From 4f9297ac3b39098547863d28fbc8d2a906d5be49 Mon Sep 17 00:00:00 2001 From: Diego Biurrun Date: Thu, 13 Oct 2016 18:33:15 +0000 Subject: [PATCH] build: Prefer NASM assembler over YASM NASM is more actively maintained and permits generating dependency information as a sideeffect of assembling, thus cutting build times in half. (Cherry-picked from libav commit 57b753b445e23363c997a8ec1c556e0b0f6e9da3) Signed-off-by: James Almer --- .travis.yml | 4 ++-- Changelog | 2 ++ configure | 6 +++--- doc/optimization.txt | 8 ++++---- doc/platform.texi | 8 ++++---- 5 files changed, 15 insertions(+), 13 deletions(-) diff --git a/.travis.yml b/.travis.yml index e541ee1608..40f01f94c2 100644 --- a/.travis.yml +++ b/.travis.yml @@ -6,7 +6,7 @@ os: addons: apt: packages: - - yasm + - nasm - diffutils compiler: - clang @@ -17,7 +17,7 @@ cache: before_install: - if [ "$TRAVIS_OS_NAME" == "osx" ]; then brew update --all; fi install: - - if [ "$TRAVIS_OS_NAME" == "osx" ]; then brew install yasm; fi + - if [ "$TRAVIS_OS_NAME" == "osx" ]; then brew install nasm; fi script: - mkdir -p ffmpeg-samples - ./configure --samples=ffmpeg-samples --cc=$CC diff --git a/Changelog b/Changelog index a893efa4f0..4f46edaddb 100644 --- a/Changelog +++ b/Changelog @@ -22,6 +22,8 @@ version : - headphone audio filter - superequalizer audio filter - roberts video filter +- The x86 assembler default switched from yasm to nasm, pass + --x86asmexe=yasm to configure to restore the old behavior. version 3.3: - CrystalHD decoder moved to new decode API diff --git a/configure b/configure index 73e973d220..d75aa7fe70 100755 --- a/configure +++ b/configure @@ -3258,7 +3258,7 @@ pkg_config_default=pkg-config ranlib_default="ranlib" strip_default="strip" version_script='--version-script' -x86asmexe_default="yasm" +x86asmexe_default="nasm" windres_default="windres" nvcc_default="nvcc" nvccflags_default="-gencode arch=compute_30,code=sm_30 -O2" @@ -5506,7 +5506,7 @@ EOF } if ! disabled_any asm mmx x86asm; then - for program in $x86asmexe yasm nasm; do + for program in $x86asmexe nasm yasm; do probe_x86asm $program test -n "$x86asm_type" && break done @@ -5518,7 +5518,7 @@ EOF esac check_x86asm "movbe ecx, [5]" && enable x86asm || - die "yasm/nasm not found or too old. Use --disable-x86asm for a crippled build." + die "nasm/yasm not found or too old. Use --disable-x86asm for a crippled build." check_x86asm "vextracti128 xmm0, ymm0, 0" || disable avx2_external check_x86asm "vpmacsdd xmm0, xmm1, xmm2, xmm3" || disable xop_external check_x86asm "vfmaddps ymm0, ymm1, ymm2, ymm3" || disable fma4_external diff --git a/doc/optimization.txt b/doc/optimization.txt index c39e1e37b9..974e2f9af2 100644 --- a/doc/optimization.txt +++ b/doc/optimization.txt @@ -161,8 +161,8 @@ do{ For x86, mark registers that are clobbered in your asm. This means both general x86 registers (e.g. eax) as well as XMM registers. This last one is particularly important on Win64, where xmm6-15 are callee-save, and not -restoring their contents leads to undefined results. In external asm (e.g. -yasm), you do this by using: +restoring their contents leads to undefined results. In external asm, +you do this by using: cglobal function_name, num_args, num_regs, num_xmm_regs In inline asm, you specify clobbered registers at the end of your asm: __asm__(".." ::: "%eax"). @@ -199,12 +199,12 @@ actual lines causing issues. Inline asm vs. external asm --------------------------- Both inline asm (__asm__("..") in a .c file, handled by a compiler such as gcc) -and external asm (.s or .asm files, handled by an assembler such as yasm/nasm) +and external asm (.s or .asm files, handled by an assembler such as nasm/yasm) are accepted in FFmpeg. Which one to use differs per specific case. - if your code is intended to be inlined in a C function, inline asm is always better, because external asm cannot be inlined -- if your code calls external functions, yasm is always better +- if your code calls external functions, external asm is always better - if your code takes huge and complex structs as function arguments (e.g. MpegEncContext; note that this is not ideal and is discouraged if there are alternatives), then inline asm is always better, because predicting diff --git a/doc/platform.texi b/doc/platform.texi index 32d97cc58b..bdfb6fd6a5 100644 --- a/doc/platform.texi +++ b/doc/platform.texi @@ -71,9 +71,9 @@ Mac OS X on PowerPC or ARM (iPhone) requires a preprocessor from assembly functions. Put the Perl script somewhere in your PATH, FFmpeg's configure will pick it up automatically. -Mac OS X on amd64 and x86 requires @command{yasm} to build most of the +Mac OS X on amd64 and x86 requires @command{nasm} to build most of the optimized assembly functions. @uref{http://www.finkproject.org/, Fink}, -@uref{http://www.gentoo.org/proj/en/gentoo-alt/prefix/bootstrap-macos.xml, Gentoo Prefix}, +@uref{https://wiki.gentoo.org/wiki/Project:Prefix, Gentoo Prefix}, @uref{https://mxcl.github.com/homebrew/, Homebrew} or @uref{http://www.macports.org, MacPorts} can easily provide it. @@ -141,7 +141,7 @@ them under @command{MinGW-w64 Win64 Shell} and @command{MinGW-w64 Win32 Shell}. pacman -S make pkgconf diffutils # mingw-w64 packages and toolchains -pacman -S mingw-w64-x86_64-yasm mingw-w64-x86_64-gcc mingw-w64-x86_64-SDL +pacman -S mingw-w64-x86_64-nasm mingw-w64-x86_64-gcc mingw-w64-x86_64-SDL2 @end example To target 32 bits replace @code{x86_64} with @code{i686} in the command above. @@ -159,7 +159,7 @@ You will need the following prerequisites: @item @uref{http://code.google.com/p/msinttypes/, msinttypes} (if using MSVC 2012 or earlier) @item @uref{http://msys2.github.io/, MSYS2} -@item @uref{http://yasm.tortall.net/, YASM} +@item @uref{http://www.nasm.us/, NASM} (Also available via MSYS2's package manager.) @end itemize