We blow up on the following testcase because we find ourselves passing [_13 + 1, INT_MAX] as a vr1 to extract_range_from_multiplicative_op_1; that's bad because this function immediately calls vrp_int_const_binop which just doesn't work for symbolic ranges, it only wants int_csts.
This started with Richards S.'s changes in r228614 -- we're now since able to recurse into SSA names, thus get better info about ranges. That means that range_includes_zero_p in extract_range_from_binary_expr_1 for the *_DIV_EXPR cases was able to determine that the range doesn't include zero, so we went through a different code path and ended up calling extract_range_from_multiplicative_op_1 even with symbolic ranges. I couldn't come up with anything better than checking that we're dealing with nonsymbolic ranges for such a case. Bootstrapped/regtested on x86_64-linux, ok for trunk? 2015-11-23 Marek Polacek <pola...@redhat.com> PR tree-optimization/68455 * tree-vrp.c (extract_range_from_binary_expr_1): Don't call extract_range_from_multiplicative_op_1 on symbolic ranges. * gcc.dg/tree-ssa/pr68455.c: New test. diff --git gcc/testsuite/gcc.dg/tree-ssa/pr68455.c gcc/testsuite/gcc.dg/tree-ssa/pr68455.c index e69de29..6b46b30 100644 --- gcc/testsuite/gcc.dg/tree-ssa/pr68455.c +++ gcc/testsuite/gcc.dg/tree-ssa/pr68455.c @@ -0,0 +1,19 @@ +/* PR tree-optimization/68455 */ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ + +int r; +int n; + +void +fn1 (void) +{ + int i; + + for (i = 0; i < 1; ++i) + { + unsigned short int u; + if (u < n) + r = 1 / n; + } +} diff --git gcc/tree-vrp.c gcc/tree-vrp.c index 7001190..acbb70b 100644 --- gcc/tree-vrp.c +++ gcc/tree-vrp.c @@ -3015,7 +3015,7 @@ extract_range_from_binary_expr_1 (value_range *vr, return; } } - else + else if (!symbolic_range_p (&vr0) && !symbolic_range_p (&vr1)) { extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1); return; Marek