+2012-09-07 Tom de Vries <tom@codesourcery.com>
+
+ PR tree-optimization/53986
+ * tree-vrp.c (extract_range_from_multiplicative_op_1): Allow
+ LSHIFT_EXPR.
+ (extract_range_from_binary_expr_1): Handle LSHIFT with constant range as
+ shift amount.
+
2012-09-07 Segher Boessenkool <segher@kernel.crashing.org>
* config/rs6000/aix43.h (RS6000_CALL_GLUE): Delete.
|| code == CEIL_DIV_EXPR
|| code == EXACT_DIV_EXPR
|| code == ROUND_DIV_EXPR
- || code == RSHIFT_EXPR);
+ || code == RSHIFT_EXPR
+ || code == LSHIFT_EXPR);
gcc_assert ((vr0->type == VR_RANGE
|| (code == MULT_EXPR && vr0->type == VR_ANTI_RANGE))
&& vr0->type == vr1->type);
flag_wrapv = saved_flag_wrapv;
return;
}
+ else if (code == LSHIFT_EXPR
+ && range_int_cst_p (&vr0))
+ {
+ int overflow_pos = TYPE_PRECISION (expr_type);
+ int bound_shift;
+ double_int bound;
+
+ if (!TYPE_UNSIGNED (expr_type))
+ overflow_pos -= 1;
+
+ bound_shift = overflow_pos - TREE_INT_CST_LOW (vr1.max);
+ bound = double_int_one.llshift (bound_shift,
+ TYPE_PRECISION (expr_type));
+ if (tree_to_double_int (vr0.max).ult (bound))
+ {
+ /* In the absense of overflow, (a << b) is equivalent
+ to (a * 2^b). */
+ extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
+ return;
+ }
+ }
}
set_value_range_to_varying (vr);
return;