// 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)
}
/*
* 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
}
func nacladdr(ctxt *obj.Link, p *obj.Prog, a *obj.Addr) {
if p.As == ALEAL || p.As == ALEAQ {
return
}
if a.Reg == REG_BP {
ctxt.Diag("invalid address: %v", p)
return
}
if a.Reg == REG_TLS {
a.Reg = REG_BP
}
if a.Type == obj.TYPE_MEM && a.Name == obj.NAME_NONE {
switch a.Reg {
// all ok
case REG_BP, REG_SP, REG_R15:
break
default:
if a.Index != REG_NONE {
ctxt.Diag("invalid address %v", p)
}
a.Index = a.Reg
if a.Index != REG_NONE {
a.Scale = 1
}
a.Reg = REG_R15
}
}
}
// copysub replaces v with s in a if f!=0 or indicates it if could if f==0.
// Returns 1 on failure to substitute (it always succeeds on mips).
func copysub(a *obj.Addr, v *obj.Addr, s *obj.Addr, f int) int {
if f != 0 {
if copyau(a, v) {
a.Reg = s.Reg
}
}
return 0
}
// setPseudoRegister sets the NAME field of addr for a pseudo-register reference such as (SB).
func (p *Parser) setPseudoRegister(addr *obj.Addr, reg string, isStatic bool, prefix rune) {
if addr.Reg != 0 {
p.errorf("internal error: reg %s already set in pseudo", reg)
}
switch reg {
case "FP":
addr.Name = obj.NAME_PARAM
case "PC":
if prefix != 0 {
p.errorf("illegal addressing mode for PC")
}
addr.Type = obj.TYPE_BRANCH // We set the type and leave NAME untouched. See asmJump.
case "SB":
addr.Name = obj.NAME_EXTERN
if isStatic {
addr.Name = obj.NAME_STATIC
}
case "SP":
addr.Name = obj.NAME_AUTO // The pseudo-stack.
default:
p.errorf("expected pseudo-register; found %s", reg)
}
if prefix == '$' {
addr.Type = obj.TYPE_ADDR
}
}
// 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)
}
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 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)
}
/*
* 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 copyas(a, v) {
reg := int(int(s.Reg))
if reg >= x86.REG_AX && reg <= x86.REG_R15 || reg >= x86.REG_X0 && reg <= x86.REG_X0+15 {
if f != 0 {
a.Reg = int16(reg)
}
}
return 0
}
if regtyp(v) {
reg := int(int(v.Reg))
if a.Type == obj.TYPE_MEM && int(a.Reg) == reg {
if (s.Reg == x86.REG_BP || s.Reg == x86.REG_R13) && a.Index != x86.REG_NONE {
return 1 /* can't use BP-base with index */
}
if f != 0 {
a.Reg = s.Reg
}
}
// return 0;
if int(a.Index) == reg {
if f != 0 {
a.Index = s.Reg
}
return 0
}
return 0
}
return 0
}
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++
}
// 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)
}
}
/*
* generate code to compute address of n,
* a reference to a (perhaps nested) field inside
* an array or struct.
* return 0 on failure, 1 on success.
* on success, leaves usable address in a.
*
* caller is responsible for calling sudoclean
* after successful sudoaddable,
* to release the register used for a.
*/
func sudoaddable(as int, n *gc.Node, a *obj.Addr) bool {
if n.Type == nil {
return false
}
*a = obj.Addr{}
switch n.Op {
case gc.OLITERAL:
if !gc.Isconst(n, gc.CTINT) {
break
}
v := n.Int()
if v >= 32000 || v <= -32000 {
break
}
switch as {
default:
return false
case arm.AADD,
arm.ASUB,
arm.AAND,
arm.AORR,
arm.AEOR,
arm.AMOVB,
arm.AMOVBS,
arm.AMOVBU,
arm.AMOVH,
arm.AMOVHS,
arm.AMOVHU,
arm.AMOVW:
break
}
cleani += 2
reg := &clean[cleani-1]
reg1 := &clean[cleani-2]
reg.Op = gc.OEMPTY
reg1.Op = gc.OEMPTY
gc.Naddr(a, n)
return true
case gc.ODOT,
gc.ODOTPTR:
cleani += 2
reg := &clean[cleani-1]
reg1 := &clean[cleani-2]
reg.Op = gc.OEMPTY
reg1.Op = gc.OEMPTY
var nn *gc.Node
var oary [10]int64
o := gc.Dotoffset(n, oary[:], &nn)
if nn == nil {
sudoclean()
return false
}
if nn.Addable && o == 1 && oary[0] >= 0 {
// directly addressable set of DOTs
n1 := *nn
n1.Type = n.Type
n1.Xoffset += oary[0]
gc.Naddr(a, &n1)
return true
}
gc.Regalloc(reg, gc.Types[gc.Tptr], nil)
n1 := *reg
n1.Op = gc.OINDREG
if oary[0] >= 0 {
gc.Agen(nn, reg)
n1.Xoffset = oary[0]
} else {
gc.Cgen(nn, reg)
gc.Cgen_checknil(reg)
n1.Xoffset = -(oary[0] + 1)
}
for i := 1; i < o; i++ {
if oary[i] >= 0 {
gc.Fatalf("can't happen")
}
gins(arm.AMOVW, &n1, reg)
gc.Cgen_checknil(reg)
n1.Xoffset = -(oary[i] + 1)
}
a.Type = obj.TYPE_NONE
a.Name = obj.NAME_NONE
n1.Type = n.Type
gc.Naddr(a, &n1)
return true
case gc.OINDEX:
return false
}
return false
}
// 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
}
func Afunclit(a *obj.Addr, n *Node) {
if a.Type == obj.TYPE_ADDR && a.Name == obj.NAME_EXTERN {
a.Type = obj.TYPE_MEM
a.Sym = Linksym(n.Sym)
}
}
/*
* 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
}
/*
* generate code to compute address of n,
* a reference to a (perhaps nested) field inside
* an array or struct.
