#define MAX_BITS_PER_WORD BITS_PER_WORD
#endif
-/* Cost of various pieces of RTL. */
+/* Cost of various pieces of RTL. Note that some of these are indexed by shift count,
+ and some by mode. */
static int add_cost, negate_cost, zero_cost;
static int shift_cost[MAX_BITS_PER_WORD];
static int shiftadd_cost[MAX_BITS_PER_WORD];
static int shiftsub_cost[MAX_BITS_PER_WORD];
+static int mul_cost[NUM_MACHINE_MODES];
+static int div_cost[NUM_MACHINE_MODES];
+static int mul_widen_cost[NUM_MACHINE_MODES];
+static int mul_highpart_cost[NUM_MACHINE_MODES];
void
init_expmed ()
rtx shift_insn, shiftadd_insn, shiftsub_insn;
int dummy;
int m;
+ enum machine_mode mode, wider_mode;
start_sequence ();
= (rtx_cost (gen_rtx (MOD, word_mode, reg, GEN_INT (32)), SET)
<= 2 * add_cost);
+ for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
+ mode != VOIDmode;
+ mode = GET_MODE_WIDER_MODE (mode))
+ {
+ reg = gen_rtx (REG, mode, 10000);
+ div_cost[(int) mode] = rtx_cost (gen_rtx (UDIV, mode, reg, reg), SET);
+ mul_cost[(int) mode] = rtx_cost (gen_rtx (MULT, mode, reg, reg), SET);
+ wider_mode = GET_MODE_WIDER_MODE (mode);
+ if (wider_mode != VOIDmode)
+ {
+ mul_widen_cost[(int) wider_mode]
+ = rtx_cost (gen_rtx (MULT, wider_mode,
+ gen_rtx (ZERO_EXTEND, wider_mode, reg),
+ gen_rtx (ZERO_EXTEND, wider_mode, reg)),
+ SET);
+ mul_highpart_cost[(int) mode]
+ = rtx_cost (gen_rtx (TRUNCATE, mode,
+ gen_rtx (LSHIFTRT, wider_mode,
+ gen_rtx (MULT, wider_mode,
+ gen_rtx (ZERO_EXTEND, wider_mode, reg),
+ gen_rtx (ZERO_EXTEND, wider_mode, reg)),
+ GEN_INT (GET_MODE_BITSIZE (mode)))),
+ SET);
+ }
+ }
+
/* Free the objects we just allocated. */
end_sequence ();
obfree (free_point);
MODE is the mode of operation and result.
- UNSIGNEDP nonzero means unsigned multiply. */
+ UNSIGNEDP nonzero means unsigned multiply.
+
+ MAX_COST is the total allowed cost for the expanded RTL. */
rtx
-expand_mult_highpart (mode, op0, cnst1, target, unsignedp)
+expand_mult_highpart (mode, op0, cnst1, target, unsignedp, max_cost)
enum machine_mode mode;
register rtx op0, target;
unsigned HOST_WIDE_INT cnst1;
int unsignedp;
+ int max_cost;
{
enum machine_mode wider_mode = GET_MODE_WIDER_MODE (mode);
optab mul_highpart_optab;
/* expand_mult handles constant multiplication of word_mode
or narrower. It does a poor job for large modes. */
- if (size < BITS_PER_WORD)
+ if (size < BITS_PER_WORD
+ && mul_cost[(int) wider_mode] + shift_cost[size-1] < max_cost)
{
/* We have to do this, since expand_binop doesn't do conversion for
multiply. Maybe change expand_binop to handle widening multiply? */
/* Firstly, try using a multiplication insn that only generates the needed
high part of the product, and in the sign flavor of unsignedp. */
- mul_highpart_optab = unsignedp ? umul_highpart_optab : smul_highpart_optab;
- target = expand_binop (mode, mul_highpart_optab,
- op0, op1, target, unsignedp, OPTAB_DIRECT);
- if (target)
- return target;
+ if (mul_highpart_cost[(int) mode] < max_cost)
+ {
+ mul_highpart_optab = unsignedp ? umul_highpart_optab : smul_highpart_optab;
+ target = expand_binop (mode, mul_highpart_optab,
+ op0, op1, target, unsignedp, OPTAB_DIRECT);
+ if (target)
+ return target;
+ }
/* Secondly, same as above, but use sign flavor opposite of unsignedp.
