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Re: [PATCH] Introduce TYPE_OVERFLOW_SANITIZED
- From: Marek Polacek <polacek at redhat dot com>
- To: Richard Biener <rguenther at suse dot de>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, Jakub Jelinek <jakub at redhat dot com>
- Date: Thu, 13 Nov 2014 11:11:41 +0100
- Subject: Re: [PATCH] Introduce TYPE_OVERFLOW_SANITIZED
- Authentication-results: sourceware.org; auth=none
- References: <20141112175500 dot GN29791 at redhat dot com> <alpine dot LSU dot 2 dot 11 dot 1411130943510 dot 374 at zhemvz dot fhfr dot qr>
On Thu, Nov 13, 2014 at 09:45:50AM +0100, Richard Biener wrote:
> Hmm, I'd have expected to test !TYPE_OVERFLOW_SANITIZED (),
> that is, have the predicate inverted. At least that's how
> I understand the name - an overflow is to be preserved for
> sanitization.
I guess that macro name is a little bit baffling ;).
> So - can you invert the predicates (and uses)? In the
> sanitizer you then can guard instrumentations with
> TYPE_OVERFLOW_SANITIZED.
Done.
> Ok with that change.
Thanks, this is the inverted version:
2014-11-13 Marek Polacek <polacek@redhat.com>
* tree.h (TYPE_OVERFLOW_SANITIZED): Define.
* fold-const.c (fold_binary_loc): Use it.
* match.pd: Likewise.
diff --git gcc/fold-const.c gcc/fold-const.c
index 4321b1e..8c19c1f 100644
--- gcc/fold-const.c
+++ gcc/fold-const.c
@@ -10538,9 +10538,7 @@ fold_binary_loc (location_t loc,
/* A - B -> A + (-B) if B is easily negatable. */
if (negate_expr_p (arg1)
- && (!INTEGRAL_TYPE_P (type)
- || TYPE_OVERFLOW_WRAPS (type)
- || (flag_sanitize & SANITIZE_SI_OVERFLOW) == 0)
+ && !TYPE_OVERFLOW_SANITIZED (type)
&& ((FLOAT_TYPE_P (type)
/* Avoid this transformation if B is a positive REAL_CST. */
&& (TREE_CODE (arg1) != REAL_CST
diff --git gcc/match.pd gcc/match.pd
index 1d7b153..9a1ce93 100644
--- gcc/match.pd
+++ gcc/match.pd
@@ -285,26 +285,20 @@ along with GCC; see the file COPYING3. If not see
/* Apply STRIP_NOPS on @0 and the negate. */
(if (tree_nop_conversion_p (type, TREE_TYPE (@0))
&& tree_nop_conversion_p (type, TREE_TYPE (@1))
- && (!INTEGRAL_TYPE_P (type)
- || TYPE_OVERFLOW_WRAPS (type)
- || (flag_sanitize & SANITIZE_SI_OVERFLOW) == 0))
+ && !TYPE_OVERFLOW_SANITIZED (type))
(minus (convert @0) (convert @1))))
/* A - (-B) -> A + B */
(simplify
(minus (convert1? @0) (convert2? (negate @1)))
(if (tree_nop_conversion_p (type, TREE_TYPE (@0))
&& tree_nop_conversion_p (type, TREE_TYPE (@1))
- && (!INTEGRAL_TYPE_P (type)
- || TYPE_OVERFLOW_WRAPS (type)
- || (flag_sanitize & SANITIZE_SI_OVERFLOW) == 0))
+ && !TYPE_OVERFLOW_SANITIZED (type))
(plus (convert @0) (convert @1))))
/* -(-A) -> A */
(simplify
(negate (convert? (negate @1)))
(if (tree_nop_conversion_p (type, TREE_TYPE (@1))
- && (!INTEGRAL_TYPE_P (type)
- || TYPE_OVERFLOW_WRAPS (type)
- || (flag_sanitize & SANITIZE_SI_OVERFLOW) == 0))
+ && !TYPE_OVERFLOW_SANITIZED (type))
(convert @1)))
/* We can't reassociate floating-point or fixed-point plus or minus
diff --git gcc/tree.h gcc/tree.h
index 0577d51..108b52d 100644
--- gcc/tree.h
+++ gcc/tree.h
@@ -789,6 +789,12 @@ extern void omp_clause_range_check_failed (const_tree, const char *, int,
#define TYPE_OVERFLOW_TRAPS(TYPE) \
(!TYPE_UNSIGNED (TYPE) && flag_trapv)
+/* True if an overflow is to be preserved for sanitization. */
+#define TYPE_OVERFLOW_SANITIZED(TYPE) \
+ (INTEGRAL_TYPE_P (TYPE) \
+ && !TYPE_OVERFLOW_WRAPS (TYPE) \
+ && (flag_sanitize & SANITIZE_SI_OVERFLOW))
+
/* True if pointer types have undefined overflow. */
#define POINTER_TYPE_OVERFLOW_UNDEFINED (flag_strict_overflow)
Marek