/*
* Copyright © 2015 Broadcom
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
/*
* This lowering pass supports (as configured via nir_lower_tex_options)
* various texture related conversions:
* + texture projector lowering: converts the coordinate division for
* texture projection to be done in ALU instructions instead of
* asking the texture operation to do so.
* + lowering RECT: converts the un-normalized RECT texture coordinates
* to normalized coordinates with txs plus ALU instructions
* + saturate s/t/r coords: to emulate certain texture clamp/wrap modes,
* inserts instructions to clamp specified coordinates to [0.0, 1.0].
* Note that this automatically triggers texture projector lowering if
* needed, since clamping must happen after projector lowering.
*/
#include "nir.h"
#include "nir_builder.h"
#include "nir_format_convert.h"
static void
project_src(nir_builder *b, nir_tex_instr *tex)
{
/* Find the projector in the srcs list, if present. */
int proj_index = nir_tex_instr_src_index(tex, nir_tex_src_projector);
if (proj_index < 0)
return;
b->cursor = nir_before_instr(&tex->instr);
nir_ssa_def *inv_proj =
nir_frcp(b, nir_ssa_for_src(b, tex->src[proj_index].src, 1));
/* Walk through the sources projecting the arguments. */
for (unsigned i = 0; i < tex->num_srcs; i++) {
switch (tex->src[i].src_type) {
case nir_tex_src_coord:
case nir_tex_src_comparator:
break;
default:
continue;
}
nir_ssa_def *unprojected =
nir_ssa_for_src(b, tex->src[i].src, nir_tex_instr_src_size(tex, i));
nir_ssa_def *projected = nir_fmul(b, unprojected, inv_proj);
/* Array indices don't get projected, so make an new vector with the
* coordinate's array index untouched.
*/
if (tex->is_array && tex->src[i].src_type == nir_tex_src_coord) {
switch (tex->coord_components) {
case 4:
projected = nir_vec4(b,
nir_channel(b, projected, 0),
nir_channel(b, projected, 1),
nir_channel(b, projected, 2),
nir_channel(b, unprojected, 3));
break;
case 3:
projected = nir_vec3(b,
nir_channel(b, projected, 0),
nir_channel(b, projected, 1),
nir_channel(b, unprojected, 2));
break;
case 2:
projected = nir_vec2(b,
nir_channel(b, projected, 0),
nir_channel(b, unprojected, 1));
break;
default:
unreachable("bad texture coord count for array");
break;
}
}
nir_instr_rewrite_src(&tex->instr,
&tex->src[i].src,
nir_src_for_ssa(projected));
}
nir_tex_instr_remove_src(tex, proj_index);
}
static nir_ssa_def *
get_texture_size(nir_builder *b, nir_tex_instr *tex)
{
b->cursor = nir_before_instr(&tex->instr);
nir_tex_instr *txs;
unsigned num_srcs = 1; /* One for the LOD */
for (unsigned i = 0; i < tex->num_srcs; i++) {
if (tex->src[i].src_type == nir_tex_src_texture_deref ||
tex->src[i].src_type == nir_tex_src_sampler_deref ||
tex->src[i].src_type == nir_tex_src_texture_offset ||
tex->src[i].src_type == nir_tex_src_sampler_offset ||
tex->src[i].src_type == nir_tex_src_texture_handle ||
tex->src[i].src_type == nir_tex_src_sampler_handle)
num_srcs++;
}
txs = nir_tex_instr_create(b->shader, num_srcs);
txs->op = nir_texop_txs;
txs->sampler_dim = tex->sampler_dim;
txs->is_array = tex->is_array;
txs->is_shadow = tex->is_shadow;
txs->is_new_style_shadow = tex->is_new_style_shadow;
txs->texture_index = tex->texture_index;
txs->sampler_index = tex->sampler_index;
txs->dest_type = nir_type_int;
unsigned idx = 0;
for (unsigned i = 0; i < tex->num_srcs; i++) {
if (tex->src[i].src_type == nir_tex_src_texture_deref ||
tex->src[i].src_type == nir_tex_src_sampler_deref ||
tex->src[i].src_type == nir_tex_src_texture_offset ||
tex->src[i].src_type == nir_tex_src_sampler_offset ||
tex->src[i].src_type == nir_tex_src_texture_handle ||
tex->src[i].src_type == nir_tex_src_sampler_handle) {
nir_src_copy(&txs->src[idx].src, &tex->src[i].src, txs);
txs->src[idx].src_type = tex->src[i].src_type;
idx++;
}
}
/* Add in an LOD because some back-ends require it */
txs->src[idx].src = nir_src_for_ssa(nir_imm_int(b, 0));
txs->src[idx].src_type = nir_tex_src_lod;
nir_ssa_dest_init(&txs->instr, &txs->dest,
nir_tex_instr_dest_size(txs), 32, NULL);
nir_builder_instr_insert(b, &txs->instr);
return nir_i2f32(b, &txs->dest.ssa);
}
static nir_ssa_def *
get_texture_lod(nir_builder *b, nir_tex_instr *tex)
{
b->cursor = nir_before_instr(&tex->instr);
nir_tex_instr *tql;
unsigned num_srcs = 0;
for (unsigned i = 0; i < tex->num_srcs; i++) {
if (tex->src[i].src_type == nir_tex_src_coord ||
tex->src[i].src_type == nir_tex_src_texture_deref ||
