR:
return "r10", "r11"
case TYPE_FLOAT:
return "xmm0", "xmm1"
case TYPE_STRING:
panic("Code generation error. String register not yet implemented")
}
return "", ""
}
func getMoreIntRegister() (string, string) {
return "r9", "r8"
}
func getMov(t Type) string {
switch t {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR:
return "mov"
case TYPE_FLOAT:
return "movq"
case TYPE_STRING:
panic("Code generation error. String register not yet implemented")
}
return ""
}
func getReturnRegister(t Type) string {
switch t {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR:
return "rax"
case TYPE_FLOAT:
return "xmm0"
case TYPE_STRING:
panic("Code generation error. String register not yet implemented")
}
return ""
}
// Right now we limit ourself to a maximum of 6 integer parameters and/or 8 floating parameters!
// https://wiki.cdot.senecacollege.ca/wiki/X86_64_Register_and_Instruction_Quick_Start
func getFunctionRegisters(t Type) []string {
switch t {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR:
return []string{"rdi", "rsi", "rdx", "rcx", "r8", "r9"}
case TYPE_FLOAT:
return []string{"xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "xmm5", "xmm6", "xmm7"}
case TYPE_STRING:
panic("Code generation error. String register not yet implemented")
}
return []string{}
}
func getCommand(t Type, op Operator) string {
switch t {
case TYPE_BOOL:
return getCommandBool(op)
case TYPE_FLOAT:
return getCommandFloat(op)
case TYPE_INT:
return getCommandInt(op)
case TYPE_CHAR:
return getCommandChar(op)
case TYPE_STRING:
panic("Code generation error. String commands not yet implemented")
}
return ""
}
func (c Constant) generateCode(asm *ASM, s *SymbolTable) {
name := ""
switch c.cType {
case TYPE_INT, TYPE_FLOAT:
name = asm.addConstant(c.cValue)
case TYPE_STRING:
name = asm.addConstant(fmt.Sprintf("\"%v\", 0", c.cValue))
case TYPE_CHAR:
name = asm.addConstant(fmt.Sprintf("%v", int(c.cValue[1])))
case TYPE_BOOL:
v := "0"
if c.cValue == "true" {
v = "-1"
}
name = asm.addConstant(v)
default:
panic("Could not generate code for Const. Unknown type!")
}
switch c.cType {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR:
asm.addLine("mov", "rax, "+name)
case TYPE_FLOAT:
register, _ := getRegister(TYPE_INT)
asm.addLine("mov", fmt.Sprintf("%v, %v", register, name))
asm.addLine("movq", fmt.Sprintf("xmm0, %v", register))
}
}
// We don't know where we were before and what expression needs to be indexed.
// All we care about, is that the array pointer is in rax and the resulting value will also be in rax!
func generateDirectAccessCode(directAccess []DirectAccess, asm *ASM, s *SymbolTable) {
for i, access := range directAccess {
if access.indexed {
address, elementSize := getRegister(TYPE_INT)
// address = rax
asm.addLine("mov", fmt.Sprintf("%v, %v", address, getReturnRegister(TYPE_INT)))
// Save the address
asm.addLine("push", address)
// The index will be in rax.
access.indexExpression.generateCode(asm, s)
asm.addLine("pop", address)
asm.addLine("mov", fmt.Sprintf("%v, [%v+16]", elementSize, address))
asm.addLine("imul", fmt.Sprintf("%v, %v", getReturnRegister(TYPE_INT), elementSize))
asm.addLine("lea", fmt.Sprintf("%v, [%v+%v*8+24]", getReturnRegister(TYPE_INT), address, getReturnRegister(TYPE_INT)))
} else {
// The offset will automatically be inverted, once we enter heap memory! This happens in the semanticAnalyzer!
// So we will move positively in heap memory and in the negative direction for stack memory!
asm.addLine("lea", fmt.Sprintf("%v, [%v+%v]", getReturnRegister(TYPE_INT), access.structOffset*8, getReturnRegister(TYPE_INT)))
}
// If the next access is indexed, we need to dereference once because we have a double pointer right now because of the lea.
// We also don't want to end up with the pointer, but the actual value!
