Files
Xenia-Canary/src/xenia/gpu/spirv_shader_translator_alu.cc
2020-10-31 17:56:46 +03:00

229 lines
9.6 KiB
C++

/**
******************************************************************************
* Xenia : Xbox 360 Emulator Research Project *
******************************************************************************
* Copyright 2020 Ben Vanik. All rights reserved. *
* Released under the BSD license - see LICENSE in the root for more details. *
******************************************************************************
*/
#include "xenia/gpu/spirv_shader_translator.h"
#include <memory>
#include "third_party/glslang/SPIRV/GLSL.std.450.h"
#include "xenia/base/assert.h"
#include "xenia/base/math.h"
namespace xe {
namespace gpu {
void SpirvShaderTranslator::ProcessAluInstruction(
const ParsedAluInstruction& instr) {
if (instr.IsNop()) {
// Don't even disassemble or update predication.
return;
}
UpdateInstructionPredication(instr.is_predicated, instr.predicate_condition);
// Floating-point arithmetic operations (addition, subtraction, negation,
// multiplication, dot product, division, modulo - see isArithmeticOperation
// in propagateNoContraction of glslang) must have the NoContraction
// decoration to prevent reordering to make sure floating-point calculations
// are optimized predictably and exactly the same in different shaders to
// allow for multipass rendering (in addition to the Invariant decoration on
// outputs).
// Whether the instruction has changed the predicate, and it needs to be
// checked again later.
bool predicate_written_vector = false;
spv::Id vector_result =
ProcessVectorAluOperation(instr, predicate_written_vector);
// TODO(Triang3l): Process the ALU scalar operation.
StoreResult(instr.vector_and_constant_result, vector_result);
if (predicate_written_vector) {
cf_exec_predicate_written_ = true;
CloseInstructionPredication();
}
}
spv::Id SpirvShaderTranslator::ProcessVectorAluOperation(
const ParsedAluInstruction& instr, bool& predicate_written) {
predicate_written = false;
uint32_t used_result_components =
instr.vector_and_constant_result.GetUsedResultComponents();
if (!used_result_components &&
!AluVectorOpHasSideEffects(instr.vector_opcode)) {
return spv::NoResult;
}
uint32_t used_result_component_count = xe::bit_count(used_result_components);
// Load operand storage without swizzle and sign modifiers.
// A small shortcut, operands of cube are the same, but swizzled.
uint32_t operand_count;
if (instr.vector_opcode == ucode::AluVectorOpcode::kCube) {
operand_count = 1;
} else {
operand_count = instr.vector_operand_count;
}
spv::Id operand_storage[3] = {};
for (uint32_t i = 0; i < operand_count; ++i) {
operand_storage[i] = LoadOperandStorage(instr.vector_operands[i]);
}
spv::Id result_type =
used_result_component_count
? type_float_vectors_[used_result_component_count - 1]
: spv::NoType;
// In case the paired scalar instruction (if processed first) terminates the
// block (like via OpKill).
EnsureBuildPointAvailable();
switch (instr.vector_opcode) {
case ucode::AluVectorOpcode::kAdd: {
spv::Id result = builder_->createBinOp(
spv::OpFAdd, result_type,
GetOperandComponents(operand_storage[0], instr.vector_operands[0],
used_result_components),
GetOperandComponents(operand_storage[1], instr.vector_operands[1],
used_result_components));
builder_->addDecoration(result, spv::DecorationNoContraction);
return result;
} break;
case ucode::AluVectorOpcode::kMul:
case ucode::AluVectorOpcode::kMad: {
spv::Id multiplicands[2];
for (uint32_t i = 0; i < 2; ++i) {
multiplicands[i] =
GetOperandComponents(operand_storage[i], instr.vector_operands[i],
used_result_components);
}
spv::Id result = builder_->createBinOp(
spv::OpFMul, result_type, multiplicands[0], multiplicands[1]);
builder_->addDecoration(result, spv::DecorationNoContraction);
uint32_t multiplicands_different =
used_result_components &
~instr.vector_operands[0].GetIdenticalComponents(
instr.vector_operands[1]);
if (multiplicands_different) {
// Shader Model 3: +0 or denormal * anything = +-0.