tex->src[i].src_type == nir_tex_src_sampler_deref ||
tex->src[i].src_type == nir_tex_src_texture_offset ||
tex->src[i].src_type == nir_tex_src_sampler_offset ||
tex->src[i].src_type == nir_tex_src_texture_handle ||
tex->src[i].src_type == nir_tex_src_sampler_handle)
num_srcs++;
}
tql = nir_tex_instr_create(b->shader, num_srcs);
tql->op = nir_texop_lod;
tql->coord_components = tex->coord_components;
tql->sampler_dim = tex->sampler_dim;
tql->is_array = tex->is_array;
tql->is_shadow = tex->is_shadow;
tql->is_new_style_shadow = tex->is_new_style_shadow;
tql->texture_index = tex->texture_index;
tql->sampler_index = tex->sampler_index;
tql->dest_type = nir_type_float;
unsigned idx = 0;
for (unsigned i = 0; i < tex->num_srcs; i++) {
if (tex->src[i].src_type == nir_tex_src_coord ||
tex->src[i].src_type == nir_tex_src_texture_deref ||
tex->src[i].src_type == nir_tex_src_sampler_deref ||
tex->src[i].src_type == nir_tex_src_texture_offset ||
tex->src[i].src_type == nir_tex_src_sampler_offset ||
tex->src[i].src_type == nir_tex_src_texture_handle ||
tex->src[i].src_type == nir_tex_src_sampler_handle) {
nir_src_copy(&tql->src[idx].src, &tex->src[i].src, tql);
tql->src[idx].src_type = tex->src[i].src_type;
idx++;
}
}
nir_ssa_dest_init(&tql->instr, &tql->dest, 2, 32, NULL);
nir_builder_instr_insert(b, &tql->instr);
/* The LOD is the y component of the result */
return nir_channel(b, &tql->dest.ssa, 1);
}
static bool
lower_offset(nir_builder *b, nir_tex_instr *tex)
{
int offset_index = nir_tex_instr_src_index(tex, nir_tex_src_offset);
if (offset_index < 0)
return false;
int coord_index = nir_tex_instr_src_index(tex, nir_tex_src_coord);
assert(coord_index >= 0);
assert(tex->src[offset_index].src.is_ssa);
assert(tex->src[coord_index].src.is_ssa);
nir_ssa_def *offset = tex->src[offset_index].src.ssa;
nir_ssa_def *coord = tex->src[coord_index].src.ssa;
b->cursor = nir_before_instr(&tex->instr);
nir_ssa_def *offset_coord;
if (nir_tex_instr_src_type(tex, coord_index) == nir_type_float) {
if (tex->sampler_dim == GLSL_SAMPLER_DIM_RECT) {
offset_coord = nir_fadd(b, coord, nir_i2f32(b, offset));
} else {
nir_ssa_def *txs = get_texture_size(b, tex);
nir_ssa_def *scale = nir_frcp(b, txs);
offset_coord = nir_fadd(b, coord,
nir_fmul(b,
nir_i2f32(b, offset),
scale));
}
} else {
offset_coord = nir_iadd(b, coord, offset);
}
if (tex->is_array) {
/* The offset is not applied to the array index */
if (tex->coord_components == 2) {
offset_coord = nir_vec2(b, nir_channel(b, offset_coord, 0),
nir_channel(b, coord, 1));
} else if (tex->coord_components == 3) {
offset_coord = nir_vec3(b, nir_channel(b, offset_coord, 0),
nir_channel(b, offset_coord, 1),
nir_channel(b, coord, 2));
} else {
unreachable("Invalid number of components");
}
}
nir_instr_rewrite_src(&tex->instr, &tex->src[coord_index].src,
nir_src_for_ssa(offset_coord));
nir_tex_instr_remove_src(tex, offset_index);
return true;
}
static void
lower_rect(nir_builder *b, nir_tex_instr *tex)
{
nir_ssa_def *txs = get_texture_size(b, tex);
nir_ssa_def *scale = nir_frcp(b, txs);
/* Walk through the sources normalizing the requested arguments. */
for (unsigned i = 0; i < tex->num_srcs; i++) {
if (tex->src[i].src_type != nir_tex_src_coord)
continue;
nir_ssa_def *coords =
nir_ssa_for_src(b, tex->src[i].src, tex->coord_components);
nir_instr_rewrite_src(&tex->instr,
&tex->src[i].src,
nir_src_for_ssa(nir_fmul(b, coords, scale)));
}
tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
}
static void
lower_implicit_lod(nir_builder *b, nir_tex_instr *tex)
{
assert(tex->op == nir_texop_tex || tex->op == nir_texop_txb);
assert(nir_tex_instr_src_index(tex, nir_tex_src_lod) < 0);
assert(nir_tex_instr_src_index(tex, nir_tex_src_ddx) < 0);
assert(nir_tex_instr_src_index(tex, nir_tex_src_ddy) < 0);
b->cursor = nir_before_instr(&tex->instr);
nir_ssa_def *lod = get_texture_lod(b, tex);
int bias_idx = nir_tex_instr_src_index(tex, nir_tex_src_bias);
if (bias_idx >= 0) {
/* If we have a bias, add it in */
lod = nir_fadd(b, lod, nir_ssa_for_src(b, tex->src[bias_idx].src, 1));
nir_tex_instr_remove_src(tex, bias_idx);
}
int min_lod_idx = nir_tex_instr_src_index(tex, nir_tex_src_min_lod);
if (min_lod_idx >= 0) {
/* If we have a minimum LOD, clamp LOD accordingly */
lod = nir_fmax(b, lod, nir_ssa_for_src(b, tex->src[min_lod_idx].src, 1));
nir_tex_instr_remove_src(tex, min_lod_idx);
}
nir_tex_instr_add_src(tex, nir_tex_src_lod, nir_src_for_ssa(lod));
tex->op = nir_texop_txl;
}
static nir_ssa_def *