// So on the last one, we also dereference!
if i == len(directAccess)-1 || directAccess[i+1].indexed {
asm.addLine("mov", fmt.Sprintf("%v, [%v]", getReturnRegister(TYPE_INT), getReturnRegister(TYPE_INT)))
}
}
}
func (v Variable) generateCode(asm *ASM, s *SymbolTable) {
symbol, ok := s.getVar(v.vName)
if !ok {
panic("Could not generate code for Variable. No symbol known!")
}
switch v.vType.t {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR, TYPE_ARRAY:
asm.addLine("mov", fmt.Sprintf("%v, [%v+rbp]", getReturnRegister(TYPE_INT), symbol.offset))
case TYPE_FLOAT:
register, _ := getRegister(TYPE_INT)
asm.addLine("mov", fmt.Sprintf("%v, [%v+rbp]", register, symbol.offset))
asm.addLine("movq", fmt.Sprintf("%v, %v", getReturnRegister(TYPE_FLOAT), register))
case TYPE_STRUCT:
// First only load the struct start address
// Then calculate the direct access by adding the offset value directly to the pointer
// Then, in the end - If the result is still a struct, - then push all the values to the stack!
asm.addLine("lea", fmt.Sprintf("%v, [%v+rbp]", getReturnRegister(TYPE_INT), symbol.offset))
}
if len(v.directAccess) > 0 {
generateDirectAccessCode(v.directAccess, asm, s)
if v.getExpressionTypes(s)[0].t == TYPE_FLOAT {
asm.addLine("movq", fmt.Sprintf("%v, %v", getReturnRegister(TYPE_FLOAT), getReturnRegister(TYPE_INT)))
}
}
types := v.getExpressionTypes(s)
if len(types) >= 1 && types[0].t == TYPE_STRUCT {
memCount := types[0].getMemCount(s)
// Same as int
// TODO: Do we need to distinguish between int/... and float types here? Do we need movq somewhere?
if memCount == 1 {
asm.addLine("mov", fmt.Sprintf("%v, [%v+rbp]", getReturnRegister(TYPE_INT), symbol.offset))
} else {
register, _ := getRegister(TYPE_INT)
// We need to push in the reverse order!
for i := memCount - 1; i >= 0; i-- {
asm.addLine("mov", fmt.Sprintf("%v, [%v+rbp-%v]", register, symbol.offset, i*8))
asm.addLine("push", register)
}
}
}
return
}
func (u UnaryOp) generateCode(asm *ASM, s *SymbolTable) {
u.expr.generateCode(asm, s)
if u.getResultCount() != 1 {
panic("Code generation error: Unary expression can only handle one result")
}
t := u.getExpressionTypes(s)[0]
switch t.t {
case TYPE_BOOL:
if u.operator == OP_NOT {
// 'not' switches between 0 and -1. So False: 0, True: -1
asm.addLine("not", "rax")
} else {
panic(fmt.Sprintf("Code generation error. Unexpected unary type: %v for %v\n", u.operator, u.opType))
}
case TYPE_INT:
if u.operator == OP_NEGATIVE {
asm.addLine("neg", "rax")
} else {
panic(fmt.Sprintf("Code generation error. Unexpected unary type: %v for %v\n", u.operator, u.opType))
}
case TYPE_FLOAT:
if u.operator == OP_NEGATIVE {
asm.addLine("mulsd", "xmm0, qword [negOneF]")
} else {
panic(fmt.Sprintf("Code generation error. Unexpected unary type: %v for %v", u.operator, u.opType))
}
case TYPE_CHAR:
panic("Code generation error. No unary expression for type char")
case TYPE_STRING:
panic("Code generation error. No unary expression for type String")
return
}
}
// binaryOperationFloat executes the operation on the two registers and writes the result into rLeft!
func binaryOperationNumber(op Operator, t Type, rLeft, rRight string, asm *ASM) {
switch op {
case OP_GE, OP_GREATER, OP_LESS, OP_LE, OP_EQ, OP_NE:
// Works for anything that should be compared.
labelTrue := asm.nextLabelName()
labelOK := asm.nextLabelName()
jump := getJumpType(op)
asm.addLine("cmp", fmt.Sprintf("%v, %v", rLeft, rRight))
asm.addLine(jump, labelTrue)
asm.addLine("mov", fmt.Sprintf("%v, 0", rLeft))
asm.addLine("jmp", labelOK)
asm.addLabel(labelTrue)
asm.addLine("mov", fmt.Sprintf("%v, -1", rLeft))
asm.addLabel(labelOK)
// add, sub, mul, div, mod...
default:
command := getCommand(t, op)
if op == OP_DIV || op == OP_MOD {
// Clear rdx! Needed for at least div and mod.
asm.addLine("xor", "rdx, rdx")
}
// idiv calculates both the integer division, as well as the remainder.
