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| author | Jakub Jelinek <jakub@redhat.com> | 2018-01-15 10:05:59 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2018-01-15 10:05:59 +0100 |
| commit | 3fccbb9ecec7daa3b6468f72379c0bd1fb5bb8d9 (patch) | |
| tree | 08c17fa7abe77e42e46b0fdf6d49c9bdf48fc9a0 /gcc/match.pd | |
| parent | 2aa89839f557b7467704ddffa4dc43a130e8d027 (diff) | |
| download | gcc-3fccbb9ecec7daa3b6468f72379c0bd1fb5bb8d9.zip gcc-3fccbb9ecec7daa3b6468f72379c0bd1fb5bb8d9.tar.gz gcc-3fccbb9ecec7daa3b6468f72379c0bd1fb5bb8d9.tar.bz2 | |
re PR middle-end/82694 (Linux kernel miscompiled since r250765)
PR middle-end/82694
* common.opt (fstrict-overflow): No longer an alias.
(fwrapv-pointer): New option.
* tree.h (TYPE_OVERFLOW_WRAPS, TYPE_OVERFLOW_UNDEFINED): Define
also for pointer types based on flag_wrapv_pointer.
* opts.c (common_handle_option) <case OPT_fstrict_overflow>: Set
opts->x_flag_wrap[pv] to !value, clear opts->x_flag_trapv if
opts->x_flag_wrapv got set.
* fold-const.c (fold_comparison, fold_binary_loc): Revert 2017-08-01
changes, just use TYPE_OVERFLOW_UNDEFINED on pointer type instead of
POINTER_TYPE_OVERFLOW_UNDEFINED.
* match.pd: Likewise in address comparison pattern.
* doc/invoke.texi: Document -fwrapv and -fstrict-overflow.
* gcc.dg/no-strict-overflow-7.c: Revert 2017-08-01 changes.
* gcc.dg/tree-ssa/pr81388-1.c: Likewise.
From-SVN: r256686
Diffstat (limited to 'gcc/match.pd')
| -rw-r--r-- | gcc/match.pd | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 435125a..3f6e009 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -3610,7 +3610,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) || TREE_CODE (base1) == STRING_CST)) equal = (base0 == base1); } - (if (equal == 1) + (if (equal == 1 + && (cmp == EQ_EXPR || cmp == NE_EXPR + /* If the offsets are equal we can ignore overflow. */ + || known_eq (off0, off1) + || TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)) + /* Or if we compare using pointers to decls or strings. */ + || (POINTER_TYPE_P (TREE_TYPE (@2)) + && (DECL_P (base0) || TREE_CODE (base0) == STRING_CST)))) (switch (if (cmp == EQ_EXPR && (known_eq (off0, off1) || known_ne (off0, off1))) { constant_boolean_node (known_eq (off0, off1), type); }) |