cregit-Linux how code gets into the kernel

Release 4.12 include/drm/drm_fixed.h

Directory: include/drm
/*
 * Copyright 2009 Red Hat Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Dave Airlie
 *          Christian König
 */
#ifndef DRM_FIXED_H

#define DRM_FIXED_H

#include <linux/math64.h>


typedef union dfixed {
	
u32 full;

} fixed20_12;



#define dfixed_const(A) (u32)(((A) << 12))
/*  + ((B + 0.000122)*4096)) */

#define dfixed_const_half(A) (u32)(((A) << 12) + 2048)

#define dfixed_const_666(A) (u32)(((A) << 12) + 2731)

#define dfixed_const_8(A) (u32)(((A) << 12) + 3277)

#define dfixed_mul(A, B) ((u64)((u64)(A).full * (B).full + 2048) >> 12)

#define dfixed_init(A) { .full = dfixed_const((A)) }

#define dfixed_init_half(A) { .full = dfixed_const_half((A)) }

#define dfixed_trunc(A) ((A).full >> 12)

#define dfixed_frac(A) ((A).full & ((1 << 12) - 1))


static inline u32 dfixed_floor(fixed20_12 A) { u32 non_frac = dfixed_trunc(A); return dfixed_const(non_frac); }

Contributors

PersonTokensPropCommitsCommitProp
Alex Deucher2187.50%150.00%
Ben Skeggs312.50%150.00%
Total24100.00%2100.00%


static inline u32 dfixed_ceil(fixed20_12 A) { u32 non_frac = dfixed_trunc(A); if (A.full > dfixed_const(non_frac)) return dfixed_const(non_frac + 1); else return dfixed_const(non_frac); }

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PersonTokensPropCommitsCommitProp
Alex Deucher3988.64%150.00%
Ben Skeggs511.36%150.00%
Total44100.00%2100.00%


static inline u32 dfixed_div(fixed20_12 A, fixed20_12 B) { u64 tmp = ((u64)A.full << 13); do_div(tmp, B.full); tmp += 1; tmp /= 2; return lower_32_bits(tmp); }

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PersonTokensPropCommitsCommitProp
Jérôme Glisse4998.00%150.00%
Ben Skeggs12.00%150.00%
Total50100.00%2100.00%

#define DRM_FIXED_POINT 32 #define DRM_FIXED_ONE (1ULL << DRM_FIXED_POINT) #define DRM_FIXED_DECIMAL_MASK (DRM_FIXED_ONE - 1) #define DRM_FIXED_DIGITS_MASK (~DRM_FIXED_DECIMAL_MASK) #define DRM_FIXED_EPSILON 1LL #define DRM_FIXED_ALMOST_ONE (DRM_FIXED_ONE - DRM_FIXED_EPSILON)
static inline s64 drm_int2fixp(int a) { return ((s64)a) << DRM_FIXED_POINT; }

Contributors

PersonTokensPropCommitsCommitProp
Alex Deucher20100.00%1100.00%
Total20100.00%1100.00%


static inline int drm_fixp2int(s64 a) { return ((s64)a) >> DRM_FIXED_POINT; }

Contributors

PersonTokensPropCommitsCommitProp
Alex Deucher1995.00%150.00%
Harry Wentland15.00%150.00%
Total20100.00%2100.00%


static inline int drm_fixp2int_ceil(s64 a) { if (a > 0) return drm_fixp2int(a + DRM_FIXED_ALMOST_ONE); else return drm_fixp2int(a - DRM_FIXED_ALMOST_ONE); }

Contributors

PersonTokensPropCommitsCommitProp
Harry Wentland33100.00%1100.00%
Total33100.00%1100.00%


static inline unsigned drm_fixp_msbset(s64 a) { unsigned shift, sign = (a >> 63) & 1; for (shift = 62; shift > 0; --shift) if (((a >> shift) & 1) != sign) return shift; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Alex Deucher5598.21%266.67%
Harry Wentland11.79%133.33%
Total56100.00%3100.00%


static inline s64 drm_fixp_mul(s64 a, s64 b) { unsigned shift = drm_fixp_msbset(a) + drm_fixp_msbset(b); s64 result; if (shift > 61) { shift = shift - 61; a >>= (shift >> 1) + (shift & 1); b >>= shift >> 1; } else shift = 0; result = a * b; if (shift > DRM_FIXED_POINT) return result << (shift - DRM_FIXED_POINT); if (shift < DRM_FIXED_POINT) return result >> (DRM_FIXED_POINT - shift); return result; }

Contributors

PersonTokensPropCommitsCommitProp
Alex Deucher107100.00%2100.00%
Total107100.00%2100.00%


static inline s64 drm_fixp_div(s64 a, s64 b) { unsigned shift = 62 - drm_fixp_msbset(a); s64 result; a <<= shift; if (shift < DRM_FIXED_POINT) b >>= (DRM_FIXED_POINT - shift); result = div64_s64(a, b); if (shift > DRM_FIXED_POINT) return result >> (shift - DRM_FIXED_POINT); return result; }

Contributors

PersonTokensPropCommitsCommitProp
Alex Deucher71100.00%2100.00%
Total71100.00%2100.00%


static inline s64 drm_fixp_from_fraction(s64 a, s64 b) { s64 res; bool a_neg = a < 0; bool b_neg = b < 0; u64 a_abs = a_neg ? -a : a; u64 b_abs = b_neg ? -b : b; u64 rem; /* determine integer part */ u64 res_abs = div64_u64_rem(a_abs, b_abs, &rem); /* determine fractional part */ { u32 i = DRM_FIXED_POINT; do { rem <<= 1; res_abs <<= 1; if (rem >= b_abs) { res_abs |= 1; rem -= b_abs; } } while (--i != 0); } /* round up LSB */ { u64 summand = (rem << 1) >= b_abs; res_abs += summand; } res = (s64) res_abs; if (a_neg ^ b_neg) res = -res; return res; }

Contributors

PersonTokensPropCommitsCommitProp
Harry Wentland149100.00%1100.00%
Total149100.00%1100.00%


static inline s64 drm_fixp_exp(s64 x) { s64 tolerance = div64_s64(DRM_FIXED_ONE, 1000000); s64 sum = DRM_FIXED_ONE, term, y = x; u64 count = 1; if (x < 0) y = -1 * x; term = y; while (term >= tolerance) { sum = sum + term; count = count + 1; term = drm_fixp_mul(term, div64_s64(y, count)); } if (x < 0) sum = drm_fixp_div(DRM_FIXED_ONE, sum); return sum; }

Contributors

PersonTokensPropCommitsCommitProp
Alex Deucher105100.00%2100.00%
Total105100.00%2100.00%

#endif

Overall Contributors

PersonTokensPropCommitsCommitProp
Alex Deucher45757.77%342.86%
Harry Wentland19224.27%114.29%
Jérôme Glisse11314.29%114.29%
Ben Skeggs222.78%114.29%
Robert Morell70.88%114.29%
Total791100.00%7100.00%
Directory: include/drm
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