sample_plane(nir_builder *b, nir_tex_instr *tex, int plane,
const nir_lower_tex_options *options)
{
assert(tex->dest.is_ssa);
assert(nir_tex_instr_dest_size(tex) == 4);
assert(nir_alu_type_get_base_type(tex->dest_type) == nir_type_float);
assert(tex->op == nir_texop_tex);
assert(tex->coord_components == 2);
nir_tex_instr *plane_tex =
nir_tex_instr_create(b->shader, tex->num_srcs + 1);
for (unsigned i = 0; i < tex->num_srcs; i++) {
nir_src_copy(&plane_tex->src[i].src, &tex->src[i].src, plane_tex);
plane_tex->src[i].src_type = tex->src[i].src_type;
}
plane_tex->src[tex->num_srcs].src = nir_src_for_ssa(nir_imm_int(b, plane));
plane_tex->src[tex->num_srcs].src_type = nir_tex_src_plane;
plane_tex->op = nir_texop_tex;
plane_tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
plane_tex->dest_type = nir_type_float;
plane_tex->coord_components = 2;
plane_tex->texture_index = tex->texture_index;
plane_tex->sampler_index = tex->sampler_index;
nir_ssa_dest_init(&plane_tex->instr, &plane_tex->dest, 4, 32, NULL);
nir_builder_instr_insert(b, &plane_tex->instr);
/* If scaling_factor is set, return a scaled value. */
if (options->scale_factors[tex->texture_index])
return nir_fmul_imm(b, &plane_tex->dest.ssa,
options->scale_factors[tex->texture_index]);
return &plane_tex->dest.ssa;
}
static void
convert_yuv_to_rgb(nir_builder *b, nir_tex_instr *tex,
nir_ssa_def *y, nir_ssa_def *u, nir_ssa_def *v,
nir_ssa_def *a)
{
nir_const_value m[3][4] = {
{ { .f32 = 1.16438356f }, { .f32 = 1.16438356f }, { .f32 = 1.16438356f }, { .f32 = 0.0f } },
{ { .f32 = 0.0f }, { .f32 = -0.39176229f }, { .f32 = 2.01723214f }, { .f32 = 0.0f } },
{ { .f32 = 1.59602678f }, { .f32 = -0.81296764f }, { .f32 = 0.0f }, { .f32 = 0.0f } },
};
nir_ssa_def *offset =
nir_vec4(b,
nir_imm_float(b, -0.874202214f),
nir_imm_float(b, 0.531667820f),
nir_imm_float(b, -1.085630787f),
a);
nir_ssa_def *result =
nir_ffma(b, y, nir_build_imm(b, 4, 32, m[0]),
nir_ffma(b, u, nir_build_imm(b, 4, 32, m[1]),
nir_ffma(b, v, nir_build_imm(b, 4, 32, m[2]),
offset)));
nir_ssa_def_rewrite_uses(&tex->dest.ssa, nir_src_for_ssa(result));
}
static void
lower_y_uv_external(nir_builder *b, nir_tex_instr *tex,
const nir_lower_tex_options *options)
{
b->cursor = nir_after_instr(&tex->instr);
nir_ssa_def *y = sample_plane(b, tex, 0, options);
nir_ssa_def *uv = sample_plane(b, tex, 1, options);
convert_yuv_to_rgb(b, tex,
nir_channel(b, y, 0),
nir_channel(b, uv, 0),
nir_channel(b, uv, 1),
nir_imm_float(b, 1.0f));
}
static void
lower_y_u_v_external(nir_builder *b, nir_tex_instr *tex,
const nir_lower_tex_options *options)
{
b->cursor = nir_after_instr(&tex->instr);
nir_ssa_def *y = sample_plane(b, tex, 0, options);
nir_ssa_def *u = sample_plane(b, tex, 1, options);
nir_ssa_def *v = sample_plane(b, tex, 2, options);
convert_yuv_to_rgb(b, tex,
nir_channel(b, y, 0),
nir_channel(b, u, 0),
nir_channel(b, v, 0),
nir_imm_float(b, 1.0f));
}
static void
lower_yx_xuxv_external(nir_builder *b, nir_tex_instr *tex,
const nir_lower_tex_options *options)
{
b->cursor = nir_after_instr(&tex->instr);
nir_ssa_def *y = sample_plane(b, tex, 0, options);
nir_ssa_def *xuxv = sample_plane(b, tex, 1, options);
convert_yuv_to_rgb(b, tex,
nir_channel(b, y, 0),
nir_channel(b, xuxv, 1),
nir_channel(b, xuxv, 3),
nir_imm_float(b, 1.0f));
}
static void
lower_xy_uxvx_external(nir_builder *b, nir_tex_instr *tex,
const nir_lower_tex_options *options)
{
b->cursor = nir_after_instr(&tex->instr);
nir_ssa_def *y = sample_plane(b, tex, 0, options);
nir_ssa_def *uxvx = sample_plane(b, tex, 1, options);
convert_yuv_to_rgb(b, tex,
nir_channel(b, y, 1),
nir_channel(b, uxvx, 0),
nir_channel(b, uxvx, 2),
nir_imm_float(b, 1.0f));
}
static void
lower_ayuv_external(nir_builder *b, nir_tex_instr *tex,
const nir_lower_tex_options *options)
{
b->cursor = nir_after_instr(&tex->instr);
nir_ssa_def *ayuv = sample_plane(b, tex, 0, options);
convert_yuv_to_rgb(b, tex,
nir_channel(b, ayuv, 2),
nir_channel(b, ayuv, 1),
nir_channel(b, ayuv, 0),
nir_channel(b, ayuv, 3));
}
static void
lower_xyuv_external(nir_builder *b, nir_tex_instr *tex,
const nir_lower_tex_options *options)
{
b->cursor = nir_after_instr(&tex->instr);
nir_ssa_def *xyuv = sample_plane(b, tex, 0, options);
convert_yuv_to_rgb(b, tex,
nir_channel(b, xyuv, 2),
nir_channel(b, xyuv, 1),
nir_channel(b, xyuv, 0),
nir_imm_float(b, 1.0f));
}
/*
* Converts a nir_texop_txd instruction to nir_texop_txl with the given lod
* computed from the gradients.
