This patch is Reviewed-by: Ian Romanick <ian.d.roman...@intel.com>
On 10/05/2018 09:10 PM, Jason Ekstrand wrote: > --- > src/util/Makefile.am | 1 + > src/util/Makefile.sources | 1 + > src/util/bigmath.h | 112 ++++++++++++++++++++++++++++++++++++++ > src/util/meson.build | 1 + > 4 files changed, 115 insertions(+) > create mode 100644 src/util/bigmath.h > > diff --git a/src/util/Makefile.am b/src/util/Makefile.am > index efb94caff71..d79f2b320be 100644 > --- a/src/util/Makefile.am > +++ b/src/util/Makefile.am > @@ -21,6 +21,7 @@ > > SUBDIRS = . \ > xmlpool \ > + tests/fast_idiv_by_const \ > tests/hash_table \ > tests/string_buffer \ > tests/set > diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources > index b562d6cd6f4..5b1548c733c 100644 > --- a/src/util/Makefile.sources > +++ b/src/util/Makefile.sources > @@ -1,4 +1,5 @@ > MESA_UTIL_FILES := \ > + bigmath.h \ > bitscan.c \ > bitscan.h \ > bitset.h \ > diff --git a/src/util/bigmath.h b/src/util/bigmath.h > new file mode 100644 > index 00000000000..6339bb6f6ca > --- /dev/null > +++ b/src/util/bigmath.h > @@ -0,0 +1,112 @@ > +/* > + * Copyright © 2018 Intel Corporation > + * > + * 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. > + */ > + > +#ifndef UTIL_BIGMATH_H > +#define UTIL_BIGMATH_H > + > +#include "macros.h" > + > +#include <assert.h> > +#include <stdint.h> > +#include <string.h> > + > +static inline bool > +_ubm_add_u32arr(uint32_t *dst, unsigned dst_len, > + uint32_t *a, unsigned a_len, > + uint32_t *b, unsigned b_len) > +{ > + uint32_t carry = 0; > + for (unsigned i = 0; i < dst_len; i++) { > + uint64_t sum = carry; > + if (i < a_len) > + sum += a[i]; > + if (i < b_len) > + sum += b[i]; > + dst[i] = sum; > + carry = sum >> 32; > + } > + > + /* Now compute overflow */ > + > + for (unsigned i = dst_len; i < a_len; i++) { > + if (a[i]) > + return true; > + } > + > + for (unsigned i = dst_len; i < b_len; i++) { > + if (b[i]) > + return true; > + } > + > + return carry; > +} > +#define ubm_add_u32arr(dst, a, b) \ > + _ubm_add_u32arr(dst, ARRAY_SIZE(dst), a, ARRAY_SIZE(a), b, ARRAY_SIZE(b)) > + > +static inline bool > +_ubm_mul_u32arr(uint32_t *dst, unsigned dst_len, > + uint32_t *a, unsigned a_len, > + uint32_t *b, unsigned b_len) > +{ > + memset(dst, 0, dst_len * sizeof(*dst)); > + > + bool overflow = false; > + > + for (unsigned i = 0; i < a_len; i++) { > + uint32_t carry = 0; > + for (unsigned j = 0; j < b_len; j++) { > + /* The maximum values of a[i] and b[i] are UINT32_MAX so the maximum > + * value of tmp is UINT32_MAX * UINT32_MAX. The maximum value that > + * will fit in tmp is > + * > + * UINT64_MAX = UINT32_MAX << 32 + UINT32_MAX > + * = UINT32_MAX * (UINT32_MAX + 1) + UINT32_MAX > + * = UINT32_MAX * UINT32_MAX + 2 * UINT32_MAX > + * > + * so we're guaranteed that we can add in two more 32-bit values > + * without overflowing tmp. > + */ > + uint64_t tmp = (uint64_t)a[i] * (uint64_t)b[j]; > + tmp += carry; > + if (i + j < dst_len) { > + tmp += dst[i + j]; > + dst[i + j] = tmp; > + carry = tmp >> 32; > + } else { > + /* We're trying to write a value that doesn't fit */ > + overflow = overflow || tmp > 0; > + break; > + } > + } > + if (i + b_len < dst_len) > + dst[i + b_len] = carry; > + else > + overflow = overflow || carry > 0; > + } > + > + return overflow; > +} > +#define ubm_mul_u32arr(dst, a, b) \ > + _ubm_mul_u32arr(dst, ARRAY_SIZE(dst), a, ARRAY_SIZE(a), b, ARRAY_SIZE(b)) > + > +#endif /* UTIL_BIGMATH_H */ > diff --git a/src/util/meson.build b/src/util/meson.build > index 027bc5b9d0d..9a99d60c158 100644 > --- a/src/util/meson.build > +++ b/src/util/meson.build > @@ -23,6 +23,7 @@ inc_util = include_directories('.') > subdir('xmlpool') > > files_mesa_util = files( > + 'bigmath.h', > 'bitscan.c', > 'bitscan.h', > 'bitset.h', > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev