diff options
Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 68 |
1 files changed, 62 insertions, 6 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index ff9a9a7..747f0036 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -291,7 +291,8 @@ in the following sections. -fsched2-use-traces -fsignaling-nans @gol -fsingle-precision-constant -fssa -fssa-ccp -fssa-dce @gol -fstrength-reduce -fstrict-aliasing -ftracer -fthread-jumps @gol --funit-at-a-time -funroll-all-loops -funroll-loops -funswitch-loops @gol +-funroll-all-loops -funroll-loops -fpeel-loops -funswitch-loops @gol +-fold-unroll-loops -fold-unroll-all-loops @gol --param @var{name}=@var{value} -O -O0 -O1 -O2 -O3 -Os} @@ -4292,17 +4293,50 @@ extra optimizations to take place but consumes more memory. @item -funroll-loops @opindex funroll-loops -Unroll loops whose number of iterations can be determined at compile -time or upon entry to the loop. @option{-funroll-loops} implies both -@option{-fstrength-reduce} and @option{-frerun-cse-after-loop}. This -option makes code larger, and may or may not make it run faster. +Unroll loops whose number of iterations can be determined at compile time or +upon entry to the loop. @option{-funroll-loops} implies +@option{-frerun-cse-after-loop}. It also turns on complete loop peeling +(i.e. complete removal of loops with small constant number of iterations). +This option makes code larger, and may or may not make it run faster. @item -funroll-all-loops @opindex funroll-all-loops Unroll all loops, even if their number of iterations is uncertain when the loop is entered. This usually makes programs run more slowly. @option{-funroll-all-loops} implies the same options as -@option{-funroll-loops}, +@option{-funroll-loops}. + +@item -fpeel-loops +@opindex fpeel-loops +Peels the loops for that there is enough information that they do not +roll much (from profile feedback). It also turns on complete loop peeling +(i.e. complete removal of loops with small constant number of iterations). + +@item -funswitch-loops +@opindex funswitch-loops +Move branches with loop invariant conditions out of the loop, with duplicates +of the loop on both branches (modified according to result of the condition). + +@item -fold-unroll-loops +@opindex fold-unroll-loops +Unroll loops whose number of iterations can be determined at compile +time or upon entry to the loop, using the old loop unroller whose loop +recognition is based on notes from frontend. @option{-fold-unroll-loops} implies +both @option{-fstrength-reduce} and @option{-frerun-cse-after-loop}. This +option makes code larger, and may or may not make it run faster. + +@item -fold-unroll-all-loops +@opindex fold-unroll-all-loops +Unroll all loops, even if their number of iterations is uncertain when +the loop is entered. This is done using the old loop unroller whose loop +recognition is based on notes from frontend. This usually makes programs run more slowly. +@option{-fold-unroll-all-loops} implies the same options as +@option{-fold-unroll-loops}. + +@item -funswitch-loops +@opindex funswitch-loops +Move branches with loop invariant conditions out of the loop, with duplicates +of the loop on both branches (modified according to result of the condition). @item -funswitch-loops @opindex funswitch-loops @@ -4418,6 +4452,28 @@ The maximum number of instructions that a loop should have if that loop is unrolled, and if the loop is unrolled, it determines how many times the loop code is unrolled. +@item max-average-unrolled-insns +The maximum number of instructions biased by probabilities of their execution +that a loop should have if that loop is unrolled, and if the loop is unrolled, +it determines how many times the loop code is unrolled. + +@item max-unroll-times +The maximum number of unrollings of a single loop. + +@item max-peeled-insns +The maximum number of instructions that a loop should have if that loop +is peeled, and if the loop is peeled, it determines how many times +the loop code is peeled. + +@item max-peel-times +The maximum number of peelings of a single loop. + +@item max-completely-peeled-insns +The maximum number of insns of a completely peeled loop. + +@item max-completely-peel-times +The maximum number of iterations of a loop to be suitable for complete peeling. + @item max-unswitch-insns The maximum number of insns of an unswitched loop. |