dawn-cmake/src/backend/common/BindGroupLayout.cpp

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// Copyright 2017 The NXT Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "BindGroupLayout.h"
#include "Device.h"
#include <functional>
namespace backend {
namespace {
// Workaround for Chrome's stdlib having a broken std::hash for enums and bitsets
template<typename T>
typename std::enable_if<std::is_enum<T>::value, size_t>::type Hash(T value) {
using Integral = typename nxt::UnderlyingType<T>::type;
return std::hash<Integral>()(static_cast<Integral>(value));
}
template<size_t N>
size_t Hash(const std::bitset<N>& value) {
static_assert(N <= sizeof(unsigned long long) * 8, "");
return std::hash<unsigned long long>()(value.to_ullong());
}
// TODO(cwallez@chromium.org): see if we can use boost's hash combined or some equivalent
// this currently assumes that size_t is 64 bits
void CombineHashes(size_t* h1, size_t h2) {
*h1 ^= (h2 << 7) + (h2 >> (64 - 7)) + 0x304975;
}
size_t HashBindingInfo(const BindGroupLayoutBase::LayoutBindingInfo& info) {
size_t hash = Hash(info.mask);
for (size_t binding = 0; binding < kMaxBindingsPerGroup; ++binding) {
if (info.mask[binding]) {
CombineHashes(&hash, Hash(info.visibilities[binding]));
CombineHashes(&hash, Hash(info.types[binding]));
}
}
return hash;
}
bool operator== (const BindGroupLayoutBase::LayoutBindingInfo& a, const BindGroupLayoutBase::LayoutBindingInfo& b) {
if (a.mask != b.mask) {
return false;
}
for (size_t binding = 0; binding < kMaxBindingsPerGroup; ++binding) {
if (a.mask[binding]) {
if (a.visibilities[binding] != b.visibilities[binding]) {
return false;
}
if (a.types[binding] != b.types[binding]) {
return false;
}
}
}
return true;
}
}
// BindGroupLayoutBase
BindGroupLayoutBase::BindGroupLayoutBase(BindGroupLayoutBuilder* builder, bool blueprint)
: device(builder->device), bindingInfo(builder->bindingInfo), blueprint(blueprint) {
}
BindGroupLayoutBase::~BindGroupLayoutBase() {
// Do not register the actual cached object if we are a blueprint
if (!blueprint) {
device->UncacheBindGroupLayout(this);
}
}
const BindGroupLayoutBase::LayoutBindingInfo& BindGroupLayoutBase::GetBindingInfo() const {
return bindingInfo;
}
// BindGroupLayoutBuilder
BindGroupLayoutBuilder::BindGroupLayoutBuilder(DeviceBase* device) : Builder(device) {
}
const BindGroupLayoutBase::LayoutBindingInfo& BindGroupLayoutBuilder::GetBindingInfo() const {
return bindingInfo;
}
BindGroupLayoutBase* BindGroupLayoutBuilder::GetResultImpl() {
BindGroupLayoutBase blueprint(this, true);
auto* result = device->GetOrCreateBindGroupLayout(&blueprint, this);
result->Reference();
return result;
}
void BindGroupLayoutBuilder::SetBindingsType(nxt::ShaderStageBit visibility, nxt::BindingType bindingType, uint32_t start, uint32_t count) {
if (start + count > kMaxBindingsPerGroup) {
HandleError("Setting bindings type over maximum number of bindings");
return;
}
for (size_t i = start; i < start + count; i++) {
if (bindingInfo.mask[i]) {
HandleError("Setting already set binding type");
return;
}
bindingInfo.mask.set(i);
bindingInfo.visibilities[i] = visibility;
bindingInfo.types[i] = bindingType;
}
}
// BindGroupLayoutCacheFuncs
size_t BindGroupLayoutCacheFuncs::operator() (const BindGroupLayoutBase* bgl) const {
return HashBindingInfo(bgl->GetBindingInfo());
}
bool BindGroupLayoutCacheFuncs::operator() (const BindGroupLayoutBase* a, const BindGroupLayoutBase* b) const {
return a->GetBindingInfo() == b->GetBindingInfo();
}
}