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| -rw-r--r-- | gcc/doc/invoke.texi | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 70dc1ab73a1..18cebf99dfd 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -504,7 +504,8 @@ Objective-C and Objective-C++ Dialects}. -fno-sched-spec -fno-signed-zeros @gol -fno-toplevel-reorder -fno-trapping-math -fno-zero-initialized-in-bss @gol -fomit-frame-pointer -foptimize-sibling-calls @gol --fpartial-inlining -fpeel-loops -fpredictive-commoning @gol +-fpartial-inlining -fparallel-jobs=@var{alg} @gol +-fpeel-loops -fpredictive-commoning @gol -fprefetch-loop-arrays @gol -fprofile-correction @gol -fprofile-use -fprofile-use=@var{path} -fprofile-partial-training @gol @@ -14511,6 +14512,35 @@ of the function name, it is considered to be a match. For C99 and C++ extended identifiers, the function name must be given in UTF-8, not using universal character names. +@item -fparallel-jobs=@var{n} +@opindex parallel +This option is experimental. + +This option enables parallel compilation of files using a maximum of +@var{n} parallel jobs. When invoked, it tries to distribute the symbols +within the file into multiple partitions and compile them in parallel. + +For now, private symbols are paritioned together with public symbols +if there are references to them to avoid code layout modifications +when compiling. This means that compiling a file +with very few public symbols will not provide noticeable improvements +in compilation time. However, you can use +@option{--param=promote-statics=1} to allow GCC to automatically +promote a symbol to be globally available, improving compilation +performance in exchange to changing code layout. + +You can also specify @option{-fparallel-jobs=jobserver} to use GNU make's +job server mode to determine the number of parallel jobs. This +is useful when the Makefile calling GCC is already executing in parallel. +You must prepend a @samp{+} to the command recipe in the parent Makefile +for this to work. This option likely only works if @env{MAKE} is +GNU make. If you specify @option{-fparallel-jobs=auto}, GCC will try to +automatically detect a running GNU make's job server. + +An extra parameter, @option{--param=balance-partitions=0} can be used to +avoid balancing created partitions. This should only be used to debug +the compiler. + @item -fpatchable-function-entry=@var{N}[,@var{M}] @opindex fpatchable-function-entry Generate @var{N} NOPs right at the beginning |