Commit graph

8 commits

Author SHA1 Message Date
Erik Faye-Lund
e350193eb5 util: remove unused lut
This was added in 153c714f2a ("util: add softfloat functions to
operate with doubles and floats"), but never used. Let's just drop it.

Reviewed-by: Yonggang Luo <luoyonggang@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25746>
2023-10-30 12:35:07 +00:00
Chia-I Wu
27e33d5c96 util: Keep quiet NaNs quiet when converting to half float.
We don't want to be throwing exceptions and changing float values later by
emitting a signaling binary16 nan.

If we don't do this, then when we convert back to f32 in NIR constant
expression evaluation, the signaling NaN can end up giving NaN for
fmax(NaN, 0.0), instead of 0.0.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/5933
Cc: mesa-stable
Reviewed-by: Emma Anholt <emma@anholt.net>
Reviewed-by: Jason Ekstrand <jason.ekstrand@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16233>
2022-05-02 23:36:50 +00:00
Adam Jackson
f2b3ecb84f softfloat: Silence a warning at -Og
../src/util/softfloat.c: In function ‘_mesa_shift_right_jam_m’:
   ../src/util/softfloat.c:432:16: warning: ‘tmp’ may be used uninitialized in this function [-Wmaybe-uninitialized]
     432 |         *tmp++ = 0;

You could actually hit this if you called _mesa_shift_right_jam_m with
size_words = 0 and dist < 32. Not that you'd _do_ that, but. In this
case do nothing instead of writing through an uninitialized pointer.

Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8724>
2021-02-18 20:59:43 +00:00
Marek Olšák
ffcdf76799 util: implement F16C using inline assembly on x86_64
F16C: https://en.wikipedia.org/wiki/F16C

This also happens to fix bptc-float-modes on llvmpipe.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6987>
2020-10-06 21:07:03 -04:00
Matt Turner
1aac47db69 Revert F16C series (MR 6774)
This reverts commit 4fb2eddfdf.
This reverts commit 7a1deb16f8.
This reverts commit 2b6a172343.
This reverts commit 5af81393e4.
This reverts commit 87900afe5b.

A couple of problems were discovered after this series was merged that
cause breakage in different configurations:

   (1) It seems that using -mf16c also enables AVX, leading to SIGILL on
   platforms that do not support AVX.
   (2) Since clang only warns about unknown flags, and as I understand
   it Meson's handling in cc.has_argument() is broken, the F16C code is
   wrongly enabled when clang is used, even for example on ARM, leading
   to a compilation error.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/3583
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6969>
2020-10-01 21:08:12 +00:00
Marek Olšák
87900afe5b util: implement f16c - fast half<->float conversions
This also happens to fix bptc-float-modes on llvmpipe.

Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6774>
2020-09-30 16:28:24 +00:00
Kristian H. Kristensen
8341f30f1e src/util: Remove out-of-range comparison
Silence the warning about this always-true comparison.

src/util/softfloat.c:214:42: warning: comparison of constant 32768
with expression of type 'int16_t' (aka 'short') is always false
[-Wtautological-constant-out-of-range-compare]
        } else if ((e > 0x1d) || (0x8000 <= m)) {
                                  ~~~~~~ ^  ~

Reviewed-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5174>
2020-05-26 12:46:18 -07:00
Samuel Iglesias Gonsálvez
153c714f2a util: add softfloat functions to operate with doubles and floats
Implemented fadd, fsub, fmul and ffma for doubles and ffma for floats,
rounding to zero, using a modified implementation from Berkely
Softfloat 3e Library.

Their implementation correctness has been checked with the Berkeley
TestFloat Release 3e tool for x86_64.

v2:
- Reuse util_last_bit64() in _mesa_count_leading_zeros64()
  implementation (Connor).

v3:
- Add a specific ffma for floats version (Connor).
- Implement the ffma for doubles version (Andres).
- Lots of fixes in fadd, fsub and fmul (Andres).
- Improved documentation (Andres).

v4:
- Added f64 -> f32 conversion function (Andres).
- Added f32 -> f16 RTZ conversion function (Andres).

Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Signed-off-by: Andres Gomez <agomez@igalia.com>
Tested-by: Andres Gomez <agomez@igalia.com>
Acked-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
2019-09-17 23:39:18 +03:00