[Bug middle-end/80362] [5/6 Regression] gcc miscompiles arithmetic with signed char

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80362

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue May  9 12:27:24 2017
New Revision: 247790

URL: https://gcc.gnu.org/viewcvs?rev=247790&root=gcc&view=rev
Log:
2017-05-09  Richard Biener  <rguenther@suse.de>

        Backport from mainline
        2017-03-28  Richard Biener  <rguenther@suse.de>

        PR middle-end/80222
        * gimple-fold.c (gimple_fold_indirect_ref): Do not touch
        TYPE_REF_CAN_ALIAS_ALL references.
        * fold-const.c (fold_indirect_ref_1): Likewise.

        * g++.dg/pr80222.C: New testcase.

        2017-04-06  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/80262
        * tree-sra.c (build_ref_for_offset): Preserve address-space
        information.
        * tree-ssa-sccvn.c (vn_reference_maybe_forwprop_address):
        Drop useless address-space information on MEM_REF offsets.

        * gcc.target/i386/pr80262.c: New testcase.

        2017-04-03  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/80275
        * fold-const.c (split_address_to_core_and_offset): Handle
        POINTER_PLUS_EXPR.

        * g++.dg/opt/pr80275.C: New testcase.

        2017-04-06  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/80334
        * tree-ssa-loop-ivopts.c (rewrite_use_address): Properly
        preserve alignment of accesses.

        * g++.dg/torture/pr80334.C: New testcase.

        2017-04-10  Richard Biener  <rguenther@suse.de>

        PR middle-end/80362
        * fold-const.c (fold_binary_loc): Look at unstripped ops when
        looking for NEGATE_EXPR in -A / -B to A / B folding.

        * gcc.dg/torture/pr80362.c: New testcase.

        2017-04-25  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/80492
        * alias.c (compare_base_decls): Handle registers with asm
        specification conservatively.

        * gcc.dg/pr80492.c: New testcase.

        2017-04-27  Richard Biener  <rguenther@suse.de>

        PR middle-end/80539
        * tree-chrec.c (chrec_fold_plus_poly_poly): Deal with not
        being in loop-closed SSA form conservatively.
        (chrec_fold_multiply_poly_poly): Likewise.

        * gcc.dg/torture/pr80539.c: New testcase.

Added:
    branches/gcc-6-branch/gcc/testsuite/g++.dg/opt/pr80275.C
    branches/gcc-6-branch/gcc/testsuite/g++.dg/pr80222.C
    branches/gcc-6-branch/gcc/testsuite/g++.dg/torture/pr80334.C
    branches/gcc-6-branch/gcc/testsuite/gcc.dg/pr80492.c
    branches/gcc-6-branch/gcc/testsuite/gcc.dg/torture/pr80362.c
    branches/gcc-6-branch/gcc/testsuite/gcc.dg/torture/pr80539.c
    branches/gcc-6-branch/gcc/testsuite/gcc.target/i386/pr80262.c
Modified:
    branches/gcc-6-branch/gcc/ChangeLog
    branches/gcc-6-branch/gcc/alias.c
    branches/gcc-6-branch/gcc/fold-const.c
    branches/gcc-6-branch/gcc/gimple-fold.c
    branches/gcc-6-branch/gcc/testsuite/ChangeLog
    branches/gcc-6-branch/gcc/tree-chrec.c
    branches/gcc-6-branch/gcc/tree-sra.c
    branches/gcc-6-branch/gcc/tree-ssa-loop-ivopts.c
    branches/gcc-6-branch/gcc/tree-ssa-sccvn.c