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Re: [PATCH 2/5] Add preferred_for_{size,speed} attributes

On 10/17/2014 10:48 AM, Richard Sandiford wrote:
> This is the main patch, to add new preferred_for_size and
> preferred_for_speed attributes that can be used to selectively disable
> alternatives when optimising for size or speed.  As explained in the
> docs, the new attributes are just optimisation hints and it is possible
> that "size-only" alternatives will sometimes end up in a block that's
> optimised for speed, or vice versa.
> The patch deals with code that directly accesses the enabled_attributes
> mask and that ought to take size/speed choices into account.  The next
> patch deals with indirect uses.  Note that I'm not making reload support
> these attributes for hopefully obvious reasons :-)
> Richard
> gcc/
> 	* doc/md.texi: Document "preferred_for_size" and "preferred_for_speed"
> 	attributes.
> 	* genattr.c (main): Handle "preferred_for_size" and
> 	"preferred_for_speed" in the same way as "enabled".
> 	* recog.h (bool_attr): New enum.
> 	(target_recog): Replace x_enabled_alternatives with x_bool_attr_masks.
> 	(get_preferred_alternatives, check_bool_attrs): Declare.
> 	* recog.c (have_bool_attr, get_bool_attr, get_bool_attr_mask_uncached)
> 	(get_bool_attr_mask, get_preferred_alternatives, check_bool_attrs):
> 	New functions.
> 	(get_enabled_alternatives): Use get_bool_attr_mask.
> 	* ira-costs.c (record_reg_classes): Use get_preferred_alternatives
> 	instead of recog_data.enabled_alternatives.
> 	* ira.c (ira_setup_alts): Likewise.
> 	* postreload.c (reload_cse_simplify_operands): Likewise.
> 	* config/i386/i386.c (ix86_legitimate_combined_insn): Likewise.
> 	* ira-lives.c (preferred_alternatives): New variable.
> 	(process_bb_node_lives): Set it.
> 	(check_and_make_def_conflict, make_early_clobber_and_input_conflicts)
> 	(single_reg_class, ira_implicitly_set_insn_hard_regs): Use it instead
> 	of recog_data.enabled_alternatives.
> 	* lra-int.h (lra_insn_recog_data): Replace enabled_alternatives
> 	to preferred_alternatives.
> 	* lra-constraints.c (process_alt_operands): Update accordingly.
> 	* lra.c (lra_set_insn_recog_data): Likewise.
> 	(lra_update_insn_recog_data): Assert check_bool_attrs.
Thanks for picking this up and making a systematic solution, Richard. 
All  RA-related changes are ok for me.  I guess other changes
(genattrr.c, recog.[ch], md.texi and i386.c) are obvious but I have no
power to approve them.

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