diff options
Diffstat (limited to 'gas/doc/c-mips.texi')
| -rw-r--r-- | gas/doc/c-mips.texi | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/gas/doc/c-mips.texi b/gas/doc/c-mips.texi index b8953be94b..060febb684 100644 --- a/gas/doc/c-mips.texi +++ b/gas/doc/c-mips.texi @@ -388,6 +388,27 @@ width register by the single width registers. By default @code{--construct-floats} is selected, allowing construction of these floating point constants. +@item --relax-branch +@itemx --no-relax-branch +The @samp{--relax-branch} option enables the relaxation of out-of-range +branches. Any branches whose target cannot be reached directly are +converted to a small instruction sequence including an inverse-condition +branch to the physically next instruction, and a jump to the original +target is inserted between the two instructions. In PIC code the jump +will involve further instructions for address calculation. + +The @code{BC1ANY2F}, @code{BC1ANY2T}, @code{BC1ANY4F}, @code{BC1ANY4T}, +@code{BPOSGE32} and @code{BPOSGE64} instructions are excluded from +relaxation, because they have no complementing counterparts. They could +be relaxed with the use of a longer sequence involving another branch, +however this has not been implemented and if their target turns out of +reach, they produce an error even if branch relaxation is enabled. + +Also no @sc{mips16} branches are ever relaxed. + +By default @samp{--no-relax-branch} is selected, causing any out-of-range +branches to produce an error. + @item --trap @itemx --no-break @c FIXME! (1) reflect these options (next item too) in option summaries; |