Re: Make more use of df_read_modify_subreg_p

2017-10-23 Thread Jeff Law
On 10/13/2017 10:08 AM, Richard Sandiford wrote: > Jeff Law writes: >> On 08/24/2017 12:25 PM, Richard Sandiford wrote: >>> Segher Boessenkool writes: On Wed, Aug 23, 2017 at 11:49:03AM +0100, Richard Sandiford wrote: > This patch uses

Re: Make more use of df_read_modify_subreg_p

2017-10-13 Thread Segher Boessenkool
On Fri, Oct 13, 2017 at 05:08:51PM +0100, Richard Sandiford wrote: > Yeah, I agree this'll change the handling of paradoxical subregs that > occupy more words than the SUBREG_REG, but I think the new version is > correct. The comment says: > > /* If the destination is anything other than

Re: Make more use of df_read_modify_subreg_p

2017-10-13 Thread Richard Sandiford
Jeff Law writes: > On 08/24/2017 12:25 PM, Richard Sandiford wrote: >> Segher Boessenkool writes: >>> On Wed, Aug 23, 2017 at 11:49:03AM +0100, Richard Sandiford wrote: This patch uses df_read_modify_subreg_p to check whether writing to a

Re: Make more use of df_read_modify_subreg_p

2017-10-13 Thread Jeff Law
On 08/24/2017 12:25 PM, Richard Sandiford wrote: > Segher Boessenkool writes: >> On Wed, Aug 23, 2017 at 11:49:03AM +0100, Richard Sandiford wrote: >>> This patch uses df_read_modify_subreg_p to check whether writing >>> to a subreg would preserve some of the existing

Re: Make more use of df_read_modify_subreg_p

2017-08-24 Thread Richard Sandiford
Segher Boessenkool writes: > On Wed, Aug 23, 2017 at 11:49:03AM +0100, Richard Sandiford wrote: >> This patch uses df_read_modify_subreg_p to check whether writing >> to a subreg would preserve some of the existing contents. > > combine does not keep the DF info

Re: Make more use of df_read_modify_subreg_p

2017-08-23 Thread Segher Boessenkool
On Wed, Aug 23, 2017 at 11:49:03AM +0100, Richard Sandiford wrote: > This patch uses df_read_modify_subreg_p to check whether writing > to a subreg would preserve some of the existing contents. combine does not keep the DF info up-to-date -- but that is no problem here, df_read_modify_subreg_p

Make more use of df_read_modify_subreg_p

2017-08-23 Thread Richard Sandiford
This patch uses df_read_modify_subreg_p to check whether writing to a subreg would preserve some of the existing contents. This has the effect of putting more emphasis on the REGMODE_NATURAL_SIZE-based definition of whether something can be partially modified, instead of using UNITS_PER_WORD