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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 1964 | serge | 1 | /* |
| 2 | * Copyright 2009 Red Hat Inc. |
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| 3 | * |
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| 4 | * Permission is hereby granted, free of charge, to any person obtaining a |
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| 5 | * copy of this software and associated documentation files (the "Software"), |
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| 6 | * to deal in the Software without restriction, including without limitation |
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| 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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| 8 | * and/or sell copies of the Software, and to permit persons to whom the |
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| 9 | * Software is furnished to do so, subject to the following conditions: |
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| 10 | * |
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| 11 | * The above copyright notice and this permission notice shall be included in |
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| 12 | * all copies or substantial portions of the Software. |
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| 13 | * |
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| 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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| 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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| 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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| 17 | * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR |
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| 18 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
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| 19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
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| 20 | * OTHER DEALINGS IN THE SOFTWARE. |
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| 21 | * |
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| 22 | * Authors: Dave Airlie |
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| 4065 | Serge | 23 | * Christian Konig |
| 1964 | serge | 24 | */ |
| 25 | #ifndef DRM_FIXED_H |
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| 26 | #define DRM_FIXED_H |
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| 27 | |||
| 28 | typedef union dfixed { |
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| 29 | u32 full; |
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| 30 | } fixed20_12; |
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| 31 | |||
| 32 | |||
| 33 | #define dfixed_const(A) (u32)(((A) << 12))/* + ((B + 0.000122)*4096)) */ |
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| 34 | #define dfixed_const_half(A) (u32)(((A) << 12) + 2048) |
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| 35 | #define dfixed_const_666(A) (u32)(((A) << 12) + 2731) |
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| 36 | #define dfixed_const_8(A) (u32)(((A) << 12) + 3277) |
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| 37 | #define dfixed_mul(A, B) ((u64)((u64)(A).full * (B).full + 2048) >> 12) |
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| 38 | #define dfixed_init(A) { .full = dfixed_const((A)) } |
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| 39 | #define dfixed_init_half(A) { .full = dfixed_const_half((A)) } |
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| 40 | #define dfixed_trunc(A) ((A).full >> 12) |
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| 3031 | serge | 41 | #define dfixed_frac(A) ((A).full & ((1 << 12) - 1)) |
| 1964 | serge | 42 | |
| 43 | static inline u32 dfixed_floor(fixed20_12 A) |
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| 44 | { |
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| 45 | u32 non_frac = dfixed_trunc(A); |
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| 46 | |||
| 47 | return dfixed_const(non_frac); |
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| 48 | } |
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| 49 | |||
| 50 | static inline u32 dfixed_ceil(fixed20_12 A) |
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| 51 | { |
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| 52 | u32 non_frac = dfixed_trunc(A); |
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| 53 | |||
| 54 | if (A.full > dfixed_const(non_frac)) |
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| 55 | return dfixed_const(non_frac + 1); |
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| 56 | else |
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| 57 | return dfixed_const(non_frac); |
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| 58 | } |
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| 59 | |||
| 60 | static inline u32 dfixed_div(fixed20_12 A, fixed20_12 B) |
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| 61 | { |
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| 62 | u64 tmp = ((u64)A.full << 13); |
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| 63 | |||
| 64 | do_div(tmp, B.full); |
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| 65 | tmp += 1; |
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| 66 | tmp /= 2; |
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| 67 | return lower_32_bits(tmp); |
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| 68 | } |
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| 4065 | Serge | 69 | |
| 70 | #define DRM_FIXED_POINT 32 |
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| 71 | #define DRM_FIXED_ONE (1ULL << DRM_FIXED_POINT) |
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| 72 | #define DRM_FIXED_DECIMAL_MASK (DRM_FIXED_ONE - 1) |
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| 73 | #define DRM_FIXED_DIGITS_MASK (~DRM_FIXED_DECIMAL_MASK) |
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| 74 | |||
| 75 | static inline s64 drm_int2fixp(int a) |
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| 76 | { |
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| 77 | return ((s64)a) << DRM_FIXED_POINT; |
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| 78 | } |
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| 79 | |||
| 80 | static inline int drm_fixp2int(int64_t a) |
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| 81 | { |
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| 82 | return ((s64)a) >> DRM_FIXED_POINT; |
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| 83 | } |
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| 84 | |||
| 85 | static inline unsigned drm_fixp_msbset(int64_t a) |
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| 86 | { |
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| 87 | unsigned shift, sign = (a >> 63) & 1; |
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| 88 | |||
| 89 | for (shift = 62; shift > 0; --shift) |
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| 90 | if (((a >> shift) & 1) != sign) |
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| 91 | return shift; |
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| 92 | |||
| 93 | return 0; |
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| 94 | } |
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| 95 | |||
| 96 | static inline s64 drm_fixp_mul(s64 a, s64 b) |
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| 97 | { |
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| 98 | unsigned shift = drm_fixp_msbset(a) + drm_fixp_msbset(b); |
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| 99 | s64 result; |
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| 100 | |||
| 101 | if (shift > 61) { |
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| 102 | shift = shift - 61; |
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| 103 | a >>= (shift >> 1) + (shift & 1); |
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| 104 | b >>= shift >> 1; |
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| 105 | } else |
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| 106 | shift = 0; |
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| 107 | |||
| 108 | result = a * b; |
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| 109 | |||
| 110 | if (shift > DRM_FIXED_POINT) |
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| 111 | return result << (shift - DRM_FIXED_POINT); |
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| 112 | |||
| 113 | if (shift < DRM_FIXED_POINT) |
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| 114 | return result >> (DRM_FIXED_POINT - shift); |
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| 115 | |||
| 116 | return result; |
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| 117 | } |
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| 118 | |||
| 119 | static inline s64 drm_fixp_div(s64 a, s64 b) |
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| 120 | { |
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| 121 | unsigned shift = 62 - drm_fixp_msbset(a); |
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| 122 | s64 result; |
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| 123 | |||
| 124 | a <<= shift; |
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| 125 | |||
| 126 | if (shift < DRM_FIXED_POINT) |
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| 127 | b >>= (DRM_FIXED_POINT - shift); |
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| 128 | |||
| 129 | result = div64_s64(a, b); |
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| 130 | |||
| 131 | if (shift > DRM_FIXED_POINT) |
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| 132 | return result >> (shift - DRM_FIXED_POINT); |
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| 133 | |||
| 134 | return result; |
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| 135 | } |
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| 136 | |||
| 137 | static inline s64 drm_fixp_exp(s64 x) |
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| 138 | { |
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| 139 | s64 tolerance = div64_s64(DRM_FIXED_ONE, 1000000); |
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| 140 | s64 sum = DRM_FIXED_ONE, term, y = x; |
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| 141 | u64 count = 1; |
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| 142 | |||
| 143 | if (x < 0) |
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| 144 | y = -1 * x; |
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| 145 | |||
| 146 | term = y; |
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| 147 | |||
| 148 | while (term >= tolerance) { |
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| 149 | sum = sum + term; |
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| 150 | count = count + 1; |
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| 151 | term = drm_fixp_mul(term, div64_s64(y, count)); |
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| 152 | } |
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| 153 | |||
| 154 | if (x < 0) |
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| 155 | sum = drm_fixp_div(DRM_FIXED_ONE, sum); |
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| 156 | |||
| 157 | return sum; |
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| 158 | } |
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| 159 | |||
| 1964 | serge | 160 | #endif |