diff options
Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 3f131fd02b4..7b20ced5483 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -321,7 +321,7 @@ Objective-C and Objective-C++ Dialects}. -femit-struct-debug-baseonly -femit-struct-debug-reduced @gol -femit-struct-debug-detailed@r{[}=@var{spec-list}@r{]} @gol -p -pg -print-file-name=@var{library} -print-libgcc-file-name @gol --print-multi-directory -print-multi-lib @gol +-print-multi-directory -print-multi-lib -print-multi-os-directory @gol -print-prog-name=@var{program} -print-search-dirs -Q @gol -print-sysroot -print-sysroot-headers-suffix @gol -save-temps -save-temps=cwd -save-temps=obj -time@r{[}=@var{file}@r{]}} @@ -346,7 +346,8 @@ Objective-C and Objective-C++ Dialects}. -finline-small-functions -fipa-cp -fipa-cp-clone -fipa-matrix-reorg -fipa-pta @gol -fipa-pure-const -fipa-reference -fipa-struct-reorg @gol -fipa-type-escape -fira-algorithm=@var{algorithm} @gol --fira-region=@var{region} -fira-coalesce -fno-ira-share-save-slots @gol +-fira-region=@var{region} -fira-coalesce @gol +-fira-loop-pressure -fno-ira-share-save-slots @gol -fno-ira-share-spill-slots -fira-verbose=@var{n} @gol -fivopts -fkeep-inline-functions -fkeep-static-consts @gol -floop-block -floop-interchange -floop-strip-mine -fgraphite-identity @gol @@ -5530,6 +5531,16 @@ that enable them. The directory name is separated from the switches by @samp{-}, without spaces between multiple switches. This is supposed to ease shell-processing. +@item -print-multi-os-directory +@opindex print-multi-os-directory +Print the path to OS libraries for the selected +multilib, relative to some @file{lib} subdirectory. If OS libraries are +present in the @file{lib} subdirectory and no multilibs are used, this is +usually just @file{.}, if OS libraries are present in @file{lib@var{suffix}} +sibling directories this prints e.g.@: @file{../lib64}, @file{../lib} or +@file{../lib32}, or if OS libraries are present in @file{lib/@var{subdir}} +subdirectories it prints e.g.@: @file{amd64}, @file{sparcv9} or @file{ev6}. + @item -print-prog-name=@var{program} @opindex print-prog-name Like @option{-print-file-name}, but searches for a program such as @samp{cpp}. @@ -5627,6 +5638,9 @@ each of them. Not all optimizations are controlled directly by a flag. Only optimizations that have a flag are listed in this section. +Most of the optimizations are not enabled if a @option{-O} level is not set on +the command line, even if individual optimization flags are specified. + Depending on the target and how GCC was configured, a slightly different set of optimizations may be enabled at each @option{-O} level than those listed here. You can invoke GCC with @samp{-Q --help=optimizers} @@ -6216,6 +6230,15 @@ give the best results in most cases and for most architectures. Do optimistic register coalescing. This option might be profitable for architectures with big regular register files. +@item -fira-loop-pressure +@opindex fira-loop-pressure +Use IRA to evaluate register pressure in loops for decision to move +loop invariants. Usage of this option usually results in generation +of faster and smaller code on machines with big register files (>= 32 +registers) but it can slow compiler down. + +This option is enabled at level @option{-O3} for some targets. + @item -fno-ira-share-save-slots @opindex fno-ira-share-save-slots Switch off sharing stack slots used for saving call used hard @@ -8387,6 +8410,14 @@ lower quality register allocation algorithm will be used. The algorithm do not use pseudo-register conflicts. The default value of the parameter is 2000. +@item ira-loop-reserved-regs +IRA can be used to evaluate more accurate register pressure in loops +for decision to move loop invariants (see @option{-O3}). The number +of available registers reserved for some other purposes is described +by this parameter. The default value of the parameter is 2 which is +minimal number of registers needed for execution of typical +instruction. This value is the best found from numerous experiments. + @item loop-invariant-max-bbs-in-loop Loop invariant motion can be very expensive, both in compile time and in amount of needed compile time memory, with very large loops. Loops |