diff options
Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 3f131fd02b4..ddcde711c20 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -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 @@ -5719,7 +5720,8 @@ invoking @option{-O2} on programs that use computed gotos. Optimize yet more. @option{-O3} turns on all optimizations specified by @option{-O2} and also turns on the @option{-finline-functions}, @option{-funswitch-loops}, @option{-fpredictive-commoning}, -@option{-fgcse-after-reload} and @option{-ftree-vectorize} options. +@option{-fgcse-after-reload}, @option{-ftree-vectorize} and +@option{-fira-loop-pressure} options. @item -O0 @opindex O0 @@ -6216,6 +6218,14 @@ 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 but can slow compiler down. + +This option is enabled at level @option{-O3}. + @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 +8397,14 @@ 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 |