diff options
Diffstat (limited to 'gcc/invoke.texi')
| -rw-r--r-- | gcc/invoke.texi | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/gcc/invoke.texi b/gcc/invoke.texi index 6e438251359..112072d37c0 100644 --- a/gcc/invoke.texi +++ b/gcc/invoke.texi @@ -145,7 +145,7 @@ in the following sections. @item Optimization Options @xref{Optimize Options,,Options that Control Optimization}. @smallexample --fbranch-probabilities +-fbranch-probabilities -foptimize-register-moves -fcaller-saves -fcse-follow-jumps -fcse-skip-blocks -fdelayed-branch -fexpensive-optimizations -ffast-math -ffloat-store -fforce-addr -fforce-mem @@ -2312,6 +2312,17 @@ This pass also performs global constant and copy propagation. @item -fexpensive-optimizations Perform a number of minor optimizations that are relatively expensive. +@item -foptimize-register-moves +@item -fregmove +Attempt to reassign register numbers in move instructions and as +operands of other simple instructions in order to maximize the amount of +register tying. This is especially helpfu on machines with two-operand +instructions. GNU CC enables this optimization by default with @samp{-O2} +or higher. + +Note @code{-fregmove} and @code{-foptimize-register-moves} are the same +optimization. + @item -fdelayed-branch If supported for the target machine, attempt to reorder instructions to exploit instruction slots available after delayed branch @@ -2413,12 +2424,6 @@ branch is mostly to take, the @samp{REG_BR_PROB} values are used to exactly determine which path is taken more often. @end ifset -@item -fregmove -Some machines only support 2 operands per instruction. On such -machines, GNU CC might have to do extra copies. The @samp{-fregmove} -option overrides the default for the machine to do the copy before -register allocation. - @item -fstrict-aliasing Allows the compiler to assume the strictest aliasing rules applicable to the language being compiled. For C (and C++), this activates @@ -4865,7 +4870,7 @@ All modules should be compiled with the same @samp{-G @var{num}} value. @item -nocpp -Tell the MIPS assembler to not run it's preprocessor over user +Tell the MIPS assembler to not run its preprocessor over user assembler files (with a @samp{.s} suffix) when assembling them. @end table |