本文整理匯總了Golang中cmd/internal/gc.Isconst函數的典型用法代碼示例。如果您正苦於以下問題：Golang Isconst函數的具體用法？Golang Isconst怎麽用？Golang Isconst使用的例子？那麽, 這裏精選的函數代碼示例或許可以為您提供幫助。
在下文中一共展示了Isconst函數的15個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的Golang代碼示例。
示例1: intLiteral
func intLiteral(n *gc.Node) (x int64, ok bool) {
switch {
case n == nil:
return
case gc.Isconst(n, gc.CTINT):
return n.Int(), true
case gc.Isconst(n, gc.CTBOOL):
return int64(obj.Bool2int(n.Bool())), true
}
return
}示例2: ginscmp
func ginscmp(op int, t *gc.Type, n1, n2 *gc.Node, likely int) *obj.Prog {
if gc.Isint[t.Etype] && n1.Op == gc.OLITERAL && n2.Op != gc.OLITERAL {
// Reverse comparison to place constant last.
op = gc.Brrev(op)
n1, n2 = n2, n1
}
var r1, r2, g1, g2 gc.Node
gc.Regalloc(&r1, t, n1)
gc.Regalloc(&g1, n1.Type, &r1)
gc.Cgen(n1, &g1)
gmove(&g1, &r1)
if gc.Isint[t.Etype] && gc.Isconst(n2, gc.CTINT) {
ginscon2(optoas(gc.OCMP, t), &r1, n2.Int())
} else {
gc.Regalloc(&r2, t, n2)
gc.Regalloc(&g2, n1.Type, &r2)
gc.Cgen(n2, &g2)
gmove(&g2, &r2)
rawgins(optoas(gc.OCMP, t), &r1, &r2)
gc.Regfree(&g2)
gc.Regfree(&r2)
}
gc.Regfree(&g1)
gc.Regfree(&r1)
return gc.Gbranch(optoas(op, t), nil, likely)
}示例3: stkof
/*
* n is on stack, either local variable
* or return value from function call.
* return n's offset from SP.
*/
func stkof(n *gc.Node) int64 {
switch n.Op {
case gc.OINDREG:
return n.Xoffset
case gc.ODOT:
t := n.Left.Type
if gc.Isptr[t.Etype] {
break
}
off := stkof(n.Left)
if off == -1000 || off == 1000 {
return off
}
return off + n.Xoffset
case gc.OINDEX:
t := n.Left.Type
if !gc.Isfixedarray(t) {
break
}
off := stkof(n.Left)
if off == -1000 || off == 1000 {
return off
}
if gc.Isconst(n.Right, gc.CTINT) {
return off + t.Type.Width*gc.Mpgetfix(n.Right.Val.U.Xval)
}
return 1000
case gc.OCALLMETH,
gc.OCALLINTER,
gc.OCALLFUNC:
t := n.Left.Type
if gc.Isptr[t.Etype] {
t = t.Type
}
var flist gc.Iter
t = gc.Structfirst(&flist, gc.Getoutarg(t))
if t != nil {
return t.Width + int64(gc.Widthptr) // +widthptr: correct for saved LR
}
}
// botch - probably failing to recognize address
// arithmetic on the above. eg INDEX and DOT
return -1000
}示例4: cgen
//.........這裏部分代碼省略.........
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)
示例5: dodiv
/*
* generate division.
* generates one of:
* res = nl / nr
* res = nl % nr
* according to op.
*/
func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
// Have to be careful about handling
// most negative int divided by -1 correctly.
// The hardware will trap.
// Also the byte divide instruction needs AH,
// which we otherwise don't have to deal with.
// Easiest way to avoid for int8, int16: use int32.
// For int32 and int64, use explicit test.
// Could use int64 hw for int32.
