/*
* substitute s for v in a
* return failure to substitute
*/
func copysub(a *obj.Addr, v *obj.Addr, s *obj.Addr, f int) int {
if f != 0 {
if copyau(a, v) {
if a.Type == obj.TYPE_SHIFT {
if a.Offset&0xf == int64(v.Reg-arm.REG_R0) {
a.Offset = a.Offset&^0xf | int64(s.Reg)&0xf
}
if (a.Offset&(1<<4) != 0) && (a.Offset>>8)&0xf == int64(v.Reg-arm.REG_R0) {
a.Offset = a.Offset&^(0xf<<8) | (int64(s.Reg)&0xf)<<8
}
} else if a.Type == obj.TYPE_REGREG || a.Type == obj.TYPE_REGREG2 {
if a.Offset == int64(v.Reg) {
a.Offset = int64(s.Reg)
}
if a.Reg == v.Reg {
a.Reg = s.Reg
}
} else {
a.Reg = s.Reg
}
}
}
return 0
}
// symbolReference parses a symbol that is known not to be a register.
func (p *Parser) symbolReference(a *obj.Addr, name string, prefix rune) {
// Identifier is a name.
switch prefix {
case 0:
a.Type = obj.TYPE_MEM
case '$':
a.Type = obj.TYPE_ADDR
case '*':
a.Type = obj.TYPE_INDIR
}
// Weirdness with statics: Might now have "<>".
isStatic := 0 // TODO: Really a boolean, but Linklookup wants a "version" integer.
if p.peek() == '<' {
isStatic = 1
p.next()
p.get('>')
}
if p.peek() == '+' || p.peek() == '-' {
a.Offset = int64(p.expr())
}
a.Sym = obj.Linklookup(p.ctxt, name, isStatic)
if p.peek() == scanner.EOF {
if prefix == 0 && p.isJump {
// Symbols without prefix or suffix are jump labels.
return
}
p.errorf("illegal or missing addressing mode for symbol %s", name)
return
}
// Expect (SB), (FP), (PC), or (SP)
p.get('(')
reg := p.get(scanner.Ident).String()
p.get(')')
p.setPseudoRegister(a, reg, isStatic != 0, prefix)
}
func datagostring(sval string, a *obj.Addr) {
symhdr, _ := stringsym(sval)
a.Type = obj.TYPE_MEM
a.Name = obj.NAME_EXTERN
a.Sym = Linksym(symhdr)
a.Node = symhdr.Def
a.Offset = 0
a.Etype = uint8(TSTRING)
}
func Datastring(s string, a *obj.Addr) {
_, symdata := stringsym(s)
a.Type = obj.TYPE_MEM
a.Name = obj.NAME_EXTERN
a.Sym = Linksym(symdata)
a.Node = symdata.Def
a.Offset = 0
a.Etype = uint8(Simtype[TINT])
}
func addreg(a *obj.Addr, rn int) {
a.Sym = nil
a.Node = nil
a.Offset = 0
a.Type = obj.TYPE_REG
a.Reg = int16(rn)
a.Name = 0
Ostats.Ncvtreg++
}
// registerList parses an ARM register list expression, a list of registers in [].
// There may be comma-separated ranges or individual registers, as in
// [R1,R3-R5]. Only R0 through R15 may appear.
// The opening bracket has been consumed.
func (p *Parser) registerList(a *obj.Addr) {
// One range per loop.
const maxReg = 16
var bits uint16
ListLoop:
for {
tok := p.next()
switch tok.ScanToken {
case ']':
break ListLoop
case scanner.EOF:
p.errorf("missing ']' in register list")
return
}
// Parse the upper and lower bounds.
lo := p.registerNumber(tok.String())
hi := lo
if p.peek() == '-' {
p.next()
hi = p.registerNumber(p.next().String())
}
if hi < lo {
lo, hi = hi, lo
}
// Check there are no duplicates in the register list.
for i := 0; lo <= hi && i < maxReg; i++ {
if bits&(1<<lo) != 0 {
p.errorf("register R%d already in list", lo)
}
bits |= 1 << lo
lo++
}
if p.peek() != ']' {
p.get(',')
}
}
a.Type = obj.TYPE_REGLIST
a.Offset = int64(bits)
}
// registerIndirect parses the general form of a register indirection.
