* - LOG_TO_LOG2
* - MOD_TO_FLOOR
* - LDEXP_TO_ARITH
+ * - DFREXP_TO_ARITH
* - BITFIELD_INSERT_TO_BFM_BFI
* - CARRY_TO_ARITH
* - BORROW_TO_ARITH
* - SAT_TO_CLAMP
+ * - DOPS_TO_DFRAC
*
* SUB_TO_ADD_NEG:
* ---------------
*
* LDEXP_TO_ARITH:
* -------------
- * Converts ir_binop_ldexp to arithmetic and bit operations.
+ * Converts ir_binop_ldexp to arithmetic and bit operations for float sources.
+ *
+ * DFREXP_DLDEXP_TO_ARITH:
+ * ---------------
+ * Converts ir_binop_ldexp, ir_unop_frexp_sig, and ir_unop_frexp_exp to
+ * arithmetic and bit ops for double arguments.
*
* BITFIELD_INSERT_TO_BFM_BFI:
* ---------------------------
* -------------
* Converts ir_unop_saturate into min(max(x, 0.0), 1.0)
*
+ * DOPS_TO_DFRAC:
+ * --------------
+ * Converts double trunc, ceil, floor, round to fract
*/
-#include "main/core.h" /* for M_LOG2E */
+#include "c99_math.h"
+#include "program/prog_instruction.h" /* for swizzle */
#include "glsl_types.h"
#include "ir.h"
#include "ir_builder.h"
void log_to_log2(ir_expression *);
void bitfield_insert_to_bfm_bfi(ir_expression *);
void ldexp_to_arith(ir_expression *);
+ void dldexp_to_arith(ir_expression *);
+ void dfrexp_sig_to_arith(ir_expression *);
+ void dfrexp_exp_to_arith(ir_expression *);
void carry_to_arith(ir_expression *);
void borrow_to_arith(ir_expression *);
void sat_to_clamp(ir_expression *);
+ void double_dot_to_fma(ir_expression *);
+ void double_lrp(ir_expression *);
+ void dceil_to_dfrac(ir_expression *);
+ void dfloor_to_dfrac(ir_expression *);
+ void dround_even_to_dfrac(ir_expression *);
+ void dtrunc_to_dfrac(ir_expression *);
+ void dsign_to_csel(ir_expression *);
};
} /* anonymous namespace */
void
lower_instructions_visitor::div_to_mul_rcp(ir_expression *ir)
{
- assert(ir->operands[1]->type->is_float());
+ assert(ir->operands[1]->type->is_float() || ir->operands[1]->type->is_double());
/* New expression for the 1.0 / op1 */
ir_rvalue *expr;
/* Don't generate new IR that would need to be lowered in an additional
* pass.
*/
- if (lowering(DIV_TO_MUL_RCP) && ir->type->is_float())
+ if (lowering(DIV_TO_MUL_RCP) && (ir->type->is_float() || ir->type->is_double()))
div_to_mul_rcp(div_expr);
ir_expression *const floor_expr =
new(ir) ir_expression(ir_unop_floor, x->type, div_expr);
+ if (lowering(DOPS_TO_DFRAC) && ir->type->is_double())
+ dfloor_to_dfrac(floor_expr);
+
ir_expression *const mul_expr =
new(ir) ir_expression(ir_binop_mul,
new(ir) ir_dereference_variable(y),
this->progress = true;
}
+void
+lower_instructions_visitor::dldexp_to_arith(ir_expression *ir)
+{
+ /* See ldexp_to_arith for structure. Uses frexp_exp to extract the exponent
+ * from the significand.
