On Oct 10, 2015 12:09 PM, "Matt Turner" <<a href="mailto:mattst88@gmail.com">mattst88@gmail.com</a>> wrote: > > On Sat, Oct 10, 2015 at 11:47 AM, Rob Clark <<a href="mailto:robdclark@gmail.com">robdclark@gmail.com</a>> wrote: > > From: Rob Clark <<a href="mailto:robclark@freedesktop.org">robclark@freedesktop.org</a>> > > > > Needed in NIR too, so move out of mesa/main/imports.c > > > > Signed-off-by: Rob Clark <<a href="mailto:robclark@freedesktop.org">robclark@freedesktop.org</a>> > > --- > > src/glsl/Makefile.am | 1 + > > src/mesa/main/imports.c | 148 -------------------------------------- > > src/mesa/main/imports.h | 38 ++++++++-- > > src/util/Makefile.sources | 2 + > > src/util/convert.c | 179 ++++++++++++++++++++++++++++++++++++++++++++++ > > src/util/convert.h | 43 +++++++++++ > > 6 files changed, 259 insertions(+), 152 deletions(-) > > create mode 100644 src/util/convert.c > > create mode 100644 src/util/convert.h > > > > diff --git a/src/glsl/Makefile.am b/src/glsl/Makefile.am > > index 3265391..347919b 100644 > > --- a/src/glsl/Makefile.am > > +++ b/src/glsl/Makefile.am > > @@ -160,6 +160,7 @@ glsl_compiler_SOURCES = \ > > glsl_compiler_LDADD = \ > > <a href="http://libglsl.la">libglsl.la</a> \ > > $(top_builddir)/src/<a href="http://libglsl_util.la">libglsl_util.la</a> \ > > + $(top_builddir)/src/util/<a href="http://libmesautil.la">libmesautil.la</a> \ > > $(PTHREAD_LIBS) > > > > glsl_test_SOURCES = \ > > diff --git a/src/mesa/main/imports.c b/src/mesa/main/imports.c > > index 350e675..230ebbc 100644 > > --- a/src/mesa/main/imports.c > > +++ b/src/mesa/main/imports.c > > @@ -307,154 +307,6 @@ _mesa_bitcount_64(uint64_t n) > > } > > #endif > > > > - > > -/** > > - * Convert a 4-byte float to a 2-byte half float. > > - * > > - * Not all float32 values can be represented exactly as a float16 value. We > > - * round such intermediate float32 values to the nearest float16. When the > > - * float32 lies exactly between to float16 values, we round to the one with > > - * an even mantissa. > > - * > > - * This rounding behavior has several benefits: > > - * - It has no sign bias. > > - * > > - * - It reproduces the behavior of real hardware: opcode F32TO16 in Intel's > > - * GPU ISA. > > - * > > - * - By reproducing the behavior of the GPU (at least on Intel hardware), > > - * compile-time evaluation of constant packHalf2x16 GLSL expressions will > > - * result in the same value as if the expression were executed on the GPU. > > - */ > > -GLhalfARB > > -_mesa_float_to_half(float val) > > -{ > > - const fi_type fi = {val}; > > - const int flt_m = fi.i & 0x7fffff; > > - const int flt_e = (fi.i >> 23) & 0xff; > > - const int flt_s = (fi.i >> 31) & 0x1; > > - int s, e, m = 0; > > - GLhalfARB result; > > - > > - /* sign bit */ > > - s = flt_s; > > - > > - /* handle special cases */ > > - if ((flt_e == 0) && (flt_m == 0)) { > > - /* zero */ > > - /* m = 0; - already set */ > > - e = 0; > > - } > > - else if ((flt_e == 0) && (flt_m != 0)) { > > - /* denorm -- denorm float maps to 0 half */ > > - /* m = 0; - already set */ > > - e = 0; > > - } > > - else if ((flt_e == 0xff) && (flt_m == 0)) { > > - /* infinity */ > > - /* m = 0; - already set */ > > - e = 31; > > - } > > - else if ((flt_e == 0xff) && (flt_m != 0)) { > > - /* NaN */ > > - m = 1; > > - e = 31; > > - } > > - else { > > - /* regular number */ > > - const int new_exp = flt_e - 127; > > - if (new_exp < -14) { > > - /* The float32 lies in the range (0.0, min_normal16) and is rounded > > - * to a nearby float16 value. The result will be either zero, subnormal, > > - * or normal. > > - */ > > - e = 0; > > - m = _mesa_lroundevenf((1 << 24) * fabsf(fi.f)); > > - } > > - else if (new_exp > 15) { > > - /* map this value to infinity */ > > - /* m = 0; - already set */ > > - e = 31; > > - } > > - else { > > - /* The float32 lies in the range > > - * [min_normal16, max_normal16 + max_step16) > > - * and is rounded to a nearby float16 value. The result will be > > - * either normal or infinite. > > - */ > > - e = new_exp + 15; > > - m = _mesa_lroundevenf(flt_m / (float) (1 << 13)); > > - } > > - } > > - > > - assert(0 <= m && m <= 1024); > > - if (m == 1024) { > > - /* The float32 was rounded upwards into the range of the next exponent, > > - * so