diff options
-rw-r--r-- | gcc-4.9/gcc/tree-ssa-loop-niter.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/gcc-4.9/gcc/tree-ssa-loop-niter.c b/gcc-4.9/gcc/tree-ssa-loop-niter.c index cb9214f..db069e0 100644 --- a/gcc-4.9/gcc/tree-ssa-loop-niter.c +++ b/gcc-4.9/gcc/tree-ssa-loop-niter.c @@ -3950,7 +3950,21 @@ loop_exits_before_overflow (tree base, tree step, if (!CONVERT_EXPR_P (e) || !operand_equal_p (e, unsigned_base, 0)) continue; e = TREE_OPERAND (e, 0); - gcc_assert (operand_equal_p (e, base, 0)); + /* It may still be possible to prove no overflow even if condition + "operand_equal_p (e, base, 0)" isn't satisfied here, like below + example: + + e : ssa_var ; unsigned long type + base : (int) ssa_var + unsigned_base : (unsigned int) ssa_var + + Unfortunately this is a rare case observed during GCC profiled + bootstrap. See PR66638 for more information. + + For now, we just skip the possibility. */ + if (!operand_equal_p (e, base, 0)) + continue; + if (tree_int_cst_sign_bit (step)) { code = LT_EXPR; |