t := nl.Type
t0 := t
check := 0
if gc.Issigned[t.Etype] {
check = 1
if gc.Isconst(nl, gc.CTINT) && gc.Mpgetfix(nl.Val.U.Xval) != -(1<<uint64(t.Width*8-1)) {
check = 0
} else if gc.Isconst(nr, gc.CTINT) && gc.Mpgetfix(nr.Val.U.Xval) != -1 {
check = 0
}
}
if t.Width < 4 {
if gc.Issigned[t.Etype] {
t = gc.Types[gc.TINT32]
} else {
t = gc.Types[gc.TUINT32]
}
check = 0
}
a := optoas(op, t)
var n3 gc.Node
gc.Regalloc(&n3, t0, nil)
var ax gc.Node
var oldax gc.Node
if nl.Ullman >= nr.Ullman {
savex(x86.REG_AX, &ax, &oldax, res, t0)
gc.Cgen(nl, &ax)
gc.Regalloc(&ax, t0, &ax) // mark ax live during cgen
gc.Cgen(nr, &n3)
gc.Regfree(&ax)
} else {
gc.Cgen(nr, &n3)
savex(x86.REG_AX, &ax, &oldax, res, t0)
gc.Cgen(nl, &ax)
}
if t != t0 {
// Convert
ax1 := ax
n31 := n3
ax.Type = t
n3.Type = t
gmove(&ax1, &ax)
gmove(&n31, &n3)
}
var n4 gc.Node
if gc.Nacl {
// Native Client does not relay the divide-by-zero trap
// to the executing program, so we must insert a check
// for ourselves.
gc.Nodconst(&n4, t, 0)
gins(optoas(gc.OCMP, t), &n3, &n4)
p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
if panicdiv == nil {
panicdiv = gc.Sysfunc("panicdivide")
}
gc.Ginscall(panicdiv, -1)
gc.Patch(p1, gc.Pc)
}
var p2 *obj.Prog
if check != 0 {
gc.Nodconst(&n4, t, -1)
gins(optoas(gc.OCMP, t), &n3, &n4)
p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
if op == gc.ODIV {
// a / (-1) is -a.
gins(optoas(gc.OMINUS, t), nil, &ax)
gmove(&ax, res)
} else {
// a % (-1) is 0.
gc.Nodconst(&n4, t, 0)
gmove(&n4, res)
}
//.........這裏部分代碼省略.........
示例6: agen
/*
* generate:
* res = &n;
* The generated code checks that the result is not nil.
*/
func agen(n *gc.Node, res *gc.Node) {
if gc.Debug['g'] != 0 {
gc.Dump("\nagen-res", res)
gc.Dump("agen-r", n)
}
if n == nil || n.Type == nil {
return
}
for n.Op == gc.OCONVNOP {
n = n.Left
}
if gc.Isconst(n, gc.CTNIL) && n.Type.Width > int64(gc.Widthptr) {
// Use of a nil interface or nil slice.
// Create a temporary we can take the address of and read.
// The generated code is just going to panic, so it need not
// be terribly efficient. See issue 3670.
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Gvardef(&n1)
clearfat(&n1)
var n2 gc.Node
regalloc(&n2, gc.Types[gc.Tptr], res)
var n3 gc.Node
n3.Op = gc.OADDR
n3.Left = &n1
gins(ppc64.AMOVD, &n3, &n2)
gmove(&n2, res)
regfree(&n2)
return
}
if n.Addable != 0 {
var n1 gc.Node
n1.Op = gc.OADDR
n1.Left = n
var n2 gc.Node
regalloc(&n2, gc.Types[gc.Tptr], res)
gins(ppc64.AMOVD, &n1, &n2)
gmove(&n2, res)
regfree(&n2)
return
}
nl := n.Left
switch n.Op {
default:
gc.Fatal("agen: unknown op %v", gc.Nconv(n, obj.FmtShort|obj.FmtSign))
// TODO(minux): 5g has this: Release res so that it is available for cgen_call.
// Pick it up again after the call for OCALLMETH and OCALLFUNC.
case gc.OCALLMETH:
gc.Cgen_callmeth(n, 0)
cgen_aret(n, res)
case gc.OCALLINTER:
cgen_callinter(n, res, 0)
cgen_aret(n, res)
case gc.OCALLFUNC:
cgen_call(n, 0)
cgen_aret(n, res)
case gc.OSLICE,
gc.OSLICEARR,
gc.OSLICESTR,
gc.OSLICE3,
gc.OSLICE3ARR:
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Cgen_slice(n, &n1)
agen(&n1, res)
case gc.OEFACE:
var n1 gc.Node
gc.Tempname(&n1, n.Type)
gc.Cgen_eface(n, &n1)
agen(&n1, res)
case gc.OINDEX:
var n1 gc.Node
agenr(n, &n1, res)
gmove(&n1, res)
regfree(&n1)
// should only get here with names in this func.
case gc.ONAME:
if n.Funcdepth > 0 && n.Funcdepth != gc.Funcdepth {
gc.Dump("bad agen", n)
gc.Fatal("agen: bad ONAME funcdepth %d != %d", n.Funcdepth, gc.Funcdepth)
//.........這裏部分代碼省略.........
