On 12/03/13 06:27, Bernd Edlinger wrote:
This comment is completely out of sync: There is no longer any force_reg in
that if-block,
and a constant address in TO_RTX has SImode or DImode in GET_MODE (XEXP
(to_rtx, 0))
I do not know how to make it a VOIDmode, therefore the comment does not help
either.
I thought that comment looked familiar... That's because it was mine...
The way that was triggered in the past can be found in this ancient posting:
http://gcc.gnu.org/ml/gcc-patches/1999-03n/msg00654.html
The code went through a major revamp in 2002 which removed the force_reg
calls without updating/removing the comment.
Additionally, the way we represent and thus ultimately expand the memory
reference has changed in ways that make it harder, if not impossible to
have a constant address at these points. Even if were to hack up the
expanders to force a constant address rather than a REG it's still
nontrivial to get into that code with a constant address.
I wouldn't be terribly surprised to find all kinds of dead code in the
expanders.
So the comment clearly needs to get zapped.
As for the consistency of bitregion_start/bitregion_end, I'm just not
familiar enough with this code or the issues for the C++ memory model to
comment.
jeff
