54 lines
2.4 KiB
Go
54 lines
2.4 KiB
Go
|
package ascii
|
||
|
|
|
||
|
|
import _ "github.com/segmentio/asm/cpu"
|
||
|
|
|
||
|
|
// https://graphics.stanford.edu/~seander/bithacks.html#HasLessInWord
|
||
|
|
const (
|
||
|
|
hasLessConstL64 = (^uint64(0)) / 255
|
||
|
|
hasLessConstR64 = hasLessConstL64 * 128
|
||
|
|
|
||
|
|
hasLessConstL32 = (^uint32(0)) / 255
|
||
|
|
hasLessConstR32 = hasLessConstL32 * 128
|
||
|
|
|
||
|
|
hasMoreConstL64 = (^uint64(0)) / 255
|
||
|
|
hasMoreConstR64 = hasMoreConstL64 * 128
|
||
|
|
|
||
|
|
hasMoreConstL32 = (^uint32(0)) / 255
|
||
|
|
hasMoreConstR32 = hasMoreConstL32 * 128
|
||
|
|
)
|
||
|
|
|
||
|
|
func hasLess64(x, n uint64) bool {
|
||
|
|
return ((x - (hasLessConstL64 * n)) & ^x & hasLessConstR64) != 0
|
||
|
|
}
|
||
|
|
|
||
|
|
func hasLess32(x, n uint32) bool {
|
||
|
|
return ((x - (hasLessConstL32 * n)) & ^x & hasLessConstR32) != 0
|
||
|
|
}
|
||
|
|
|
||
|
|
func hasMore64(x, n uint64) bool {
|
||
|
|
return (((x + (hasMoreConstL64 * (127 - n))) | x) & hasMoreConstR64) != 0
|
||
|
|
}
|
||
|
|
|
||
|
|
func hasMore32(x, n uint32) bool {
|
||
|
|
return (((x + (hasMoreConstL32 * (127 - n))) | x) & hasMoreConstR32) != 0
|
||
|
|
}
|
||
|
|
|
||
|
|
var lowerCase = [256]byte{
|
||
|
|
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
|
||
|
|
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
|
||
|
|
0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
|
||
|
|
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
|
||
|
|
0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
|
||
|
|
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
|
||
|
|
0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
|
||
|
|
0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
|
||
|
|
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
|
||
|
|
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
|
||
|
|
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
|
||
|
|
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
|
||
|
|
0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
|
||
|
|
0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
|
||
|
|
0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
|
||
|
|
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
|
||
|
|
}
|