diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr79666.c | 30 | ||||
| -rw-r--r-- | gcc/tree-vrp.c | 26 |
4 files changed, 64 insertions, 4 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 1911946..aa7a1cf 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2017-02-22 Richard Biener <rguenther@suse.de> + + PR tree-optimization/79666 + * tree-vrp.c (extract_range_from_binary_expr_1): Make sure + to not symbolically negate if that may introduce undefined + overflow. + 2017-02-22 Martin Liska <mliska@suse.cz> PR lto/79587 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 19ddc6e..af56482 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-02-22 Richard Biener <rguenther@suse.de> + + PR tree-optimization/79666 + * gcc.dg/torture/pr79666.c: New testcase. + 2017-02-22 Martin Liska <mliska@suse.cz> PR lto/79587 diff --git a/gcc/testsuite/gcc.dg/torture/pr79666.c b/gcc/testsuite/gcc.dg/torture/pr79666.c new file mode 100644 index 0000000..3d83229 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr79666.c @@ -0,0 +1,30 @@ +/* { dg-do run } */ + +struct +{ + unsigned a:6; +} b; + +int c, e, g = 7; +signed char d, f = 6, h = -10; + +void fn1 () +{ + for (; c < 9; c++) + { + if (f) + g = ~(~0 / (g ^ e)); + b.a = ~0; + d = ~((h ^ b.a) & 132 & (~(f && g) | (d && 1))); + e = ~0; + if (d < 127 || f < 1) + continue; + g = 0; + } +} + +int main () +{ + fn1 (); + return 0; +} diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 95bf1cf..6420041 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -2631,8 +2631,17 @@ extract_range_from_binary_expr_1 (value_range *vr, min = build_symbolic_expr (expr_type, sym_min_op0, neg_min_op0, min); else if (sym_min_op1) - min = build_symbolic_expr (expr_type, sym_min_op1, - neg_min_op1 ^ minus_p, min); + { + /* We may not negate if that might introduce + undefined overflow. */ + if (! minus_p + || neg_min_op1 + || TYPE_OVERFLOW_WRAPS (expr_type)) + min = build_symbolic_expr (expr_type, sym_min_op1, + neg_min_op1 ^ minus_p, min); + else + min = NULL_TREE; + } /* Likewise for the upper bound. */ if (sym_max_op0 == sym_max_op1) @@ -2641,8 +2650,17 @@ extract_range_from_binary_expr_1 (value_range *vr, max = build_symbolic_expr (expr_type, sym_max_op0, neg_max_op0, max); else if (sym_max_op1) - max = build_symbolic_expr (expr_type, sym_max_op1, - neg_max_op1 ^ minus_p, max); + { + /* We may not negate if that might introduce + undefined overflow. */ + if (! minus_p + || neg_max_op1 + || TYPE_OVERFLOW_WRAPS (expr_type)) + max = build_symbolic_expr (expr_type, sym_max_op1, + neg_max_op1 ^ minus_p, max); + else + max = NULL_TREE; + } } else { |