vkd3d/libs/vkd3d-shader/hlsl_constant_ops.c
2023-06-27 22:34:33 +02:00

819 lines
25 KiB
C

/*
* HLSL constant value operations for constant folding
*
* Copyright 2022 Francisco Casas for CodeWeavers
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <math.h>
#include "hlsl.h"
static bool fold_abs(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst,
const struct hlsl_type *dst_type, const struct hlsl_ir_constant *src)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src->node.data_type->base_type);
for (k = 0; k < dst_type->dimx; ++k)
{
switch (type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].f = fabsf(src->value.u[k].f);
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].d = fabs(src->value.u[k].d);
break;
case HLSL_TYPE_INT:
/* C's abs(INT_MIN) is undefined, but HLSL evaluates this to INT_MIN */
if (src->value.u[k].i == INT_MIN)
dst->u[k].i = INT_MIN;
else
dst->u[k].i = abs(src->value.u[k].i);
break;
case HLSL_TYPE_UINT:
dst->u[k].u = src->value.u[k].u;
break;
default:
FIXME("Fold abs() for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_cast(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst,
const struct hlsl_type *dst_type, const struct hlsl_ir_constant *src)
{
unsigned int k;
uint32_t u;
int32_t i;
double d;
float f;
if (dst_type->dimx != src->node.data_type->dimx
|| dst_type->dimy != src->node.data_type->dimy)
{
FIXME("Cast from %s to %s.\n", debug_hlsl_type(ctx, src->node.data_type),
debug_hlsl_type(ctx, dst_type));
return false;
}
for (k = 0; k < 4; ++k)
{
switch (src->node.data_type->base_type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
u = src->value.u[k].f;
i = src->value.u[k].f;
f = src->value.u[k].f;
d = src->value.u[k].f;
break;
case HLSL_TYPE_DOUBLE:
u = src->value.u[k].d;
i = src->value.u[k].d;
f = src->value.u[k].d;
d = src->value.u[k].d;
break;
case HLSL_TYPE_INT:
u = src->value.u[k].i;
i = src->value.u[k].i;
f = src->value.u[k].i;
d = src->value.u[k].i;
break;
case HLSL_TYPE_UINT:
u = src->value.u[k].u;
i = src->value.u[k].u;
f = src->value.u[k].u;
d = src->value.u[k].u;
break;
case HLSL_TYPE_BOOL:
u = !!src->value.u[k].u;
i = !!src->value.u[k].u;
f = !!src->value.u[k].u;
d = !!src->value.u[k].u;
break;
default:
vkd3d_unreachable();
}
switch (dst_type->base_type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].f = f;
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].d = d;
break;
case HLSL_TYPE_INT:
dst->u[k].i = i;
break;
case HLSL_TYPE_UINT:
dst->u[k].u = u;
break;
case HLSL_TYPE_BOOL:
/* Casts to bool should have already been lowered. */
default:
vkd3d_unreachable();
}
}
return true;
}
static bool fold_neg(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst,
const struct hlsl_type *dst_type, const struct hlsl_ir_constant *src)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src->node.data_type->base_type);
for (k = 0; k < 4; ++k)
{
switch (type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].f = -src->value.u[k].f;
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].d = -src->value.u[k].d;
break;
case HLSL_TYPE_INT:
case HLSL_TYPE_UINT:
dst->u[k].u = -src->value.u[k].u;
break;
default:
FIXME("Fold negation for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_add(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src1->node.data_type->base_type);
assert(type == src2->node.data_type->base_type);
for (k = 0; k < 4; ++k)
{
switch (type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].f = src1->value.u[k].f + src2->value.u[k].f;
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].d = src1->value.u[k].d + src2->value.u[k].d;
break;
/* Handling HLSL_TYPE_INT through the unsigned field to avoid
* undefined behavior with signed integers in C. */
case HLSL_TYPE_INT:
case HLSL_TYPE_UINT:
dst->u[k].u = src1->value.u[k].u + src2->value.u[k].u;
break;
default:
FIXME("Fold addition for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_and(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src1->node.data_type->base_type);
