[Bug target/64580] very high rs6000_stack_info() usage during LTO Firefox build on ppc64

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64580

--- Comment #13 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Author: segher
Date: Thu Feb  5 15:01:49 2015
New Revision: 220453

URL: https://gcc.gnu.org/viewcvs?rev=220453&root=gcc&view=rev
Log:
    PR target/64580
    Backport from mainline
    * config.rs6000/rs6000.c (compute_vrsave_mask): Reverse loop order.
    (rs6000_stack_info): Add assert.
    (rs6000_output_savres_externs): New function, split off from...
    (rs6000_output_function_prologue): ... here.  Do not call it for
    thunks.

Modified:
    branches/gcc-4_9-branch/gcc/ChangeLog
    branches/gcc-4_9-branch/gcc/config/rs6000/rs6000.c