*/
static void
replace_gradient_with_lod(nir_builder *b, nir_ssa_def *lod, nir_tex_instr *tex)
{
assert(tex->op == nir_texop_txd);
nir_tex_instr_remove_src(tex, nir_tex_instr_src_index(tex, nir_tex_src_ddx));
nir_tex_instr_remove_src(tex, nir_tex_instr_src_index(tex, nir_tex_src_ddy));
int min_lod_idx = nir_tex_instr_src_index(tex, nir_tex_src_min_lod);
if (min_lod_idx >= 0) {
/* If we have a minimum LOD, clamp LOD accordingly */
lod = nir_fmax(b, lod, nir_ssa_for_src(b, tex->src[min_lod_idx].src, 1));
nir_tex_instr_remove_src(tex, min_lod_idx);
}
nir_tex_instr_add_src(tex, nir_tex_src_lod, nir_src_for_ssa(lod));
tex->op = nir_texop_txl;
}
static void
lower_gradient_cube_map(nir_builder *b, nir_tex_instr *tex)
{
assert(tex->sampler_dim == GLSL_SAMPLER_DIM_CUBE);
assert(tex->op == nir_texop_txd);
assert(tex->dest.is_ssa);
/* Use textureSize() to get the width and height of LOD 0 */
nir_ssa_def *size = get_texture_size(b, tex);
/* Cubemap texture lookups first generate a texture coordinate normalized
* to [-1, 1] on the appropiate face. The appropiate face is determined
* by which component has largest magnitude and its sign. The texture
* coordinate is the quotient of the remaining texture coordinates against
* that absolute value of the component of largest magnitude. This
* division requires that the computing of the derivative of the texel
* coordinate must use the quotient rule. The high level GLSL code is as
* follows:
*
* Step 1: selection
*
* vec3 abs_p, Q, dQdx, dQdy;
* abs_p = abs(ir->coordinate);
* if (abs_p.x >= max(abs_p.y, abs_p.z)) {
* Q = ir->coordinate.yzx;
* dQdx = ir->lod_info.grad.dPdx.yzx;
* dQdy = ir->lod_info.grad.dPdy.yzx;
* }
* if (abs_p.y >= max(abs_p.x, abs_p.z)) {
* Q = ir->coordinate.xzy;
* dQdx = ir->lod_info.grad.dPdx.xzy;
* dQdy = ir->lod_info.grad.dPdy.xzy;
* }
* if (abs_p.z >= max(abs_p.x, abs_p.y)) {
* Q = ir->coordinate;
* dQdx = ir->lod_info.grad.dPdx;
* dQdy = ir->lod_info.grad.dPdy;
* }
*
* Step 2: use quotient rule to compute derivative. The normalized to
* [-1, 1] texel coordinate is given by Q.xy / (sign(Q.z) * Q.z). We are
* only concerned with the magnitudes of the derivatives whose values are
* not affected by the sign. We drop the sign from the computation.
*
* vec2 dx, dy;
* float recip;
*
* recip = 1.0 / Q.z;
* dx = recip * ( dQdx.xy - Q.xy * (dQdx.z * recip) );
* dy = recip * ( dQdy.xy - Q.xy * (dQdy.z * recip) );
*
* Step 3: compute LOD. At this point we have the derivatives of the
* texture coordinates normalized to [-1,1]. We take the LOD to be
* result = log2(max(sqrt(dot(dx, dx)), sqrt(dy, dy)) * 0.5 * L)
* = -1.0 + log2(max(sqrt(dot(dx, dx)), sqrt(dy, dy)) * L)
* = -1.0 + log2(sqrt(max(dot(dx, dx), dot(dy,dy))) * L)
* = -1.0 + log2(sqrt(L * L * max(dot(dx, dx), dot(dy,dy))))
* = -1.0 + 0.5 * log2(L * L * max(dot(dx, dx), dot(dy,dy)))
* where L is the dimension of the cubemap. The code is:
*
* float M, result;
* M = max(dot(dx, dx), dot(dy, dy));
* L = textureSize(sampler, 0).x;
* result = -1.0 + 0.5 * log2(L * L * M);
*/
/* coordinate */
nir_ssa_def *p =
