diff options
| author | Juan A. Suarez Romero <jasuarez@igalia.com> | 2024-04-02 13:56:48 +0200 |
|---|---|---|
| committer | Marge Bot <emma+marge@anholt.net> | 2024-04-19 10:11:06 +0000 |
| commit | 7f40f35a34010675ccbdf5bc583920f0d10968e6 (patch) | |
| tree | 70401a44be71e1f469554581141538adeaff0e5d | |
| parent | f7ece74a107a2f99b2f494d978c84f8d51faa703 (diff) | |
Add float from half function
Converts a 16-bit float to 32-bit float.
Reviewed-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/piglit/-/merge_requests/899>
| -rw-r--r-- | tests/util/piglit-util-gl.c | 36 | ||||
| -rw-r--r-- | tests/util/piglit-util-gl.h | 1 |
2 files changed, 36 insertions, 1 deletions
diff --git a/tests/util/piglit-util-gl.c b/tests/util/piglit-util-gl.c index 5b665d874..03e6dde05 100644 --- a/tests/util/piglit-util-gl.c +++ b/tests/util/piglit-util-gl.c @@ -307,7 +307,7 @@ piglit_set_tolerance_for_bits(int rbits, int gbits, int bbits, int abits) } } -typedef union { GLfloat f; GLint i; } fi_type; +typedef union { GLfloat f; GLint i; GLuint ui; } fi_type; /** * Convert a 4-byte float to a 2-byte half float. @@ -396,6 +396,40 @@ piglit_half_from_float(float val) return result; } +/** + * Convert a 2-byte half float to a 4-byte float. + * Based on code from: + * http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html + * + * Taken from Mesa. + */ +float +piglit_float_from_half(unsigned short val) +{ + fi_type infnan; + fi_type magic; + fi_type f32; + + infnan.ui = 0x8f << 23; + infnan.f = 65536.0f; + magic.ui = 0xef << 23; + + /* Exponent / Mantissa */ + f32.ui = (val & 0x7fff) << 13; + + /* Adjust */ + f32.f *= magic.f; + /* XXX: The magic mul relies on denorms being available */ + + /* Inf / NaN */ + if (f32.f >= infnan.f) + f32.ui |= 0xff << 23; + + /* Sign */ + f32.ui |= (uint32_t)(val & 0x8000) << 16; + + return f32.f; +} /** * Return block size info for a specific texture compression format. diff --git a/tests/util/piglit-util-gl.h b/tests/util/piglit-util-gl.h index e53f3a3c8..d76eb18df 100644 --- a/tests/util/piglit-util-gl.h +++ b/tests/util/piglit-util-gl.h @@ -260,6 +260,7 @@ void piglit_draw_rect_from_arrays(const void *verts, const void *tex, bool use_patches, unsigned instance_count); unsigned short piglit_half_from_float(float val); +float piglit_float_from_half(unsigned short val); /** * Wrapper for piglit_half_from_float() which allows using an exact |