/*
* Copyright (c) 2016 Intel Corporation
*
* 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.
*/
#include "brw_nir.h"
#include "compiler/nir/nir_builder.h"
struct lower_intrinsics_state {
nir_shader *nir;
nir_function_impl *impl;
bool progress;
nir_builder builder;
};
static bool
lower_cs_intrinsics_convert_block(struct lower_intrinsics_state *state,
nir_block *block)
{
bool progress = false;
nir_builder *b = &state->builder;
nir_shader *nir = state->nir;
/* Reuse calculated values inside the block. */
nir_ssa_def *local_index = NULL;
nir_ssa_def *local_id = NULL;
nir_foreach_instr_safe(instr, block) {
if (instr->type != nir_instr_type_intrinsic)
continue;
nir_intrinsic_instr *intrinsic = nir_instr_as_intrinsic(instr);
b->cursor = nir_after_instr(&intrinsic->instr);
nir_ssa_def *sysval;
switch (intrinsic->intrinsic) {
case nir_intrinsic_load_workgroup_size:
case nir_intrinsic_load_workgroup_id:
case nir_intrinsic_load_num_workgroups:
/* Convert this to 32-bit if it's not */
if (intrinsic->dest.ssa.bit_size == 64) {
intrinsic->dest.ssa.bit_size = 32;
sysval = nir_u2u64(b, &intrinsic->dest.ssa);
nir_ssa_def_rewrite_uses_after(&intrinsic->dest.ssa,
sysval,
sysval->parent_instr);
}
continue;
case nir_intrinsic_load_local_invocation_index:
case nir_intrinsic_load_local_invocation_id: {
/* First time we are using those, so let's calculate them. */
if (!local_index) {
assert(!local_id);
nir_ssa_def *subgroup_id = nir_load_subgroup_id(b);
nir_ssa_def *thread_local_id =
nir_imul(b, subgroup_id, nir_load_simd_width_intel(b));
nir_ssa_def *channel = nir_load_subgroup_invocation(b);
nir_ssa_def *linear = nir_iadd(b, channel, thread_local_id);
nir_ssa_def *size_x;
nir_ssa_def *size_y;
if (state->nir->info.workgroup_size_variable) {
nir_ssa_def *size_xyz = nir_load_workgroup_size(b);
size_x = nir_channel(b, size_xyz, 0);
size_y = nir_channel(b, size_xyz, 1);
} else {
size_x = nir_imm_int(b, nir->info.workgroup_size[0]);
size_y = nir_imm_int(b, nir->info.workgroup_size[1]);
}
nir_ssa_def *size_xy = nir_imul(b, size_x, size_y);
/* The local invocation index and ID must respect the following
*
* gl_LocalInvocationID.x =
* gl_LocalInvocationIndex % gl_WorkGroupSize.x;
* gl_LocalInvocationID.y =
* (gl_LocalInvocationIndex / gl_WorkGroupSize.x) %
* gl_WorkGroupSize.y;
* gl_LocalInvocationID.z =
* (gl_LocalInvocationIndex /
* (gl_WorkGroupSize.x * gl_WorkGroupSize.y)) %
* gl_WorkGroupSize.z;
*
* However, the final % gl_WorkGroupSize.z does nothing unless we
* accidentally end up with a gl_LocalInvocationIndex that is too
* large so it can safely be omitted.
*/
nir_ssa_def *id_x, *id_y, *id_z;
switch (state->nir->info.cs.derivative_group) {
case DERIVATIVE_GROUP_NONE:
if (nir->info.num_images == 0 &&
nir->info.num_textures == 0) {
/* X-major lid order. Optimal for linear accesses only,
* which are usually buffers. X,Y ordering will look like:
* (0,0) (1,0) (2,0) ... (size_x-1,0) (0,1) (1,1) ...
*/
id_x = nir_umod(b, linear, size_x);
id_y = nir_umod(b, nir_udiv(b, linear, size_x), size_y);
local_index = linear;
} else if (!nir->info.workgroup_size_variable &&
nir->info.workgroup_size[1] % 4 == 0) {
/* 1x4 block X-major lid order. Same as X-major except increments in
* blocks of width=1 height=4. Always optimal for tileY and usually
* optimal for linear accesses.
* x = (linear / 4) % size_x
* y = ((linear % 4) + (linear / 4 / size_x) * 4) % size_y
* X,Y ordering will look like: (0,0) (0,1) (0,2) (0,3) (1,0) (1,1)
* (1,2) (1,3) (2,0) ... (size_x-1,3) (0,4) (0,5) (0,6) (0,7) (1,4) ...
*/
const unsigned height = 4;
nir_ssa_def *block = nir_udiv_imm(b, linear, height);
id_x = nir_umod(b, block, size_x);
id_y = nir_umod(b,
nir_iadd(b,
nir_umod(b, linear, nir_imm_int(b, height)),
nir_imul_imm(b,
nir_udiv(b, block, size_x),
height)),
size_y);
} else {
/* Y-major lid order. Optimal for tileY accesses only,
* which are usually images. X,Y ordering will look like:
* (0,0) (0,1) (0,2) ... (0,size_y-1) (1,0) (1,1) ...
