From 1a57267a17c2fc17fb6e104846fabc3e363c326c Mon Sep 17 00:00:00 2001 From: Emile Date: Fri, 16 Aug 2024 19:50:26 +0200 Subject: initial commit --- vendor/modernc.org/mathutil/bits.go | 207 ++++++++++++++++++++++++++++++++++++ 1 file changed, 207 insertions(+) create mode 100644 vendor/modernc.org/mathutil/bits.go (limited to 'vendor/modernc.org/mathutil/bits.go') diff --git a/vendor/modernc.org/mathutil/bits.go b/vendor/modernc.org/mathutil/bits.go new file mode 100644 index 0000000..ab51854 --- /dev/null +++ b/vendor/modernc.org/mathutil/bits.go @@ -0,0 +1,207 @@ +// Copyright (c) 2014 The mathutil 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 mathutil // import "modernc.org/mathutil" + +import ( + "math/big" +) + +// BitLenByte returns the bit width of the non zero part of n. +func BitLenByte(n byte) int { + return log2[n] + 1 +} + +// BitLenUint16 returns the bit width of the non zero part of n. +func BitLenUint16(n uint16) int { + if b := n >> 8; b != 0 { + return log2[b] + 8 + 1 + } + + return log2[n] + 1 +} + +// BitLenUint32 returns the bit width of the non zero part of n. +func BitLenUint32(n uint32) int { + if b := n >> 24; b != 0 { + return log2[b] + 24 + 1 + } + + if b := n >> 16; b != 0 { + return log2[b] + 16 + 1 + } + + if b := n >> 8; b != 0 { + return log2[b] + 8 + 1 + } + + return log2[n] + 1 +} + +// BitLen returns the bit width of the non zero part of n. +func BitLen(n int) int { // Should handle correctly [future] 64 bit Go ints + if IntBits == 64 { + return BitLenUint64(uint64(n)) + } + + if b := byte(n >> 24); b != 0 { + return log2[b] + 24 + 1 + } + + if b := byte(n >> 16); b != 0 { + return log2[b] + 16 + 1 + } + + if b := byte(n >> 8); b != 0 { + return log2[b] + 8 + 1 + } + + return log2[byte(n)] + 1 +} + +// BitLenUint returns the bit width of the non zero part of n. +func BitLenUint(n uint) int { // Should handle correctly [future] 64 bit Go uints + if IntBits == 64 { + return BitLenUint64(uint64(n)) + } + + if b := n >> 24; b != 0 { + return log2[b] + 24 + 1 + } + + if b := n >> 16; b != 0 { + return log2[b] + 16 + 1 + } + + if b := n >> 8; b != 0 { + return log2[b] + 8 + 1 + } + + return log2[n] + 1 +} + +// BitLenUint64 returns the bit width of the non zero part of n. +func BitLenUint64(n uint64) int { + if b := n >> 56; b != 0 { + return log2[b] + 56 + 1 + } + + if b := n >> 48; b != 0 { + return log2[b] + 48 + 1 + } + + if b := n >> 40; b != 0 { + return log2[b] + 40 + 1 + } + + if b := n >> 32; b != 0 { + return log2[b] + 32 + 1 + } + + if b := n >> 24; b != 0 { + return log2[b] + 24 + 1 + } + + if b := n >> 16; b != 0 { + return log2[b] + 16 + 1 + } + + if b := n >> 8; b != 0 { + return log2[b] + 8 + 1 + } + + return log2[n] + 1 +} + +// BitLenUintptr returns the bit width of the non zero part of n. +func BitLenUintptr(n uintptr) int { + if b := n >> 56; b != 0 { + return log2[b] + 56 + 1 + } + + if b := n >> 48; b != 0 { + return log2[b] + 48 + 1 + } + + if b := n >> 40; b != 0 { + return log2[b] + 40 + 1 + } + + if b := n >> 32; b != 0 { + return log2[b] + 32 + 1 + } + + if b := n >> 24; b != 0 { + return log2[b] + 24 + 1 + } + + if b := n >> 16; b != 0 { + return log2[b] + 16 + 1 + } + + if b := n >> 8; b != 0 { + return log2[b] + 8 + 1 + } + + return log2[n] + 1 +} + +// PopCountByte returns population count of n (number of bits set in n). +func PopCountByte(n byte) int { + return int(popcnt[n]) +} + +// PopCountUint16 returns population count of n (number of bits set in n). +func PopCountUint16(n uint16) int { + return int(popcnt[byte(n>>8)]) + int(popcnt[byte(n)]) +} + +// PopCountUint32 returns population count of n (number of bits set in n). +func PopCountUint32(n uint32) int { + return int(popcnt[byte(n>>24)]) + int(popcnt[byte(n>>16)]) + + int(popcnt[byte(n>>8)]) + int(popcnt[byte(n)]) +} + +// PopCount returns population count of n (number of bits set in n). +func PopCount(n int) int { // Should handle correctly [future] 64 bit Go ints + if IntBits == 64 { + return PopCountUint64(uint64(n)) + } + + return PopCountUint32(uint32(n)) +} + +// PopCountUint returns population count of n (number of bits set in n). +func PopCountUint(n uint) int { // Should handle correctly [future] 64 bit Go uints + if IntBits == 64 { + return PopCountUint64(uint64(n)) + } + + return PopCountUint32(uint32(n)) +} + +// PopCountUintptr returns population count of n (number of bits set in n). +func PopCountUintptr(n uintptr) int { + if UintPtrBits == 64 { + return PopCountUint64(uint64(n)) + } + + return PopCountUint32(uint32(n)) +} + +// PopCountUint64 returns population count of n (number of bits set in n). +func PopCountUint64(n uint64) int { + return int(popcnt[byte(n>>56)]) + int(popcnt[byte(n>>48)]) + + int(popcnt[byte(n>>40)]) + int(popcnt[byte(n>>32)]) + + int(popcnt[byte(n>>24)]) + int(popcnt[byte(n>>16)]) + + int(popcnt[byte(n>>8)]) + int(popcnt[byte(n)]) +} + +// PopCountBigInt returns population count of |n| (number of bits set in |n|). +func PopCountBigInt(n *big.Int) (r int) { + for _, v := range n.Bits() { + r += PopCountUintptr(uintptr(v)) + } + return +} -- cgit 1.4.1