/*
* copy a composite value by moving its individual components.
* Slices, strings and interfaces are supported.
* Small structs or arrays with elements of basic type are
* also supported.
* nr is N when assigning a zero value.
* return 1 if can do, 0 if can't.
*/
func componentgen(nr *gc.Node, nl *gc.Node) bool {
var nodl gc.Node
var nodr gc.Node
freel := 0
freer := 0
switch nl.Type.Etype {
default:
goto no
case gc.TARRAY:
t := nl.Type
// Slices are ok.
if gc.Isslice(t) {
break
}
// Small arrays are ok.
if t.Bound > 0 && t.Bound <= 3 && !gc.Isfat(t.Type) {
break
}
goto no
// Small structs with non-fat types are ok.
// Zero-sized structs are treated separately elsewhere.
case gc.TSTRUCT:
fldcount := int64(0)
for t := nl.Type.Type; t != nil; t = t.Down {
if gc.Isfat(t.Type) {
goto no
}
if t.Etype != gc.TFIELD {
gc.Fatal("componentgen: not a TFIELD: %v", gc.Tconv(t, obj.FmtLong))
}
fldcount++
}
if fldcount == 0 || fldcount > 4 {
goto no
}
case gc.TSTRING,
gc.TINTER:
break
}
nodl = *nl
if !cadable(nl) {
if nr != nil && !cadable(nr) {
goto no
}
igen(nl, &nodl, nil)
freel = 1
}
if nr != nil {
nodr = *nr
if !cadable(nr) {
igen(nr, &nodr, nil)
freer = 1
}
} else {
// When zeroing, prepare a register containing zero.
var tmp gc.Node
gc.Nodconst(&tmp, nl.Type, 0)
regalloc(&nodr, gc.Types[gc.TUINT], nil)
gmove(&tmp, &nodr)
freer = 1
}
// nl and nr are 'cadable' which basically means they are names (variables) now.
// If they are the same variable, don't generate any code, because the
// VARDEF we generate will mark the old value as dead incorrectly.
// (And also the assignments are useless.)
if nr != nil && nl.Op == gc.ONAME && nr.Op == gc.ONAME && nl == nr {
goto yes
}
switch nl.Type.Etype {
// componentgen for arrays.
case gc.TARRAY:
if nl.Op == gc.ONAME {
gc.Gvardef(nl)
}
t := nl.Type
if !gc.Isslice(t) {
nodl.Type = t.Type
nodr.Type = nodl.Type
for fldcount := int64(0); fldcount < t.Bound; fldcount++ {
if nr == nil {
gc.Clearslim(&nodl)
} else {
gmove(&nodr, &nodl)
}
nodl.Xoffset += t.Type.Width
nodr.Xoffset += t.Type.Width
}
goto yes
}
// componentgen for slices.
nodl.Xoffset += int64(gc.Array_array)
nodl.Type = gc.Ptrto(nl.Type.Type)
if nr != nil {
nodr.Xoffset += int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
nodl.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodl.Type = gc.Types[gc.Simtype[gc.TUINT]]
if nr != nil {
nodr.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
nodl.Xoffset += int64(gc.Array_cap) - int64(gc.Array_nel)
nodl.Type = gc.Types[gc.Simtype[gc.TUINT]]
if nr != nil {
nodr.Xoffset += int64(gc.Array_cap) - int64(gc.Array_nel)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
goto yes
case gc.TSTRING:
if nl.Op == gc.ONAME {
gc.Gvardef(nl)
}
nodl.Xoffset += int64(gc.Array_array)
nodl.Type = gc.Ptrto(gc.Types[gc.TUINT8])
if nr != nil {
nodr.Xoffset += int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
nodl.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodl.Type = gc.Types[gc.Simtype[gc.TUINT]]
if nr != nil {
nodr.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
goto yes
case gc.TINTER:
if nl.Op == gc.ONAME {
gc.Gvardef(nl)
}
nodl.Xoffset += int64(gc.Array_array)
nodl.Type = gc.Ptrto(gc.Types[gc.TUINT8])
if nr != nil {
nodr.Xoffset += int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
nodl.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodl.Type = gc.Ptrto(gc.Types[gc.TUINT8])
if nr != nil {
nodr.Xoffset += int64(gc.Array_nel) - int64(gc.Array_array)
nodr.Type = nodl.Type
}
gmove(&nodr, &nodl)
goto yes
case gc.TSTRUCT:
if nl.Op == gc.ONAME {
gc.Gvardef(nl)
}
loffset := nodl.Xoffset
roffset := nodr.Xoffset
// funarg structs may not begin at offset zero.
