[Bug middle-end/36262] [4.3 Regression] Extreme memory usage of VRP compared to older versions

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

------- Comment #7 from rguenth at gcc dot gnu dot org  2008-05-31 13:01 -------
Subject: Bug 36262

Author: rguenth
Date: Sat May 31 13:01:10 2008
New Revision: 136237

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=136237
Log:
2008-05-31  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/34244
        * fold-const.c (tree_expr_nonnegative_warnv_p): Do not ask VRP.
        (tree_expr_nonzero_warnv_p): Likewise.
        * tree-vrp.c (vrp_expr_computes_nonnegative): Call
        ssa_name_nonnegative_p.
        (vrp_expr_computes_nonzero): Call ssa_name_nonzero_p.
        (extract_range_from_unary_expr): Use vrp_expr_computes_nonzero,
        not tree_expr_nonzero_warnv_p.

        PR tree-optimization/36262
        Revert
        2007-11-29  Zdenek Dvorak  <ook@ucw.cz>

        PR tree-optimization/34244
        * tree-vrp.c (adjust_range_with_scev): Clear scev cache.
        (record_numbers_of_iterations): New function.
        (execute_vrp): Cache the numbers of iterations of loops.
        * tree-scalar-evolution.c (scev_reset_except_niters):
        New function.
        (scev_reset): Use scev_reset_except_niters.
        * tree-scalar-evolution.h (scev_reset_except_niters): Declare.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fold-const.c
    trunk/gcc/tree-scalar-evolution.c
    trunk/gcc/tree-scalar-evolution.h
    trunk/gcc/tree-vrp.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36262