tex->src[nir_tex_instr_src_index(tex, nir_tex_src_coord)].src.ssa;
/* unmodified dPdx, dPdy values */
nir_ssa_def *dPdx =
tex->src[nir_tex_instr_src_index(tex, nir_tex_src_ddx)].src.ssa;
nir_ssa_def *dPdy =
tex->src[nir_tex_instr_src_index(tex, nir_tex_src_ddy)].src.ssa;
nir_ssa_def *abs_p = nir_fabs(b, p);
nir_ssa_def *abs_p_x = nir_channel(b, abs_p, 0);
nir_ssa_def *abs_p_y = nir_channel(b, abs_p, 1);
nir_ssa_def *abs_p_z = nir_channel(b, abs_p, 2);
/* 1. compute selector */
nir_ssa_def *Q, *dQdx, *dQdy;
nir_ssa_def *cond_z = nir_fge(b, abs_p_z, nir_fmax(b, abs_p_x, abs_p_y));
nir_ssa_def *cond_y = nir_fge(b, abs_p_y, nir_fmax(b, abs_p_x, abs_p_z));
unsigned yzx[3] = { 1, 2, 0 };
unsigned xzy[3] = { 0, 2, 1 };
Q = nir_bcsel(b, cond_z,
p,
nir_bcsel(b, cond_y,
nir_swizzle(b, p, xzy, 3, false),
nir_swizzle(b, p, yzx, 3, false)));
dQdx = nir_bcsel(b, cond_z,
dPdx,
nir_bcsel(b, cond_y,
nir_swizzle(b, dPdx, xzy, 3, false),
nir_swizzle(b, dPdx, yzx, 3, false)));
dQdy = nir_bcsel(b, cond_z,
dPdy,
nir_bcsel(b, cond_y,
nir_swizzle(b, dPdy, xzy, 3, false),
nir_swizzle(b, dPdy, yzx, 3, false)));
/* 2. quotient rule */
/* tmp = Q.xy * recip;
* dx = recip * ( dQdx.xy - (tmp * dQdx.z) );
* dy = recip * ( dQdy.xy - (tmp * dQdy.z) );
*/
nir_ssa_def *rcp_Q_z = nir_frcp(b, nir_channel(b, Q, 2));
nir_ssa_def *Q_xy = nir_channels(b, Q, 0x3);
nir_ssa_def *tmp = nir_fmul(b, Q_xy, rcp_Q_z);
nir_ssa_def *dQdx_xy = nir_channels(b, dQdx, 0x3);
nir_ssa_def *dQdx_z = nir_channel(b, dQdx, 2);
nir_ssa_def *dx =
nir_fmul(b, rcp_Q_z, nir_fsub(b, dQdx_xy, nir_fmul(b, tmp, dQdx_z)));
nir_ssa_def *dQdy_xy = nir_channels(b, dQdy, 0x3);
nir_ssa_def *dQdy_z = nir_channel(b, dQdy, 2);
nir_ssa_def *dy =
nir_fmul(b, rcp_Q_z, nir_fsub(b, dQdy_xy, nir_fmul(b, tmp, dQdy_z)));
/* M = max(dot(dx, dx), dot(dy, dy)); */
nir_ssa_def *M = nir_fmax(b, nir_fdot(b, dx, dx), nir_fdot(b, dy, dy));
/* size has textureSize() of LOD 0 */
nir_ssa_def *L = nir_channel(b, size, 0);
/* lod = -1.0 + 0.5 * log2(L * L * M); */
nir_ssa_def *lod =
nir_fadd(b,
nir_imm_float(b, -1.0f),
nir_fmul(b,
nir_imm_float(b, 0.5f),
nir_flog2(b, nir_fmul(b, L, nir_fmul(b, L, M)))));
/* 3. Replace the gradient instruction with an equivalent lod instruction */
replace_gradient_with_lod(b, lod, tex);
}
static void
lower_gradient(nir_builder *b, nir_tex_instr *tex)
{
/* Cubes are more complicated and have their own function */
if (tex->sampler_dim == GLSL_SAMPLER_DIM_CUBE) {
lower_gradient_cube_map(b, tex);
return;
}
assert(tex->sampler_dim != GLSL_SAMPLER_DIM_CUBE);
assert(tex->op == nir_texop_txd);
assert(tex->dest.is_ssa);
/* Use textureSize() to get the width and height of LOD 0 */
unsigned component_mask;
switch (tex->sampler_dim) {
case GLSL_SAMPLER_DIM_3D:
component_mask = 7;
break;
case GLSL_SAMPLER_DIM_1D:
component_mask = 1;
break;
default:
component_mask = 3;
break;
}
nir_ssa_def *size =
nir_channels(b, get_texture_size(b, tex), component_mask);
/* Scale the gradients by width and height. Effectively, the incoming
* gradients are s'(x,y), t'(x,y), and r'(x,y) from equation 3.19 in the
* GL 3.0 spec; we want u'(x,y), which is w_t * s'(x,y).