+ */
+
+ const unsigned vec_elem = ir->type->vector_elements;
+
+ /* Types */
+ const glsl_type *ivec = glsl_type::get_instance(GLSL_TYPE_INT, vec_elem, 1);
+ const glsl_type *bvec = glsl_type::get_instance(GLSL_TYPE_BOOL, vec_elem, 1);
+
+ /* Constants */
+ ir_constant *zeroi = ir_constant::zero(ir, ivec);
+
+ ir_constant *sign_mask = new(ir) ir_constant(0x80000000u);
+
+ ir_constant *exp_shift = new(ir) ir_constant(20);
+ ir_constant *exp_width = new(ir) ir_constant(11);
+ ir_constant *exp_bias = new(ir) ir_constant(1022, vec_elem);
+
+ /* Temporary variables */
+ ir_variable *x = new(ir) ir_variable(ir->type, "x", ir_var_temporary);
+ ir_variable *exp = new(ir) ir_variable(ivec, "exp", ir_var_temporary);
+
+ ir_variable *zero_sign_x = new(ir) ir_variable(ir->type, "zero_sign_x",
+ ir_var_temporary);
+
+ ir_variable *extracted_biased_exp =
+ new(ir) ir_variable(ivec, "extracted_biased_exp", ir_var_temporary);
+ ir_variable *resulting_biased_exp =
+ new(ir) ir_variable(ivec, "resulting_biased_exp", ir_var_temporary);
+
+ ir_variable *is_not_zero_or_underflow =
+ new(ir) ir_variable(bvec, "is_not_zero_or_underflow", ir_var_temporary);
+
+ ir_instruction &i = *base_ir;
+
+ /* Copy <x> and <exp> arguments. */
+ i.insert_before(x);
+ i.insert_before(assign(x, ir->operands[0]));
+ i.insert_before(exp);
+ i.insert_before(assign(exp, ir->operands[1]));
+
+ ir_expression *frexp_exp = expr(ir_unop_frexp_exp, x);
+ if (lowering(DFREXP_DLDEXP_TO_ARITH))
+ dfrexp_exp_to_arith(frexp_exp);
+
+ /* Extract the biased exponent from <x>. */
+ i.insert_before(extracted_biased_exp);
+ i.insert_before(assign(extracted_biased_exp, add(frexp_exp, exp_bias)));
+
+ i.insert_before(resulting_biased_exp);
+ i.insert_before(assign(resulting_biased_exp,
+ add(extracted_biased_exp, exp)));
+
+ /* Test if result is ±0.0, subnormal, or underflow by checking if the
+ * resulting biased exponent would be less than 0x1. If so, the result is
+ * 0.0 with the sign of x. (Actually, invert the conditions so that
+ * immediate values are the second arguments, which is better for i965)
+ * TODO: Implement in a vector fashion.
+ */
+ i.insert_before(zero_sign_x);
+ for (unsigned elem = 0; elem < vec_elem; elem++) {
+ ir_variable *unpacked =
+ new(ir) ir_variable(glsl_type::uvec2_type, "unpacked", ir_var_temporary);
+ i.insert_before(unpacked);
+ i.insert_before(
+ assign(unpacked,
+ expr(ir_unop_unpack_double_2x32, swizzle(x, elem, 1))));
+ i.insert_before(assign(unpacked, bit_and(swizzle_y(unpacked), sign_mask->clone(ir, NULL)),
+ WRITEMASK_Y));
+ i.insert_before(assign(unpacked, ir_constant::zero(ir, glsl_type::uint_type), WRITEMASK_X));
+ i.insert_before(assign(zero_sign_x,
+ expr(ir_unop_pack_double_2x32, unpacked),
+ 1 << elem));
+ }
+ i.insert_before(is_not_zero_or_underflow);
+ i.insert_before(assign(is_not_zero_or_underflow,
+ gequal(resulting_biased_exp,
+ new(ir) ir_constant(0x1, vec_elem))));
+ i.insert_before(assign(x, csel(is_not_zero_or_underflow,
+ x, zero_sign_x)));
+ i.insert_before(assign(resulting_biased_exp,
+ csel(is_not_zero_or_underflow,
+ resulting_biased_exp, zeroi)));
+
+ /* We could test for overflows by checking if the resulting biased exponent
+ * would be greater than 0xFE. Turns out we don't need to because the GLSL
+ * spec says:
+ *
+ * "If this product is too large to be represented in the
+ * floating-point type, the result is undefined."