// The reminder will be written to rdx. So move back to rax.
if op == OP_MOD {
asm.addLine(command, fmt.Sprintf("%v, %v", rLeft, rRight))
asm.addLine("mov", fmt.Sprintf("%v, rdx", rLeft))
} else {
asm.addLine(command, fmt.Sprintf("%v, %v", rLeft, rRight))
}
}
}
func (b BinaryOp) generateCode(asm *ASM, s *SymbolTable) {
if b.leftExpr.getResultCount() != 1 {
panic("Code generation error: Binary expression can only handle one result each")
}
if b.rightExpr.getResultCount() != 1 {
panic("Code generation error: Binary expression can only handle one result each")
}
t := b.leftExpr.getExpressionTypes(s)[0]
b.rightExpr.generateCode(asm, s)
// mov rsi, rax
// mov xmm1, xmm0
//asm.addLine(getMov(t), fmt.Sprintf("%v, %v", rRight, getReturnRegister(t)))
switch t.t {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR:
asm.addLine("push", getReturnRegister(t.t))
case TYPE_FLOAT:
tmpR, _ := getRegister(TYPE_INT)
asm.addLine("movq", fmt.Sprintf("%v, %v", tmpR, getReturnRegister(t.t)))
asm.addLine("push", tmpR)
}
// Result will be left in rax/xmm0
b.leftExpr.generateCode(asm, s)
rLeft := getReturnRegister(t.t)
_, rRight := getRegister(t.t)
switch t.t {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR:
asm.addLine("pop", rRight)
case TYPE_FLOAT:
tmpR, _ := getRegister(TYPE_INT)
asm.addLine("pop", tmpR)
asm.addLine("movq", fmt.Sprintf("%v, %v", rRight, tmpR))
}
switch t.t {
case TYPE_INT, TYPE_FLOAT, TYPE_BOOL, TYPE_CHAR:
binaryOperationNumber(b.operator, b.opType.t, rLeft, rRight, asm)
case TYPE_STRING:
panic("Code generation error: Strings not supported yet.")
default:
panic(fmt.Sprintf("Code generation error: Unknown operation type %v\n", int(b.opType.t)))
}
}
func (a Array) generateCode(asm *ASM, s *SymbolTable) {
elementSize := a.aType.subType.getMemCount(s)
asm.addLine("mov", "rax, sys_mmap")
// Null pointer
asm.addLine("mov", "rdi, 0x00")
asm.addLine("mov", fmt.Sprintf("rsi, %v", a.aCount*elementSize*8+24))
// PROT_READ | PROT_WRITE
asm.addLine("mov", "rdx, 0x03")
// MAP_PRIVATE | MAP_ANONYMOUS
asm.addLine("mov", "r10, 0x22")
// OFFSET == 0
asm.addLine("mov", "r9, 0x00")
asm.addLine("mov", "r8, -1")
asm.addLine("syscall", "")
asm.addLine("push", "rax")
// Check memory error
asm.addLine("cmp", "rax, 0")
asm.addLine("jl", "exit")
// Initialize array with 0s, if they are not initialized.
if len(a.aExpressions) == 0 {
// rdi is now the highest available address
asm.addLine("mov", "rdi, rax")
// Number of memory blocks we want to clear
asm.addLine("mov", fmt.Sprintf("rcx, %v", a.aCount*elementSize+3))
// rax == What to write into memory (default). So we fill it up with 0s
asm.addLine("xor", "rax, rax")
// store the value of rax into what rdi points to at every position and decrement rcx.
asm.addLine("rep", "stosq")
} else {
for i := len(a.aExpressions) - 1; i >= 0; i-- {
e := a.aExpressions[i]
// Calculate expression
e.generateCode(asm, s)
// Multiple return values are already on the stack, single ones not!