*/
nir_ssa_def *ddx =
tex->src[nir_tex_instr_src_index(tex, nir_tex_src_ddx)].src.ssa;
nir_ssa_def *ddy =
tex->src[nir_tex_instr_src_index(tex, nir_tex_src_ddy)].src.ssa;
nir_ssa_def *dPdx = nir_fmul(b, ddx, size);
nir_ssa_def *dPdy = nir_fmul(b, ddy, size);
nir_ssa_def *rho;
if (dPdx->num_components == 1) {
rho = nir_fmax(b, nir_fabs(b, dPdx), nir_fabs(b, dPdy));
} else {
rho = nir_fmax(b,
nir_fsqrt(b, nir_fdot(b, dPdx, dPdx)),
nir_fsqrt(b, nir_fdot(b, dPdy, dPdy)));
}
/* lod = log2(rho). We're ignoring GL state biases for now. */
nir_ssa_def *lod = nir_flog2(b, rho);
/* Replace the gradient instruction with an equivalent lod instruction */
replace_gradient_with_lod(b, lod, tex);
}
static void
saturate_src(nir_builder *b, nir_tex_instr *tex, unsigned sat_mask)
{
b->cursor = nir_before_instr(&tex->instr);
/* Walk through the sources saturating the requested arguments. */
for (unsigned i = 0; i < tex->num_srcs; i++) {
if (tex->src[i].src_type != nir_tex_src_coord)
continue;
nir_ssa_def *src =
nir_ssa_for_src(b, tex->src[i].src, tex->coord_components);
/* split src into components: */
nir_ssa_def *comp[4];
assume(tex->coord_components >= 1);
for (unsigned j = 0; j < tex->coord_components; j++)
comp[j] = nir_channel(b, src, j);
/* clamp requested components, array index does not get clamped: */
unsigned ncomp = tex->coord_components;
if (tex->is_array)
ncomp--;
for (unsigned j = 0; j < ncomp; j++) {
if ((1 << j) & sat_mask) {
if (tex->sampler_dim == GLSL_SAMPLER_DIM_RECT) {
/* non-normalized texture coords, so clamp to texture
* size rather than [0.0, 1.0]
*/
nir_ssa_def *txs = get_texture_size(b, tex);
comp[j] = nir_fmax(b, comp[j], nir_imm_float(b, 0.0));
comp[j] = nir_fmin(b, comp[j], nir_channel(b, txs, j));
} else {
comp[j] = nir_fsat(b, comp[j]);
}
}
}
/* and move the result back into a single vecN: */
src = nir_vec(b, comp, tex->coord_components);
nir_instr_rewrite_src(&tex->instr,
&tex->src[i].src,
nir_src_for_ssa(src));
}
}
static nir_ssa_def *
get_zero_or_one(nir_builder *b, nir_alu_type type, uint8_t swizzle_val)
{
nir_const_value v[4];
memset(&v, 0, sizeof(v));
if (swizzle_val == 4) {
v[0].u32 = v[1].u32 = v[2].u32 = v[3].u32 = 0;
} else {
assert(swizzle_val == 5);
if (type == nir_type_float)
v[0].f32 = v[1].f32 = v[2].f32 = v[3].f32 = 1.0;
else
v[0].u32 = v[1].u32 = v[2].u32 = v[3].u32 = 1;
}
return nir_build_imm(b, 4, 32, v);
}
static void
swizzle_tg4_broadcom(nir_builder *b, nir_tex_instr *tex)
{
assert(tex->dest.is_ssa);
b->cursor = nir_after_instr(&tex->instr);
assert(nir_tex_instr_dest_size(tex) == 4);
unsigned swiz[4] = { 2, 3, 1, 0 };
nir_ssa_def *swizzled = nir_swizzle(b, &tex->dest.ssa, swiz, 4, false);
nir_ssa_def_rewrite_uses_after(&tex->dest.ssa, nir_src_for_ssa(swizzled),
swizzled->parent_instr);
}
static void
swizzle_result(nir_builder *b, nir_tex_instr *tex, const uint8_t swizzle[4])
{
assert(tex->dest.is_ssa);
b->cursor = nir_after_instr(&tex->instr);
nir_ssa_def *swizzled;
if (tex->op == nir_texop_tg4) {
if (swizzle[tex->component] < 4) {
/* This one's easy */
tex->component = swizzle[tex->component];
return;
} else {
swizzled = get_zero_or_one(b, tex->dest_type, swizzle[tex->component]);
}
} else {
assert(nir_tex_instr_dest_size(tex) == 4);
if (swizzle[0] < 4 && swizzle[1] < 4 &&
swizzle[2] < 4 && swizzle[3] < 4) {
unsigned swiz[4] = { swizzle[0], swizzle[1], swizzle[2], swizzle[3] };
/* We have no 0s or 1s, just emit a swizzling MOV */
swizzled = nir_swizzle(b, &tex->dest.ssa, swiz, 4, false);
} else {
nir_ssa_def *srcs[4];
for (unsigned i = 0; i < 4; i++) {
if (swizzle[i] < 4) {
srcs[i] = nir_channel(b, &tex->dest.ssa, swizzle[i]);
} else {
srcs[i] = get_zero_or_one(b, tex->dest_type, swizzle[i]);
}
}
swizzled = nir_vec(b, srcs, 4);
}
}
nir_ssa_def_rewrite_uses_after(&tex->dest.ssa, nir_src_for_ssa(swizzled),
swizzled->parent_instr);
}
static void
linearize_srgb_result(nir_builder *b, nir_tex_instr *tex)
{
assert(tex->dest.is_ssa);
assert(nir_tex_instr_dest_size(tex) == 4);
assert(nir_alu_type_get_base_type(tex->dest_type) == nir_type_float);
b->cursor = nir_after_instr(&tex->instr);
nir_ssa_def *rgb =
nir_format_srgb_to_linear(b, nir_channels(b, &tex->dest.ssa, 0x7));
/* alpha is untouched: */
nir_ssa_def *result = nir_vec4(b,
nir_channel(b, rgb, 0),
nir_channel(b, rgb, 1),
nir_channel(b, rgb, 2),
nir_channel(b, &tex->dest.ssa, 3));
nir_ssa_def_rewrite_uses_after(&tex->dest.ssa, nir_src_for_ssa(result),
result->parent_instr);
}
/**
* Lowers texture instructions from giving a vec4 result to a vec2 of f16,
* i16, or u16, or a single unorm4x8 value.
*
* Note that we don't change the destination num_components, because
* nir_tex_instr_dest_size() will still return 4. The driver is just expected
* to not store the other channels, given that nothing at the NIR level will
* read them.
