yuzu/src/shader_recompiler/backend/glsl/reg_alloc.cpp
2021-07-22 21:51:35 -04:00

97 lines
2.8 KiB
C++

// Copyright 2021 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <string>
#include <string_view>
#include <fmt/format.h>
#include "shader_recompiler/backend/glsl/reg_alloc.h"
#include "shader_recompiler/exception.h"
#include "shader_recompiler/frontend/ir/value.h"
namespace Shader::Backend::GLSL {
namespace {
constexpr std::string_view SWIZZLE = "xyzw";
std::string Representation(Id id) {
if (id.is_condition_code != 0) {
throw NotImplementedException("Condition code");
}
if (id.is_spill != 0) {
throw NotImplementedException("Spilling");
}
const u32 num_elements{id.num_elements_minus_one + 1};
const u32 index{static_cast<u32>(id.index)};
if (num_elements == 4) {
return fmt::format("R{}", index);
} else {
return fmt::format("R{}.{}", index, SWIZZLE.substr(id.base_element, num_elements));
}
}
std::string MakeImm(const IR::Value& value) {
switch (value.Type()) {
case IR::Type::U1:
return fmt::format("{}", value.U1() ? "true" : "false");
case IR::Type::U32:
return fmt::format("{}", value.U32());
case IR::Type::F32:
return fmt::format("{}", value.F32());
case IR::Type::U64:
return fmt::format("{}", value.U64());
case IR::Type::F64:
return fmt::format("{}", value.F64());
default:
throw NotImplementedException("Immediate type {}", value.Type());
}
}
} // Anonymous namespace
std::string RegAlloc::Define(IR::Inst& inst, u32 num_elements, u32 alignment) {
const Id id{Alloc(num_elements, alignment)};
inst.SetDefinition<Id>(id);
return Representation(id);
}
std::string RegAlloc::Consume(const IR::Value& value) {
return value.IsImmediate() ? MakeImm(value) : Consume(*value.Inst());
}
std::string RegAlloc::Consume(IR::Inst& inst) {
const Id id{inst.Definition<Id>()};
inst.DestructiveRemoveUsage();
if (!inst.HasUses()) {
Free(id);
}
return Representation(inst.Definition<Id>());
}
Id RegAlloc::Alloc(u32 num_elements, [[maybe_unused]] u32 alignment) {
for (size_t reg = 0; reg < NUM_REGS; ++reg) {
if (register_use[reg]) {
continue;
}
num_used_registers = std::max(num_used_registers, reg + 1);
register_use[reg] = true;
return Id{
.base_element = 0,
.num_elements_minus_one = num_elements - 1,
.index = static_cast<u32>(reg),
.is_spill = 0,
.is_condition_code = 0,
};
}
throw NotImplementedException("Register spilling");
}
void RegAlloc::Free(Id id) {
if (id.is_spill != 0) {
throw NotImplementedException("Free spill");
}
register_use[id.index] = false;
}
} // namespace Shader::Backend::GLSL