diff options
Diffstat (limited to 'gcc/doc')
-rw-r--r-- | gcc/doc/install.texi | 19 | ||||
-rw-r--r-- | gcc/doc/invoke.texi | 11 |
2 files changed, 26 insertions, 4 deletions
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi index 112f83d..bc63a53 100644 --- a/gcc/doc/install.texi +++ b/gcc/doc/install.texi @@ -1523,6 +1523,25 @@ systems that support conditional traps). Division by zero checks use the break instruction. @end table +@item --with-compact-branches=@var{policy} +Specify how the compiler should generate branch instructions. +This option is only supported on the MIPS target. +The possibilities for @var{type} are: +@table @code +@item optimal +Cause a delay slot branch to be used if one is available in the +current ISA and the delay slot is successfully filled. If the delay slot +is not filled, a compact branch will be chosen if one is available. +@item never +Ensures that compact branch instructions will never be generated. +@item always +Ensures that a compact branch instruction will be generated if available. +If a compact branch instruction is not available, +a delay slot form of the branch will be used instead. +This option is supported from MIPS Release 6 onwards. +For pre-R6/microMIPS/MIPS16, this option is just same as never/optimal. +@end table + @c If you make --with-llsc the default for additional targets, @c update the --with-llsc description in the MIPS section below. diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 4db4bcb..ed79440 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -10421,6 +10421,7 @@ of the following functions for working with file descriptors: @item @code{close} @item @code{creat} @item @code{dup}, @code{dup2} and @code{dup3} +@item @code{pipe}, and @code{pipe2} @item @code{read} @item @code{write} @end itemize @@ -27048,11 +27049,13 @@ The @option{-mcompact-branches=never} option ensures that compact branch instructions will never be generated. The @option{-mcompact-branches=always} option ensures that a compact -branch instruction will be generated if available. If a compact branch -instruction is not available, a delay slot form of the branch will be -used instead. +branch instruction will be generated if available for MIPS Release 6 onwards. +If a compact branch instruction is not available (or pre-R6), +a delay slot form of the branch will be used instead. -This option is supported from MIPS Release 6 onwards. +If it is used for MIPS16/microMIPS targets, it will be just ignored now. +The behaviour for MIPS16/microMIPS may change in future, +since they do have some compact branch instructions. The @option{-mcompact-branches=optimal} option will cause a delay slot branch to be used if one is available in the current ISA and the delay |