[Bug rtl-optimization/42502] [4.4/4.5/4.6 Regression] Bad register allocation in a very simple code

["bernds at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #7 from bernds at gcc dot gnu dot org  2010-06-04 12:44 -------
Subject: Bug 42502

Author: bernds
Date: Fri Jun  4 12:44:01 2010
New Revision: 160260

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=160260
Log:
        PR rtl-optimization/39871
        PR rtl-optimization/40615
        PR rtl-optimization/42500
        PR rtl-optimization/42502
        * ira.c (init_reg_equiv_memory_loc: New function.
        (ira): Call it twice.
        * reload.h (calculate_elim_costs_all_insns): Declare.
        * ira-costs.c: Include "reload.h".
        (regno_equiv_gains): New static variable.
        (init_costs): Allocate it.
        (finish_costs): Free it.
        (ira_costs): Call calculate_elim_costs_all_insns.
        (find_costs_and_classes): Take estimated elimination costs
        into account.
        (ira_adjust_equiv_reg_cost): New function.
        * ira.h (ira_adjust_equiv_reg_cost): Declare it.
        * reload1.c (init_eliminable_invariants, free_reg_equiv,
        elimination_costs_in_insn, note_reg_elim_costly): New static
        functions.
        (elim_bb): New static variable.
        (reload): Move code out of here into init_eliminable_invariants and
        free_reg_equiv.  Call them.
        (calculate_elim_costs_all_insns): New function.
        (eliminate_regs_1): Declare.  Add extra arg FOR_COSTS;
        all callers changed.  If FOR_COSTS is true, don't call alter_reg,
        but call note_reg_elim_costly if we turned a valid memory address
        into an invalid one.
        * Makefile.in (ira-costs.o): Depend on reload.h.

testsuite/
        PR rtl-optimization/39871
        PR rtl-optimization/40615
        PR rtl-optimization/42500
        PR rtl-optimization/42502
        * gcc.target/arm/eliminate.c: New test.


Added:
    trunk/gcc/testsuite/gcc.target/arm/eliminate.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/Makefile.in
    trunk/gcc/ira-costs.c
    trunk/gcc/ira.c
    trunk/gcc/ira.h
    trunk/gcc/reload.h
    trunk/gcc/reload1.c
    trunk/gcc/testsuite/ChangeLog


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42502