diff options
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 32aa0eca3e2..ae6931e3d62 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -1346,7 +1346,7 @@ size_htab_hash (x) tree t = (tree) x; return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t) - ^ (hashval_t) ((long) TREE_TYPE (t) >> 3) + ^ htab_hash_pointer (TREE_TYPE (t)) ^ (TREE_OVERFLOW (t) << 20)); } @@ -5771,12 +5771,25 @@ fold (expr) goto binary; - case LSHIFT_EXPR: - case RSHIFT_EXPR: case LROTATE_EXPR: case RROTATE_EXPR: + if (integer_all_onesp (arg0)) + return omit_one_operand (type, arg0, arg1); + goto shift; + + case RSHIFT_EXPR: + /* Optimize -1 >> x for arithmetic right shifts. */ + if (integer_all_onesp (arg0) && ! TREE_UNSIGNED (type)) + return omit_one_operand (type, arg0, arg1); + /* ... fall through ... */ + + case LSHIFT_EXPR: + shift: if (integer_zerop (arg1)) return non_lvalue (convert (type, arg0)); + if (integer_zerop (arg0)) + return omit_one_operand (type, arg0, arg1); + /* Since negative shift count is not well-defined, don't try to compute it in the compiler. */ if (TREE_CODE (arg1) == INTEGER_CST && tree_int_cst_sgn (arg1) < 0) |