*/
static void
lower_tex_packing(nir_builder *b, nir_tex_instr *tex,
const nir_lower_tex_options *options)
{
nir_ssa_def *color = &tex->dest.ssa;
b->cursor = nir_after_instr(&tex->instr);
switch (options->lower_tex_packing[tex->sampler_index]) {
case nir_lower_tex_packing_none:
return;
case nir_lower_tex_packing_16: {
static const unsigned bits[4] = {16, 16, 16, 16};
switch (nir_alu_type_get_base_type(tex->dest_type)) {
case nir_type_float:
if (tex->is_shadow && tex->is_new_style_shadow) {
color = nir_unpack_half_2x16_split_x(b, nir_channel(b, color, 0));
} else {
nir_ssa_def *rg = nir_channel(b, color, 0);
nir_ssa_def *ba = nir_channel(b, color, 1);
color = nir_vec4(b,
nir_unpack_half_2x16_split_x(b, rg),
nir_unpack_half_2x16_split_y(b, rg),
nir_unpack_half_2x16_split_x(b, ba),
nir_unpack_half_2x16_split_y(b, ba));
}
break;
case nir_type_int:
color = nir_format_unpack_sint(b, color, bits, 4);
break;
case nir_type_uint:
color = nir_format_unpack_uint(b, color, bits, 4);
break;
default:
unreachable("unknown base type");
}
break;
}
case nir_lower_tex_packing_8:
assert(nir_alu_type_get_base_type(tex->dest_type) == nir_type_float);
color = nir_unpack_unorm_4x8(b, nir_channel(b, color, 0));
break;
}
nir_ssa_def_rewrite_uses_after(&tex->dest.ssa, nir_src_for_ssa(color),
color->parent_instr);
}
static bool
sampler_index_lt(nir_tex_instr *tex, unsigned max)
{
assert(nir_tex_instr_src_index(tex, nir_tex_src_sampler_deref) == -1);
unsigned sampler_index = tex->sampler_index;
int sampler_offset_idx =
nir_tex_instr_src_index(tex, nir_tex_src_sampler_offset);
if (sampler_offset_idx >= 0) {
if (!nir_src_is_const(tex->src[sampler_offset_idx].src))
return false;
sampler_index += nir_src_as_uint(tex->src[sampler_offset_idx].src);
}
return sampler_index < max;
}
static bool
lower_tg4_offsets(nir_builder *b, nir_tex_instr *tex)
{
assert(tex->op == nir_texop_tg4);
assert(nir_tex_instr_has_explicit_tg4_offsets(tex));
assert(nir_tex_instr_src_index(tex, nir_tex_src_offset) == -1);
b->cursor = nir_after_instr(&tex->instr);
nir_ssa_def *dest[4];
for (unsigned i = 0; i < 4; ++i) {
nir_tex_instr *tex_copy = nir_tex_instr_create(b->shader, tex->num_srcs + 1);
tex_copy->op = tex->op;
tex_copy->coord_components = tex->coord_components;
tex_copy->sampler_dim = tex->sampler_dim;
tex_copy->is_array = tex->is_array;
tex_copy->is_shadow = tex->is_shadow;
tex_copy->is_new_style_shadow = tex->is_new_style_shadow;
tex_copy->component = tex->component;
tex_copy->dest_type = tex->dest_type;
for (unsigned j = 0; j < tex->num_srcs; ++j) {
nir_src_copy(&tex_copy->src[j].src, &tex->src[j].src, tex_copy);
tex_copy->src[j].src_type = tex->src[j].src_type;
}
nir_tex_src src;
src.src = nir_src_for_ssa(nir_imm_ivec2(b, tex->tg4_offsets[i][0],
tex->tg4_offsets[i][1]));
src.src_type = nir_tex_src_offset;
tex_copy->src[tex_copy->num_srcs - 1] = src;
nir_ssa_dest_init(&tex_copy->instr, &tex_copy->dest,
nir_tex_instr_dest_size(tex), 32, NULL);
nir_builder_instr_insert(b, &tex_copy->instr);
dest[i] = nir_channel(b, &tex_copy->dest.ssa, 3);
}
nir_ssa_def *res = nir_vec4(b, dest[0], dest[1], dest[2], dest[3]);
nir_ssa_def_rewrite_uses(&tex->dest.ssa, nir_src_for_ssa(res));
nir_instr_remove(&tex->instr);
return true;
}
static bool
nir_lower_tex_block(nir_block *block, nir_builder *b,
const nir_lower_tex_options *options)
{
bool progress = false;
nir_foreach_instr_safe(instr, block) {
if (instr->type != nir_instr_type_tex)
continue;
nir_tex_instr *tex = nir_instr_as_tex(instr);
bool lower_txp = !!(options->lower_txp & (1 << tex->sampler_dim));
/* mask of src coords to saturate (clamp): */
unsigned sat_mask = 0;
if ((1 << tex->sampler_index) & options->saturate_r)
sat_mask |= (1 << 2); /* .z */
if ((1 << tex->sampler_index) & options->saturate_t)
sat_mask |= (1 << 1); /* .y */
if ((1 << tex->sampler_index) & options->saturate_s)
sat_mask |= (1 << 0); /* .x */
/* If we are clamping any coords, we must lower projector first
* as clamping happens *after* projection:
*/
if (lower_txp || sat_mask) {
project_src(b, tex);
progress = true;
}
if ((tex->op == nir_texop_txf && options->lower_txf_offset) ||
(sat_mask && nir_tex_instr_src_index(tex, nir_tex_src_coord) >= 0) ||
(tex->sampler_dim == GLSL_SAMPLER_DIM_RECT &&
options->lower_rect_offset)) {
progress = lower_offset(b, tex) || progress;
}
if ((tex->sampler_dim == GLSL_SAMPLER_DIM_RECT) && options->lower_rect) {
