[Bug tree-optimization/71915] A missed opportunity for SLSR

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71915

--- Comment #6 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
Author: wschmidt
Date: Mon Oct 31 03:04:59 2016
New Revision: 241695

URL: https://gcc.gnu.org/viewcvs?rev=241695&root=gcc&view=rev
Log:
[gcc]

2016-10-30  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

        PR tree-optimization/71915
        PR tree-optimization/71490
        * gimple-ssa-strength-reduction.c (struct slsr_cand_d): Add
        stride_type field.
        (find_basis_for_base_expr): Require stride types to match when
        seeking a basis.
        (alloc_cand_and_find_basis): Record the stride type.
        (slsr_process_phi): Pass stride type to alloc_cand_and_find_basis.
        (backtrace_base_for_ref): Pass types to legal_cast_p_1 rather than
        the expressions having those types.
        (slsr_process_ref): Pass stride type to alloc_cand_and_find_basis.
        (create_mul_ssa_cand): Likewise.
        (create_mul_imm_cand): Likewise.
        (create_add_ssa_cand): Likewise.
        (create_add_imm_cand): Likewise.
        (legal_cast_p_1): Change interface to accept types rather than the
        expressions having those types.
        (legal_cast_p): Pass types to legal_cast_p_1.
        (slsr_process_cast): Pass stride type to
        alloc_cand_and_find_basis.
        (slsr_process_copy): Likewise.
        (dump_candidate): Display stride type when a cast exists.
        (create_add_on_incoming_edge): Introduce a cast when necessary for
        the stride type.
        (analyze_increments): Change the code checking for invalid casts
        to rely on the stride type, and update the documentation and
        example.  Change the code checking for pointer multiplies to rely
        on the stride type.
        (insert_initializers): Introduce a cast when necessary for the
        stride type.  Use the stride type for the type of the initializer.

[gcc/testsuite]

2016-10-30  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

        PR tree-optimization/71915
        PR tree-optimization/71490
        * gcc.dg/tree-ssa/pr54245.c: Delete.
        * gcc.dg/tree-ssa/slsr-8.c: Adjust for new optimization and
        document why.



Removed:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr54245.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/gimple-ssa-strength-reduction.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/tree-ssa/slsr-8.c