libyuv/docs/environment_variables.md
Frank Barchard 3b81288ece Remove Mips DSPR2 code
Bug: libyuv:765
Test: build for mips still passes
Change-Id: I99105ad3951d2210c0793e3b9241c178442fdc37
Reviewed-on: https://chromium-review.googlesource.com/826404
Reviewed-by: Weiyong Yao <braveyao@chromium.org>
Commit-Queue: Frank Barchard <fbarchard@chromium.org>
2017-12-14 18:22:16 +00:00

33 lines
1.1 KiB
Markdown

# Introduction
For test purposes, environment variables can be set to control libyuv behavior. These should only be used for testing, to narrow down bugs or to test performance.
# CPU
By default the cpu is detected and the most advanced form of SIMD is used. But you can disable instruction sets selectively, or completely, falling back on C code. Set the variable to 1 to disable the specified instruction set.
LIBYUV_DISABLE_ASM
LIBYUV_DISABLE_X86
LIBYUV_DISABLE_SSE2
LIBYUV_DISABLE_SSSE3
LIBYUV_DISABLE_SSE41
LIBYUV_DISABLE_SSE42
LIBYUV_DISABLE_AVX
LIBYUV_DISABLE_AVX2
LIBYUV_DISABLE_AVX512BW
LIBYUV_DISABLE_ERMS
LIBYUV_DISABLE_FMA3
LIBYUV_DISABLE_MSA
LIBYUV_DISABLE_NEON
# Test Width/Height/Repeat
The unittests default to a small image (128x72) to run fast. This can be set by environment variable to test a specific resolutions.
You can also repeat the test a specified number of iterations, allowing benchmarking and profiling.
set LIBYUV_WIDTH=1280
set LIBYUV_HEIGHT=720
set LIBYUV_REPEAT=999
set LIBYUV_FLAGS=-1
set LIBYUV_CPU_INFO=-1