示例7: igen
/*
* generate:
* newreg = &n;
* res = newreg
*
* on exit, a has been changed to be *newreg.
* caller must regfree(a).
* The generated code checks that the result is not *nil.
*/
func igen(n *gc.Node, a *gc.Node, res *gc.Node) {
if gc.Debug['g'] != 0 {
gc.Dump("\nigen-n", n)
}
switch n.Op {
case gc.ONAME:
if (n.Class&gc.PHEAP != 0) || n.Class == gc.PPARAMREF {
break
}
*a = *n
return
// Increase the refcount of the register so that igen's caller
// has to call regfree.
case gc.OINDREG:
if n.Val.U.Reg != ppc64.REGSP {
reg[n.Val.U.Reg]++
}
*a = *n
return
case gc.ODOT:
igen(n.Left, a, res)
a.Xoffset += n.Xoffset
a.Type = n.Type
fixlargeoffset(a)
return
case gc.ODOTPTR:
cgenr(n.Left, a, res)
gc.Cgen_checknil(a)
a.Op = gc.OINDREG
a.Xoffset += n.Xoffset
a.Type = n.Type
fixlargeoffset(a)
return
case gc.OCALLFUNC,
gc.OCALLMETH,
gc.OCALLINTER:
switch n.Op {
case gc.OCALLFUNC:
cgen_call(n, 0)
case gc.OCALLMETH:
gc.Cgen_callmeth(n, 0)
case gc.OCALLINTER:
cgen_callinter(n, nil, 0)
}
var flist gc.Iter
fp := gc.Structfirst(&flist, gc.Getoutarg(n.Left.Type))
*a = gc.Node{}
a.Op = gc.OINDREG
a.Val.U.Reg = ppc64.REGSP
a.Addable = 1
a.Xoffset = fp.Width + int64(gc.Widthptr) // +widthptr: saved lr at 0(SP)
a.Type = n.Type
return
// Index of fixed-size array by constant can
// put the offset in the addressing.
// Could do the same for slice except that we need
// to use the real index for the bounds checking.
case gc.OINDEX:
if gc.Isfixedarray(n.Left.Type) || (gc.Isptr[n.Left.Type.Etype] && gc.Isfixedarray(n.Left.Left.Type)) {
if gc.Isconst(n.Right, gc.CTINT) {
// Compute &a.
if !gc.Isptr[n.Left.Type.Etype] {
igen(n.Left, a, res)
} else {
var n1 gc.Node
igen(n.Left, &n1, res)
gc.Cgen_checknil(&n1)
regalloc(a, gc.Types[gc.Tptr], res)
gmove(&n1, a)
regfree(&n1)
a.Op = gc.OINDREG
}
// Compute &a[i] as &a + i*width.
a.Type = n.Type
a.Xoffset += gc.Mpgetfix(n.Right.Val.U.Xval) * n.Type.Width
fixlargeoffset(a)
return
}
}
}
//.........這裏部分代碼省略.........
示例8: agenr
/*
* generate:
* newreg = &n;
*
* caller must regfree(a).
* The generated code checks that the result is not nil.
*/
func agenr(n *gc.Node, a *gc.Node, res *gc.Node) {
if gc.Debug['g'] != 0 {
gc.Dump("agenr-n", n)
}
nl := n.Left
nr := n.Right
switch n.Op {
case gc.ODOT,
gc.ODOTPTR,
gc.OCALLFUNC,
gc.OCALLMETH,
gc.OCALLINTER:
var n1 gc.Node
igen(n, &n1, res)
regalloc(a, gc.Types[gc.Tptr], &n1)
agen(&n1, a)
regfree(&n1)
case gc.OIND:
cgenr(n.Left, a, res)
gc.Cgen_checknil(a)
case gc.OINDEX:
var p2 *obj.Prog // to be patched to panicindex.
