agb/mgba-test-runner/c/include/mgba-util/math.h
2021-04-19 22:47:43 +01:00

107 lines
2.7 KiB
C

/* Copyright (c) 2013-2015 Jeffrey Pfau
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef UTIL_MATH_H
#define UTIL_MATH_H
#include <mgba-util/common.h>
CXX_GUARD_START
static inline uint32_t popcount32(unsigned bits) {
bits = bits - ((bits >> 1) & 0x55555555);
bits = (bits & 0x33333333) + ((bits >> 2) & 0x33333333);
return (((bits + (bits >> 4)) & 0xF0F0F0F) * 0x1010101) >> 24;
}
static inline unsigned clz32(uint32_t bits) {
#if defined(__GNUC__) || __clang__
if (!bits) {
return 32;
}
return __builtin_clz(bits);
#else
static const int table[256] = {
8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
if (bits & 0xFF000000) {
return table[bits >> 24];
} else if (bits & 0x00FF0000) {
return table[bits >> 16] + 8;
} else if (bits & 0x0000FF00) {
return table[bits >> 8] + 16;
}
return table[bits] + 24;
#endif
}
static inline uint32_t toPow2(uint32_t bits) {
if (!bits) {
return 0;
}
unsigned lz = clz32(bits - 1);
return 1 << (32 - lz);
}
static inline int reduceFraction(int* num, int* den) {
int n = *num;
int d = *den;
while (d != 0) {
int temp = n % d;
n = d;
d = temp;
}
*num /= n;
*den /= n;
return n;
}
#define TYPE_GENERICIZE(MACRO) \
MACRO(int, Int) \
MACRO(unsigned, UInt)
#define LOCK_ASPECT_RATIO(T, t) \
static inline void lockAspectRatio ## t(T refW, T refH, T* w, T* h) { \
if (*w * refH > *h * refW) { \
*w = *h * refW / refH; \
} else if (*w * refH < *h * refW) { \
*h = *w * refH / refW; \
} \
}
TYPE_GENERICIZE(LOCK_ASPECT_RATIO)
#undef LOCK_ASPECT_RATIO
#define LOCK_INTEGER_RATIO(T, t) \
static inline void lockIntegerRatio ## t(T ref, T* val) { \
if (*val >= ref) { \
*val -= *val % ref; \
} \
}
TYPE_GENERICIZE(LOCK_INTEGER_RATIO)
#undef LOCK_INTEGER_RATIO
#undef TYPE_GENERICIZE
CXX_GUARD_END
#endif