if e.getResultCount() == 1 && e.getExpressionTypes(s)[0].getMemCount(s) == 1 {
switch e.getExpressionTypes(s)[0].getMemTypes(s)[0] {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR, TYPE_ARRAY:
asm.addLine("push", getReturnRegister(TYPE_INT))
case TYPE_FLOAT:
tmpR, _ := getRegister(TYPE_INT)
asm.addLine("movq", fmt.Sprintf("%v, %v", tmpR, getReturnRegister(TYPE_FLOAT)))
asm.addLine("push", tmpR)
default:
panic("Code generation error. Array doesn't know, what type it got")
}
}
}
value, pointer := getRegister(TYPE_INT)
// Calculate, where our pointer is on the stack and reference it directly!
// There should be a.aCount additional values pushed on stack right now.
// So our array should be at [rsp+a.aCount*8]
asm.addLine("mov", fmt.Sprintf("%v, [rsp+%v*8]", pointer, a.aCount*elementSize))
for i := 0; i < a.aCount*elementSize; i++ {
// Pop our value from the stack
asm.addLine("pop", value)
asm.addLine("mov", fmt.Sprintf("[%v+%v], %v", pointer, i*8+24, value))
}
}
// Write capacity into first position in array
register, pointer := getRegister(TYPE_INT)
asm.addLine("pop", pointer)
asm.addLine("mov", fmt.Sprintf("%v, %v", register, a.aCount))
asm.addLine("mov", fmt.Sprintf("[%v], %v", pointer, register))
// len into second position
asm.addLine("mov", fmt.Sprintf("[%v+8], %v", pointer, register))
// Element size into the third position
asm.addLine("mov", fmt.Sprintf("%v, %v", register, a.aType.subType.getMemCount(s)))
asm.addLine("mov", fmt.Sprintf("[%v+16], %v", pointer, register))
asm.addLine("mov", "rax, "+pointer)
if len(a.directAccess) > 0 {
generateDirectAccessCode(a.directAccess, asm, s)
if a.getExpressionTypes(s)[0].t == TYPE_FLOAT {
asm.addLine("movq", fmt.Sprintf("%v, %v", getReturnRegister(TYPE_FLOAT), getReturnRegister(TYPE_INT)))
}
}
}
func expressionsToTypes(expressions []Expression, s *SymbolTable) []ComplexType {
var types []ComplexType
for _, e := range expressions {
types = append(types, e.getExpressionTypes(s)...)
}
return types
}
func generateStructExprCode(asm *ASM, s *SymbolTable, f FunCall) {
// First generate code for all expressions, THEN put them in function parameter registers!
// To avoid register overwriting by functions!
for i := len(f.args) - 1; i >= 0; i-- {
e := f.args[i]
e.generateCode(asm, s)
// Multiple return values are already on the stack, single ones not!
if e.getResultCount() == 1 {
switch e.getExpressionTypes(s)[0].t {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR, TYPE_ARRAY:
asm.addLine("push", getReturnRegister(TYPE_INT))
case TYPE_FLOAT:
tmpR, _ := getRegister(TYPE_INT)
asm.addLine("movq", fmt.Sprintf("%v, %v", tmpR, getReturnRegister(TYPE_FLOAT)))
asm.addLine("push", tmpR)
}
}
}
}
func (f FunCall) generateCode(asm *ASM, s *SymbolTable) {
if f.createStruct {
generateStructExprCode(asm, s, f)
return
}
intRegisters := getFunctionRegisters(TYPE_INT)
intRegIndex := 0
floatRegisters := getFunctionRegisters(TYPE_FLOAT)
floatRegIndex := 0
// In case we have multiple return values, we want to provide a pointer to the stack space to write to
// as very first argument to the function. So we skip the first register here on purpose!
// Make space on (our) stack, if f has multiple return values!
// The return stack space is now BEFORE the parameter stack space! So we can just pop used parameters
// from the stack after the function call.
returnMemCount := typesToMemCount(f.retTypes, s)
if returnMemCount > 1 {
intRegIndex++
asm.addLine("sub", fmt.Sprintf("rsp, %v", 8*returnMemCount))
asm.addLine("lea", fmt.Sprintf("%v, [rsp]", getFunctionRegisters(TYPE_INT)[0]))
// We cannot guarantee, that no argument expression overwrites rdi...
asm.addLine("push", getFunctionRegisters(TYPE_INT)[0])
}
// We need this to refer to rdi later... Just if we have multiple return values and
// have to make sure rdi is not overwritten when evaluating argument expressions.
argsOnStack := 0
// Expect value in rax/xmm0 instead of stack.