bump the exponent. This correctly handles the case where f32 > > - * should be rounded up to float16 infinity. > > - */ > > - ++e; > > - m = 0; > > - } > > - > > - result = (s << 15) | (e << 10) | m; > > - return result; > > -} > > - > > - > > -/** > > - * Convert a 2-byte half float to a 4-byte float. > > - * Based on code from: > > - * <a href="http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html">http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html</a> > > - */ > > -float > > -_mesa_half_to_float(GLhalfARB val) > > -{ > > - /* XXX could also use a 64K-entry lookup table */ > > - const int m = val & 0x3ff; > > - const int e = (val >> 10) & 0x1f; > > - const int s = (val >> 15) & 0x1; > > - int flt_m, flt_e, flt_s; > > - fi_type fi; > > - float result; > > - > > - /* sign bit */ > > - flt_s = s; > > - > > - /* handle special cases */ > > - if ((e == 0) && (m == 0)) { > > - /* zero */ > > - flt_m = 0; > > - flt_e = 0; > > - } > > - else if ((e == 0) && (m != 0)) { > > - /* denorm -- denorm half will fit in non-denorm single */ > > - const float half_denorm = 1.0f / 16384.0f; /* 2^-14 */ > > - float mantissa = ((float) (m)) / 1024.0f; > > - float sign = s ? -1.0f : 1.0f; > > - return sign * mantissa * half_denorm; > > - } > > - else if ((e == 31) && (m == 0)) { > > - /* infinity */ > > - flt_e = 0xff; > > - flt_m = 0; > > - } > > - else if ((e == 31) && (m != 0)) { > > - /* NaN */ > > - flt_e = 0xff; > > - flt_m = 1; > > - } > > - else { > > - /* regular */ > > - flt_e = e + 112; > > - flt_m = m << 13; > > - } > > - > > - fi.i = (flt_s << 31) | (flt_e << 23) | flt_m; > > - result = fi.f; > > - return result; > > -} > > - > > /*@}*/ > > > > > > diff --git a/src/mesa/main/imports.h b/src/mesa/main/imports.h > > index 9024758..3a09304 100644 > > --- a/src/mesa/main/imports.h > > +++ b/src/mesa/main/imports.h > > @@ -42,6 +42,7 @@ > > #include "compiler.h" > > #include "glheader.h" > > #include "errors.h" > > +#include "util/convert.h" > > > > #ifdef __cplusplus > > extern "C" { > > @@ -396,12 +397,41 @@ _mesa_flsll(uint64_t n) > > #endif > > } > > > > +/** > > + * Convert a 4-byte float to a 2-byte half float. > > + * > > + * Not all float32 values can be represented exactly as a float16 value. We > > + * round such intermediate float32 values to the nearest float16. When the > > + * float32 lies exactly between to float16 values, we round to the one with > > + * an even mantissa. > > + * > > + * This rounding behavior has several benefits: > > + * - It has no sign bias. > > + * > > + * - It reproduces the behavior of real hardware: opcode F32TO16 in Intel's > > + * GPU ISA. > > + * > > + * - By reproducing the behavior of the GPU (at least on Intel hardware), > > + * compile-time evaluation of constant packHalf2x16 GLSL expressions will > > + * result in the same value as if the expression were executed on the GPU. > > + */ > > +static inline GLhalfARB > > +_mesa_float_to_half(float val) > > +{ > > + return float_to_half(val); > > +} > > > > -extern GLhalfARB > > -_mesa_float_to_half(float f); > > > > -extern float > > -_mesa_half_to_float(GLhalfARB h); > > +/** > > + * Convert a 2-byte half float to a 4-byte float. > > + * Based on code from: > > + * <a href="http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html">http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html</a> > > + */ > > +static inline float > > +_mesa_half_to_float(GLhalfARB val) > > +{ > > + return half_to_float(val); > > +} This is kind of ugly. How hard would it really be to just replace the uses with the new name? I don't think its used *that* often. > > static inline bool > > _mesa_half_is_negative(GLhalfARB h) > > diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources > > index e45431d..71b2a25 100644 > > --- a/src/util/Makefile.sources > > +++ b/src/util/Makefile.sources > > @@ -1,5 +1,7 @@ > > MESA_UTIL_FILES := \ > > bitset.h \ > > + convert.c \ > > + convert.h \ > > debug.c \ > > debug.h \ > > format_srgb.h \ > > diff --git a/src/util/convert.c b/src/util/convert.c > > new file mode 100644 > > index 0000000..e86e322 > > --- /dev/null > > +++ b/src/util/convert.c > > half-float.c seems like a better name. Agreed. > > @@ -0,0 +1,179 @@ > > +/* > > + * Copyright © 2015 Red