Need to adjust the result after the multiplication. */
- mul_highpart_optab = unsignedp ? smul_highpart_optab : umul_highpart_optab;
- target = expand_binop (mode, mul_highpart_optab,
- op0, op1, target, unsignedp, OPTAB_DIRECT);
- if (target)
- /* We used the wrong signedness. Adjust the result. */
- return expand_mult_highpart_adjust (mode, target, op0,
- op1, target, unsignedp);
-
- /* Thirdly, we try to use a widening multiplication, or a wider mode
- multiplication. */
+ if (mul_highpart_cost[(int) mode] + 2 * shift_cost[size-1] + 4 * add_cost < max_cost)
+ {
+ mul_highpart_optab = unsignedp ? smul_highpart_optab : umul_highpart_optab;
+ target = expand_binop (mode, mul_highpart_optab,
+ op0, op1, target, unsignedp, OPTAB_DIRECT);
+ if (target)
+ /* We used the wrong signedness. Adjust the result. */
+ return expand_mult_highpart_adjust (mode, target, op0,
+ op1, target, unsignedp);
+ }
+ /* Try widening multiplication. */
moptab = unsignedp ? umul_widen_optab : smul_widen_optab;
- if (moptab->handlers[(int) wider_mode].insn_code != CODE_FOR_nothing)
- ;
- else if (smul_optab->handlers[(int) wider_mode].insn_code != CODE_FOR_nothing)
- moptab = smul_optab;
- else
+ if (moptab->handlers[(int) wider_mode].insn_code != CODE_FOR_nothing
+ && mul_widen_cost[(int) wider_mode] < max_cost)
+ goto try;
+
+ /* Try widening the mode and perform a non-widening multiplication. */
+ moptab = smul_optab;
+ if (smul_optab->handlers[(int) wider_mode].insn_code != CODE_FOR_nothing
+ && mul_cost[(int) wider_mode] + shift_cost[size-1] < max_cost)
+ goto try;
+
+ /* Try widening multiplication of opposite signedness, and adjust. */
+ moptab = unsignedp ? smul_widen_optab : umul_widen_optab;
+ if (moptab->handlers[(int) wider_mode].insn_code != CODE_FOR_nothing
+ && (mul_widen_cost[(int) wider_mode]
+ + 2 * shift_cost[size-1] + 4 * add_cost < max_cost))
{
- /* Try widening multiplication of opposite signedness, and adjust. */
- moptab = unsignedp ? smul_widen_optab : umul_widen_optab;
- if (moptab->handlers[(int) wider_mode].insn_code != CODE_FOR_nothing)
+ tem = expand_binop (wider_mode, moptab, op0, wide_op1,
+ NULL_RTX, ! unsignedp, OPTAB_WIDEN);
+ if (tem != 0)
{
- tem = expand_binop (wider_mode, moptab, op0, wide_op1,
- NULL_RTX, ! unsignedp, OPTAB_WIDEN);
- if (tem != 0)
- {
- /* Extract the high half of the just generated product. */
- tem = expand_shift (RSHIFT_EXPR, wider_mode, tem,
- build_int_2 (size, 0), NULL_RTX, 1);
- tem = convert_modes (mode, wider_mode, tem, unsignedp);
- /* We used the wrong signedness. Adjust the result. */
- return expand_mult_highpart_adjust (mode, tem, op0, op1,
- target, unsignedp);
- }
+ /* Extract the high half of the just generated product. */
+ tem = expand_shift (RSHIFT_EXPR, wider_mode, tem,
+ build_int_2 (size, 0), NULL_RTX, 1);
+ tem = convert_modes (mode, wider_mode, tem, unsignedp);