// For floating point, the first parameter is already xmm0, so we are done.
// Int must be moved into rax.
if len(f.args) == 1 && f.args[0].getExpressionTypes(s)[0].getMemCount(s) == 1 {
f.args[0].generateCode(asm, s)
// If we have a struct on hand, we have to find out, what type the member is!
// We already know, that we have exactly ONE value.
switch f.args[0].getExpressionTypes(s)[0].getMemTypes(s)[0] {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR, TYPE_ARRAY:
asm.addLine("mov", fmt.Sprintf("%v, %v", intRegisters[intRegIndex], getReturnRegister(TYPE_INT)))
intRegIndex++
case TYPE_FLOAT:
// For float, xmm0 is both the expected return and the first parameter. So everything is fine!
// Even for multiple return values, as this is a pointer to the stack, which is an int-parameter.
floatRegIndex++
}
} else {
// First generate code for all expressions, THEN put them in function parameter registers!
// To avoid register overwriting by functions!
for i := len(f.args) - 1; i >= 0; i-- {
e := f.args[i]
e.generateCode(asm, s)
resultMemory := e.getExpressionTypes(s)[0].getMemCount(s)
// Multiple return values are already on the stack, single ones not!
if e.getResultCount() == 1 && resultMemory == 1 {
// If we have a struct on hand, we have to find out, what type the member is!
// We already know, that we have exactly ONE value.
switch e.getExpressionTypes(s)[0].getMemTypes(s)[0] {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR, TYPE_ARRAY:
asm.addLine("push", getReturnRegister(TYPE_INT))
case TYPE_FLOAT:
tmpR, _ := getRegister(TYPE_INT)
asm.addLine("movq", fmt.Sprintf("%v, %v", tmpR, getReturnRegister(TYPE_FLOAT)))
asm.addLine("push", tmpR)
}
}
}
for _, e := range f.args {
for _, t := range e.getExpressionTypes(s) {
for _, endType := range t.getMemTypes(s) {
switch endType {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR, TYPE_ARRAY:
// All further values stay on the stack and are not assigned to registers!
if intRegIndex < len(intRegisters) {
asm.addLine("pop", intRegisters[intRegIndex])
intRegIndex++
} else {
argsOnStack++
}
case TYPE_FLOAT:
if floatRegIndex < len(floatRegisters) {
tmpR, _ := getRegister(TYPE_INT)
asm.addLine("pop", tmpR)
asm.addLine("movq", fmt.Sprintf("%v, %v", floatRegisters[floatRegIndex], tmpR))
floatRegIndex++
} else {
argsOnStack++
}
}
}
}
}
}
// Reset rdi!
if returnMemCount > 1 {
asm.addLine("mov", fmt.Sprintf("%v, [rsp+%v]", getFunctionRegisters(TYPE_INT)[0], argsOnStack*8))
}
if entry, ok := s.getFun(f.funName, expressionsToTypes(f.args, s), false); ok {
if !entry.inline {
asm.addLine("call", entry.jumpLabel)
} else {
// Instead of calling the function, copy its content directly into the source code!
asm.addLines(asm.getFunctionCode(entry.jumpLabel))
}
asm.setFunIsUsed(entry.jumpLabel, true)
paramCount := len(entry.paramTypes)
if returnMemCount > 1 {
paramCount++
}
// Remove the stack space used for the parameters for the function by resetting rsp by the
// amount of stack space we used.
if argsOnStack > 0 {
freeStackSpace := 8 * argsOnStack
if returnMemCount > 1 {
freeStackSpace += 8
}
asm.addLine("add", fmt.Sprintf("rsp, %v ; Remove function parameters from stack", freeStackSpace))
} else {
if returnMemCount > 1 {
asm.addLine("add", "rsp, 8")
}
}
} else {
panic("Code generation error: Unknown function called")
}
if len(f.directAccess) > 0 {
generateDirectAccessCode(f.directAccess, asm, s)
if f.retTypes[0].subType.t == TYPE_FLOAT {
asm.addLine("movq", fmt.Sprintf("%v, %v", getReturnRegister(TYPE_FLOAT), getReturnRegister(TYPE_INT)))
}
}
}
func (a Assignment) generateCode(asm *ASM, s *SymbolTable) {
for i := len(a.expressions) - 1; i >= 0; i-- {
e := a.expressions[i]
// Calculate expression
e.generateCode(asm, s)
// Multiple return values are already on the stack, single ones not!
