FROMLIST: mesa: Fix uf10_to_f32() scale factor in the E == 0 and M != 0 case.
GL_EXT_packed_float, 2.1.B Unsigned 10-Bit Floating-Point Numbers:
0.0, if E == 0 and M == 0,
2^-14 * (M / 32), if E == 0 and M != 0,
2^(E-15) * (1 + M/32), if 0 < E < 31,
INF, if E == 31 and M == 0, or
NaN, if E == 31 and M != 0,
In the second case (E == 0 and M != 0), we were multiplying the mantissa
by 2^-20, when we should have been multiplying by 2^-19 (which is
2^(-14 + -5), or 2^-14 * 2^-5, or 2^-14 / 32).
The previous section defines the formula for 11-bit numbers, which is:
2^-14 * (M / 64), if E == 0 and M != 0,
In other words, we had accidentally copy and pasted the 11-bit code
to the 10-bit case, and neglected to change the exponent.
Fixes dEQP-GLES3.functional.pbo.renderbuffer.r11f_g11f_b10f_triangles
when run with surface dimensions of 1536x1152 or 1920x1080.
References: https://code.google.com/p/chrome-os-partner/issues/detail?id=56244
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Stephane Marchesin <stephane.marchesin@gmail.com>
(am from https://patchwork.freedesktop.org/patch/105285/)
Conflicts:
src/util/format_r11g11b10f.h
Change-Id: Ie7e7859bf573bd9b990d63f01e633d1c603fe8d2
Signed-off-by: Haixia Shi <hshi@chromium.org>
Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/370802
Reviewed-by: Ilja H. Friedel <ihf@chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
1 file changed