Hat > > What the? > > No. This code was written by Brian (commit 7eb3e9b) and Chad (commit > 529b6d1). Its copyright belongs to VMware and Intel (and probably > "gking" from [1]) > > [1] <a href="https://web.archive.org/web/20030303115125/http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html">https://web.archive.org/web/20030303115125/http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html</a> > > > + * > > + * Permission is hereby granted, free of charge, to any person obtaining a > > + * copy of this software and associated documentation files (the "Software"), > > + * to deal in the Software without restriction, including without limitation > > + * the rights to use, copy, modify, merge, publish, distribute, sublicense, > > + * and/or sell copies of the Software, and to permit persons to whom the > > + * Software is furnished to do so, subject to the following conditions: > > + * > > + * The above copyright notice and this permission notice (including the next > > + * paragraph) shall be included in all copies or substantial portions of the > > + * Software. > > + * > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL > > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER > > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS > > + * IN THE SOFTWARE. > > + * > > + * Authors: > > + * Rob Clark <<a href="mailto:robclark@freedesktop.org">robclark@freedesktop.org</a>> > > We're trying to stop with author lists generally, but listing yourself > as an author on some code you copied from somewhere else is not okay. > > > + */ > > + > > +#include <math.h> > > +#include <assert.h> > > +#include "convert.h" > > +#include "rounding.h" > > + > > +typedef union { float f; int32_t i; uint32_t u; } fi_type; > > + > > +/** > > + * Convert a 4-byte float to a 2-byte half float. > > + * > > + * Not all float32 values can be represented exactly as a float16 value. We > > + * round such intermediate float32 values to the nearest float16. When the > > + * float32 lies exactly between to float16 values, we round to the one with > > + * an even mantissa. > > + * > > + * This rounding behavior has several benefits: > > + * - It has no sign bias. > > + * > > + * - It reproduces the behavior of real hardware: opcode F32TO16 in Intel's > > + * GPU ISA. > > + * > > + * - By reproducing the behavior of the GPU (at least on Intel hardware), > > + * compile-time evaluation of constant packHalf2x16 GLSL expressions will > > + * result in the same value as if the expression were executed on the GPU. > > + */ > > +uint16_t > > +float_to_half(float val) > > +{ > > + const fi_type fi = {val}; > > + const int flt_m = fi.i & 0x7fffff; > > + const int flt_e = (fi.i >> 23) & 0xff; > > + const int flt_s = (fi.i >> 31) & 0x1; > > + int s, e, m = 0; > > + uint16_t result; > > + > > + /* sign bit */ > > + s = flt_s; > > + > > + /* handle special cases */ > > + if ((flt_e == 0) && (flt_m == 0)) { > > + /* zero */ > > + /* m = 0; - already set */ > > + e = 0; > > + } > > + else if ((flt_e == 0) && (flt_m != 0)) { > > + /* denorm -- denorm float maps to 0 half */ > > + /* m = 0; - already set */ > > + e = 0; > > + } > > + else if ((flt_e == 0xff) && (flt_m == 0)) { > > + /* infinity */ > > + /* m = 0; - already set */ > > + e = 31; > > + } > > + else if ((flt_e == 0xff) && (flt_m != 0)) { > > + /* NaN */ > > + m = 1; > > + e = 31; > > + } > > + else { > > + /* regular number */ > > + const int new_exp = flt_e - 127; > > + if (new_exp < -14) { > > + /* The float32 lies in the range (0.0, min_normal16) and is rounded > > + * to a nearby float16 value. The result will be either zero, subnormal, > > + * or normal. > > + */ > > + e = 0; > > + m = _mesa_lroundevenf((1 << 24) * fabsf(fi.f)); > > + } > > + else if (new_exp > 15) { > > + /* map this value to infinity */ > > + /* m = 0; - already set */ > > + e = 31; > > + } > > + else { > > + /* The float32 lies in the range > > + * [min_normal16, max_normal16 + max_step16) > > + * and is rounded to a nearby float16 value. The result will be > > + * either normal or infinite. > > + */ > > + e = new_exp + 15; > > + m = _mesa_lroundevenf(flt_m / (float) (1 << 13)); > > + } > > + } > > + > > + assert(0 <= m && m <= 1024); > > + if (m == 1024) { > > + /* The float32 was