spv::Id different_operands[2] = {multiplicands[0], multiplicands[1]};
spv::Id different_result = result;
uint32_t different_count = xe::bit_count(multiplicands_different);
spv::Id different_type = type_float_vectors_[different_count - 1];
// Extract the different components, if not all are different.
if (multiplicands_different != used_result_components) {
uint_vector_temp_.clear();
uint_vector_temp_.reserve(different_count);
uint32_t components_remaining = used_result_components;
for (uint32_t i = 0; i < used_result_component_count; ++i) {
uint32_t component;
xe::bit_scan_forward(components_remaining, &component);
components_remaining &= ~(1 << component);
if (multiplicands_different & (1 << component)) {
uint_vector_temp_.push_back(i);
}
}
assert_true(uint_vector_temp_.size() == different_count);
if (different_count > 1) {
for (uint32_t i = 0; i < 2; ++i) {
different_operands[i] = builder_->createRvalueSwizzle(
spv::NoPrecision, different_type, different_operands[i],
uint_vector_temp_);
}
different_result = builder_->createRvalueSwizzle(
spv::NoPrecision, different_type, different_result,
uint_vector_temp_);
} else {
for (uint32_t i = 0; i < 2; ++i) {
different_operands[i] = builder_->createCompositeExtract(
different_operands[i], different_type, uint_vector_temp_[0]);
}
different_result = builder_->createCompositeExtract(
different_result, different_type, uint_vector_temp_[0]);
}
}
// Check if the different components in any of the operands are zero,
// even if the other is NaN - if min(|a|, |b|) is 0.
for (uint32_t i = 0; i < 2; ++i) {
if (instr.vector_operands[i].is_absolute_value &&
!instr.vector_operands[i].is_negated) {
continue;
}
id_vector_temp_.clear();
id_vector_temp_.push_back(different_operands[i]);
different_operands[i] = builder_->createBuiltinCall(
different_type, ext_inst_glsl_std_450_, GLSLstd450FAbs,
id_vector_temp_);
}
id_vector_temp_.clear();
id_vector_temp_.reserve(2);
id_vector_temp_.push_back(different_operands[0]);
id_vector_temp_.push_back(different_operands[1]);
spv::Id different_abs_min =
builder_->createBuiltinCall(different_type, ext_inst_glsl_std_450_,
GLSLstd450NMin, id_vector_temp_);
spv::Id different_zero = builder_->createBinOp(
spv::OpFOrdEqual, type_bool_vectors_[different_count - 1],
different_abs_min, const_float_vectors_0_[different_count - 1]);
// Replace with +0.
different_result = builder_->createTriOp(
spv::OpSelect, different_type, different_zero,
const_float_vectors_0_[different_count - 1], different_result);
// Insert the different components back to the result.
if (multiplicands_different != used_result_components) {
if (different_count > 1) {
std::unique_ptr<spv::Instruction> shuffle_op =
std::make_unique<spv::Instruction>(
builder_->getUniqueId(), result_type, spv::OpVectorShuffle);
shuffle_op->addIdOperand(result);
shuffle_op->addIdOperand(different_result);
uint32_t components_remaining = used_result_components;
unsigned int different_shuffle_index = used_result_component_count;
for (uint32_t i = 0; i < used_result_component_count; ++i) {
uint32_t component;
xe::bit_scan_forward(components_remaining, &component);
components_remaining &= ~(1 << component);
shuffle_op->addImmediateOperand(
(multiplicands_different & (1 << component))
? different_shuffle_index++
: i);
}
result = shuffle_op->getResultId();
builder_->getBuildPoint()->addInstruction(std::move(shuffle_op));
} else {
result = builder_->createCompositeInsert(
different_result, result, result_type,
xe::bit_count(used_result_components &
(multiplicands_different - 1)));
}
} else {
result = different_result;
}
}
if (instr.vector_opcode == ucode::AluVectorOpcode::kMad) {
// Not replacing true `0 + term` with conditional selection of the term
// because +0 + -0 should result in +0, not -0.
result = builder_->createBinOp(
spv::OpFAdd, result_type, result,
GetOperandComponents(operand_storage[2], instr.vector_operands[2],
used_result_components));
builder_->addDecoration(result, spv::DecorationNoContraction);
}
} break;
// TODO(Triang3l): Handle all instructions.
default:
break;
}
// Invalid instruction.
return spv::NoResult;
}
} // namespace gpu
} // namespace xe