[Bug target/46030] registers trashed with -Os

[amodra at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46030

--- Comment #3 from Alan Modra <amodra at gcc dot gnu.org> 2011-02-15 02:33:37 UTC ---
Author: amodra
Date: Tue Feb 15 02:33:33 2011
New Revision: 170165

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=170165
Log:
    Backport from mainline
    2010-11-01  Alan Modra  <amodra@gmail.com>
    PR target/46030
    * config/rs6000/rs6000.c (struct rs6000_stack): Add reload_completed
    and savres_strategy.
    (stack_info): New file scope var.
    (rs6000_init_machine_status): Init stack_info.
    (SAVRES_INLINE_FPRS, SAVRES_INLINE_GPRS,
    SAVRES_NOINLINE_GPRS_SAVES_LR, SAVRES_NOINLINE_FPRS_SAVES_LR,
    SAVRES_NOINLINE_FPRS_DOESNT_RESTORE_LR): Replace with..
    (SAVE_INLINE_FPRS, SAVE_INLINE_GPRS, REST_INLINE_FPRS, REST_INLINE_GPRS,
    SAVE_NOINLINE_GPRS_SAVES_LR, SAVE_NOINLINE_FPRS_SAVES_LR
    REST_NOINLINE_FPRS_DOESNT_RESTORE_LR): ..this.  Update all refs.
    (rs6000_savres_strategy): Rewrite.
    (rs6000_stack_info): Use "stack_info" in place of local "info".
    Return cached stack info when reload_completed unless ENABLE_CHECKING
    in which case confirm newly calculated stack info matches old info.
    Delay calculation of lr_save_p, set it for out of line gp save/restore
    as well as fp.  Call rs6000_savres_strategy from here..
    (rs6000_emit_prologue, rs6000_emit_epilogue): ..rather than here.
    (rs6000_output_function_prologue): Use info->savres_strategy to
    determine whether fp save/restore externs need to be emitted.


Modified:
    branches/ibm/gcc-4_5-branch/gcc/ChangeLog.ibm
    branches/ibm/gcc-4_5-branch/gcc/config/rs6000/rs6000.c