gcc_assert (op0);
return op0;
}
+
+/* Perform a widening multiplication and return an rtx for the result.
+ MODE is mode of value; OP0 and OP1 are what to multiply (rtx's);
+ TARGET is a suggestion for where to store the result (an rtx).
+ THIS_OPTAB is the optab we should use, it must be either umul_widen_optab
+ or smul_widen_optab.
+
+ We check specially for a constant integer as OP1, comparing the
+ cost of a widening multiply against the cost of a sequence of shifts
+ and adds. */
+
+rtx
+expand_widening_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target,
+ int unsignedp, optab this_optab)
+{
+ bool speed = optimize_insn_for_speed_p ();
+
+ if (CONST_INT_P (op1)
+ && (INTVAL (op1) >= 0
+ || GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT))
+ {
+ HOST_WIDE_INT coeff = INTVAL (op1);
+ int max_cost;
+ enum mult_variant variant;
+ struct algorithm algorithm;
+
+ /* Special case powers of two. */
+ if (EXACT_POWER_OF_2_OR_ZERO_P (coeff))
+ {
+ op0 = convert_to_mode (mode, op0, this_optab == umul_widen_optab);
+ return expand_shift (LSHIFT_EXPR, mode, op0,
+ build_int_cst (NULL_TREE, floor_log2 (coeff)),
+ target, unsignedp);
+ }
+
+ /* Exclude cost of op0 from max_cost to match the cost
+ calculation of the synth_mult. */
+ max_cost = mul_widen_cost[speed][mode];
+ if (choose_mult_variant (mode, coeff, &algorithm, &variant,
+ max_cost))
+ {
+ op0 = convert_to_mode (mode, op0, this_optab == umul_widen_optab);
+ return expand_mult_const (mode, op0, coeff, target,
+ &algorithm, variant);
+ }
+ }
+ return expand_binop (mode, this_optab, op0, op1, target,
+ unsignedp, OPTAB_LIB_WIDEN);
+}
\f
/* Return the smallest n such that 2**n >= X. */