assert(type == src2->node.data_type->base_type);
for (k = 0; k < dst_type->dimx; ++k)
{
switch (type)
{
case HLSL_TYPE_INT:
case HLSL_TYPE_UINT:
case HLSL_TYPE_BOOL:
dst->u[k].u = src1->value.u[k].u & src2->value.u[k].u;
break;
default:
FIXME("Fold bit/logic and for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_or(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src1->node.data_type->base_type);
assert(type == src2->node.data_type->base_type);
for (k = 0; k < dst_type->dimx; ++k)
{
switch (type)
{
case HLSL_TYPE_INT:
case HLSL_TYPE_UINT:
case HLSL_TYPE_BOOL:
dst->u[k].u = src1->value.u[k].u | src2->value.u[k].u;
break;
default:
FIXME("Fold bit/logic or for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_bit_xor(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src1->node.data_type->base_type);
assert(type == src2->node.data_type->base_type);
for (k = 0; k < dst_type->dimx; ++k)
{
switch (type)
{
case HLSL_TYPE_INT:
case HLSL_TYPE_UINT:
dst->u[k].u = src1->value.u[k].u ^ src2->value.u[k].u;
break;
default:
FIXME("Fold bit xor for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_div(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2,
const struct vkd3d_shader_location *loc)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src1->node.data_type->base_type);
assert(type == src2->node.data_type->base_type);
for (k = 0; k < dst_type->dimx; ++k)
{
switch (type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
if (ctx->profile->major_version >= 4 && src2->value.u[k].f == 0)
{
hlsl_warning(ctx, loc, VKD3D_SHADER_WARNING_HLSL_DIVISION_BY_ZERO,
"Floating point division by zero.");
}
dst->u[k].f = src1->value.u[k].f / src2->value.u[k].f;
if (ctx->profile->major_version < 4 && !isfinite(dst->u[k].f))
{
hlsl_error(ctx, loc, VKD3D_SHADER_ERROR_HLSL_DIVISION_BY_ZERO,
"Infinities and NaNs are not allowed by the shader model.");
}
break;
case HLSL_TYPE_DOUBLE:
if (src2->value.u[k].d == 0)
{
hlsl_warning(ctx, loc, VKD3D_SHADER_WARNING_HLSL_DIVISION_BY_ZERO,
"Floating point division by zero.");
}
dst->u[k].d = src1->value.u[k].d / src2->value.u[k].d;
break;
case HLSL_TYPE_INT:
if (src2->value.u[k].i == 0)
{
hlsl_error(ctx, loc, VKD3D_SHADER_ERROR_HLSL_DIVISION_BY_ZERO,
"Division by zero.");
return false;
}
if (src1->value.u[k].i == INT_MIN && src2->value.u[k].i == -1)
dst->u[k].i = INT_MIN;
else
dst->u[k].i = src1->value.u[k].i / src2->value.u[k].i;
break;
case HLSL_TYPE_UINT:
if (src2->value.u[k].u == 0)
{
hlsl_error(ctx, loc, VKD3D_SHADER_ERROR_HLSL_DIVISION_BY_ZERO,
"Division by zero.");
return false;
}
dst->u[k].u = src1->value.u[k].u / src2->value.u[k].u;
break;
default:
FIXME("Fold division for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_equal(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
unsigned int k;
assert(dst_type->base_type == HLSL_TYPE_BOOL);
assert(src1->node.data_type->base_type == src2->node.data_type->base_type);
for (k = 0; k < 4; ++k)
{
switch (src1->node.data_type->base_type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].u = src1->value.u[k].f == src2->value.u[k].f;
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].u = src1->value.u[k].d == src2->value.u[k].d;
break;
case HLSL_TYPE_INT:
case HLSL_TYPE_UINT:
case HLSL_TYPE_BOOL:
dst->u[k].u = src1->value.u[k].u == src2->value.u[k].u;
break;
default:
vkd3d_unreachable();
}
dst->u[k].u *= ~0u;
}
return true;
}
static bool fold_gequal(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
unsigned int k;
assert(dst_type->base_type == HLSL_TYPE_BOOL);
assert(src1->node.data_type->base_type == src2->node.data_type->base_type);
for (k = 0; k < 4; ++k)
{
switch (src1->node.data_type->base_type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].u = src1->value.u[k].f >= src2->value.u[k].f;
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].u = src1->value.u[k].d >= src2->value.u[k].d;
break;
case HLSL_TYPE_INT:
dst->u[k].u = src1->value.u[k].i >= src2->value.u[k].i;
break;
case HLSL_TYPE_UINT:
case HLSL_TYPE_BOOL:
