1 files changed, 207 insertions, 0 deletions
diff --git a/vendor/modernc.org/mathutil/bits.go b/vendor/modernc.org/mathutil/bits.go
new file mode 100644
index 00000000..ab518544
--- /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
+}