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| author | Brian Paul <brian.paul@tungstengraphics.com> | 2008-11-14 12:55:05 -0700 |
|---|---|---|
| committer | Brian Paul <brian.paul@tungstengraphics.com> | 2008-11-14 12:58:12 -0700 |
| commit | 7e584a70c492698be18bf4d6372b50d1a1c38385 (patch) | |
| tree | 05f9ca9d5fa10246bc45766dd4e6e419a28a16a4 /src/gallium/auxiliary/util/u_math.h | |
| parent | 6afab9001e5ebe5a970810b0e12dbfac0d9abe14 (diff) | |
gallium: increase table size for fast log/pow functions
The various conformance tests pass now.
Diffstat (limited to 'src/gallium/auxiliary/util/u_math.h')
| -rw-r--r-- | src/gallium/auxiliary/util/u_math.h | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h index aee69ab7ba..ac11d7001b 100644 --- a/src/gallium/auxiliary/util/u_math.h +++ b/src/gallium/auxiliary/util/u_math.h @@ -246,8 +246,9 @@ util_fast_exp(float x) } -#define LOG2_TABLE_SIZE_LOG2 8 -#define LOG2_TABLE_SIZE (1 << LOG2_TABLE_SIZE_LOG2) +#define LOG2_TABLE_SIZE_LOG2 16 +#define LOG2_TABLE_SCALE (1 << LOG2_TABLE_SIZE_LOG2) +#define LOG2_TABLE_SIZE (LOG2_TABLE_SCALE + 1) extern float log2_table[LOG2_TABLE_SIZE]; @@ -258,7 +259,8 @@ util_fast_log2(float x) float epart, mpart; num.f = x; epart = (float)(((num.i & 0x7f800000) >> 23) - 127); - mpart = log2_table[(num.i & 0x007fffff) >> (23 - LOG2_TABLE_SIZE_LOG2)]; + /* mpart = log2_table[mantissa*LOG2_TABLE_SCALE + 0.5] */ + mpart = log2_table[((num.i & 0x007fffff) + (1 << (22 - LOG2_TABLE_SIZE_LOG2))) >> (23 - LOG2_TABLE_SIZE_LOG2)]; return epart + mpart; } |