diff options
Diffstat (limited to 'gcc/expr.c')
| -rw-r--r-- | gcc/expr.c | 23 |
1 files changed, 12 insertions, 11 deletions
@@ -5827,20 +5827,21 @@ highest_pow2_factor (exp) switch (TREE_CODE (exp)) { case INTEGER_CST: - /* If the integer is expressable in a HOST_WIDE_INT, we can find the - lowest bit that's a one. If the result is zero, return - BIGGEST_ALIGNMENT. We need to handle this case since we can find it - in a COND_EXPR, a MIN_EXPR, or a MAX_EXPR. If the constant overlows, - we have an erroneous program, so return BIGGEST_ALIGNMENT to avoid any + /* We can find the lowest bit that's a one. If the low + HOST_BITS_PER_WIDE_INT bits are zero, return BIGGEST_ALIGNMENT. + We need to handle this case since we can find it in a COND_EXPR, + a MIN_EXPR, or a MAX_EXPR. If the constant overlows, we have an + erroneous program, so return BIGGEST_ALIGNMENT to avoid any later ICE. */ - if (TREE_CONSTANT_OVERFLOW (exp) - || integer_zerop (exp)) + if (TREE_CONSTANT_OVERFLOW (exp)) return BIGGEST_ALIGNMENT; - else if (host_integerp (exp, 0)) + else { - c0 = tree_low_cst (exp, 0); - c0 = c0 < 0 ? - c0 : c0; - return c0 & -c0; + /* Note: tree_low_cst is intentionally not used here, + we don't care about the upper bits. */ + c0 = TREE_INT_CST_LOW (exp); + c0 &= -c0; + return c0 ? c0 : BIGGEST_ALIGNMENT; } break; |