// It is can be (R1), (R2*scale), or (R1)(R2*scale) where R1 may be a simple
// register or register pair R:R or (R, R) or (R+R).
// Or it might be a pseudo-indirection like (FP).
// We are sitting on the opening parenthesis.
func (p *Parser) registerIndirect(a *obj.Addr, prefix rune) {
p.get('(')
tok := p.next()
name := tok.String()
r1, r2, scale, ok := p.register(name, 0)
if !ok {
p.errorf("indirect through non-register %s", tok)
}
p.get(')')
a.Type = obj.TYPE_MEM
if r1 < 0 {
// Pseudo-register reference.
if r2 != 0 {
p.errorf("cannot use pseudo-register in pair")
return
}
// For SB, SP, and FP, there must be a name here. 0(FP) is not legal.
if name != "PC" && a.Name == obj.NAME_NONE {
p.errorf("cannot reference %s without a symbol", name)
}
p.setPseudoRegister(a, name, false, prefix)
return
}
a.Reg = r1
if r2 != 0 {
// TODO: Consistency in the encoding would be nice here.
if p.arch.Thechar == '5' || p.arch.Thechar == '7' {
// Special form
// ARM: destination register pair (R1, R2).
// ARM64: register pair (R1, R2) for LDP/STP.
if prefix != 0 || scale != 0 {
p.errorf("illegal address mode for register pair")
return
}
a.Type = obj.TYPE_REGREG
a.Offset = int64(r2)
// Nothing may follow
return
}
if p.arch.Thechar == '9' {
// Special form for PPC64: (R1+R2); alias for (R1)(R2*1).
if prefix != 0 || scale != 0 {
p.errorf("illegal address mode for register+register")
return
}
a.Type = obj.TYPE_MEM
a.Scale = 1
a.Index = r2
// Nothing may follow.
return
}
}
if r2 != 0 {
p.errorf("indirect through register pair")
}
if prefix == '$' {
a.Type = obj.TYPE_ADDR
}
if r1 == arch.RPC && prefix != 0 {
p.errorf("illegal addressing mode for PC")
}
if scale == 0 && p.peek() == '(' {
// General form (R)(R*scale).
p.next()
tok := p.next()
r1, r2, scale, ok = p.register(tok.String(), 0)
if !ok {
p.errorf("indirect through non-register %s", tok)
}
if r2 != 0 {
p.errorf("unimplemented two-register form")
}
a.Index = r1
a.Scale = int16(scale)
p.get(')')
} else if scale != 0 {
// First (R) was missing, all we have is (R*scale).
a.Reg = 0
a.Index = r1
a.Scale = int16(scale)
}
}
// operand parses a general operand and stores the result in *a.
func (p *Parser) operand(a *obj.Addr) bool {
//fmt.Printf("Operand: %v\n", p.input)
if len(p.input) == 0 {
p.errorf("empty operand: cannot happen")
return false
}
// General address (with a few exceptions) looks like
// $sym±offset(SB)(reg)(index*scale)
// Exceptions are:
//
// R1
// offset
// $offset
// Every piece is optional, so we scan left to right and what
// we discover tells us where we are.
// Prefix: $.
var prefix rune
switch tok := p.peek(); tok {
case '$', '*':
prefix = rune(tok)
p.next()
}
// Symbol: sym±offset(SB)
tok := p.next()
name := tok.String()
if tok.ScanToken == scanner.Ident && !p.atStartOfRegister(name) {
// We have a symbol. Parse $sym±offset(symkind)
p.symbolReference(a, name, prefix)
// fmt.Printf("SYM %s\n", obj.Dconv(&emptyProg, 0, a))
if p.peek() == scanner.EOF {
return true
}
}
// Special register list syntax for arm: [R1,R3-R7]
if tok.ScanToken == '[' {
if prefix != 0 {
p.errorf("illegal use of register list")
}
p.registerList(a)
p.expect(scanner.EOF)
return true
}
// Register: R1
if tok.ScanToken == scanner.Ident && p.atStartOfRegister(name) {
if p.atRegisterShift() {
// ARM shifted register such as R1<<R2 or R1>>2.
a.Type = obj.TYPE_SHIFT
a.Offset = p.registerShift(tok.String(), prefix)
if p.peek() == '(' {
// Can only be a literal register here.