* return 0 on failure, 1 on success.
* on success, leaves usable address in a.
*
* caller is responsible for calling sudoclean
* after successful sudoaddable,
* to release the register used for a.
*/
func sudoaddable(as int, n *gc.Node, a *obj.Addr) bool {
if n.Type == nil {
return false
}
*a = obj.Addr{}
switch n.Op {
case gc.OLITERAL:
if !gc.Isconst(n, gc.CTINT) {
break
}
v := n.Int()
if v >= 32000 || v <= -32000 {
break
}
switch as {
default:
return false
case x86.AADDB,
x86.AADDW,
x86.AADDL,
x86.AADDQ,
x86.ASUBB,
x86.ASUBW,
x86.ASUBL,
x86.ASUBQ,
x86.AANDB,
x86.AANDW,
x86.AANDL,
x86.AANDQ,
x86.AORB,
x86.AORW,
x86.AORL,
x86.AORQ,
x86.AXORB,
x86.AXORW,
x86.AXORL,
x86.AXORQ,
x86.AINCB,
x86.AINCW,
x86.AINCL,
x86.AINCQ,
x86.ADECB,
x86.ADECW,
x86.ADECL,
x86.ADECQ,
x86.AMOVB,
x86.AMOVW,
x86.AMOVL,
x86.AMOVQ:
break
}
cleani += 2
reg := &clean[cleani-1]
reg1 := &clean[cleani-2]
reg.Op = gc.OEMPTY
reg1.Op = gc.OEMPTY
gc.Naddr(a, n)
return true
case gc.ODOT,
gc.ODOTPTR:
cleani += 2
reg := &clean[cleani-1]
reg1 := &clean[cleani-2]
reg.Op = gc.OEMPTY
reg1.Op = gc.OEMPTY
var nn *gc.Node
var oary [10]int64
o := gc.Dotoffset(n, oary[:], &nn)
if nn == nil {
sudoclean()
return false
}
if nn.Addable && o == 1 && oary[0] >= 0 {
// directly addressable set of DOTs
n1 := *nn
n1.Type = n.Type
n1.Xoffset += oary[0]
gc.Naddr(a, &n1)
return true
}
gc.Regalloc(reg, gc.Types[gc.Tptr], nil)
n1 := *reg
n1.Op = gc.OINDREG
if oary[0] >= 0 {
gc.Agen(nn, reg)
n1.Xoffset = oary[0]
} else {
gc.Cgen(nn, reg)
gc.Cgen_checknil(reg)
n1.Xoffset = -(oary[0] + 1)
}
for i := 1; i < o; i++ {
if oary[i] >= 0 {
gc.Fatalf("can't happen")
}
gins(movptr, &n1, reg)
gc.Cgen_checknil(reg)
n1.Xoffset = -(oary[i] + 1)
}
a.Type = obj.TYPE_NONE
a.Index = obj.TYPE_NONE
gc.Fixlargeoffset(&n1)
gc.Naddr(a, &n1)
return true
case gc.OINDEX:
return false
}
return false
}
func mkvar(f *Flow, a *obj.Addr) Bits {
// mark registers used
if a.Type == obj.TYPE_NONE {
return zbits
}
r := f.Data.(*Reg)
r.use1.b[0] |= Thearch.Doregbits(int(a.Index)) // TODO: Use RtoB
var n int
switch a.Type {
default:
regu := Thearch.Doregbits(int(a.Reg)) | Thearch.RtoB(int(a.Reg)) // TODO: Use RtoB
if regu == 0 {
return zbits
}
bit := zbits
bit.b[0] = regu
return bit
// TODO(rsc): Remove special case here.
case obj.TYPE_ADDR:
var bit Bits
if Thearch.Thechar == '0' || Thearch.Thechar == '5' || Thearch.Thechar == '7' || Thearch.Thechar == '9' {
goto memcase
}
a.Type = obj.TYPE_MEM
bit = mkvar(f, a)
setaddrs(bit)
a.Type = obj.TYPE_ADDR
Ostats.Naddr++
return zbits
memcase:
fallthrough
case obj.TYPE_MEM:
if r != nil {
r.use1.b[0] |= Thearch.RtoB(int(a.Reg))
}
/* NOTE: 5g did
if(r->f.prog->scond & (C_PBIT|C_WBIT))
r->set.b[0] |= RtoB(a->reg);
*/
switch a.Name {
default:
// Note: This case handles NAME_EXTERN and NAME_STATIC.
