diff options
Diffstat (limited to 'gcc/doc/tm.texi')
| -rw-r--r-- | gcc/doc/tm.texi | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index 03e0c4a..f357436 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -8657,21 +8657,21 @@ bits outside of @var{mem_mode} to be either the sign-extension or the zero-extension of the data read. Return @code{SIGN_EXTEND} for values of @var{mem_mode} for which the insn sign-extends, @code{ZERO_EXTEND} for which it zero-extends, and -@code{NIL} for other modes. +@code{UNKNOWN} for other modes. This macro is not called with @var{mem_mode} non-integral or with a width greater than or equal to @code{BITS_PER_WORD}, so you may return any value in this case. Do not define this macro if it would always return -@code{NIL}. On machines where this macro is defined, you will normally +@code{UNKNOWN}. On machines where this macro is defined, you will normally define it as the constant @code{SIGN_EXTEND} or @code{ZERO_EXTEND}. -You may return a non-@code{NIL} value even if for some hard registers +You may return a non-@code{UNKNOWN} value even if for some hard registers the sign extension is not performed, if for the @code{REGNO_REG_CLASS} of these hard registers @code{CANNOT_CHANGE_MODE_CLASS} returns nonzero when the @var{from} mode is @var{mem_mode} and the @var{to} mode is any integral mode larger than this but not larger than @code{word_mode}. -You must return @code{NIL} if for some hard registers that allow this +You must return @code{UNKNOWN} if for some hard registers that allow this mode, @code{CANNOT_CHANGE_MODE_CLASS} says that they cannot change to @code{word_mode}, but that they can change to another integral mode that is larger then @var{mem_mode} but still smaller than @code{word_mode}. |