[Bug tree-optimization/38049] points-to results imprecise

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

------- Comment #1 from rguenth at gcc dot gnu dot org  2009-02-03 10:20 -------
Subject: Bug 38049

Author: rguenth
Date: Tue Feb  3 10:20:20 2009
New Revision: 143890

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143890
Log:
2009-02-03  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/38049
        * tree-ssa-structalias.c (struct constraint_expr): Make offset signed.
        (UNKNOWN_OFFSET): Define special value.
        (dump_constraint): Dump UNKNOWN_OFFSET as UNKNOWN.
        (solution_set_expand): New helper function split out from ...
        (do_sd_constraint): ... here.
        (solution_set_add): Handle UNKNOWN_OFFSET.  Handle negative offsets.
        (do_ds_constraint): Likewise.
        (do_sd_constraint): Likewise.  Do not special-case ESCAPED = *ESCAPED
        and CALLUSED = *CALLUSED.
        (set_union_with_increment): Make inc argument signed.
        (type_safe): Remove.
        (get_constraint_for_ptr_offset): Handle unknown and negative
        constant offsets.
        (first_vi_for_offset): Handle offsets before start.  Bail
        out early for offsets beyond the variable extent.
        (first_or_preceding_vi_for_offset): New function.
        (init_base_vars): Add ESCAPED = ESCAPED + UNKNOWN_OFFSET constraint.
        Together with ESCAPED = *ESCAPED this properly computes reachability.

        * gcc.dg/torture/pta-ptrarith-3.c: New testcase.
        * gcc.dg/tree-ssa/pta-ptrarith-1.c: Likewise.
        * gcc.dg/tree-ssa/pta-ptrarith-2.c: Likewise.
        * gcc.dg/vect/no-vfa-vect-43.c: Adjust.

Added:
    branches/alias-improvements/gcc/testsuite/gcc.dg/torture/pta-ptrarith-3.c
    branches/alias-improvements/gcc/testsuite/gcc.dg/tree-ssa/pta-ptrarith-1.c
    branches/alias-improvements/gcc/testsuite/gcc.dg/tree-ssa/pta-ptrarith-2.c
Modified:
    branches/alias-improvements/gcc/ChangeLog.alias
    branches/alias-improvements/gcc/testsuite/gcc.dg/vect/no-vfa-vect-43.c
    branches/alias-improvements/gcc/tree-ssa-structalias.c


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38049