- Use a lookup table for log2.
- Compute (float) (1 << ipart) by tweaking with the exponent directly to
avoid integer overflow and float conversion.
- Also table negative exponents to avoid float division and branching.
- Implement util_fast_exp as function of util_fast_exp2.
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Cherry-picked from gallium-0.2: 8415d06d90
This fixes some pow() glitches seen in fslight.c, spectex.c, etc.
Conflicts:
src/gallium/auxiliary/util/u_math.h
Michal Krol
Brian
José Fonseca