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| author | Richard Kenner <kenner@gcc.gnu.org> | 1995-10-03 19:15:52 -0400 |
|---|---|---|
| committer | Richard Kenner <kenner@gcc.gnu.org> | 1995-10-03 19:15:52 -0400 |
| commit | e24ff9733326709acd0add575db7e9962abf7554 (patch) | |
| tree | dbbf3893c7fcbb0adff6ee1dd5bc91f2f21540b9 /gcc | |
| parent | 675f0e7cb2931a7f0d08f422b1a6564fb3b28b6b (diff) | |
| download | gcc-e24ff9733326709acd0add575db7e9962abf7554.zip gcc-e24ff9733326709acd0add575db7e9962abf7554.tar.gz gcc-e24ff9733326709acd0add575db7e9962abf7554.tar.bz2 | |
(layout_type...
(layout_type, case ARRAY_TYPE): Strip MAX_EXPR from upper bound when
computing length if it just protects against negative length.
From-SVN: r10430
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/stor-layout.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c index 3156c58..8cdbf86 100644 --- a/gcc/stor-layout.c +++ b/gcc/stor-layout.c @@ -747,10 +747,28 @@ layout_type (type) if (index && TYPE_MAX_VALUE (index) && TYPE_MIN_VALUE (index) && TYPE_SIZE (element)) { - tree length - = size_binop (PLUS_EXPR, size_one_node, - size_binop (MINUS_EXPR, TYPE_MAX_VALUE (index), - TYPE_MIN_VALUE (index))); + tree ub = TYPE_MAX_VALUE (index); + tree lb = TYPE_MIN_VALUE (index); + tree length; + + /* If UB is max (lb - 1, x), remove the MAX_EXPR since the + test for negative below covers it. */ + if (TREE_CODE (ub) == MAX_EXPR + && TREE_CODE (TREE_OPERAND (ub, 0)) == MINUS_EXPR + && integer_onep (TREE_OPERAND (TREE_OPERAND (ub, 0), 1)) + && operand_equal_p (TREE_OPERAND (TREE_OPERAND (ub, 0), 0), + lb, 0)) + ub = TREE_OPERAND (ub, 1); + else if (TREE_CODE (ub) == MAX_EXPR + && TREE_CODE (TREE_OPERAND (ub, 1)) == MINUS_EXPR + && integer_onep (TREE_OPERAND (TREE_OPERAND (ub, 1), 1)) + && operand_equal_p (TREE_OPERAND (TREE_OPERAND (ub, 1), + 0), + lb, 0)) + ub = TREE_OPERAND (ub, 0); + + length = size_binop (PLUS_EXPR, size_one_node, + size_binop (MINUS_EXPR, ub, lb)); /* If neither bound is a constant and sizetype is signed, make sure the size is never negative. We should really do this |