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re PR middle-end/56917 (-ftrapv detects a overflow wrongly.)

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PR middle-end/56917
	* fold-const.c (fold_unary_loc): Perform the negation in A's type
	when transforming ~ (A - 1) or ~ (A + -1) to -A.

	* c-c++-common/ubsan/pr56917.c: New test.

From-SVN: r218395
This commit is contained in:
Marek Polacek 2014-12-04 19:20:12 +00:00 committed by Marek Polacek
parent d348be26b9
commit 3119ac2925
4 changed files with 53 additions and 3 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2014-12-04 Marek Polacek <polacek@redhat.com>
PR middle-end/56917
* fold-const.c (fold_unary_loc): Perform the negation in A's type
when transforming ~ (A - 1) or ~ (A + -1) to -A.
2014-12-04 Tobias Burnus <burnus@net-b.de>
* Makefile.in: Remove CLOOGLIB and CLOOGINC.

11
gcc/fold-const.c
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@ -8141,9 +8141,14 @@ fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0)
&& integer_onep (TREE_OPERAND (arg0, 1)))
|| (TREE_CODE (arg0) == PLUS_EXPR
&& integer_all_onesp (TREE_OPERAND (arg0, 1)))))
return fold_build1_loc (loc, NEGATE_EXPR, type,
fold_convert_loc (loc, type,
TREE_OPERAND (arg0, 0)));
{
/* Perform the negation in ARG0's type and only then convert
to TYPE as to avoid introducing undefined behavior. */
tree t = fold_build1_loc (loc, NEGATE_EXPR,
TREE_TYPE (TREE_OPERAND (arg0, 0)),
TREE_OPERAND (arg0, 0));
return fold_convert_loc (loc, type, t);
}
/* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
else if (TREE_CODE (arg0) == BIT_XOR_EXPR
&& (tem = fold_unary_loc (loc, BIT_NOT_EXPR, type,

5
gcc/testsuite/ChangeLog
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@ -1,3 +1,8 @@
2014-12-04 Marek Polacek <polacek@redhat.com>
PR middle-end/56917
* c-c++-common/ubsan/pr56917.c: New test.
2014-12-04 Martin Jambor <mjambor@suse.cz>
* gcc.dg/ipa/propalign-1.c: New test.

34
gcc/testsuite/c-c++-common/ubsan/pr56917.c Normal file
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@ -0,0 +1,34 @@
/* PR middle-end/56917 */
/* { dg-do run } */
/* { dg-options "-fsanitize=undefined -fno-sanitize-recover=undefined" } */
#define INT_MIN (-__INT_MAX__ - 1)
#define LONG_MIN (-__LONG_MAX__ - 1L)
#define LLONG_MIN (-__LONG_LONG_MAX__ - 1LL)
int __attribute__ ((noinline,noclone))
fn1 (unsigned int u)
{
return (-(int) (u - 1U)) - 1;
}
long __attribute__ ((noinline,noclone))
fn2 (unsigned long int ul)
{
return (-(long) (ul - 1UL)) - 1L;
}
long long __attribute__ ((noinline,noclone))
fn3 (unsigned long long int ull)
{
return (-(long long) (ull - 1ULL)) - 1LL;
}
int
main (void)
{
if (fn1 (__INT_MAX__ + 1U) != INT_MIN
|| fn2 (__LONG_MAX__ + 1UL) != LONG_MIN
|| fn3 (__LONG_LONG_MAX__ + 1ULL) != LLONG_MIN)
__builtin_abort ();
}