dst->u[k].u = src1->value.u[k].u >= src2->value.u[k].u;
break;
default:
vkd3d_unreachable();
}
dst->u[k].u *= ~0u;
}
return true;
}
static bool fold_less(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
unsigned int k;
assert(dst_type->base_type == HLSL_TYPE_BOOL);
assert(src1->node.data_type->base_type == src2->node.data_type->base_type);
for (k = 0; k < 4; ++k)
{
switch (src1->node.data_type->base_type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].u = src1->value.u[k].f < src2->value.u[k].f;
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].u = src1->value.u[k].d < src2->value.u[k].d;
break;
case HLSL_TYPE_INT:
dst->u[k].u = src1->value.u[k].i < src2->value.u[k].i;
break;
case HLSL_TYPE_UINT:
case HLSL_TYPE_BOOL:
dst->u[k].u = src1->value.u[k].u < src2->value.u[k].u;
break;
default:
vkd3d_unreachable();
}
dst->u[k].u *= ~0u;
}
return true;
}
static bool fold_max(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src1->node.data_type->base_type);
assert(type == src2->node.data_type->base_type);
for (k = 0; k < dst_type->dimx; ++k)
{
switch (type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].f = fmaxf(src1->value.u[k].f, src2->value.u[k].f);
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].d = fmax(src1->value.u[k].d, src2->value.u[k].d);
break;
case HLSL_TYPE_INT:
dst->u[k].i = max(src1->value.u[k].i, src2->value.u[k].i);
break;
case HLSL_TYPE_UINT:
dst->u[k].u = max(src1->value.u[k].u, src2->value.u[k].u);
break;
default:
FIXME("Fold max for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_min(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src1->node.data_type->base_type);
assert(type == src2->node.data_type->base_type);
for (k = 0; k < dst_type->dimx; ++k)
{
switch (type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].f = fminf(src1->value.u[k].f, src2->value.u[k].f);
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].d = fmin(src1->value.u[k].d, src2->value.u[k].d);
break;
case HLSL_TYPE_INT:
dst->u[k].i = min(src1->value.u[k].i, src2->value.u[k].i);
break;
case HLSL_TYPE_UINT:
dst->u[k].u = min(src1->value.u[k].u, src2->value.u[k].u);
break;
default:
FIXME("Fold min for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_mod(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2,
const struct vkd3d_shader_location *loc)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src1->node.data_type->base_type);
assert(type == src2->node.data_type->base_type);
for (k = 0; k < dst_type->dimx; ++k)
{
switch (type)
{
case HLSL_TYPE_INT:
if (src2->value.u[k].i == 0)
{
hlsl_error(ctx, loc, VKD3D_SHADER_ERROR_HLSL_DIVISION_BY_ZERO, "Division by zero.");
return false;
}
if (src1->value.u[k].i == INT_MIN && src2->value.u[k].i == -1)
dst->u[k].i = 0;
else
dst->u[k].i = src1->value.u[k].i % src2->value.u[k].i;
break;
case HLSL_TYPE_UINT:
if (src2->value.u[k].u == 0)
{
hlsl_error(ctx, loc, VKD3D_SHADER_ERROR_HLSL_DIVISION_BY_ZERO, "Division by zero.");
return false;
}
dst->u[k].u = src1->value.u[k].u % src2->value.u[k].u;
break;
default:
FIXME("Fold modulus for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_mul(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
enum hlsl_base_type type = dst_type->base_type;
unsigned int k;
assert(type == src1->node.data_type->base_type);
assert(type == src2->node.data_type->base_type);
for (k = 0; k < 4; ++k)
{
switch (type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].f = src1->value.u[k].f * src2->value.u[k].f;
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].d = src1->value.u[k].d * src2->value.u[k].d;
break;
case HLSL_TYPE_INT:
case HLSL_TYPE_UINT:
dst->u[k].u = src1->value.u[k].u * src2->value.u[k].u;
break;
default:
FIXME("Fold multiplication for type %s.\n", debug_hlsl_type(ctx, dst_type));
return false;
}
}
return true;
}
static bool fold_nequal(struct hlsl_ctx *ctx, struct hlsl_constant_value *dst, const struct hlsl_type *dst_type,
const struct hlsl_ir_constant *src1, const struct hlsl_ir_constant *src2)