w := uint32(n.Type.Width)
bounded := gc.Debug['B'] != 0 || n.Bounded
var n1 gc.Node
var n3 gc.Node
if nr.Addable != 0 {
var tmp gc.Node
if !gc.Isconst(nr, gc.CTINT) {
gc.Tempname(&tmp, gc.Types[gc.TINT32])
}
if !gc.Isconst(nl, gc.CTSTR) {
agenr(nl, &n3, res)
}
if !gc.Isconst(nr, gc.CTINT) {
p2 = cgenindex(nr, &tmp, bounded)
regalloc(&n1, tmp.Type, nil)
gmove(&tmp, &n1)
}
} else if nl.Addable != 0 {
if !gc.Isconst(nr, gc.CTINT) {
var tmp gc.Node
gc.Tempname(&tmp, gc.Types[gc.TINT32])
p2 = cgenindex(nr, &tmp, bounded)
regalloc(&n1, tmp.Type, nil)
gmove(&tmp, &n1)
}
if !gc.Isconst(nl, gc.CTSTR) {
agenr(nl, &n3, res)
}
} else {
var tmp gc.Node
gc.Tempname(&tmp, gc.Types[gc.TINT32])
p2 = cgenindex(nr, &tmp, bounded)
nr = &tmp
if !gc.Isconst(nl, gc.CTSTR) {
agenr(nl, &n3, res)
}
regalloc(&n1, tmp.Type, nil)
gins(optoas(gc.OAS, tmp.Type), &tmp, &n1)
}
// &a is in &n3 (allocated in res)
// i is in &n1 (if not constant)
// w is width
// constant index
if gc.Isconst(nr, gc.CTINT) {
if gc.Isconst(nl, gc.CTSTR) {
gc.Fatal("constant string constant index")
}
v := uint64(gc.Mpgetfix(nr.Val.U.Xval))
var n2 gc.Node
if gc.Isslice(nl.Type) || nl.Type.Etype == gc.TSTRING {
if gc.Debug['B'] == 0 && !n.Bounded {
n1 = n3
n1.Op = gc.OINDREG
n1.Type = gc.Types[gc.Tptr]
n1.Xoffset = int64(gc.Array_nel)
var n4 gc.Node
regalloc(&n4, n1.Type, nil)
gmove(&n1, &n4)
gc.Nodconst(&n2, gc.Types[gc.TUINT32], int64(v))
gcmp(optoas(gc.OCMP, gc.Types[gc.TUINT32]), &n4, &n2)
regfree(&n4)
p1 := gc.Gbranch(optoas(gc.OGT, gc.Types[gc.TUINT32]), nil, +1)
ginscall(gc.Panicindex, 0)
gc.Patch(p1, gc.Pc)
//.........這裏部分代碼省略.........
示例9: bgen
//.........這裏部分代碼省略.........
igen(nl, &n1, nil)
n1.Type = gc.Types[gc.Tptr]
n1.Xoffset += 0
gencmp0(&n1, gc.Types[gc.Tptr], a, likely, to)
regfree(&n1)
break
}
if gc.Iscomplex[nl.Type.Etype] {
gc.Complexbool(a, nl, nr, true_, likely, to)
break
}
if gc.Is64(nr.Type) {
if nl.Addable == 0 {
var n1 gc.Node
gc.Tempname(&n1, nl.Type)
cgen(nl, &n1)
nl = &n1
}
if nr.Addable == 0 {
var n2 gc.Node
gc.Tempname(&n2, nr.Type)
cgen(nr, &n2)
nr = &n2
}
cmp64(nl, nr, a, likely, to)
break
}
if nr.Op == gc.OLITERAL {
if gc.Isconst(nr, gc.CTINT) && gc.Mpgetfix(nr.Val.U.Xval) == 0 {
gencmp0(nl, nl.Type, a, likely, to)
break
}
if nr.Val.Ctype == gc.CTNIL {
gencmp0(nl, nl.Type, a, likely, to)
break
}
}
a = optoas(a, nr.Type)
if nr.Ullman >= gc.UINF {
var n1 gc.Node
regalloc(&n1, nl.Type, nil)
cgen(nl, &n1)
var tmp gc.Node
gc.Tempname(&tmp, nl.Type)
gmove(&n1, &tmp)
regfree(&n1)
var n2 gc.Node
regalloc(&n2, nr.Type, nil)
cgen(nr, &n2)
regalloc(&n1, nl.Type, nil)
cgen(&tmp, &n1)
gcmp(optoas(gc.OCMP, nr.Type), &n1, &n2)
gc.Patch(gc.Gbranch(a, nr.Type, likely), to)
示例10: dodiv
/*
* generate division.
* generates one of:
* res = nl / nr
* res = nl % nr
* according to op.