*/
id_y = nir_umod(b, linear, size_y);
id_x = nir_umod(b, nir_udiv(b, linear, size_y), size_x);
}
id_z = nir_udiv(b, linear, size_xy);
local_id = nir_vec3(b, id_x, id_y, id_z);
if (!local_index) {
local_index = nir_iadd(b, nir_iadd(b, id_x,
nir_imul(b, id_y, size_x)),
nir_imul(b, id_z, size_xy));
}
break;
case DERIVATIVE_GROUP_LINEAR:
/* For linear, just set the local invocation index linearly,
* and calculate local invocation ID from that.
*/
id_x = nir_umod(b, linear, size_x);
id_y = nir_umod(b, nir_udiv(b, linear, size_x), size_y);
id_z = nir_udiv(b, linear, size_xy);
local_id = nir_vec3(b, id_x, id_y, id_z);
local_index = linear;
break;
case DERIVATIVE_GROUP_QUADS: {
/* For quads, first we figure out the 2x2 grid the invocation
* belongs to -- treating extra Z layers as just more rows.
* Then map that into local invocation ID (trivial) and local
* invocation index. Skipping Z simplify index calculation.
*/
nir_ssa_def *one = nir_imm_int(b, 1);
nir_ssa_def *double_size_x = nir_ishl(b, size_x, one);
/* ID within a pair of rows, where each group of 4 is 2x2 quad. */
nir_ssa_def *row_pair_id = nir_umod(b, linear, double_size_x);
nir_ssa_def *y_row_pairs = nir_udiv(b, linear, double_size_x);
nir_ssa_def *x =
nir_ior(b,
nir_iand(b, row_pair_id, one),
nir_iand(b, nir_ishr(b, row_pair_id, one),
nir_imm_int(b, 0xfffffffe)));
nir_ssa_def *y =
nir_ior(b,
nir_ishl(b, y_row_pairs, one),
nir_iand(b, nir_ishr(b, row_pair_id, one), one));
local_id = nir_vec3(b, x,
nir_umod(b, y, size_y),
nir_udiv(b, y, size_y));
local_index = nir_iadd(b, x, nir_imul(b, y, size_x));
break;
}
default:
unreachable("invalid derivative group");
}
}
assert(local_id);
assert(local_index);
if (intrinsic->intrinsic == nir_intrinsic_load_local_invocation_id)
sysval = local_id;
else
sysval = local_index;
break;
}
case nir_intrinsic_load_num_subgroups: {
nir_ssa_def *size;
if (state->nir->info.workgroup_size_variable) {
nir_ssa_def *size_xyz = nir_load_workgroup_size(b);
nir_ssa_def *size_x = nir_channel(b, size_xyz, 0);
nir_ssa_def *size_y = nir_channel(b, size_xyz, 1);
nir_ssa_def *size_z = nir_channel(b, size_xyz, 2);
size = nir_imul(b, nir_imul(b, size_x, size_y), size_z);
} else {
size = nir_imm_int(b, nir->info.workgroup_size[0] *
nir->info.workgroup_size[1] *
nir->info.workgroup_size[2]);
}
/* Calculate the equivalent of DIV_ROUND_UP. */
nir_ssa_def *simd_width = nir_load_simd_width_intel(b);
sysval =
nir_udiv(b, nir_iadd_imm(b, nir_iadd(b, size, simd_width), -1),
simd_width);
break;
}
default:
continue;
}
if (intrinsic->dest.ssa.bit_size == 64)
sysval = nir_u2u64(b, sysval);
nir_ssa_def_rewrite_uses(&intrinsic->dest.ssa, sysval);
nir_instr_remove(&intrinsic->instr);
state->progress = true;
}
return progress;
}
static void
lower_cs_intrinsics_convert_impl(struct lower_intrinsics_state *state)
{
nir_builder_init(&state->builder, state->impl);
nir_foreach_block(block, state->impl) {
lower_cs_intrinsics_convert_block(state, block);
}
nir_metadata_preserve(state->impl,
nir_metadata_block_index | nir_metadata_dominance);
}
bool
brw_nir_lower_cs_intrinsics(nir_shader *nir)
{
assert(nir->info.stage == MESA_SHADER_COMPUTE ||
nir->info.stage == MESA_SHADER_KERNEL);
struct lower_intrinsics_state state = {
.nir = nir,
};
/* Constraints from NV_compute_shader_derivatives. */
if (!nir->info.workgroup_size_variable) {
if (nir->info.cs.derivative_group == DERIVATIVE_GROUP_QUADS) {
assert(nir->info.workgroup_size[0] % 2 == 0);
assert(nir->info.workgroup_size[1] % 2 == 0);
} else if (nir->info.cs.derivative_group == DERIVATIVE_GROUP_LINEAR) {
ASSERTED unsigned workgroup_size =
nir->info.workgroup_size[0] *
nir->info.workgroup_size[1] *
nir->info.workgroup_size[2];
assert(workgroup_size % 4 == 0);
}
}
nir_foreach_function(function, nir) {
if (function->impl) {
state.impl = function->impl;
lower_cs_intrinsics_convert_impl(&state);
}
}
return state.progress;
}