re PR middle-end/68142 (unsafe association of multiplication)
2015-10-29 Richard Biener <rguenther@suse.de> PR middle-end/68142 * fold-const.c (extract_muldiv_1): Avoid introducing undefined overflow. * c-c++-common/ubsan/pr68142.c: New testcase. From-SVN: r229528
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2015-10-29 Richard Biener <rguenther@suse.de>
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PR middle-end/68142
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* fold-const.c (extract_muldiv_1): Avoid introducing undefined
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overflow.
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2015-10-29 Andrew MacLeod <amacleod@redhat.com>
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* alias.c: Reorder #include statements and remove duplicates.
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@ -6008,8 +6008,17 @@ extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type,
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or (for divide and modulus) if it is a multiple of our constant. */
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if (code == MULT_EXPR
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|| wi::multiple_of_p (t, c, TYPE_SIGN (type)))
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return const_binop (code, fold_convert (ctype, t),
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fold_convert (ctype, c));
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{
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tree tem = const_binop (code, fold_convert (ctype, t),
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fold_convert (ctype, c));
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/* If the multiplication overflowed to INT_MIN then we lost sign
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information on it and a subsequent multiplication might
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spuriously overflow. See PR68142. */
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if (TREE_OVERFLOW (tem)
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&& wi::eq_p (tem, wi::min_value (TYPE_PRECISION (ctype), SIGNED)))
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return NULL_TREE;
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return tem;
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}
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break;
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CASE_CONVERT: case NON_LVALUE_EXPR:
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@ -1,3 +1,8 @@
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2015-10-29 Richard Biener <rguenther@suse.de>
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PR middle-end/68142
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* c-c++-common/ubsan/pr68142.c: New testcase.
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2015-10-29 Paolo Carlini <paolo.carlini@oracle.com>
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PR c++/67845
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@ -0,0 +1,31 @@
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/* { dg-do run } */
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/* { dg-options "-fsanitize=undefined -fsanitize-undefined-trap-on-error" } */
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int __attribute__((noinline,noclone))
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h(int a)
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{
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return 2 * (a * (__INT_MAX__/2 + 1));
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}
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int __attribute__((noinline,noclone))
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i(int a)
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{
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return (2 * a) * (__INT_MAX__/2 + 1);
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}
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int __attribute__((noinline,noclone))
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j(int a, int b)
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{
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return (b * a) * (__INT_MAX__/2 + 1);
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}
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int __attribute__((noinline,noclone))
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k(int a, int b)
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{
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return (2 * a) * b;
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}
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int main()
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{
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volatile int tem = h(-1);
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tem = i(-1);
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tem = j(-1, 2);
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tem = k(-1, __INT_MAX__/2 + 1);
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return 0;
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}
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