tag | 47c7773ebf6a4ee892fa0e0889c7f113f32f3345 | |
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tagger | The Android Open Source Project <initial-contribution@android.com> | Wed May 08 00:17:59 2024 -0700 |
object | d53440bf8505d97f4c9492f6d8e48a2ba9cdc348 |
Android CTS 14.0 Release 4 (11801623)
commit | d53440bf8505d97f4c9492f6d8e48a2ba9cdc348 | [log] [tgz] |
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author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Thu Jul 21 01:07:18 2022 +0000 |
committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Thu Jul 21 01:07:18 2022 +0000 |
tree | b0d778382e65123821d6af73cf53d38d94ecdd68 | |
parent | e3abe6d470f96474bcdb3df867f9d4cd451b9e71 [diff] | |
parent | a555e78cea9d472dc5c3dfe6a1cb2f0979d93864 [diff] |
Snap for 8853148 from a555e78cea9d472dc5c3dfe6a1cb2f0979d93864 to udc-release Change-Id: I5db4ecc91d7ca50f7f875e79fe216b923d86e05b
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