+ */
+
+ ir_rvalue *results[4] = {NULL};
+ for (unsigned elem = 0; elem < vec_elem; elem++) {
+ ir_variable *unpacked =
+ new(ir) ir_variable(glsl_type::uvec2_type, "unpacked", ir_var_temporary);
+ i.insert_before(unpacked);
+ i.insert_before(
+ assign(unpacked,
+ expr(ir_unop_unpack_double_2x32, swizzle(x, elem, 1))));
+
+ ir_expression *bfi = bitfield_insert(
+ swizzle_y(unpacked),
+ i2u(swizzle(resulting_biased_exp, elem, 1)),
+ exp_shift->clone(ir, NULL),
+ exp_width->clone(ir, NULL));
+
+ if (lowering(BITFIELD_INSERT_TO_BFM_BFI))
+ bitfield_insert_to_bfm_bfi(bfi);
+
+ i.insert_before(assign(unpacked, bfi, WRITEMASK_Y));
+
+ results[elem] = expr(ir_unop_pack_double_2x32, unpacked);
+ }
+
+ ir->operation = ir_quadop_vector;
+ ir->operands[0] = results[0];
+ ir->operands[1] = results[1];
+ ir->operands[2] = results[2];
+ ir->operands[3] = results[3];
+
+ /* Don't generate new IR that would need to be lowered in an additional
+ * pass.
+ */
+
+ this->progress = true;
+}
+
+void
+lower_instructions_visitor::dfrexp_sig_to_arith(ir_expression *ir)
+{
+ const unsigned vec_elem = ir->type->vector_elements;
+ const glsl_type *bvec = glsl_type::get_instance(GLSL_TYPE_BOOL, vec_elem, 1);
+
+ /* Double-precision floating-point values are stored as
+ * 1 sign bit;
+ * 11 exponent bits;
+ * 52 mantissa bits.
+ *
+ * We're just extracting the significand here, so we only need to modify
+ * the upper 32-bit uint. Unfortunately we must extract each double
+ * independently as there is no vector version of unpackDouble.
+ */
+
+ ir_instruction &i = *base_ir;
+
+ ir_variable *is_not_zero =
+ new(ir) ir_variable(bvec, "is_not_zero", ir_var_temporary);
+ ir_rvalue *results[4] = {NULL};
+
+ ir_constant *dzero = new(ir) ir_constant(0.0, vec_elem);
+ i.insert_before(is_not_zero);
+ i.insert_before(
+ assign(is_not_zero,
+ nequal(abs(ir->operands[0]->clone(ir, NULL)), dzero)));
+
+ /* TODO: Remake this as more vector-friendly when int64 support is
+ * available.
+ */
+ for (unsigned elem = 0; elem < vec_elem; elem++) {
+ ir_constant *zero = new(ir) ir_constant(0u, 1);
+ ir_constant *sign_mantissa_mask = new(ir) ir_constant(0x800fffffu, 1);
+
+ /* Exponent of double floating-point values in the range [0.5, 1.0). */
+ ir_constant *exponent_value = new(ir) ir_constant(0x3fe00000u, 1);
+
+ ir_variable *bits =
+ new(ir) ir_variable(glsl_type::uint_type, "bits", ir_var_temporary);
+ ir_variable *unpacked =
+ new(ir) ir_variable(glsl_type::uvec2_type, "unpacked", ir_var_temporary);
+
+ ir_rvalue *x = swizzle(ir->operands[0]->clone(ir, NULL), elem, 1);
+
+ i.insert_before(bits);
+ i.insert_before(unpacked);
+ i.insert_before(assign(unpacked, expr(ir_unop_unpack_double_2x32, x)));
+
+ /* Manipulate the high uint to remove the exponent and replace it with
+ * either the default exponent or zero.
+ */
+ i.insert_before(assign(bits, swizzle_y(unpacked)));
+ i.insert_before(assign(bits, bit_and(bits, sign_mantissa_mask)));
+ i.insert_before(assign(bits, bit_or(bits,
+ csel(swizzle(is_not_zero, elem, 1),
+ exponent_value,
+ zero))));
+ i.insert_before(assign(unpacked, bits, WRITEMASK_Y));
+ results[elem] = expr(ir_unop_pack_double_2x32, unpacked);
+ }
+
+ /* Put the dvec back together */
+ ir->operation = ir_quadop_vector;
+ ir->operands[0] = results[0];
+ ir->operands[1] = results[1];
+ ir->operands[2] = results[2];
+ ir->operands[3] = results[3];
+
+ this->progress = true;
+}
+
+void
+lower_instructions_visitor::dfrexp_exp_to_arith(ir_expression *ir)
+{
+ const unsigned vec_elem = ir->type->vector_elements;
+ const glsl_type *bvec = glsl_type::get_instance(GLSL_TYPE_BOOL, vec_elem, 1);
+ const glsl_type *uvec = glsl_type::get_instance(GLSL_TYPE_UINT, vec_elem, 1);
+
+ /* Double-precision floating-point values are stored as
+ * 1 sign bit;
+ * 11 exponent bits;
+ * 52 mantissa bits.
