mirror of https://github.com/bsnes-emu/bsnes.git
52 lines
1.4 KiB
C++
Executable File
52 lines
1.4 KiB
C++
Executable File
#ifndef NALL_BIT_HPP
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#define NALL_BIT_HPP
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namespace nall {
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template<int bits> constexpr inline unsigned uclamp(const unsigned x) {
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enum { y = (1U << (bits - 1)) + ((1U << (bits - 1)) - 1) };
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return y + ((x - y) & -(x < y)); //min(x, y);
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}
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template<int bits> constexpr inline unsigned uclip(const unsigned x) {
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enum { m = (1U << (bits - 1)) + ((1U << (bits - 1)) - 1) };
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return (x & m);
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}
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template<int bits> constexpr inline signed sclamp(const signed x) {
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enum { b = 1U << (bits - 1), m = (1U << (bits - 1)) - 1 };
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return (x > m) ? m : (x < -b) ? -b : x;
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}
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template<int bits> constexpr inline signed sclip(const signed x) {
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enum { b = 1U << (bits - 1), m = (1U << bits) - 1 };
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return ((x & m) ^ b) - b;
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}
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namespace bit {
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//lowest(0b1110) == 0b0010
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template<typename T> constexpr inline T lowest(const T x) {
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return x & -x;
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}
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//clear_lowest(0b1110) == 0b1100
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template<typename T> constexpr inline T clear_lowest(const T x) {
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return x & (x - 1);
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}
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//set_lowest(0b0101) == 0b0111
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template<typename T> constexpr inline T set_lowest(const T x) {
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return x | (x + 1);
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}
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//round up to next highest single bit:
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//round(15) == 16, round(16) == 16, round(17) == 32
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inline unsigned round(unsigned x) {
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if((x & (x - 1)) == 0) return x;
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while(x & (x - 1)) x &= x - 1;
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return x << 1;
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}
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}
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}
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#endif
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