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Diffstat (limited to 'gcc/doc/tm.texi')
| -rw-r--r-- | gcc/doc/tm.texi | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index 10184154df1..8870d76e7be 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -2504,6 +2504,10 @@ looking for one that is valid, and will reload one or both registers only if neither labeling works. @end defmac +@deftypefn {Target Hook} reg_class_t TARGET_PREFERRED_RENAME_CLASS (reg_class_t @var{rclass}) +A target hook that places additional preference on the register class to use when it is necessary to rename a register in class @var{class} to another class, or perhaps @var{NO_REGS}, if no prefered register class is found or hook @code{preferred_rename_class} is not implemented. Sometimes returning a more restrictive class makes better code. For example, on ARM, thumb-2 instructions using @code{LO_REGS} may be smaller than instructions using @code{GENERIC_REGS}. By returning @code{LO_REGS} from @code{preferred_rename_class}, code size can be reduced. +@end deftypefn + @deftypefn {Target Hook} reg_class_t TARGET_PREFERRED_RELOAD_CLASS (rtx @var{x}, reg_class_t @var{rclass}) A target hook that places additional restrictions on the register class to use when it is necessary to copy value @var{x} into a register in class |