+ *
+ * We're just extracting the exponent here, so we only care about the upper
+ * 32-bit uint.
+ */
+
+ ir_instruction &i = *base_ir;
+
+ ir_variable *is_not_zero =
+ new(ir) ir_variable(bvec, "is_not_zero", ir_var_temporary);
+ ir_variable *high_words =
+ new(ir) ir_variable(uvec, "high_words", ir_var_temporary);
+ ir_constant *dzero = new(ir) ir_constant(0.0, vec_elem);
+ ir_constant *izero = new(ir) ir_constant(0, vec_elem);
+
+ ir_rvalue *absval = abs(ir->operands[0]);
+
+ i.insert_before(is_not_zero);
+ i.insert_before(high_words);
+ i.insert_before(assign(is_not_zero, nequal(absval->clone(ir, NULL), dzero)));
+
+ /* Extract all of the upper uints. */
+ for (unsigned elem = 0; elem < vec_elem; elem++) {
+ ir_rvalue *x = swizzle(absval->clone(ir, NULL), elem, 1);
+
+ i.insert_before(assign(high_words,
+ swizzle_y(expr(ir_unop_unpack_double_2x32, x)),
+ 1 << elem));
+
+ }
+ ir_constant *exponent_shift = new(ir) ir_constant(20, vec_elem);
+ ir_constant *exponent_bias = new(ir) ir_constant(-1022, vec_elem);
+
+ /* For non-zero inputs, shift the exponent down and apply bias. */
+ ir->operation = ir_triop_csel;
+ ir->operands[0] = new(ir) ir_dereference_variable(is_not_zero);
+ ir->operands[1] = add(exponent_bias, u2i(rshift(high_words, exponent_shift)));
+ ir->operands[2] = izero;
+
+ this->progress = true;
+}
+
void
lower_instructions_visitor::carry_to_arith(ir_expression *ir)
{
this->progress = true;
}
+void
+lower_instructions_visitor::double_dot_to_fma(ir_expression *ir)
+{
+ ir_variable *temp = new(ir) ir_variable(ir->operands[0]->type->get_base_type(), "dot_res",
+ ir_var_temporary);
+ this->base_ir->insert_before(temp);
+
+ int nc = ir->operands[0]->type->components();
+ for (int i = nc - 1; i >= 1; i--) {
+ ir_assignment *assig;
+ if (i == (nc - 1)) {
+ assig = assign(temp, mul(swizzle(ir->operands[0]->clone(ir, NULL), i, 1),
+ swizzle(ir->operands[1]->clone(ir, NULL), i, 1)));
+ } else {
+ assig = assign(temp, fma(swizzle(ir->operands[0]->clone(ir, NULL), i, 1),
+ swizzle(ir->operands[1]->clone(ir, NULL), i, 1),
+ temp));
+ }
+ this->base_ir->insert_before(assig);
+ }
+
+ ir->operation = ir_triop_fma;
+ ir->operands[0] = swizzle(ir->operands[0], 0, 1);
+ ir->operands[1] = swizzle(ir->operands[1], 0, 1);
+ ir->operands[2] = new(ir) ir_dereference_variable(temp);
+
+ this->progress = true;
+
+}
+
+void
+lower_instructions_visitor::double_lrp(ir_expression *ir)
+{
+ int swizval;
+ ir_rvalue *op0 = ir->operands[0], *op2 = ir->operands[2];
+ ir_constant *one = new(ir) ir_constant(1.0, op2->type->vector_elements);
+
+ switch (op2->type->vector_elements) {
+ case 1:
+ swizval = SWIZZLE_XXXX;
+ break;
+ default:
+ assert(op0->type->vector_elements == op2->type->vector_elements);
+ swizval = SWIZZLE_XYZW;
+ break;
+ }
+
+ ir->operation = ir_triop_fma;
+ ir->operands[0] = swizzle(op2, swizval, op0->type->vector_elements);
+ ir->operands[2] = mul(sub(one, op2->clone(ir, NULL)), op0);
+
+ this->progress = true;
+}
+
+void