if nl.Type.Etype == gc.TSTRUCT && nl.Type.Funarg != 0 && nl.Type.Type != nil {
loffset -= nl.Type.Type.Width
}
if nr != nil && nr.Type.Etype == gc.TSTRUCT && nr.Type.Funarg != 0 && nr.Type.Type != nil {
roffset -= nr.Type.Type.Width
}
for t := nl.Type.Type; t != nil; t = t.Down {
nodl.Xoffset = loffset + t.Width
nodl.Type = t.Type
if nr == nil {
gc.Clearslim(&nodl)
} else {
nodr.Xoffset = roffset + t.Width
nodr.Type = nodl.Type
gmove(&nodr, &nodl)
}
}
goto yes
}
no:
if freer != 0 {
regfree(&nodr)
}
if freel != 0 {
regfree(&nodl)
}
return false
yes:
if freer != 0 {
regfree(&nodr)
}
if freel != 0 {
regfree(&nodl)
}
return true
}
/*
* generate:
* res = n;
* simplifies and calls gmove.
*
* TODO:
* sudoaddable
*/
func cgen(n *gc.Node, res *gc.Node) {
if gc.Debug['g'] != 0 {
gc.Dump("\ncgen-n", n)
gc.Dump("cgen-res", res)
}
if n == nil || n.Type == nil {
gc.Fatal("cgen: n nil")
}
if res == nil || res.Type == nil {
gc.Fatal("cgen: res nil")
}
switch n.Op {
case gc.OSLICE,
gc.OSLICEARR,
gc.OSLICESTR,
gc.OSLICE3,
gc.OSLICE3ARR:
if res.Op != gc.ONAME || res.Addable == 0 {
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Cgen_slice(n, &n1)
cgen(&n1, res)
} else {
gc.Cgen_slice(n, res)
}
return
case gc.OEFACE:
if res.Op != gc.ONAME || res.Addable == 0 {
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Cgen_eface(n, &n1)
cgen(&n1, res)
} else {
gc.Cgen_eface(n, res)
}
return
}
for n.Op == gc.OCONVNOP {
n = n.Left
}
// function calls on both sides? introduce temporary
if n.Ullman >= gc.UINF && res.Ullman >= gc.UINF {
var n1 gc.Node
gc.Tempname(&n1, n.Type)
cgen(n, &n1)
cgen(&n1, res)
return
}
// structs etc get handled specially
if gc.Isfat(n.Type) {
if n.Type.Width < 0 {
gc.Fatal("forgot to compute width for %v", gc.Tconv(n.Type, 0))
}
sgen(n, res, n.Type.Width)
return
}
// update addressability for string, slice
// can't do in walk because n->left->addable
// changes if n->left is an escaping local variable.
switch n.Op {
case gc.OSPTR,
gc.OLEN:
if gc.Isslice(n.Left.Type) || gc.Istype(n.Left.Type, gc.TSTRING) {
n.Addable = n.Left.Addable
}
case gc.OCAP:
if gc.Isslice(n.Left.Type) {
n.Addable = n.Left.Addable
}
case gc.OITAB:
n.Addable = n.Left.Addable
}
// if both are addressable, move
if n.Addable != 0 && res.Addable != 0 {
gmove(n, res)
return
}
// if both are not addressable, use a temporary.
if n.Addable == 0 && res.Addable == 0 {
// could use regalloc here sometimes,
// but have to check for ullman >= UINF.
var n1 gc.Node
gc.Tempname(&n1, n.Type)
cgen(n, &n1)
cgen(&n1, res)
return
}
// if result is not addressable directly but n is,
// compute its address and then store via the address.
if res.Addable == 0 {
var n1 gc.Node
igen(res, &n1, nil)
cgen(n, &n1)
regfree(&n1)
return
}
// complex types
if gc.Complexop(n, res) {
gc.Complexgen(n, res)
return
}
// otherwise, the result is addressable but n is not.
// let's do some computation.