rounded upwards into the range of the next exponent, > > + * so bump the exponent. This correctly handles the case where f32 > > + * should be rounded up to float16 infinity. > > + */ > > + ++e; > > + m = 0; > > + } > > + > > + result = (s << 15) | (e << 10) | m; > > + return result; > > +} > > + > > + > > +/** > > + * Convert a 2-byte half float to a 4-byte float. > > + * Based on code from: > > + * <a href="http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html">http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/008786.html</a> > > + */ > > +float > > +half_to_float(uint16_t val) > > +{ > > + /* XXX could also use a 64K-entry lookup table */ > > + const int m = val & 0x3ff; > > + const int e = (val >> 10) & 0x1f; > > + const int s = (val >> 15) & 0x1; > > + int flt_m, flt_e, flt_s; > > + fi_type fi; > > + float result; > > + > > + /* sign bit */ > > + flt_s = s; > > + > > + /* handle special cases */ > > + if ((e == 0) && (m == 0)) { > > + /* zero */ > > + flt_m = 0; > > + flt_e = 0; > > + } > > + else if ((e == 0) && (m != 0)) { > > + /* denorm -- denorm half will fit in non-denorm single */ > > + const float half_denorm = 1.0f / 16384.0f; /* 2^-14 */ > > + float mantissa = ((float) (m)) / 1024.0f; > > + float sign = s ? -1.0f : 1.0f; > > + return sign * mantissa * half_denorm; > > + } > > + else if ((e == 31) && (m == 0)) { > > + /* infinity */ > > + flt_e = 0xff; > > + flt_m = 0; > > + } > > + else if ((e == 31) && (m != 0)) { > > + /* NaN */ > > + flt_e = 0xff; > > + flt_m = 1; > > + } > > + else { > > + /* regular */ > > + flt_e = e + 112; > > + flt_m = m << 13; > > + } > > + > > + fi.i = (flt_s << 31) | (flt_e << 23) | flt_m; > > + result = fi.f; > > + return result; > > +} > > diff --git a/src/util/convert.h b/src/util/convert.h > > new file mode 100644 > > index 0000000..30d36a1 > > --- /dev/null > > +++ b/src/util/convert.h > > @@ -0,0 +1,43 @@ > > +/* > > + * Copyright © 2015 Red Hat > > Seems fishy. > > > + * > > + * Permission is hereby granted, free of charge, to any person obtaining a > > + * copy of this software and associated documentation files (the "Software"), > > + * to deal in the Software without restriction, including without limitation > > + * the rights to use, copy, modify, merge, publish, distribute, sublicense, > > + * and/or sell copies of the Software, and to permit persons to whom the > > + * Software is furnished to do so, subject to the following conditions: > > + * > > + * The above copyright notice and this permission notice (including the next > > + * paragraph) shall be included in all copies or substantial portions of the > > + * Software. > > + * > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR > > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, > > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL > > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER > > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS > > + * IN THE SOFTWARE. > > + * > > + * Authors: > > + * Rob Clark <<a href="mailto:robclark@freedesktop.org">robclark@freedesktop.org</a>> > > Again, no author list. > > > + */ > > + > > +#ifndef _MATH_H_ > > +#define _MATH_H_ > > Wrong name. > > > + > > +#include <stdint.h> > > + > > +#ifdef __cplusplus > > +extern "C" { > > +#endif > > + > > +uint16_t float_to_half(float val); > > +float half_to_float(uint16_t val); > > I think these functions need to be prefixed with something -- util_* > or something or just leave them as _mesa_*. Unfortunately, until is kind of a grab-bag right now. Some stuff has a util_ prefix, some has kept its _mesa_ or u_ prefix depending on whether it was copied from Mesa or gallium, and some (hash_table for example) isn't prefixed at all. Personally, I'd go with either util_ (it is a utility library) or just keep _mesa_ (this is still the mesa project after all). I'm not going to be too insistent though > > + > > +#ifdef __cplusplus > > +} /* extern C */ > > +#endif > > + > > +#endif /* _MATH_H_ */ > _______________________________________________ > mesa-dev mailing list > <a href="mailto:mesa-dev@lists.freedesktop.org">mesa-dev@lists.freedesktop.org</a> > <a href="http://lists.freedesktop.org/mailman/listinfo/mesa-dev">http://lists.freedesktop.org/mailman/listinfo/mesa-dev</a>