diff options
Diffstat (limited to 'gcc/tree-vrp.c')
| -rw-r--r-- | gcc/tree-vrp.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index d487df6..1734d44 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -409,6 +409,22 @@ vrp_expr_computes_nonzero (tree expr) return false; } +/* Returns true if EXPR is a valid value (as expected by compare_values) -- + a gimple invariant, or SSA_NAME +- CST. */ + +static bool +valid_value_p (tree expr) +{ + if (TREE_CODE (expr) == SSA_NAME) + return true; + + if (TREE_CODE (expr) == PLUS_EXPR + || TREE_CODE (expr) == MINUS_EXPR) + return (TREE_CODE (TREE_OPERAND (expr, 0)) == SSA_NAME + && TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST); + + return is_gimple_min_invariant (expr); +} /* Compare two values VAL1 and VAL2. Return @@ -1974,9 +1990,12 @@ adjust_range_with_scev (value_range_t *vr, struct loop *loop, tree stmt, step = evolution_part_in_loop_num (chrec, loop->num); /* If STEP is symbolic, we can't know whether INIT will be the - minimum or maximum value in the range. */ + minimum or maximum value in the range. Also, unless INIT is + a simple expression, compare_values and possibly other functions + in tree-vrp won't be able to handle it. */ if (step == NULL_TREE - || !is_gimple_min_invariant (step)) + || !is_gimple_min_invariant (step) + || !valid_value_p (init)) return; /* Do not adjust ranges when chrec may wrap. */ |