From 3119ac2925882e0e7b30984d71093eef349cabcc Mon Sep 17 00:00:00 2001 From: Marek Polacek Date: Thu, 4 Dec 2014 19:20:12 +0000 Subject: [PATCH] re PR middle-end/56917 (-ftrapv detects a overflow wrongly.) 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 --- gcc/ChangeLog | 6 ++++ gcc/fold-const.c | 11 +++++-- gcc/testsuite/ChangeLog | 5 ++++ gcc/testsuite/c-c++-common/ubsan/pr56917.c | 34 ++++++++++++++++++++++ 4 files changed, 53 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/c-c++-common/ubsan/pr56917.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 056ced259cf..2d41d93b171 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2014-12-04 Marek Polacek + + 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 * Makefile.in: Remove CLOOGLIB and CLOOGINC. diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 17eb5bb9f0f..c268007415c 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -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, diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index a0a78dc62b1..0b3a9d682a9 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2014-12-04 Marek Polacek + + PR middle-end/56917 + * c-c++-common/ubsan/pr56917.c: New test. + 2014-12-04 Martin Jambor * gcc.dg/ipa/propalign-1.c: New test. diff --git a/gcc/testsuite/c-c++-common/ubsan/pr56917.c b/gcc/testsuite/c-c++-common/ubsan/pr56917.c new file mode 100644 index 00000000000..cfbae97c0c6 --- /dev/null +++ b/gcc/testsuite/c-c++-common/ubsan/pr56917.c @@ -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 (); +} -- 2.30.2