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r242488 - in /trunk/gcc: ChangeLog cprop.c
- From: rsandifo at gcc dot gnu dot org
- To: gcc-cvs at gcc dot gnu dot org
- Date: Wed, 16 Nov 2016 13:07:08 -0000
- Subject: r242488 - in /trunk/gcc: ChangeLog cprop.c
Date: Wed Nov 16 13:07:08 2016
New Revision: 242488
Use df_read_modify_subreg_p in cprop.c
local_cprop_find_used_regs punted on all multiword registers,
with the comment:
/* Setting a subreg of a register larger than word_mode leaves
the non-written words unchanged. */
But this only applies if the outer mode is smaller than the
inner mode. If they're the same size then writes to the subreg
are a normal full update.
This patch uses df_read_modify_subreg_p instead. A later patch
adds more uses of the same routine, but this part had a (positive)
effect on code generation for the testsuite whereas the others
seemed to be simple clean-ups.
2016-11-15 Richard Sandiford <firstname.lastname@example.org>
Alan Hayward <email@example.com>
David Sherwood <firstname.lastname@example.org>
* cprop.c (local_cprop_find_used_regs): Use df_read_modify_subreg_p.