p.next()
tok := p.next()
name := tok.String()
if !p.atStartOfRegister(name) {
p.errorf("expected register; found %s", name)
}
a.Reg, _ = p.registerReference(name)
p.get(')')
}
} else if r1, r2, scale, ok := p.register(tok.String(), prefix); ok {
if scale != 0 {
p.errorf("expected simple register reference")
}
a.Type = obj.TYPE_REG
a.Reg = r1
if r2 != 0 {
// Form is R1:R2. It is on RHS and the second register
// needs to go into the LHS.
panic("cannot happen (Addr.Reg2)")
}
}
// fmt.Printf("REG %s\n", obj.Dconv(&emptyProg, 0, a))
p.expect(scanner.EOF)
return true
}
// Constant.
haveConstant := false
switch tok.ScanToken {
case scanner.Int, scanner.Float, scanner.String, scanner.Char, '+', '-', '~':
haveConstant = true
case '(':
// Could be parenthesized expression or (R). Must be something, though.
tok := p.next()
if tok.ScanToken == scanner.EOF {
p.errorf("missing right parenthesis")
return false
}
rname := tok.String()
p.back()
haveConstant = !p.atStartOfRegister(rname)
if !haveConstant {
p.back() // Put back the '('.
}
}
if haveConstant {
p.back()
if p.have(scanner.Float) {
if prefix != '$' {
p.errorf("floating-point constant must be an immediate")
}
a.Type = obj.TYPE_FCONST
a.Val = p.floatExpr()
// fmt.Printf("FCONST %s\n", obj.Dconv(&emptyProg, 0, a))
p.expect(scanner.EOF)
return true
}
if p.have(scanner.String) {
if prefix != '$' {
p.errorf("string constant must be an immediate")
return false
}
str, err := strconv.Unquote(p.get(scanner.String).String())
if err != nil {
p.errorf("string parse error: %s", err)
}
a.Type = obj.TYPE_SCONST
a.Val = str
// fmt.Printf("SCONST %s\n", obj.Dconv(&emptyProg, 0, a))
p.expect(scanner.EOF)
return true
}
a.Offset = int64(p.expr())
if p.peek() != '(' {
switch prefix {
case '$':
a.Type = obj.TYPE_CONST
case '*':
a.Type = obj.TYPE_INDIR // Can appear but is illegal, will be rejected by the linker.
default:
a.Type = obj.TYPE_MEM
}
// fmt.Printf("CONST %d %s\n", a.Offset, obj.Dconv(&emptyProg, 0, a))
p.expect(scanner.EOF)
return true
}
// fmt.Printf("offset %d \n", a.Offset)
}
// Register indirection: (reg) or (index*scale). We are on the opening paren.
p.registerIndirect(a, prefix)
// fmt.Printf("DONE %s\n", p.arch.Dconv(&emptyProg, 0, a))
p.expect(scanner.EOF)
return true
}
/*
* xtramodes enables the ARM post increment and
* shift offset addressing modes to transform
* MOVW 0(R3),R1
* ADD $4,R3,R3
* into
* MOVW.P 4(R3),R1
* and
* ADD R0,R1
* MOVBU 0(R1),R0
* into
* MOVBU R0<<0(R1),R0
*/
func xtramodes(g *gc.Graph, r *gc.Flow, a *obj.Addr) bool {
p := (*obj.Prog)(r.Prog)
v := obj.Addr(*a)
v.Type = obj.TYPE_REG
r1 := (*gc.Flow)(findpre(r, &v))
if r1 != nil {
p1 := r1.Prog
if p1.To.Type == obj.TYPE_REG && p1.To.Reg == v.Reg {
switch p1.As {
case arm.AADD:
if p1.Scond&arm.C_SBIT != 0 {
// avoid altering ADD.S/ADC sequences.