// use ullman to pick operand to eval first.
nl := n.Left
nr := n.Right
if nl != nil && nl.Ullman >= gc.UINF {
if nr != nil && nr.Ullman >= gc.UINF {
// both are hard
var n1 gc.Node
gc.Tempname(&n1, nl.Type)
cgen(nl, &n1)
n2 := *n
n2.Left = &n1
cgen(&n2, res)
return
}
}
// 64-bit ops are hard on 32-bit machine.
if gc.Is64(n.Type) || gc.Is64(res.Type) || n.Left != nil && gc.Is64(n.Left.Type) {
switch n.Op {
// math goes to cgen64.
case gc.OMINUS,
gc.OCOM,
gc.OADD,
gc.OSUB,
gc.OMUL,
gc.OLROT,
gc.OLSH,
gc.ORSH,
gc.OAND,
gc.OOR,
gc.OXOR:
cgen64(n, res)
return
}
}
if nl != nil && gc.Isfloat[n.Type.Etype] && gc.Isfloat[nl.Type.Etype] {
cgen_float(n, res)
return
}
var a int
switch n.Op {
default:
gc.Dump("cgen", n)
gc.Fatal("cgen %v", gc.Oconv(int(n.Op), 0))
case gc.OREAL,
gc.OIMAG,
gc.OCOMPLEX:
gc.Fatal("unexpected complex")
return
// these call bgen to get a bool value
case gc.OOROR,
gc.OANDAND,
gc.OEQ,
gc.ONE,
gc.OLT,
gc.OLE,
gc.OGE,
gc.OGT,
gc.ONOT:
p1 := gc.Gbranch(obj.AJMP, nil, 0)
p2 := gc.Pc
gmove(gc.Nodbool(true), res)
p3 := gc.Gbranch(obj.AJMP, nil, 0)
gc.Patch(p1, gc.Pc)
bgen(n, true, 0, p2)
gmove(gc.Nodbool(false), res)
gc.Patch(p3, gc.Pc)
return
case gc.OPLUS:
cgen(nl, res)
return
case gc.OMINUS,
gc.OCOM:
a := optoas(int(n.Op), nl.Type)
// unary
var n1 gc.Node
gc.Tempname(&n1, nl.Type)
cgen(nl, &n1)
gins(a, nil, &n1)
gmove(&n1, res)
return
// symmetric binary
case gc.OAND,
gc.OOR,
gc.OXOR,
gc.OADD,
gc.OMUL:
a = optoas(int(n.Op), nl.Type)
if a == x86.AIMULB {
cgen_bmul(int(n.Op), nl, nr, res)
break
}
// symmetric binary
if nl.Ullman < nr.Ullman || nl.Op == gc.OLITERAL {
r := nl
nl = nr
nr = r
}
goto abop
// asymmetric binary
case gc.OSUB:
a = optoas(int(n.Op), nl.Type)
goto abop
case gc.OHMUL:
cgen_hmul(nl, nr, res)
case gc.OCONV:
if gc.Eqtype(n.Type, nl.Type) || gc.Noconv(n.Type, nl.Type) {
cgen(nl, res)
break
}
var n2 gc.Node
gc.Tempname(&n2, n.Type)
var n1 gc.Node
mgen(nl, &n1, res)
gmove(&n1, &n2)
gmove(&n2, res)
mfree(&n1)
case gc.ODOT,
gc.ODOTPTR,
gc.OINDEX,
gc.OIND,
gc.ONAME: // PHEAP or PPARAMREF var
var n1 gc.Node
igen(n, &n1, res)
gmove(&n1, res)
regfree(&n1)
case gc.OITAB:
var n1 gc.Node
igen(nl, &n1, res)
n1.Type = gc.Ptrto(gc.Types[gc.TUINTPTR])
gmove(&n1, res)
regfree(&n1)
// pointer is the first word of string or slice.
case gc.OSPTR:
if gc.Isconst(nl, gc.CTSTR) {
var n1 gc.Node
regalloc(&n1, gc.Types[gc.Tptr], res)
p1 := gins(x86.ALEAL, nil, &n1)
gc.Datastring(nl.Val.U.Sval, &p1.From)
gmove(&n1, res)
regfree(&n1)
break
}
var n1 gc.Node
igen(nl, &n1, res)
n1.Type = n.Type
gmove(&n1, res)
regfree(&n1)
case gc.OLEN:
if gc.Istype(nl.Type, gc.TMAP) || gc.Istype(nl.Type, gc.TCHAN) {
// map has len in the first 32-bit word.
