tag | 7f6f65bc159e28298b43e47cccec63550c87e495 | |
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tagger | The Android Open Source Project <initial-contribution@android.com> | Fri Feb 03 17:02:09 2023 -0800 |
object | b0813806ef54363ac541b32f6cc2c74b9e49a5ca |
Platform Tools Release 34.0.0 (9560563)
commit | b0813806ef54363ac541b32f6cc2c74b9e49a5ca | [log] [tgz] |
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author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Wed Feb 01 10:53:32 2023 +0000 |
committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Wed Feb 01 10:53:32 2023 +0000 |
tree | b0d778382e65123821d6af73cf53d38d94ecdd68 | |
parent | 41b13846d58b5de3e046d93fe93751984ce88002 [diff] | |
parent | 2cc0161e9b80bcd7e23e235f8c5682d8c8306f81 [diff] |
Snap for 9550355 from 2cc0161e9b80bcd7e23e235f8c5682d8c8306f81 to sdk-release Change-Id: I4ab0beed1d74debdceb88187a9bf44e55b344e2b
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); } }
Currently working features:
Platform | uint32_t | uint64_t | size_t |
---|---|---|---|
x86-64 gcc | Works | Works | Works |
x86-64 clang | Works | Works | Works |
x86-64 MSVC | Works | Works | Works |
x86 gcc | Works | Works | Works |
x86 clang | Works | Works | Works |
x86 MSVC | Works | Works | Works |
ARMv7 gcc | Works | Works | Works |
ARMv7 clang | Works | Works | Works |
ARMv7 MSVC* | Compiles | Compiles | Compiles |
ARM64 gcc | Works | Works | Works |
ARM64 clang | Works | Works | Works |
ARM64 MSVC* | Compiles | Compiles | Compiles |
PPC64 gcc | Works | Works | Works |
WAsm clang | Works | Works | Works |
Asm.js clang | Works | Works | Works |
PNaCl clang | Works | Works | Works |
CUDA | Untested | Untested | Untested |
OpenCL | Untested | Untested | Untested |
*ARMv7 and ARM64 builds with MSVC are presumed to work, but were only verified to compile successfully