mesa/src/panfrost/midgard/midgard_address.c

303 lines
9.6 KiB
C

/*
* Copyright (C) 2019 Collabora, Ltd.
*
* 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.
*
* Authors (Collabora):
* Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
*/
#include "compiler.h"
/* Midgard's generic load/store instructions, particularly to implement SSBOs
* and globals, have support for address arithmetic natively. In particularly,
* they take two indirect arguments A, B and two immediates #s, #c, calculating
* the address:
*
* A + (zext?(B) << #s) + #c
*
* This allows for fast indexing into arrays. This file tries to pattern match the offset in NIR with this form to reduce pressure on the ALU pipe.
*/
struct mir_address {
nir_ssa_scalar A;
nir_ssa_scalar B;
midgard_index_address_format type;
unsigned shift;
unsigned bias;
};
static bool
mir_args_ssa(nir_ssa_scalar s, unsigned count)
{
nir_alu_instr *alu = nir_instr_as_alu(s.def->parent_instr);
if (count > nir_op_infos[alu->op].num_inputs)
return false;
for (unsigned i = 0; i < count; ++i) {
if (!alu->src[i].src.is_ssa)
return false;
}
return true;
}
/* Matches a constant in either slot and moves it to the bias */
static void
mir_match_constant(struct mir_address *address)
{
if (address->A.def && nir_ssa_scalar_is_const(address->A)) {
address->bias += nir_ssa_scalar_as_uint(address->A);
address->A.def = NULL;
}
if (address->B.def && nir_ssa_scalar_is_const(address->B)) {
address->bias += nir_ssa_scalar_as_uint(address->B);
address->B.def = NULL;
}
}
/* Matches an iadd when there is a free slot or constant */
/* The offset field is a 18-bit signed integer */
#define MAX_POSITIVE_OFFSET ((1 << 17) - 1)
static void
mir_match_iadd(struct mir_address *address, bool first_free)
{
if (!address->B.def || !nir_ssa_scalar_is_alu(address->B))
return;
if (!mir_args_ssa(address->B, 2))
return;
nir_op op = nir_ssa_scalar_alu_op(address->B);
if (op != nir_op_iadd) return;
nir_ssa_scalar op1 = nir_ssa_scalar_chase_alu_src(address->B, 0);
nir_ssa_scalar op2 = nir_ssa_scalar_chase_alu_src(address->B, 1);
if (nir_ssa_scalar_is_const(op1) &&
nir_ssa_scalar_as_uint(op1) <= MAX_POSITIVE_OFFSET) {
address->bias += nir_ssa_scalar_as_uint(op1);
address->B = op2;
} else if (nir_ssa_scalar_is_const(op2) &&
nir_ssa_scalar_as_uint(op2) <= MAX_POSITIVE_OFFSET) {
address->bias += nir_ssa_scalar_as_uint(op2);
address->B = op1;
} else if (!nir_ssa_scalar_is_const(op1) &&
!nir_ssa_scalar_is_const(op2) &&
first_free && !address->A.def) {
address->A = op1;
address->B = op2;
}
}
/* Matches u2u64 and sets type */
static void
mir_match_u2u64(struct mir_address *address)
{
if (!address->B.def || !nir_ssa_scalar_is_alu(address->B))
return;
if (!mir_args_ssa(address->B, 1))
return;
nir_op op = nir_ssa_scalar_alu_op(address->B);
if (op != nir_op_u2u64) return;
nir_ssa_scalar arg = nir_ssa_scalar_chase_alu_src(address->B, 0);
address->B = arg;
address->type = midgard_index_address_u32;
}
/* Matches i2i64 and sets type */
static void
mir_match_i2i64(struct mir_address *address)
{
if (!address->B.def || !nir_ssa_scalar_is_alu(address->B))
return;
if (!mir_args_ssa(address->B, 1))
return;
nir_op op = nir_ssa_scalar_alu_op(address->B);
if (op != nir_op_i2i64) return;
nir_ssa_scalar arg = nir_ssa_scalar_chase_alu_src(address->B, 0);
address->B = arg;
address->type = midgard_index_address_s32;
}
/* Matches ishl to shift */
static void
mir_match_ishl(struct mir_address *address)
{
if (!address->B.def || !nir_ssa_scalar_is_alu(address->B))
return;