// We treat these as requiring eager writes to memory, due to
// the possibility of a fault handler looking at them, so there is
// not much point in registerizing the loads.
// If we later choose the set of candidate variables from a
// larger list, these cases could be deprioritized instead of
// removed entirely.
return zbits
case obj.NAME_PARAM,
obj.NAME_AUTO:
n = int(a.Name)
}
}
node, _ := a.Node.(*Node)
if node == nil || node.Op != ONAME || node.Orig == nil {
return zbits
}
node = node.Orig
if node.Orig != node {
Fatalf("%v: bad node", Ctxt.Dconv(a))
}
if node.Sym == nil || node.Sym.Name[0] == '.' {
return zbits
}
et := EType(a.Etype)
o := a.Offset
w := a.Width
if w < 0 {
Fatalf("bad width %d for %v", w, Ctxt.Dconv(a))
}
flag := 0
var v *Var
for i := 0; i < nvar; i++ {
v = &vars[i]
if v.node == node && int(v.name) == n {
if v.offset == o {
if v.etype == et {
if int64(v.width) == w {
// TODO(rsc): Remove special case for arm here.
if flag == 0 || Thearch.Thechar != '5' {
return blsh(uint(i))
}
}
}
}
// if they overlap, disable both
if overlap_reg(v.offset, v.width, o, int(w)) {
// print("disable overlap %s %d %d %d %d, %E != %E\n", s->name, v->offset, v->width, o, w, v->etype, et);
v.addr = 1
flag = 1
}
}
}
switch et {
case 0, TFUNC:
return zbits
}
if nvar >= NVAR {
if Debug['w'] > 1 && node != nil {
Fatalf("variable not optimized: %v", Nconv(node, obj.FmtSharp))
}
if Debug['v'] > 0 {
Warn("variable not optimized: %v", Nconv(node, obj.FmtSharp))
}
// If we're not tracking a word in a variable, mark the rest as
// having its address taken, so that we keep the whole thing
// live at all calls. otherwise we might optimize away part of
// a variable but not all of it.
var v *Var
for i := 0; i < nvar; i++ {
v = &vars[i]
if v.node == node {
v.addr = 1
}
}
return zbits
}
i := nvar
nvar++
v = &vars[i]
v.id = i
v.offset = o
v.name = int8(n)
v.etype = et
v.width = int(w)
v.addr = int8(flag) // funny punning
v.node = node
// node->opt is the head of a linked list
// of Vars within the given Node, so that
// we can start at a Var and find all the other
// Vars in the same Go variable.
v.nextinnode, _ = node.Opt().(*Var)
node.SetOpt(v)
bit := blsh(uint(i))
if n == obj.NAME_EXTERN || n == obj.NAME_STATIC {
for z := 0; z < BITS; z++ {
externs.b[z] |= bit.b[z]
}
}
if n == obj.NAME_PARAM {
for z := 0; z < BITS; z++ {
params.b[z] |= bit.b[z]
}
}
if node.Class == PPARAM {
for z := 0; z < BITS; z++ {
ivar.b[z] |= bit.b[z]
}
}
if node.Class == PPARAMOUT {
for z := 0; z < BITS; z++ {
ovar.b[z] |= bit.b[z]
}
}
// Treat values with their address taken as live at calls,
// because the garbage collector's liveness analysis in plive.go does.
// These must be consistent or else we will elide stores and the garbage
// collector will see uninitialized data.
// The typical case where our own analysis is out of sync is when the
// node appears to have its address taken but that code doesn't actually
// get generated and therefore doesn't show up as an address being
// taken when we analyze the instruction stream.
// One instance of this case is when a closure uses the same name as
// an outer variable for one of its own variables declared with :=.
// The parser flags the outer variable as possibly shared, and therefore
// sets addrtaken, even though it ends up not being actually shared.
// If we were better about _ elision, _ = &x would suffice too.
// The broader := in a closure problem is mentioned in a comment in
// closure.go:/^typecheckclosure and dcl.go:/^oldname.
if node.Addrtaken {
v.addr = 1
}
// Disable registerization for globals, because:
// (1) we might panic at any time and we want the recovery code
// to see the latest values (issue 1304).
// (2) we don't know what pointers might point at them and we want
// loads via those pointers to see updated values and vice versa (issue 7995).
//
// Disable registerization for results if using defer, because the deferred func
// might recover and return, causing the current values to be used.
if node.Class == PEXTERN || (hasdefer && node.Class == PPARAMOUT) {
v.addr = 1
}
if Debug['R'] != 0 {
fmt.Printf("bit=%2d et=%v w=%d+%d %v %v flag=%d\n", i, Econv(et), o, w, Nconv(node, obj.FmtSharp), Ctxt.Dconv(a), v.addr)
}
Ostats.Nvar++
return bit
}