break
}
if p1.From.Type == obj.TYPE_REG || (p1.From.Type == obj.TYPE_SHIFT && p1.From.Offset&(1<<4) == 0 && ((p.As != arm.AMOVB && p.As != arm.AMOVBS) || (a == &p.From && p1.From.Offset&^0xf == 0))) || ((p1.From.Type == obj.TYPE_ADDR || p1.From.Type == obj.TYPE_CONST) && p1.From.Offset > -4096 && p1.From.Offset < 4096) {
if nochange(gc.Uniqs(r1), r, p1) {
if a != &p.From || v.Reg != p.To.Reg {
if finduse(g, r.S1, &v) {
if p1.Reg == 0 || p1.Reg == v.Reg {
/* pre-indexing */
p.Scond |= arm.C_WBIT
} else {
return false
}
}
}
switch p1.From.Type {
/* register offset */
case obj.TYPE_REG:
if gc.Nacl {
return false
}
*a = obj.Addr{}
a.Type = obj.TYPE_SHIFT
a.Offset = int64(p1.From.Reg) & 15
/* scaled register offset */
case obj.TYPE_SHIFT:
if gc.Nacl {
return false
}
*a = obj.Addr{}
a.Type = obj.TYPE_SHIFT
fallthrough
/* immediate offset */
case obj.TYPE_CONST,
obj.TYPE_ADDR:
a.Offset = p1.From.Offset
}
if p1.Reg != 0 {
a.Reg = p1.Reg
}
excise(r1)
return true
}
}
case arm.AMOVW:
if p1.From.Type == obj.TYPE_REG {
r2 := (*gc.Flow)(findinc(r1, r, &p1.From))
if r2 != nil {
var r3 *gc.Flow
for r3 = gc.Uniqs(r2); r3.Prog.As == obj.ANOP; r3 = gc.Uniqs(r3) {
}
if r3 == r {
/* post-indexing */
p1 := r2.Prog
a.Reg = p1.To.Reg
a.Offset = p1.From.Offset
p.Scond |= arm.C_PBIT
if !finduse(g, r, &r1.Prog.To) {
excise(r1)
}
excise(r2)
return true
}
}
}
}
}
}
if a != &p.From || a.Reg != p.To.Reg {
r1 := (*gc.Flow)(findinc(r, nil, &v))
if r1 != nil {
/* post-indexing */
p1 := r1.Prog
a.Offset = p1.From.Offset
p.Scond |= arm.C_PBIT
excise(r1)
return true
}
}
return false
}
// Naddr rewrites a to refer to n.
// It assumes that a is zeroed on entry.
func Naddr(a *obj.Addr, n *Node) {
if n == nil {
return
}
if n.Type != nil && n.Type.Etype != TIDEAL {
// TODO(rsc): This is undone by the selective clearing of width below,
// to match architectures that were not as aggressive in setting width
// during naddr. Those widths must be cleared to avoid triggering
// failures in gins when it detects real but heretofore latent (and one
// hopes innocuous) type mismatches.
// The type mismatches should be fixed and the clearing below removed.
dowidth(n.Type)
a.Width = n.Type.Width
}
switch n.Op {
default:
a := a // copy to let escape into Ctxt.Dconv
Debug['h'] = 1
Dump("naddr", n)
Fatalf("naddr: bad %v %v", Oconv(int(n.Op), 0), Ctxt.Dconv(a))
case OREGISTER:
a.Type = obj.TYPE_REG
a.Reg = n.Reg
a.Sym = nil
if Thearch.Thechar == '8' { // TODO(rsc): Never clear a->width.
a.Width = 0
}
case OINDREG:
a.Type = obj.TYPE_MEM
a.Reg = n.Reg
a.Sym = Linksym(n.Sym)
a.Offset = n.Xoffset
if a.Offset != int64(int32(a.Offset)) {
Yyerror("offset %d too large for OINDREG", a.Offset)
}
if Thearch.Thechar == '8' { // TODO(rsc): Never clear a->width.
a.Width = 0
}
// n->left is PHEAP ONAME for stack parameter.
// compute address of actual parameter on stack.
