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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4103 | 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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| 23 | * Christian König |
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| 24 | */ |
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| 25 | #ifndef DRM_FIXED_H |
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| 26 | #define DRM_FIXED_H |
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| 27 | |||
| 28 | #include |
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| 29 | |||
| 30 | typedef union dfixed { |
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| 31 | u32 full; |
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| 32 | } fixed20_12; |
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| 33 | |||
| 34 | |||
| 35 | #define dfixed_const(A) (u32)(((A) << 12))/* + ((B + 0.000122)*4096)) */ |
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| 36 | #define dfixed_const_half(A) (u32)(((A) << 12) + 2048) |
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| 37 | #define dfixed_const_666(A) (u32)(((A) << 12) + 2731) |
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| 38 | #define dfixed_const_8(A) (u32)(((A) << 12) + 3277) |
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| 39 | #define dfixed_mul(A, B) ((u64)((u64)(A).full * (B).full + 2048) >> 12) |
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| 40 | #define dfixed_init(A) { .full = dfixed_const((A)) } |
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| 41 | #define dfixed_init_half(A) { .full = dfixed_const_half((A)) } |
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| 42 | #define dfixed_trunc(A) ((A).full >> 12) |
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| 43 | #define dfixed_frac(A) ((A).full & ((1 << 12) - 1)) |
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| 44 | |||
| 45 | static inline u32 dfixed_floor(fixed20_12 A) |
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| 46 | { |
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| 47 | u32 non_frac = dfixed_trunc(A); |
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| 48 | |||
| 49 | return dfixed_const(non_frac); |
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| 50 | } |
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| 51 | |||
| 52 | static inline u32 dfixed_ceil(fixed20_12 A) |
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| 53 | { |
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| 54 | u32 non_frac = dfixed_trunc(A); |
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| 55 | |||
| 56 | if (A.full > dfixed_const(non_frac)) |
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| 57 | return dfixed_const(non_frac + 1); |
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| 58 | else |
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| 59 | return dfixed_const(non_frac); |
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| 60 | } |
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| 61 | |||
| 62 | static inline u32 dfixed_div(fixed20_12 A, fixed20_12 B) |
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| 63 | { |
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| 64 | u64 tmp = ((u64)A.full << 13); |
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| 65 | |||
| 66 | do_div(tmp, B.full); |
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| 67 | tmp += 1; |
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| 68 | tmp /= 2; |
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| 69 | return lower_32_bits(tmp); |
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| 70 | } |
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| 71 | |||
| 72 | #define DRM_FIXED_POINT 32 |
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| 73 | #define DRM_FIXED_ONE (1ULL << DRM_FIXED_POINT) |
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| 74 | #define DRM_FIXED_DECIMAL_MASK (DRM_FIXED_ONE - 1) |
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| 75 | #define DRM_FIXED_DIGITS_MASK (~DRM_FIXED_DECIMAL_MASK) |
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| 76 | |||
| 77 | static inline s64 drm_int2fixp(int a) |
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| 78 | { |
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| 79 | return ((s64)a) << DRM_FIXED_POINT; |
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| 80 | } |
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| 81 | |||
| 82 | static inline int drm_fixp2int(int64_t a) |
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| 83 | { |
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| 84 | return ((s64)a) >> DRM_FIXED_POINT; |
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| 85 | } |
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| 86 | |||
| 87 | static inline unsigned drm_fixp_msbset(int64_t a) |
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| 88 | { |
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| 89 | unsigned shift, sign = (a >> 63) & 1; |
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| 90 | |||
| 91 | for (shift = 62; shift > 0; --shift) |
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| 92 | if (((a >> shift) & 1) != sign) |
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| 93 | return shift; |
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| 94 | |||
| 95 | return 0; |
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| 96 | } |
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| 97 | |||
| 98 | static inline s64 drm_fixp_mul(s64 a, s64 b) |
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| 99 | { |
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| 100 | unsigned shift = drm_fixp_msbset(a) + drm_fixp_msbset(b); |
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| 101 | s64 result; |
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| 102 | |||
| 103 | if (shift > 61) { |
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| 104 | shift = shift - 61; |
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| 105 | a >>= (shift >> 1) + (shift & 1); |
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| 106 | b >>= shift >> 1; |
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| 107 | } else |
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| 108 | shift = 0; |
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| 109 | |||
| 110 | result = a * b; |
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| 111 | |||
| 112 | if (shift > DRM_FIXED_POINT) |
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| 113 | return result << (shift - DRM_FIXED_POINT); |
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| 114 | |||
| 115 | if (shift < DRM_FIXED_POINT) |
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| 116 | return result >> (DRM_FIXED_POINT - shift); |
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| 117 | |||
| 118 | return result; |
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| 119 | } |
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| 120 | |||
| 121 | static inline s64 drm_fixp_div(s64 a, s64 b) |
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| 122 | { |
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| 123 | unsigned shift = 62 - drm_fixp_msbset(a); |
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| 124 | s64 result; |
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| 125 | |||
| 126 | a <<= shift; |
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| 127 | |||
| 128 | if (shift < DRM_FIXED_POINT) |
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| 129 | b >>= (DRM_FIXED_POINT - shift); |
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| 130 | |||
| 131 | result = div64_s64(a, b); |
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| 132 | |||
| 133 | if (shift > DRM_FIXED_POINT) |
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| 134 | return result >> (shift - DRM_FIXED_POINT); |
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| 135 | |||
| 136 | return result; |
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| 137 | } |
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| 138 | |||
| 139 | static inline s64 drm_fixp_exp(s64 x) |
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| 140 | { |
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| 141 | s64 tolerance = div64_s64(DRM_FIXED_ONE, 1000000); |
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| 142 | s64 sum = DRM_FIXED_ONE, term, y = x; |
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| 143 | u64 count = 1; |
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| 144 | |||
| 145 | if (x < 0) |
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| 146 | y = -1 * x; |
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| 147 | |||
| 148 | term = y; |
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| 149 | |||
| 150 | while (term >= tolerance) { |
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| 151 | sum = sum + term; |
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| 152 | count = count + 1; |
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| 153 | term = drm_fixp_mul(term, div64_s64(y, count)); |
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| 154 | } |
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| 155 | |||
| 156 | if (x < 0) |
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| 157 | sum = drm_fixp_div(DRM_FIXED_ONE, sum); |
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| 158 | |||
| 159 | return sum; |
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| 160 | } |
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| 161 | |||
| 162 | #endif |