diff options
Diffstat (limited to 'src/gallium/auxiliary/util/u_half.h')
| -rw-r--r-- | src/gallium/auxiliary/util/u_half.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/util/u_half.h b/src/gallium/auxiliary/util/u_half.h new file mode 100644 index 00000000000..464d43df8a0 --- /dev/null +++ b/src/gallium/auxiliary/util/u_half.h @@ -0,0 +1,55 @@ +#ifndef U_HALF_H +#define U_HALF_H + +#include "pipe/p_compiler.h" + +extern uint32_t util_half_to_float_mantissa_table[2048]; +extern uint32_t util_half_to_float_exponent_table[64]; +extern uint32_t util_half_to_float_offset_table[64]; +extern uint16_t util_float_to_half_base_table[512]; +extern uint8_t util_float_to_half_shift_table[512]; + +/* + * Note that if the half float is a signaling NaN, the x87 FPU will turn + * it into a quiet NaN immediately upon loading into a float. + * + * Additionally, denormals may be flushed to zero. + * + * To avoid this, use the floatui functions instead of the float ones + * when just doing conversion rather than computation on the resulting + * floats. + */ + +static INLINE uint32_t +util_half_to_floatui(half h) +{ + unsigned exp = h >> 10; + return util_half_to_float_mantissa_table[util_half_to_float_offset_table[exp] + (h & 0x3ff)] + + util_half_to_float_exponent_table[exp]; +} + +static INLINE float +util_half_to_float(half h) +{ + union {float f; uint32_t v;} r; + r.v = util_half_to_floatui(h); + return r.f; +} + +static INLINE half +util_floatui_to_half(uint32_t v) +{ + unsigned signexp = v >> 23; + return util_float_to_half_base_table[signexp] + + ((v & 0x007fffff) >> util_float_to_half_shift_table[signexp]); +} + +static INLINE half +util_float_to_half(float f) +{ + union {float f; uint32_t v;} i; + i.f = f; + return util_floatui_to_half(i.v); +} + +#endif /* U_HALF_H */ |