This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] Do not mark pseudo-copies decomposable during first lower-subreg pass
- From: Jay Foad <jay dot foad at gmail dot com>
- To: Ulrich Weigand <uweigand at de dot ibm dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, rsandiford at googlemail dot com
- Date: Thu, 22 Aug 2013 11:27:11 +0100
- Subject: Re: [PATCH] Do not mark pseudo-copies decomposable during first lower-subreg pass
- References: <201209261211 dot q8QCBbl1023270 at d06av02 dot portsmouth dot uk dot ibm dot com>
On 26 September 2012 13:11, Ulrich Weigand <uweigand@de.ibm.com> wrote:
> ChangeLog:
>
> * lower-subreg.c (enum classify_move_insn): Rename
> SIMPLE_PSEUDO_REG_MOVE to DECOMPOSABLE_SIMPLE_MOVE.
> (find_decomposable_subregs): Update.
> (decompose_multiword_subregs): Add DECOMPOSE_COPIES parameter.
> Only mark pseudo-to-pseudo copies as DECOMPOSABLE_SIMPLE_MOVE
> if that parameter is true.
> (rest_of_handle_lower_subreg): Call decompose_multiword_subregs
> with DECOMPOSE_COPIES false.
> (rest_of_handle_lower_subreg2): Call decompose_multiword_subregs
> with DECOMPOSE_COPIES true.
This patch seems to have caused a slight regression in ARM register allocation:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58166
Jay.