case OPARAM:
a.Etype = uint8(Simtype[n.Left.Type.Etype])
a.Width = n.Left.Type.Width
a.Offset = n.Xoffset
a.Sym = Linksym(n.Left.Sym)
a.Type = obj.TYPE_MEM
a.Name = obj.NAME_PARAM
a.Node = n.Left.Orig
case OCLOSUREVAR:
if !Curfn.Func.Needctxt {
Fatalf("closurevar without needctxt")
}
a.Type = obj.TYPE_MEM
a.Reg = int16(Thearch.REGCTXT)
a.Sym = nil
a.Offset = n.Xoffset
case OCFUNC:
Naddr(a, n.Left)
a.Sym = Linksym(n.Left.Sym)
case ONAME:
a.Etype = 0
if n.Type != nil {
a.Etype = uint8(Simtype[n.Type.Etype])
}
a.Offset = n.Xoffset
s := n.Sym
a.Node = n.Orig
//if(a->node >= (Node*)&n)
// fatal("stack node");
if s == nil {
s = Lookup(".noname")
}
if n.Name.Method {
if n.Type != nil {
if n.Type.Sym != nil {
if n.Type.Sym.Pkg != nil {
s = Pkglookup(s.Name, n.Type.Sym.Pkg)
}
}
}
}
a.Type = obj.TYPE_MEM
switch n.Class {
default:
Fatalf("naddr: ONAME class %v %d\n", n.Sym, n.Class)
case PEXTERN:
a.Name = obj.NAME_EXTERN
case PAUTO:
a.Name = obj.NAME_AUTO
case PPARAM, PPARAMOUT:
a.Name = obj.NAME_PARAM
case PFUNC:
a.Name = obj.NAME_EXTERN
a.Type = obj.TYPE_ADDR
a.Width = int64(Widthptr)
s = funcsym(s)
}
a.Sym = Linksym(s)
case ODOT:
// A special case to make write barriers more efficient.
// Taking the address of the first field of a named struct
// is the same as taking the address of the struct.
if n.Left.Type.Etype != TSTRUCT || n.Left.Type.Type.Sym != n.Right.Sym {
Debug['h'] = 1
Dump("naddr", n)
Fatalf("naddr: bad %v %v", Oconv(int(n.Op), 0), Ctxt.Dconv(a))
}
Naddr(a, n.Left)
case OLITERAL:
if Thearch.Thechar == '8' {
a.Width = 0
}
switch n.Val().Ctype() {
default:
Fatalf("naddr: const %v", Tconv(n.Type, obj.FmtLong))
case CTFLT:
a.Type = obj.TYPE_FCONST
a.Val = mpgetflt(n.Val().U.(*Mpflt))
case CTINT, CTRUNE:
a.Sym = nil
a.Type = obj.TYPE_CONST
a.Offset = Mpgetfix(n.Val().U.(*Mpint))
case CTSTR:
datagostring(n.Val().U.(string), a)
case CTBOOL:
a.Sym = nil
a.Type = obj.TYPE_CONST
a.Offset = int64(obj.Bool2int(n.Val().U.(bool)))
case CTNIL:
a.Sym = nil
a.Type = obj.TYPE_CONST
a.Offset = 0
}
case OADDR:
Naddr(a, n.Left)
a.Etype = uint8(Tptr)
if Thearch.Thechar != '0' && Thearch.Thechar != '5' && Thearch.Thechar != '7' && Thearch.Thechar != '9' { // TODO(rsc): Do this even for arm, ppc64.
a.Width = int64(Widthptr)
}
if a.Type != obj.TYPE_MEM {
a := a // copy to let escape into Ctxt.Dconv
Fatalf("naddr: OADDR %v (from %v)", Ctxt.Dconv(a), Oconv(int(n.Left.Op), 0))
}
a.Type = obj.TYPE_ADDR
// itable of interface value
case OITAB:
Naddr(a, n.Left)
if a.Type == obj.TYPE_CONST && a.Offset == 0 {
break // itab(nil)
}
a.Etype = uint8(Tptr)
a.Width = int64(Widthptr)
// pointer in a string or slice
case OSPTR:
Naddr(a, n.Left)
if a.Type == obj.TYPE_CONST && a.Offset == 0 {
break // ptr(nil)
}
a.Etype = uint8(Simtype[Tptr])
a.Offset += int64(Array_array)
a.Width = int64(Widthptr)
// len of string or slice
case OLEN:
Naddr(a, n.Left)
if a.Type == obj.TYPE_CONST && a.Offset == 0 {
break // len(nil)
}
a.Etype = uint8(Simtype[TUINT])
a.Offset += int64(Array_nel)
if Thearch.Thechar != '5' { // TODO(rsc): Do this even on arm.
a.Width = int64(Widthint)
}
// cap of string or slice
case OCAP:
Naddr(a, n.Left)
if a.Type == obj.TYPE_CONST && a.Offset == 0 {
break // cap(nil)
}
a.Etype = uint8(Simtype[TUINT])
a.Offset += int64(Array_cap)
if Thearch.Thechar != '5' { // TODO(rsc): Do this even on arm.
a.Width = int64(Widthint)
}
}
return
}