diff options
Diffstat (limited to 'mesalib/src/gallium/auxiliary/util/u_half.h')
| -rw-r--r-- | mesalib/src/gallium/auxiliary/util/u_half.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/mesalib/src/gallium/auxiliary/util/u_half.h b/mesalib/src/gallium/auxiliary/util/u_half.h index f7009f548..d340b9a7a 100644 --- a/mesalib/src/gallium/auxiliary/util/u_half.h +++ b/mesalib/src/gallium/auxiliary/util/u_half.h @@ -75,9 +75,17 @@ util_float_to_half(float f) f32.f *= magic.f; f32.ui -= round_mask; - /* Clamp to infinity if overflowed */ + /* + * Clamp to max finite value if overflowed. + * OpenGL has completely undefined rounding behavior for float to + * half-float conversions, and this matches what is mandated for float + * to fp11/fp10, which recommend round-to-nearest-finite too. + * (d3d10 is deeply unhappy about flushing such values to infinity, and + * while it also mandates round-to-zero it doesn't care nearly as much + * about that.) + */ if (f32.ui > f16inf) - f32.ui = f16inf; + f32.ui = f16inf - 1; f16 = f32.ui >> 13; } |