diff options
Diffstat (limited to 'gcc/tree-scalar-evolution.c')
| -rw-r--r-- | gcc/tree-scalar-evolution.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c index 88a0eaa..d6f2a2f 100644 --- a/gcc/tree-scalar-evolution.c +++ b/gcc/tree-scalar-evolution.c @@ -1937,6 +1937,36 @@ interpret_rhs_expr (struct loop *loop, gimple *at_stmt, res = chrec_convert (type, chrec1, at_stmt); break; + case BIT_AND_EXPR: + /* Given int variable A, handle A&0xffff as (int)(unsigned short)A. + If A is SCEV and its value is in the range of representable set + of type unsigned short, the result expression is a (no-overflow) + SCEV. */ + res = chrec_dont_know; + if (tree_fits_uhwi_p (rhs2)) + { + int precision; + unsigned HOST_WIDE_INT val = tree_to_uhwi (rhs2); + + val ++; + /* Skip if value of rhs2 wraps in unsigned HOST_WIDE_INT or + it's not the maximum value of a smaller type than rhs1. */ + if (val != 0 + && (precision = exact_log2 (val)) > 0 + && (unsigned) precision < TYPE_PRECISION (TREE_TYPE (rhs1))) + { + tree utype = build_nonstandard_integer_type (precision, 1); + + if (TYPE_PRECISION (utype) < TYPE_PRECISION (TREE_TYPE (rhs1))) + { + chrec1 = analyze_scalar_evolution (loop, rhs1); + chrec1 = chrec_convert (utype, chrec1, at_stmt); + res = chrec_convert (TREE_TYPE (rhs1), chrec1, at_stmt); + } + } + } + break; + default: res = chrec_dont_know; break; |