// a zero pointer means zero length
var n1 gc.Node
gc.Tempname(&n1, gc.Types[gc.Tptr])
cgen(nl, &n1)
var n2 gc.Node
regalloc(&n2, gc.Types[gc.Tptr], nil)
gmove(&n1, &n2)
n1 = n2
gc.Nodconst(&n2, gc.Types[gc.Tptr], 0)
gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &n2)
p1 := gc.Gbranch(optoas(gc.OEQ, gc.Types[gc.Tptr]), nil, -1)
n2 = n1
n2.Op = gc.OINDREG
n2.Type = gc.Types[gc.TINT32]
gmove(&n2, &n1)
gc.Patch(p1, gc.Pc)
gmove(&n1, res)
regfree(&n1)
break
}
if gc.Istype(nl.Type, gc.TSTRING) || gc.Isslice(nl.Type) {
// both slice and string have len one pointer into the struct.
var n1 gc.Node
igen(nl, &n1, res)
n1.Type = gc.Types[gc.TUINT32]
n1.Xoffset += int64(gc.Array_nel)
gmove(&n1, res)
regfree(&n1)
break
}
gc.Fatal("cgen: OLEN: unknown type %v", gc.Tconv(nl.Type, obj.FmtLong))
case gc.OCAP:
if gc.Istype(nl.Type, gc.TCHAN) {
// chan has cap in the second 32-bit word.
// a zero pointer means zero length
var n1 gc.Node
gc.Tempname(&n1, gc.Types[gc.Tptr])
cgen(nl, &n1)
var n2 gc.Node
regalloc(&n2, gc.Types[gc.Tptr], nil)
gmove(&n1, &n2)
n1 = n2
gc.Nodconst(&n2, gc.Types[gc.Tptr], 0)
gins(optoas(gc.OCMP, gc.Types[gc.Tptr]), &n1, &n2)
p1 := gc.Gbranch(optoas(gc.OEQ, gc.Types[gc.Tptr]), nil, -1)
n2 = n1
n2.Op = gc.OINDREG
n2.Xoffset = 4
n2.Type = gc.Types[gc.TINT32]
gmove(&n2, &n1)
gc.Patch(p1, gc.Pc)
gmove(&n1, res)
regfree(&n1)
break
}
if gc.Isslice(nl.Type) {
var n1 gc.Node
igen(nl, &n1, res)
n1.Type = gc.Types[gc.TUINT32]
n1.Xoffset += int64(gc.Array_cap)
gmove(&n1, res)
regfree(&n1)
break
}
gc.Fatal("cgen: OCAP: unknown type %v", gc.Tconv(nl.Type, obj.FmtLong))
case gc.OADDR:
agen(nl, res)
case gc.OCALLMETH:
gc.Cgen_callmeth(n, 0)
cgen_callret(n, res)
case gc.OCALLINTER:
cgen_callinter(n, res, 0)
cgen_callret(n, res)
case gc.OCALLFUNC:
cgen_call(n, 0)
cgen_callret(n, res)
case gc.OMOD,
gc.ODIV:
cgen_div(int(n.Op), nl, nr, res)
case gc.OLSH,
gc.ORSH,
gc.OLROT:
cgen_shift(int(n.Op), n.Bounded, nl, nr, res)
}
return
abop: // asymmetric binary
if gc.Smallintconst(nr) {
var n1 gc.Node
mgen(nl, &n1, res)
var n2 gc.Node
regalloc(&n2, nl.Type, &n1)
gmove(&n1, &n2)
gins(a, nr, &n2)
gmove(&n2, res)
regfree(&n2)
mfree(&n1)
} else if nl.Ullman >= nr.Ullman {
var nt gc.Node
gc.Tempname(&nt, nl.Type)
cgen(nl, &nt)
var n2 gc.Node
mgen(nr, &n2, nil)
var n1 gc.Node
regalloc(&n1, nl.Type, res)
gmove(&nt, &n1)
gins(a, &n2, &n1)
gmove(&n1, res)
regfree(&n1)
mfree(&n2)
} else {
var n2 gc.Node
regalloc(&n2, nr.Type, res)
cgen(nr, &n2)
var n1 gc.Node
regalloc(&n1, nl.Type, nil)
cgen(nl, &n1)
gins(a, &n2, &n1)
regfree(&n2)
gmove(&n1, res)
regfree(&n1)
}
return
}