The following patch is for solution of PR65862
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65862
In some cases, calculations of reg class costs are not enough to choose
the right class. For example, in some cases you don't want to start fp
unit for energy saving considerations if you don't really need it. Such
case can occur when we have non-floating point mode pseudo and
calculation costs in ira says that it would be profitable to put it in a
floating point register.
The full solution will need to add a hook to mips.c. I hope mips
maintainers will do that soon.
The patch was bootstrapped on x86-64.
Committed as rev. 223202.
2015-05-14 Vladimir Makarov <vmaka...@redhat.com>
PR rtl-optimization/65862
* target.def (ira_change_pseudo_allocno_class): New hook.
* targhooks.c (default_ira_change_pseudo_allocno_class): Default
value of the hook.
* targhooks.h (default_ira_change_pseudo_allocno_class): New
extern
* doc/tm.texi.in (TARGET_IRA_CHANGE_PSEUDO_ALLOCNO_CLASS): Add the
hook.
* ira-costs.c (find_costs_and_classes): Call the hook and change
classes when it is necessary.
* doc/tm.texi: Update.