*/
func dodiv(op int, nl *gc.Node, nr *gc.Node, res *gc.Node) {
// Have to be careful about handling
// most negative int divided by -1 correctly.
// The hardware will generate undefined result.
// Also need to explicitly trap on division on zero,
// the hardware will silently generate undefined result.
// DIVW will leave unpredicable result in higher 32-bit,
// so always use DIVD/DIVDU.
t := nl.Type
t0 := t
check := 0
if gc.Issigned[t.Etype] {
check = 1
if gc.Isconst(nl, gc.CTINT) && gc.Mpgetfix(nl.Val.U.Xval) != -(1<<uint64(t.Width*8-1)) {
check = 0
} else if gc.Isconst(nr, gc.CTINT) && gc.Mpgetfix(nr.Val.U.Xval) != -1 {
check = 0
}
}
if t.Width < 8 {
if gc.Issigned[t.Etype] {
t = gc.Types[gc.TINT64]
} else {
t = gc.Types[gc.TUINT64]
}
check = 0
}
a := optoas(gc.ODIV, t)
var tl gc.Node
gc.Regalloc(&tl, t0, nil)
var tr gc.Node
gc.Regalloc(&tr, t0, nil)
if nl.Ullman >= nr.Ullman {
gc.Cgen(nl, &tl)
gc.Cgen(nr, &tr)
} else {
gc.Cgen(nr, &tr)
gc.Cgen(nl, &tl)
}
if t != t0 {
// Convert
tl2 := tl
tr2 := tr
tl.Type = t
tr.Type = t
gmove(&tl2, &tl)
gmove(&tr2, &tr)
}
// Handle divide-by-zero panic.
p1 := gins(optoas(gc.OCMP, t), &tr, nil)
p1.To.Type = obj.TYPE_REG
p1.To.Reg = ppc64.REGZERO
p1 = gc.Gbranch(optoas(gc.ONE, t), nil, +1)
if panicdiv == nil {
panicdiv = gc.Sysfunc("panicdivide")
}
gc.Ginscall(panicdiv, -1)
gc.Patch(p1, gc.Pc)
var p2 *obj.Prog
if check != 0 {
var nm1 gc.Node
gc.Nodconst(&nm1, t, -1)
gins(optoas(gc.OCMP, t), &tr, &nm1)
p1 := gc.Gbranch(optoas(gc.ONE, t), nil, +1)
if op == gc.ODIV {
// a / (-1) is -a.
gins(optoas(gc.OMINUS, t), nil, &tl)
gmove(&tl, res)
} else {
// a % (-1) is 0.
var nz gc.Node
gc.Nodconst(&nz, t, 0)
gmove(&nz, res)
}
p2 = gc.Gbranch(obj.AJMP, nil, 0)
gc.Patch(p1, gc.Pc)
}
p1 = gins(a, &tr, &tl)
if op == gc.ODIV {
gc.Regfree(&tr)
//.........這裏部分代碼省略.........
示例11: sudoaddable
/*
* 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 := gc.Mpgetfix(n.Val.U.Xval)
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.Fatal("can't happen")
}
gins(arm.AMOVW, &n1, reg)
gc.Cgen_checknil(reg)
n1.Xoffset = -(oary[i] + 1)
}
//.........這裏部分代碼省略.........
示例12: anyregalloc
//.........這裏部分代碼省略.........
var oary [10]int64
var nn *gc.Node
o := gc.Dotoffset(n, oary[:], &nn)
if nn != nil && nn.Addable != 0 && o == 1 && oary[0] >= 0 {
*n1 = *nn
n1.Type = n.Type
n1.Xoffset += oary[0]
return true
}
return false
}
/*
* 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, w *int) bool {
if n.Type == nil {
return false
}
*a = obj.Addr{}
switch n.Op {
case gc.OLITERAL:
if !gc.Isconst(n, gc.CTINT) {
break
}
v := gc.Mpgetfix(n.Val.U.Xval)
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
*a = gc.Naddr(n)
return true示例13: sudoaddable
/*
* 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)
//.........這裏部分代碼省略.........