if e.getResultCount() == 1 {
switch e.getExpressionTypes(s)[0].t {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR, TYPE_ARRAY:
asm.addLine("push", getReturnRegister(TYPE_INT))
case TYPE_FLOAT:
tmpR, _ := getRegister(TYPE_INT)
asm.addLine("movq", fmt.Sprintf("%v, %v", tmpR, getReturnRegister(TYPE_FLOAT)))
asm.addLine("push", tmpR)
}
}
}
// Just to get it from the stack into the variable.
valueRegister, _ := getRegister(TYPE_INT)
for _, v := range a.variables {
// This can not/should not fail!
entry, _ := s.getVar(v.vName)
if len(v.directAccess) > 0 {
index, address := getRegister(TYPE_INT)
// If we are working with an array, this is already an address! So mov is good.
// For a struct, we need lea to achieve the same!
if entry.sType.t == TYPE_ARRAY {
asm.addLine("mov", fmt.Sprintf("%v, [%v+rbp]", address, entry.offset))
} else {
asm.addLine("lea", fmt.Sprintf("%v, [%v+rbp]", address, entry.offset))
}
// We go through the indexing to determine the last index and address to write to!
for _, access := range v.directAccess {
if access.indexed {
asm.addLine("push", address)
access.indexExpression.generateCode(asm, s)
asm.addLine("mov", fmt.Sprintf("%v, %v", index, getReturnRegister(TYPE_INT)))
asm.addLine("pop", address)
// The the element size!
size, _ := getMoreIntRegister()
asm.addLine("mov", fmt.Sprintf("%v, [%v+16]", size, address))
asm.addLine("imul", fmt.Sprintf("%v, %v", index, size))
// Go one level down.
asm.addLine("lea", fmt.Sprintf("%v, [%v+%v*8+24]", address, address, index))
} else {
asm.addLine("lea", fmt.Sprintf("%v, [%v+%v]", address, access.structOffset*8, address))
}
}
for i := 0; i < v.vType.getMemCount(s); i++ {
asm.addLine("pop", valueRegister)
asm.addLine("mov", fmt.Sprintf("[%v+%v], %v", address, i*8, valueRegister))
}
} else {
// For multiple memory locations, we have to fill all of them.
// The corresponding values are expected on the stack!
for i := 0; i < v.vType.getMemCount(s); i++ {
asm.addLine("pop", valueRegister)
asm.addLine("mov", fmt.Sprintf("[%v+rbp-%v], %v", entry.offset, i*8, valueRegister))
}
}
}
}
func (c Condition) generateCode(asm *ASM, s *SymbolTable) {
c.expression.generateCode(asm, s)
register, _ := getRegister(TYPE_BOOL)
// For now, we assume an else case. Even if it is just empty!