+ /* We used the wrong signedness. Adjust the result. */
+ return expand_mult_highpart_adjust (mode, tem, op0, op1,
+ target, unsignedp);
}
-
- /* As a last resort, try widening the mode and perform a
- non-widening multiplication. */
- moptab = smul_optab;
}
+ return 0;
+
+ try:
/* Pass NULL_RTX as target since TARGET has wrong mode. */
tem = expand_binop (wider_mode, moptab, op0, wide_op1,
NULL_RTX, unsignedp, OPTAB_WIDEN);
rtx insn, set;
optab optab1, optab2;
int op1_is_constant, op1_is_pow2;
+ int max_cost, extra_cost;
op1_is_constant = GET_CODE (op1) == CONST_INT;
op1_is_pow2 = (op1_is_constant
size = GET_MODE_BITSIZE (compute_mode);
#if 0
/* It should be possible to restrict the precision to GET_MODE_BITSIZE
- (mode), and thereby get better code when OP1 is a constant. Do that for
- GCC 2.7. It will require going over all usages of SIZE below. */
+ (mode), and thereby get better code when OP1 is a constant. Do that
+ later. It will require going over all usages of SIZE below. */
size = GET_MODE_BITSIZE (mode);
#endif
+ max_cost = div_cost[(int) compute_mode]
+ - (rem_flag ? mul_cost[(int) compute_mode] + add_cost : 0);
+
/* Now convert to the best mode to use. */
if (compute_mode != mode)
{
{
rtx t1, t2, t3, t4;
+ extra_cost = (shift_cost[post_shift - 1]
+ + shift_cost[1] + 2 * add_cost);
t1 = expand_mult_highpart (compute_mode, op0, ml,
- NULL_RTX, 1);
+ NULL_RTX, 1,
+ max_cost - extra_cost);
if (t1 == 0)
goto fail1;
t2 = force_operand (gen_rtx (MINUS, compute_mode,
t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0,
build_int_2 (pre_shift, 0),
NULL_RTX, 1);
+ extra_cost = (shift_cost[pre_shift]
+ + shift_cost[post_shift]);
t2 = expand_mult_highpart (compute_mode, t1, ml,
- NULL_RTX, 1);
+ NULL_RTX, 1,
+ max_cost - extra_cost);
if (t2 == 0)
goto fail1;
quotient = expand_shift (RSHIFT_EXPR, compute_mode, t2,
{
rtx t1, t2, t3;
+ extra_cost = (shift_cost[post_shift]
+ + shift_cost[size - 1] + add_cost);
t1 = expand_mult_highpart (compute_mode, op0, ml,
- NULL_RTX, 0);
+ NULL_RTX, 0,
+ max_cost - extra_cost);
if (t1 == 0)
goto fail1;
t2 = expand_shift (RSHIFT_EXPR, compute_mode, t1,
rtx t1, t2, t3, t4;
ml |= (~(unsigned HOST_WIDE_INT) 0) << (size - 1);
+ extra_cost = (shift_cost[post_shift]
+ + shift_cost[size - 1] + 2 * add_cost);
t1 = expand_mult_highpart (compute_mode, op0, ml,
- NULL_RTX, 0);
+ NULL_RTX, 0,
+ max_cost - extra_cost);
if (t1 == 0)
goto fail1;
t2 = force_operand (gen_rtx (PLUS, compute_mode, t1, op0),
build_int_2 (size - 1, 0), NULL_RTX, 0);
t2 = expand_binop (compute_mode, xor_optab, op0, t1,
NULL_RTX, 0, OPTAB_WIDEN);
+ extra_cost = (shift_cost[post_shift]
+ + shift_cost[size - 1] + 2 * add_cost);
t3 = expand_mult_highpart (compute_mode, t2, ml,
- NULL_RTX, 1);
+ NULL_RTX, 1,
+ max_cost - extra_cost);
if (t3 != 0)
{
t4 = expand_shift (RSHIFT_EXPR, compute_mode, t3,
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