{
unsigned int k;
assert(dst_type->base_type == HLSL_TYPE_BOOL);
assert(src1->node.data_type->base_type == src2->node.data_type->base_type);
for (k = 0; k < 4; ++k)
{
switch (src1->node.data_type->base_type)
{
case HLSL_TYPE_FLOAT:
case HLSL_TYPE_HALF:
dst->u[k].u = src1->value.u[k].f != src2->value.u[k].f;
break;
case HLSL_TYPE_DOUBLE:
dst->u[k].u = src1->value.u[k].d != src2->value.u[k].d;
break;
case HLSL_TYPE_INT:
case HLSL_TYPE_UINT:
case HLSL_TYPE_BOOL:
dst->u[k].u = src1->value.u[k].u != src2->value.u[k].u;
break;
default:
vkd3d_unreachable();
}
dst->u[k].u *= ~0u;
}
return true;
}
bool hlsl_fold_constant_exprs(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr, void *context)
{
struct hlsl_ir_constant *arg1, *arg2 = NULL;
struct hlsl_constant_value res = {0};
struct hlsl_ir_node *res_node;
struct hlsl_ir_expr *expr;
unsigned int i;
bool success;
if (instr->type != HLSL_IR_EXPR)
return false;
expr = hlsl_ir_expr(instr);
if (!expr->operands[0].node)
return false;
if (instr->data_type->class > HLSL_CLASS_VECTOR)
return false;
for (i = 0; i < ARRAY_SIZE(expr->operands); ++i)
{
if (expr->operands[i].node)
{
if (expr->operands[i].node->type != HLSL_IR_CONSTANT)
return false;
assert(expr->operands[i].node->data_type->class <= HLSL_CLASS_VECTOR);
}
}
arg1 = hlsl_ir_constant(expr->operands[0].node);
if (expr->operands[1].node)
arg2 = hlsl_ir_constant(expr->operands[1].node);
switch (expr->op)
{
case HLSL_OP1_ABS:
success = fold_abs(ctx, &res, instr->data_type, arg1);
break;
case HLSL_OP1_CAST:
success = fold_cast(ctx, &res, instr->data_type, arg1);
break;
case HLSL_OP1_NEG:
success = fold_neg(ctx, &res, instr->data_type, arg1);
break;
case HLSL_OP2_ADD:
success = fold_add(ctx, &res, instr->data_type, arg1, arg2);
break;
case HLSL_OP2_BIT_AND:
case HLSL_OP2_LOGIC_AND:
success = fold_and(ctx, &res, instr->data_type, arg1, arg2);
break;
case HLSL_OP2_BIT_OR:
case HLSL_OP2_LOGIC_OR:
success = fold_or(ctx, &res, instr->data_type, arg1, arg2);
break;
case HLSL_OP2_BIT_XOR:
success = fold_bit_xor(ctx, &res, instr->data_type, arg1, arg2);
break;
case HLSL_OP2_DIV:
success = fold_div(ctx, &res, instr->data_type, arg1, arg2, &instr->loc);
break;
case HLSL_OP2_EQUAL:
success = fold_equal(ctx, &res, instr->data_type, arg1, arg2);
break;
case HLSL_OP2_GEQUAL:
success = fold_gequal(ctx, &res, instr->data_type, arg1, arg2);
break;
case HLSL_OP2_LESS:
success = fold_less(ctx, &res, instr->data_type, arg1, arg2);
break;
case HLSL_OP2_MAX:
success = fold_max(ctx, &res, instr->data_type, arg1, arg2);
break;
case HLSL_OP2_MIN:
success = fold_min(ctx, &res, instr->data_type, arg1, arg2);
break;
case HLSL_OP2_MOD:
success = fold_mod(ctx, &res, instr->data_type, arg1, arg2, &instr->loc);
break;
case HLSL_OP2_MUL:
success = fold_mul(ctx, &res, instr->data_type, arg1, arg2);
break;
case HLSL_OP2_NEQUAL:
success = fold_nequal(ctx, &res, instr->data_type, arg1, arg2);
break;
default:
FIXME("Fold \"%s\" expression.\n", debug_hlsl_expr_op(expr->op));
success = false;
break;
}
if (success)
{
if (!(res_node = hlsl_new_constant(ctx, instr->data_type, &res, &instr->loc)))
return false;
list_add_before(&expr->node.entry, &res_node->entry);
hlsl_replace_node(&expr->node, res_node);
}
return success;
}
bool hlsl_fold_constant_swizzles(struct hlsl_ctx *ctx, struct hlsl_ir_node *instr, void *context)
{
struct hlsl_constant_value value;
struct hlsl_ir_swizzle *swizzle;
struct hlsl_ir_constant *src;
struct hlsl_ir_node *dst;
unsigned int i;
if (instr->type != HLSL_IR_SWIZZLE)
return false;
swizzle = hlsl_ir_swizzle(instr);
if (swizzle->val.node->type != HLSL_IR_CONSTANT)
return false;
src = hlsl_ir_constant(swizzle->val.node);
for (i = 0; i < swizzle->node.data_type->dimx; ++i)
value.u[i] = src->value.u[hlsl_swizzle_get_component(swizzle->swizzle, i)];
if (!(dst = hlsl_new_constant(ctx, instr->data_type, &value, &instr->loc)))
return false;
list_add_before(&swizzle->node.entry, &dst->entry);
hlsl_replace_node(&swizzle->node, dst);
return true;
}