Merge pull request #2149 from davesisson/master
Changed rotation to support 32 and 64-bit architectures as noted in issue #2060.
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commit
c349ba3c8a
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@ -353,6 +353,34 @@ func PrintArrayJavaStyle(sa []string) string {
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return buffer.String()
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}
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// The following routines were lifted from bits.rotate* available in Go 1.9.
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const uintSize = 32 << (^uint(0) >> 32 & 1) // 32 or 64
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// rotateLeft returns the value of x rotated left by (k mod UintSize) bits.
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// To rotate x right by k bits, call RotateLeft(x, -k).
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func rotateLeft(x uint, k int) uint {
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if uintSize == 32 {
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return uint(rotateLeft32(uint32(x), k))
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}
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return uint(rotateLeft64(uint64(x), k))
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}
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// rotateLeft32 returns the value of x rotated left by (k mod 32) bits.
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func rotateLeft32(x uint32, k int) uint32 {
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const n = 32
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s := uint(k) & (n - 1)
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return x<<s | x>>(n-s)
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}
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// rotateLeft64 returns the value of x rotated left by (k mod 64) bits.
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func rotateLeft64(x uint64, k int) uint64 {
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const n = 64
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s := uint(k) & (n - 1)
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return x<<s | x>>(n-s)
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}
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// murmur hash
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const (
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c1_32 uint = 0xCC9E2D51
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@ -367,11 +395,11 @@ func murmurInit(seed int) int {
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func murmurUpdate(h1 int, k1 int) int {
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var k1u uint
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k1u = uint(k1) * c1_32
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k1u = (k1u << 15) | (k1u >> 17) // rotl32(k1u, 15)
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k1u = rotateLeft(k1u, 15)
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k1u *= c2_32
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var h1u = uint(h1) ^ k1u
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h1u = (h1u << 13) | (h1u >> 19) // rotl32(h1u, 13)
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k1u = rotateLeft(k1u, 13)
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h1u = h1u*5 + 0xe6546b64
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return int(h1u)
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}
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