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Diffstat (limited to 'gcc/doc/tm.texi.in')
| -rw-r--r-- | gcc/doc/tm.texi.in | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in index 7990c763a73..01beeb47920 100644 --- a/gcc/doc/tm.texi.in +++ b/gcc/doc/tm.texi.in @@ -2832,6 +2832,23 @@ the only effect of such implementation would be to slow down register allocation. @end deftypefn +@hook TARGET_CLASS_MAX_NREGS +A target hook returns the maximum number of consecutive registers +of class @var{rclass} needed to hold a value of mode @var{mode}. + +This is closely related to the macro @code{HARD_REGNO_NREGS}. In fact, +the value returned by @code{TERGET_CLASS_MAX_NREGS (@var{rclass}, +@var{mode})} target hook should be the maximum value of +@code{HARD_REGNO_NREGS (@var{regno}, @var{mode})} for all @var{regno} +values in the class @var{rclass}. + +This target hook helps control the handling of multiple-word values +in the reload pass. + +The default version of this target hook returns the size of @var{mode} +in words. +@end deftypefn + @defmac CLASS_MAX_NREGS (@var{class}, @var{mode}) A C expression for the maximum number of consecutive registers of class @var{class} needed to hold a value of mode @var{mode}. |