elseLabel := asm.nextLabelName()
endLabel := asm.nextLabelName()
switch c.expression.getExpressionTypes(s)[0].t {
case TYPE_BOOL, TYPE_INT, TYPE_CHAR:
register = getReturnRegister(TYPE_INT)
case TYPE_FLOAT:
asm.addLine("movq", fmt.Sprintf("%v, %v", register, getReturnRegister(TYPE_FLOAT)))
}
asm.addLine("cmp", fmt.Sprintf("%v, 0", register))
asm.addLine("je", elseLabel)
c.block.generateCode(asm, s)
asm.addLine("jmp", endLabel)
asm.addLabel(elseLabel)
c.elseBlock.generateCode(asm, s)
asm.addLabel(endLabel)
}
func (br Break) generateCode(asm *ASM, s *SymbolTable) {
asm.addLine("jmp", s.getLoopBreakLabel())
}
func (cont Continue) generateCode(asm *ASM, s *SymbolTable) {
asm.addLine("jmp", s.getLoopContinueLabel())
}
func (sc Switch) generateCode(asm *ASM, s *SymbolTable) {
switchEnd := asm.nextLabelName()
vReg, _ := getRegister(TYPE_INT)
ret := getReturnRegister(TYPE_INT)
if sc.expression != nil {
sc.expression.generateCode(asm, s)
asm.addLine("mov", fmt.Sprintf("%v, %v", vReg, ret))
}
caseLabels := make([]string, len(sc.cases))
for i, c := range sc.cases {
caseLabels[i] = asm.nextLabelName()
// Default case for compare-switches
if len(c.expressions) == 0 {
asm.addLine("jmp", caseLabels[i])
}
for _, ce := range c.expressions {
if sc.expression != nil {
asm.addLine("push", vReg)
ce.generateCode(asm, s)
asm.addLine("pop", vReg)
asm.addLine("cmp", fmt.Sprintf("%v, %v", ret, vReg))
asm.addLine("je", caseLabels[i])
} else {
ce.generateCode(asm, s)
asm.addLine("cmp", fmt.Sprintf("%v, 0", ret))
asm.addLine("jne", caseLabels[i])
}
}
}
asm.addLine("jmp", switchEnd)
for i, c := range sc.cases {
asm.addLabel(caseLabels[i])
c.block.generateCode(asm, s)
asm.addLine("jmp", switchEnd)
}
asm.addLabel(switchEnd)
}
func (l Loop) generateCode(asm *ASM, s *SymbolTable) {
register, _ := getRegister(TYPE_BOOL)
startLabel := asm.nextLabelName()
incLabel := asm.nextLabelName()
evalLabel := asm.nextLabelName()
endLabel := asm.nextLabelName()
s.setLoopJumpLabels(endLabel, incLabel)
// The initial assignment is logically moved inside the for-block
l.assignment.generateCode(asm, l.block.symbolTable)
asm.addLine("jmp", evalLabel)
asm.addLabel(startLabel)
l.block.generateCode(asm, s)
asm.addLabel(incLabel)
// The increment assignment is logically moved inside the for-block
l.incrAssignment.generateCode(asm, l.block.symbolTable)
asm.addLabel(evalLabel)
// If any of the expressions result in False (0), we jump to the end!
for _, e := range l.expressions {
e.generateCode(asm, l.block.symbolTable)
switch e.getExpressionTypes(s)[0].t {
case TYPE_INT, TYPE_BOOL, TYPE_CHAR:
register = getReturnRegister(TYPE_INT)
case TYPE_FLOAT:
asm.addLine("movq", fmt.Sprintf("%v, %v", register, getReturnRegister(TYPE_FLOAT)))
}
asm.addLine("cmp", fmt.Sprintf("%v, 0", register))
asm.addLine("je", endLabel)
}
// So if we getVar here, all expressions were true. So jump to start again.
asm.addLine("jmp", startLabel)
asm.addLabel(endLabel)
}
func (l RangedLoop) generateCode(asm *ASM, s *SymbolTable) {
// This can not/should not fail!
entryI, ok := l.block.symbolTable.getVar(l.counter.vName)
if !ok {
panic("No counter variable availabe for ranged loop")
}
signI := "+"
if entryI.offset < 0 {
signI = ""
}
entryE, ok := l.block.symbolTable.getVar(l.elem.vName)
if !ok {
panic("No counter variable availabe for ranged loop")
}
signE := "+"
if entryE.offset < 0 {
signE = ""
}
startLabel := asm.nextLabelName()
incLabel := asm.nextLabelName()
evalLabel := asm.nextLabelName()
endLabel := asm.nextLabelName()
l.block.symbolTable.setLoopJumpLabels(endLabel, incLabel)
// initialize counter and assign to variable/stack
asm.addLine("mov", "r10, 0")
asm.addLine("mov", fmt.Sprintf("[rbp%v%v], r10", signI, entryI.offset))
asm.addLine("jmp", evalLabel)
asm.addLabel(startLabel)
// result will be in rax
l.rangeExpression.generateCode(asm, l.block.symbolTable)
// load i
asm.addLine("mov", fmt.Sprintf("r10, [rbp%v%v]", signI, entryI.offset))
// calculate a[i]
asm.addLine("mov", "r10, [rax+r10*8+24]")
// assign element variable