+lower_instructions_visitor::dceil_to_dfrac(ir_expression *ir)
+{
+ /*
+ * frtemp = frac(x);
+ * temp = sub(x, frtemp);
+ * result = temp + ((frtemp != 0.0) ? 1.0 : 0.0);
+ */
+ ir_instruction &i = *base_ir;
+ ir_constant *zero = new(ir) ir_constant(0.0, ir->operands[0]->type->vector_elements);
+ ir_constant *one = new(ir) ir_constant(1.0, ir->operands[0]->type->vector_elements);
+ ir_variable *frtemp = new(ir) ir_variable(ir->operands[0]->type, "frtemp",
+ ir_var_temporary);
+
+ i.insert_before(frtemp);
+ i.insert_before(assign(frtemp, fract(ir->operands[0])));
+
+ ir->operation = ir_binop_add;
+ ir->operands[0] = sub(ir->operands[0]->clone(ir, NULL), frtemp);
+ ir->operands[1] = csel(nequal(frtemp, zero), one, zero->clone(ir, NULL));
+
+ this->progress = true;
+}
+
+void
+lower_instructions_visitor::dfloor_to_dfrac(ir_expression *ir)
+{
+ /*
+ * frtemp = frac(x);
+ * result = sub(x, frtemp);
+ */
+ ir->operation = ir_binop_sub;
+ ir->operands[1] = fract(ir->operands[0]->clone(ir, NULL));
+
+ this->progress = true;
+}
+void
+lower_instructions_visitor::dround_even_to_dfrac(ir_expression *ir)
+{
+ /*
+ * insane but works
+ * temp = x + 0.5;
+ * frtemp = frac(temp);
+ * t2 = sub(temp, frtemp);
+ * if (frac(x) == 0.5)
+ * result = frac(t2 * 0.5) == 0 ? t2 : t2 - 1;
+ * else
+ * result = t2;
+
+ */
+ ir_instruction &i = *base_ir;
+ ir_variable *frtemp = new(ir) ir_variable(ir->operands[0]->type, "frtemp",
+ ir_var_temporary);
+ ir_variable *temp = new(ir) ir_variable(ir->operands[0]->type, "temp",
+ ir_var_temporary);
+ ir_variable *t2 = new(ir) ir_variable(ir->operands[0]->type, "t2",
+ ir_var_temporary);
+ ir_constant *p5 = new(ir) ir_constant(0.5, ir->operands[0]->type->vector_elements);
+ ir_constant *one = new(ir) ir_constant(1.0, ir->operands[0]->type->vector_elements);
+ ir_constant *zero = new(ir) ir_constant(0.0, ir->operands[0]->type->vector_elements);
+
+ i.insert_before(temp);
+ i.insert_before(assign(temp, add(ir->operands[0], p5)));
+
+ i.insert_before(frtemp);
+ i.insert_before(assign(frtemp, fract(temp)));
+
+ i.insert_before(t2);
+ i.insert_before(assign(t2, sub(temp, frtemp)));
+
+ ir->operation = ir_triop_csel;
+ ir->operands[0] = equal(fract(ir->operands[0]->clone(ir, NULL)),
+ p5->clone(ir, NULL));
+ ir->operands[1] = csel(equal(fract(mul(t2, p5->clone(ir, NULL))),
+ zero),
+ t2,
+ sub(t2, one));
+ ir->operands[2] = new(ir) ir_dereference_variable(t2);
+
+ this->progress = true;
+}
+
+void
+lower_instructions_visitor::dtrunc_to_dfrac(ir_expression *ir)
+{
+ /*
+ * frtemp = frac(x);
+ * temp = sub(x, frtemp);
+ * result = x >= 0 ? temp : temp + (frtemp == 0.0) ? 0 : 1;
+ */
+ ir_rvalue *arg = ir->operands[0];
+ ir_instruction &i = *base_ir;
+
+ ir_constant *zero = new(ir) ir_constant(0.0, arg->type->vector_elements);
+ ir_constant *one = new(ir) ir_constant(1.0, arg->type->vector_elements);
+ ir_variable *frtemp = new(ir) ir_variable(arg->type, "frtemp",
+ ir_var_temporary);
+ ir_variable *temp = new(ir) ir_variable(ir->operands[0]->type, "temp",
