diff options
| author | Jeff Law <law@gcc.gnu.org> | 1996-10-31 20:10:33 -0700 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 1996-10-31 20:10:33 -0700 |
| commit | 3c00684e55149e43d4daa3a702668803fa6c8e15 (patch) | |
| tree | 45414137ed5da40d6019a632d509c46603f585c8 /gcc/fold-const.c | |
| parent | 273dbe6785ece0d5b76a98bbf2432c8316bbb4fd (diff) | |
| download | gcc-3c00684e55149e43d4daa3a702668803fa6c8e15.zip gcc-3c00684e55149e43d4daa3a702668803fa6c8e15.tar.gz gcc-3c00684e55149e43d4daa3a702668803fa6c8e15.tar.bz2 | |
fold-const.c (make_range, [...]): Correct normalization of an unsigned range that wraps around zero.
* fold-const.c (make_range, case PLUS_EXPR): Correct
normalization of an unsigned range that wraps around zero.
From-SVN: r13089
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 9e75466..e662403 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -2814,10 +2814,16 @@ make_range (exp, pin_p, plow, phigh) || (n_high != 0 && TREE_OVERFLOW (n_high))) break; - /* Check for a range which has wrapped around the maximum value - thus making n_high < n_low. Normalize any such range it. */ + /* Check for an unsigned range which has wrapped around the maximum + value thus making n_high < n_low, and normalize it. */ if (n_low && n_high && tree_int_cst_lt (n_high, n_low)) - low = n_high, high = n_low, in_p = ! in_p; + { + low = range_binop (PLUS_EXPR, type, n_high, 0, + convert (type, integer_one_node), 0); + high = range_binop (MINUS_EXPR, type, n_low, 0, + convert (type, integer_one_node), 0); + in_p = ! in_p; + } else low = n_low, high = n_high; |