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| author | Nick Clifton <nickc@cygnus.com> | 2000-05-24 18:24:06 +0000 |
|---|---|---|
| committer | Nick Clifton <nickc@gcc.gnu.org> | 2000-05-24 18:24:06 +0000 |
| commit | d08230fe7def51b5ff3abfd4bde7da222989aa6c (patch) | |
| tree | 96df4fe16b6a8a7bb9b22654c0440baf2fc77f11 | |
| parent | 3c7673a5970950c685a3d962a4157cf519d931a6 (diff) | |
| download | gcc-d08230fe7def51b5ff3abfd4bde7da222989aa6c.zip gcc-d08230fe7def51b5ff3abfd4bde7da222989aa6c.tar.gz gcc-d08230fe7def51b5ff3abfd4bde7da222989aa6c.tar.bz2 | |
(extract_muldiv): When constructing a multiplier/divisor...
(extract_muldiv): When constructing a multiplier/divisor, do not expect
const_binop to correctly determine if overflow has occured, so check explicitly.
From-SVN: r34135
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/fold-const.c | 4 |
2 files changed, 10 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index b874d9f..d3f281e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2000-05-24 Nick Clifton <nickc@cygnus.com> + + * fold-const.c (extract_muldiv): When constructing a + multiplier/divisor, do not expect const_binop to correctly + determine if overflow has occured, so check explicitly. + 2000-05-24 Alexandre Oliva <aoliva@cygnus.com> * c-decl.c (build_enumerator): Don't modify the value's type, diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 12a8d1a..eec3bc4 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -4451,6 +4451,10 @@ extract_muldiv (t, c, code, wide_type) or floor division, by a power of two, so we can treat it that way unless the multiplier or divisor overflows. */ if (TREE_CODE (op1) == INTEGER_CST + /* const_binop may not detect overflow correctly, + so check for it explicitly here. */ + && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1) + && TREE_INT_CST_HIGH (op1) == 0 && 0 != (t1 = convert (ctype, const_binop (LSHIFT_EXPR, size_one_node, op1, 0))) |