+ ir_var_temporary);
+
+ i.insert_before(frtemp);
+ i.insert_before(assign(frtemp, fract(arg)));
+ i.insert_before(temp);
+ i.insert_before(assign(temp, sub(arg->clone(ir, NULL), frtemp)));
+
+ ir->operation = ir_triop_csel;
+ ir->operands[0] = gequal(arg->clone(ir, NULL), zero);
+ ir->operands[1] = new (ir) ir_dereference_variable(temp);
+ ir->operands[2] = add(temp,
+ csel(equal(frtemp, zero->clone(ir, NULL)),
+ zero->clone(ir, NULL),
+ one));
+
+ this->progress = true;
+}
+
+void
+lower_instructions_visitor::dsign_to_csel(ir_expression *ir)
+{
+ /*
+ * temp = x > 0.0 ? 1.0 : 0.0;
+ * result = x < 0.0 ? -1.0 : temp;
+ */
+ ir_rvalue *arg = ir->operands[0];
+ ir_constant *zero = new(ir) ir_constant(0.0, arg->type->vector_elements);
+ ir_constant *one = new(ir) ir_constant(1.0, arg->type->vector_elements);
+ ir_constant *neg_one = new(ir) ir_constant(-1.0, arg->type->vector_elements);
+
+ ir->operation = ir_triop_csel;
+ ir->operands[0] = less(arg->clone(ir, NULL),
+ zero->clone(ir, NULL));
+ ir->operands[1] = neg_one;
+ ir->operands[2] = csel(greater(arg, zero),
+ one,
+ zero->clone(ir, NULL));
+
+ this->progress = true;
+}
+
ir_visitor_status
lower_instructions_visitor::visit_leave(ir_expression *ir)
{
switch (ir->operation) {
+ case ir_binop_dot:
+ if (ir->operands[0]->type->is_double())
+ double_dot_to_fma(ir);
+ break;
+ case ir_triop_lrp:
+ if (ir->operands[0]->type->is_double())
+ double_lrp(ir);
+ break;
case ir_binop_sub:
if (lowering(SUB_TO_ADD_NEG))
sub_to_add_neg(ir);
case ir_binop_div:
if (ir->operands[1]->type->is_integer() && lowering(INT_DIV_TO_MUL_RCP))
int_div_to_mul_rcp(ir);
- else if (ir->operands[1]->type->is_float() && lowering(DIV_TO_MUL_RCP))
+ else if ((ir->operands[1]->type->is_float() ||
+ ir->operands[1]->type->is_double()) && lowering(DIV_TO_MUL_RCP))
div_to_mul_rcp(ir);
break;
case ir_binop_ldexp:
if (lowering(LDEXP_TO_ARITH) && ir->type->is_float())
ldexp_to_arith(ir);
+ if (lowering(DFREXP_DLDEXP_TO_ARITH) && ir->type->is_double())
+ dldexp_to_arith(ir);
+ break;
+
+ case ir_unop_frexp_exp:
+ if (lowering(DFREXP_DLDEXP_TO_ARITH) && ir->operands[0]->type->is_double())
+ dfrexp_exp_to_arith(ir);
+ break;
+
+ case ir_unop_frexp_sig:
+ if (lowering(DFREXP_DLDEXP_TO_ARITH) && ir->operands[0]->type->is_double())
+ dfrexp_sig_to_arith(ir);
break;
case ir_binop_carry:
sat_to_clamp(ir);
break;
+ case ir_unop_trunc:
+ if (lowering(DOPS_TO_DFRAC) && ir->type->is_double())
+ dtrunc_to_dfrac(ir);
+ break;
+
+ case ir_unop_ceil:
+ if (lowering(DOPS_TO_DFRAC) && ir->type->is_double())
+ dceil_to_dfrac(ir);
+ break;
+
+ case ir_unop_floor:
+ if (lowering(DOPS_TO_DFRAC) && ir->type->is_double())
+ dfloor_to_dfrac(ir);
+ break;
+
+ case ir_unop_round_even:
+ if (lowering(DOPS_TO_DFRAC) && ir->type->is_double())
+ dround_even_to_dfrac(ir);
+ break;
+
+ case ir_unop_sign:
+ if (lowering(DOPS_TO_DFRAC) && ir->type->is_double())
+ dsign_to_csel(ir);
+ break;
default:
return visit_continue;
}