| // Copyright 2017 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package gc |
| |
| type bitset8 uint8 |
| |
| func (f *bitset8) set(mask uint8, b bool) { |
| if b { |
| *(*uint8)(f) |= mask |
| } else { |
| *(*uint8)(f) &^= mask |
| } |
| } |
| |
| type bitset32 uint32 |
| |
| func (f *bitset32) set(mask uint32, b bool) { |
| if b { |
| *(*uint32)(f) |= mask |
| } else { |
| *(*uint32)(f) &^= mask |
| } |
| } |
| |
| func (f bitset32) get2(shift uint8) uint8 { |
| return uint8(f>>shift) & 3 |
| } |
| |
| // set2 sets two bits in f using the bottom two bits of b. |
| func (f *bitset32) set2(shift uint8, b uint8) { |
| // Clear old bits. |
| *(*uint32)(f) &^= 3 << shift |
| // Set new bits. |
| *(*uint32)(f) |= uint32(b&3) << shift |
| } |
| |
| func (f bitset32) get3(shift uint8) uint8 { |
| return uint8(f>>shift) & 7 |
| } |
| |
| // set3 sets three bits in f using the bottom three bits of b. |
| func (f *bitset32) set3(shift uint8, b uint8) { |
| // Clear old bits. |
| *(*uint32)(f) &^= 7 << shift |
| // Set new bits. |
| *(*uint32)(f) |= uint32(b&7) << shift |
| } |
