1 // Copyright 2017 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package gc 6 7 type bitset8 uint8 8 9 func (f *bitset8) set(mask uint8, b bool) { 10 if b { 11 *(*uint8)(f) |= mask 12 } else { 13 *(*uint8)(f) &^= mask 14 } 15 } 16 17 type bitset16 uint16 18 19 func (f *bitset16) set(mask uint16, b bool) { 20 if b { 21 *(*uint16)(f) |= mask 22 } else { 23 *(*uint16)(f) &^= mask 24 } 25 } 26 27 type bitset32 uint32 28 29 func (f *bitset32) set(mask uint32, b bool) { 30 if b { 31 *(*uint32)(f) |= mask 32 } else { 33 *(*uint32)(f) &^= mask 34 } 35 } 36 37 func (f bitset32) get2(shift uint8) uint8 { 38 return uint8(f>>shift) & 3 39 } 40 41 // set2 sets two bits in f using the bottom two bits of b. 42 func (f *bitset32) set2(shift uint8, b uint8) { 43 // Clear old bits. 44 *(*uint32)(f) &^= 3 << shift 45 // Set new bits. 46 *(*uint32)(f) |= uint32(b&3) << shift 47 } 48 49 func (f bitset32) get3(shift uint8) uint8 { 50 return uint8(f>>shift) & 7 51 } 52 53 // set3 sets three bits in f using the bottom three bits of b. 54 func (f *bitset32) set3(shift uint8, b uint8) { 55 // Clear old bits. 56 *(*uint32)(f) &^= 7 << shift 57 // Set new bits. 58 *(*uint32)(f) |= uint32(b&7) << shift 59 } 60
