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utils.go
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utils.go
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package x86_64
import (
`encoding/binary`
`errors`
`reflect`
`strconv`
`unicode/utf8`
`unsafe`
)
const (
_CC_digit = 1 << iota
_CC_ident
_CC_ident0
_CC_number
)
func ispow2(v uint64) bool {
return (v & (v - 1)) == 0
}
func isdigit(cc rune) bool {
return '0' <= cc && cc <= '9'
}
func isalpha(cc rune) bool {
return (cc >= 'a' && cc <= 'z') || (cc >= 'A' && cc <= 'Z')
}
func isident(cc rune) bool {
return cc == '_' || isalpha(cc) || isdigit(cc)
}
func isident0(cc rune) bool {
return cc == '_' || isalpha(cc)
}
func isnumber(cc rune) bool {
return (cc == 'b' || cc == 'B') ||
(cc == 'o' || cc == 'O') ||
(cc == 'x' || cc == 'X') ||
(cc >= '0' && cc <= '9') ||
(cc >= 'a' && cc <= 'f') ||
(cc >= 'A' && cc <= 'F')
}
func align(v int, n int) int {
return (((v - 1) >> n) + 1) << n
}
func append8(m *[]byte, v byte) {
*m = append(*m, v)
}
func append16(m *[]byte, v uint16) {
p := len(*m)
*m = append(*m, 0, 0)
binary.LittleEndian.PutUint16((*m)[p:], v)
}
func append32(m *[]byte, v uint32) {
p := len(*m)
*m = append(*m, 0, 0, 0, 0)
binary.LittleEndian.PutUint32((*m)[p:], v)
}
func append64(m *[]byte, v uint64) {
p := len(*m)
*m = append(*m, 0, 0, 0, 0, 0, 0, 0, 0)
binary.LittleEndian.PutUint64((*m)[p:], v)
}
func expandmm(m *[]byte, n int, v byte) {
sl := (*_GoSlice)(unsafe.Pointer(m))
nb := sl.len + n
/* grow as needed */
if nb > cap(*m) {
*m = growslice(byteType, *m, nb)
}
/* fill the new area */
memset(unsafe.Pointer(uintptr(sl.ptr) + uintptr(sl.len)), v, uintptr(n))
sl.len = nb
}
func memset(p unsafe.Pointer, c byte, n uintptr) {
if c != 0 {
memsetv(p, c, n)
} else {
memclrNoHeapPointers(p, n)
}
}
func memsetv(p unsafe.Pointer, c byte, n uintptr) {
for i := uintptr(0); i < n; i++ {
*(*byte)(unsafe.Pointer(uintptr(p) + i)) = c
}
}
func literal64(v string) (uint64, error) {
var nb int
var ch rune
var ex error
var mm [12]byte
/* unquote the runes */
for v != "" {
if ch, _, v, ex = strconv.UnquoteChar(v, '\''); ex != nil {
return 0, ex
} else if nb += utf8.EncodeRune(mm[nb:], ch); nb > 8 {
return 0, errors.New("multi-char constant too large")
}
}
/* convert to uint64 */
return *(*uint64)(unsafe.Pointer(&mm)), nil
}
var (
byteWrap = reflect.TypeOf(byte(0))
byteType = (*_GoType)(efaceOf(byteWrap).ptr)
)
//go:linkname growslice runtime.growslice
func growslice(_ *_GoType, _ []byte, _ int) []byte
//go:noescape
//go:linkname memclrNoHeapPointers runtime.memclrNoHeapPointers
func memclrNoHeapPointers(_ unsafe.Pointer, _ uintptr)