if (!mir_args_ssa(address->B, 2))
return;
nir_op op = nir_ssa_scalar_alu_op(address->B);
if (op != nir_op_ishl) return;
nir_ssa_scalar op1 = nir_ssa_scalar_chase_alu_src(address->B, 0);
nir_ssa_scalar op2 = nir_ssa_scalar_chase_alu_src(address->B, 1);
if (!nir_ssa_scalar_is_const(op2)) return;
unsigned shift = nir_ssa_scalar_as_uint(op2);
if (shift > 0x7) return;
address->B = op1;
address->shift = shift;
}
/* Strings through mov which can happen from NIR vectorization */
static void
mir_match_mov(struct mir_address *address)
{
if (address->A.def && nir_ssa_scalar_is_alu(address->A)) {
nir_op op = nir_ssa_scalar_alu_op(address->A);
if (op == nir_op_mov && mir_args_ssa(address->A, 1))
address->A = nir_ssa_scalar_chase_alu_src(address->A, 0);
}
if (address->B.def && nir_ssa_scalar_is_alu(address->B)) {
nir_op op = nir_ssa_scalar_alu_op(address->B);
if (op == nir_op_mov && mir_args_ssa(address->B, 1))
address->B = nir_ssa_scalar_chase_alu_src(address->B, 0);
}
}
/* Tries to pattern match into mir_address */
static struct mir_address
mir_match_offset(nir_ssa_def *offset, bool first_free, bool extend)
{
struct mir_address address = {
.B = { .def = offset },
.type = extend ? midgard_index_address_u64 : midgard_index_address_u32,
};
mir_match_mov(&address);
mir_match_constant(&address);
mir_match_mov(&address);
mir_match_iadd(&address, first_free);
mir_match_mov(&address);
if (extend) {
mir_match_u2u64(&address);
mir_match_i2i64(&address);
mir_match_mov(&address);
}
mir_match_ishl(&address);
return address;
}
void
mir_set_offset(compiler_context *ctx, midgard_instruction *ins, nir_src *offset, unsigned seg)
{
for(unsigned i = 0; i < 16; ++i) {
ins->swizzle[1][i] = 0;
ins->swizzle[2][i] = 0;
}
/* Sign extend instead of zero extend in case the address is something
* like `base + offset + 20`, where offset could be negative. */
bool force_sext = (nir_src_bit_size(*offset) < 64);
if (!offset->is_ssa) {
ins->load_store.bitsize_toggle = true;
ins->load_store.arg_comp = seg & 0x3;
ins->load_store.arg_reg = (seg >> 2) & 0x7;
ins->src[2] = nir_src_index(ctx, offset);
ins->src_types[2] = nir_type_uint | nir_src_bit_size(*offset);
if (force_sext)
ins->load_store.index_format = midgard_index_address_s32;
else
ins->load_store.index_format = midgard_index_address_u64;
return;
}
bool first_free = (seg == LDST_GLOBAL);
struct mir_address match = mir_match_offset(offset->ssa, first_free, true);
if (match.A.def) {
ins->src[1] = nir_ssa_index(match.A.def);
ins->swizzle[1][0] = match.A.comp;
ins->src_types[1] = nir_type_uint | match.A.def->bit_size;
} else {
ins->load_store.bitsize_toggle = true;
ins->load_store.arg_comp = seg & 0x3;
ins->load_store.arg_reg = (seg >> 2) & 0x7;
}
if (match.B.def) {
ins->src[2] = nir_ssa_index(match.B.def);
ins->swizzle[2][0] = match.B.comp;
ins->src_types[2] = nir_type_uint | match.B.def->bit_size;
} else
ins->load_store.index_reg = REGISTER_LDST_ZERO;
if (force_sext)
match.type = midgard_index_address_s32;
ins->load_store.index_format = match.type;
assert(match.shift <= 7);
ins->load_store.index_shift = match.shift;
ins->constants.u32[0] = match.bias;
}
void
mir_set_ubo_offset(midgard_instruction *ins, nir_src *src, unsigned bias)
{
assert(src->is_ssa);
struct mir_address match = mir_match_offset(src->ssa, false, false);
if (match.B.def) {
ins->src[2] = nir_ssa_index(match.B.def);
for (unsigned i = 0; i < ARRAY_SIZE(ins->swizzle[2]); ++i)
ins->swizzle[2][i] = match.B.comp;
}
ins->load_store.index_shift = match.shift;
ins->constants.u32[0] = match.bias + bias;
}