commit | 83162b362b3f6274fc31a6261489f1bf57677a37 | [log] [tgz] |
---|---|---|
author | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Wed Feb 12 02:43:37 2020 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Wed Feb 12 02:43:37 2020 +0000 |
tree | c4c16e82d07bcfb917864111f3dad01a207e9e6c | |
parent | f834e5b8ab89a1aa9ca18bdf28a69dec4894a629 [diff] | |
parent | bdf53b664000631575f808b8f1bb8ab8f475cf79 [diff] |
Add build files and meta data files am: 320f701e6e am: eef023d31c am: bdf53b6640 Change-Id: I13550644e2f1eeb2f6d6246a3e82c5ecd346ea87
Header-only library for division via fixed-point multiplication by inverse
On modern CPUs and GPUs integer division is several times slower than multiplication. FXdiv implements an algorithm to replace an integer division with a multiplication and two shifts. This algorithm improves performance when an application performs repeated divisions by the same divisor.
uint32_t
, uint64_t
, and size_t
#include <fxdiv.h> /* Division of array by a constant: reference implementation */ void divide_array_c(size_t length, uint32_t array[], uint32_t divisor) { for (size_t i = 0; i < length; i++) { array[i] /= divisor; } } /* Division of array by a constant: implementation with FXdiv */ void divide_array_fxdiv(size_t length, uint32_t array[], uint32_t divisor) { const struct fxdiv_divisor_uint32_t precomputed_divisor = fxdiv_init_uint32_t(divisor); for (size_t i = 0; i < length; i++) { array[i] = fxdiv_quotient_uint32_t(array[i], precomputed_divisor); } }
Project is in alpha stage. API is unstable. Currently working features:
Platform | uint32_t | uint64_t | size_t |
---|---|---|---|
x86-64 gcc | Works | Works | Works |
x86-64 MSVC | Works | Works | Works |
x86 gcc | Works | Works | Works |
x86 MSVC | Works | Works | Works |
ARMv7 gcc | Works | Works | Works |
PPC64 gcc | Works | Works | Works |
PNaCl clang | Works | Works | Works |
Asm.js clang | Works | Works | Works |
CUDA | Untested | Untested | Untested |
OpenCL | Untested | Untested | Untested |