示例14: gins
/*
* generate one instruction:
* as f, t
*/
func gins(as int, f *gc.Node, t *gc.Node) *obj.Prog {
if as == x86.AFMOVF && f != nil && f.Op == gc.OREGISTER && t != nil && t.Op == gc.OREGISTER {
gc.Fatal("gins MOVF reg, reg")
}
if as == x86.ACVTSD2SS && f != nil && f.Op == gc.OLITERAL {
gc.Fatal("gins CVTSD2SS const")
}
if as == x86.AMOVSD && t != nil && t.Op == gc.OREGISTER && t.Reg == x86.REG_F0 {
gc.Fatal("gins MOVSD into F0")
}
if as == x86.AMOVL && f != nil && f.Op == gc.OADDR && f.Left.Op == gc.ONAME && f.Left.Class != gc.PEXTERN && f.Left.Class != gc.PFUNC {
// Turn MOVL $xxx(FP/SP) into LEAL xxx.
// These should be equivalent but most of the backend
// only expects to see LEAL, because that's what we had
// historically generated. Various hidden assumptions are baked in by now.
as = x86.ALEAL
f = f.Left
}
switch as {
case x86.AMOVB,
x86.AMOVW,
x86.AMOVL:
if f != nil && t != nil && samaddr(f, t) {
return nil
}
case x86.ALEAL:
if f != nil && gc.Isconst(f, gc.CTNIL) {
gc.Fatal("gins LEAL nil %v", gc.Tconv(f.Type, 0))
}
}
p := gc.Prog(as)
gc.Naddr(&p.From, f)
gc.Naddr(&p.To, t)
if gc.Debug['g'] != 0 {
fmt.Printf("%v\n", p)
}
w := 0
switch as {
case x86.AMOVB:
w = 1
case x86.AMOVW:
w = 2
case x86.AMOVL:
w = 4
}
if true && w != 0 && f != nil && (p.From.Width > int64(w) || p.To.Width > int64(w)) {
gc.Dump("bad width from:", f)
gc.Dump("bad width to:", t)
gc.Fatal("bad width: %v (%d, %d)\n", p, p.From.Width, p.To.Width)
}
if p.To.Type == obj.TYPE_ADDR && w > 0 {
gc.Fatal("bad use of addr: %v", p)
}
return p
}示例15: gins
/*
* generate one instruction:
* as f, t
*/
func gins(as int, f *gc.Node, t *gc.Node) *obj.Prog {
// Node nod;
// if(f != N && f->op == OINDEX) {
// gc.Regalloc(&nod, ®node, Z);
// v = constnode.vconst;
// gc.Cgen(f->right, &nod);
// constnode.vconst = v;
// idx.reg = nod.reg;
// gc.Regfree(&nod);
// }
// if(t != N && t->op == OINDEX) {
// gc.Regalloc(&nod, ®node, Z);
// v = constnode.vconst;
// gc.Cgen(t->right, &nod);
// constnode.vconst = v;
// idx.reg = nod.reg;
// gc.Regfree(&nod);
// }
if f != nil && f.Op == gc.OADDR && (as == x86.AMOVL || as == x86.AMOVQ) {
// Turn MOVL $xxx into LEAL xxx.
// These should be equivalent but most of the backend
// only expects to see LEAL, because that's what we had
// historically generated. Various hidden assumptions are baked in by now.
if as == x86.AMOVL {
as = x86.ALEAL
} else {
as = x86.ALEAQ
}
f = f.Left
}
switch as {
case x86.AMOVB,
x86.AMOVW,
x86.AMOVL,
x86.AMOVQ,
x86.AMOVSS,
x86.AMOVSD:
if f != nil && t != nil && samaddr(f, t) {
return nil
}
case x86.ALEAQ:
if f != nil && gc.Isconst(f, gc.CTNIL) {
gc.Fatal("gins LEAQ nil %v", f.Type)
}
}
p := gc.Prog(as)
gc.Naddr(&p.From, f)
gc.Naddr(&p.To, t)
if gc.Debug['g'] != 0 {
fmt.Printf("%v\n", p)
}
w := int32(0)
switch as {
case x86.AMOVB:
w = 1
case x86.AMOVW:
w = 2
case x86.AMOVL:
w = 4
case x86.AMOVQ:
w = 8
}
if w != 0 && ((f != nil && p.From.Width < int64(w)) || (t != nil && p.To.Width > int64(w))) {
gc.Dump("f", f)
gc.Dump("t", t)
gc.Fatal("bad width: %v (%d, %d)\n", p, p.From.Width, p.To.Width)
}
if p.To.Type == obj.TYPE_ADDR && w > 0 {
gc.Fatal("bad use of addr: %v", p)
}
return p
}