lower_rect(b, tex);
progress = true;
}
if ((1 << tex->texture_index) & options->lower_y_uv_external) {
lower_y_uv_external(b, tex, options);
progress = true;
}
if ((1 << tex->texture_index) & options->lower_y_u_v_external) {
lower_y_u_v_external(b, tex, options);
progress = true;
}
if ((1 << tex->texture_index) & options->lower_yx_xuxv_external) {
lower_yx_xuxv_external(b, tex, options);
progress = true;
}
if ((1 << tex->texture_index) & options->lower_xy_uxvx_external) {
lower_xy_uxvx_external(b, tex, options);
progress = true;
}
if ((1 << tex->texture_index) & options->lower_ayuv_external) {
lower_ayuv_external(b, tex, options);
progress = true;
}
if ((1 << tex->texture_index) & options->lower_xyuv_external) {
lower_xyuv_external(b, tex, options);
progress = true;
}
if (sat_mask) {
saturate_src(b, tex, sat_mask);
progress = true;
}
if (tex->op == nir_texop_tg4 && options->lower_tg4_broadcom_swizzle) {
swizzle_tg4_broadcom(b, tex);
progress = true;
}
if (((1 << tex->texture_index) & options->swizzle_result) &&
!nir_tex_instr_is_query(tex) &&
!(tex->is_shadow && tex->is_new_style_shadow)) {
swizzle_result(b, tex, options->swizzles[tex->texture_index]);
progress = true;
}
/* should be after swizzle so we know which channels are rgb: */
if (((1 << tex->texture_index) & options->lower_srgb) &&
!nir_tex_instr_is_query(tex) && !tex->is_shadow) {
linearize_srgb_result(b, tex);
progress = true;
}
const bool has_min_lod =
nir_tex_instr_src_index(tex, nir_tex_src_min_lod) >= 0;
const bool has_offset =
nir_tex_instr_src_index(tex, nir_tex_src_offset) >= 0;
if (tex->op == nir_texop_txb && tex->is_shadow && has_min_lod &&
options->lower_txb_shadow_clamp) {
lower_implicit_lod(b, tex);
progress = true;
}
if (options->lower_tex_packing[tex->sampler_index] !=
nir_lower_tex_packing_none &&
tex->op != nir_texop_txs &&
tex->op != nir_texop_query_levels) {
lower_tex_packing(b, tex, options);
progress = true;
}
if (tex->op == nir_texop_txd &&
(options->lower_txd ||
(options->lower_txd_shadow && tex->is_shadow) ||
(options->lower_txd_shadow_clamp && tex->is_shadow && has_min_lod) ||
(options->lower_txd_offset_clamp && has_offset && has_min_lod) ||
(options->lower_txd_clamp_bindless_sampler && has_min_lod &&
nir_tex_instr_src_index(tex, nir_tex_src_sampler_handle) != -1) ||
(options->lower_txd_clamp_if_sampler_index_not_lt_16 &&
has_min_lod && !sampler_index_lt(tex, 16)) ||
(options->lower_txd_cube_map &&
tex->sampler_dim == GLSL_SAMPLER_DIM_CUBE) ||
(options->lower_txd_3d &&
tex->sampler_dim == GLSL_SAMPLER_DIM_3D))) {
lower_gradient(b, tex);
progress = true;
continue;
}
bool shader_supports_implicit_lod =
b->shader->info.stage == MESA_SHADER_FRAGMENT ||
(b->shader->info.stage == MESA_SHADER_COMPUTE &&
b->shader->info.cs.derivative_group != DERIVATIVE_GROUP_NONE);
/* TXF, TXS and TXL require a LOD but not everything we implement using those
* three opcodes provides one. Provide a default LOD of 0.
*/
if ((nir_tex_instr_src_index(tex, nir_tex_src_lod) == -1) &&
(tex->op == nir_texop_txf || tex->op == nir_texop_txs ||
tex->op == nir_texop_txl || tex->op == nir_texop_query_levels ||
(tex->op == nir_texop_tex && !shader_supports_implicit_lod))) {
b->cursor = nir_before_instr(&tex->instr);
nir_tex_instr_add_src(tex, nir_tex_src_lod, nir_src_for_ssa(nir_imm_int(b, 0)));
if (tex->op == nir_texop_tex && options->lower_tex_without_implicit_lod)
tex->op = nir_texop_txl;
progress = true;
continue;
}
/* has to happen after all the other lowerings as the original tg4 gets
* replaced by 4 tg4 instructions.
*/
if (tex->op == nir_texop_tg4 &&
nir_tex_instr_has_explicit_tg4_offsets(tex) &&
options->lower_tg4_offsets) {
progress |= lower_tg4_offsets(b, tex);
continue;
}
}
return progress;
}
static bool
nir_lower_tex_impl(nir_function_impl *impl,
const nir_lower_tex_options *options)
{
bool progress = false;
nir_builder builder;
nir_builder_init(&builder, impl);
nir_foreach_block(block, impl) {
progress |= nir_lower_tex_block(block, &builder, options);
}
nir_metadata_preserve(impl, nir_metadata_block_index |
nir_metadata_dominance);
return progress;
}
bool
nir_lower_tex(nir_shader *shader, const nir_lower_tex_options *options)
{
bool progress = false;
nir_foreach_function(function, shader) {
if (function->impl)
progress |= nir_lower_tex_impl(function->impl, options);
}
return progress;
}