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-rw-r--r--src/3rdparty/SPIRV-Cross/spirv_cross.cpp4121
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diff --git a/src/3rdparty/SPIRV-Cross/spirv_cross.cpp b/src/3rdparty/SPIRV-Cross/spirv_cross.cpp
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--- /dev/null
+++ b/src/3rdparty/SPIRV-Cross/spirv_cross.cpp
@@ -0,0 +1,4121 @@
+/*
+ * Copyright 2015-2019 Arm Limited
+ *
+ * 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 "spirv_cross.hpp"
+#include "GLSL.std.450.h"
+#include "spirv_cfg.hpp"
+#include "spirv_parser.hpp"
+#include <algorithm>
+#include <cstring>
+#include <utility>
+
+using namespace std;
+using namespace spv;
+using namespace spirv_cross;
+
+Compiler::Compiler(vector<uint32_t> ir_)
+{
+ Parser parser(move(ir_));
+ parser.parse();
+ set_ir(move(parser.get_parsed_ir()));
+}
+
+Compiler::Compiler(const uint32_t *ir_, size_t word_count)
+{
+ Parser parser(ir_, word_count);
+ parser.parse();
+ set_ir(move(parser.get_parsed_ir()));
+}
+
+Compiler::Compiler(const ParsedIR &ir_)
+{
+ set_ir(ir_);
+}
+
+Compiler::Compiler(ParsedIR &&ir_)
+{
+ set_ir(move(ir_));
+}
+
+void Compiler::set_ir(ParsedIR &&ir_)
+{
+ ir = move(ir_);
+ parse_fixup();
+}
+
+void Compiler::set_ir(const ParsedIR &ir_)
+{
+ ir = ir_;
+ parse_fixup();
+}
+
+string Compiler::compile()
+{
+ return "";
+}
+
+bool Compiler::variable_storage_is_aliased(const SPIRVariable &v)
+{
+ auto &type = get<SPIRType>(v.basetype);
+ bool ssbo = v.storage == StorageClassStorageBuffer ||
+ ir.meta[type.self].decoration.decoration_flags.get(DecorationBufferBlock);
+ bool image = type.basetype == SPIRType::Image;
+ bool counter = type.basetype == SPIRType::AtomicCounter;
+
+ bool is_restrict;
+ if (ssbo)
+ is_restrict = ir.get_buffer_block_flags(v).get(DecorationRestrict);
+ else
+ is_restrict = has_decoration(v.self, DecorationRestrict);
+
+ return !is_restrict && (ssbo || image || counter);
+}
+
+bool Compiler::block_is_pure(const SPIRBlock &block)
+{
+ for (auto &i : block.ops)
+ {
+ auto ops = stream(i);
+ auto op = static_cast<Op>(i.op);
+
+ switch (op)
+ {
+ case OpFunctionCall:
+ {
+ uint32_t func = ops[2];
+ if (!function_is_pure(get<SPIRFunction>(func)))
+ return false;
+ break;
+ }
+
+ case OpCopyMemory:
+ case OpStore:
+ {
+ auto &type = expression_type(ops[0]);
+ if (type.storage != StorageClassFunction)
+ return false;
+ break;
+ }
+
+ case OpImageWrite:
+ return false;
+
+ // Atomics are impure.
+ case OpAtomicLoad:
+ case OpAtomicStore:
+ case OpAtomicExchange:
+ case OpAtomicCompareExchange:
+ case OpAtomicCompareExchangeWeak:
+ case OpAtomicIIncrement:
+ case OpAtomicIDecrement:
+ case OpAtomicIAdd:
+ case OpAtomicISub:
+ case OpAtomicSMin:
+ case OpAtomicUMin:
+ case OpAtomicSMax:
+ case OpAtomicUMax:
+ case OpAtomicAnd:
+ case OpAtomicOr:
+ case OpAtomicXor:
+ return false;
+
+ // Geometry shader builtins modify global state.
+ case OpEndPrimitive:
+ case OpEmitStreamVertex:
+ case OpEndStreamPrimitive:
+ case OpEmitVertex:
+ return false;
+
+ // Barriers disallow any reordering, so we should treat blocks with barrier as writing.
+ case OpControlBarrier:
+ case OpMemoryBarrier:
+ return false;
+
+ // Ray tracing builtins are impure.
+ case OpReportIntersectionNV:
+ case OpIgnoreIntersectionNV:
+ case OpTerminateRayNV:
+ case OpTraceNV:
+ case OpExecuteCallableNV:
+ return false;
+
+ // OpExtInst is potentially impure depending on extension, but GLSL builtins are at least pure.
+
+ default:
+ break;
+ }
+ }
+
+ return true;
+}
+
+string Compiler::to_name(uint32_t id, bool allow_alias) const
+{
+ if (allow_alias && ir.ids[id].get_type() == TypeType)
+ {
+ // If this type is a simple alias, emit the
+ // name of the original type instead.
+ // We don't want to override the meta alias
+ // as that can be overridden by the reflection APIs after parse.
+ auto &type = get<SPIRType>(id);
+ if (type.type_alias)
+ {
+ // If the alias master has been specially packed, we will have emitted a clean variant as well,
+ // so skip the name aliasing here.
+ if (!has_extended_decoration(type.type_alias, SPIRVCrossDecorationPacked))
+ return to_name(type.type_alias);
+ }
+ }
+
+ auto &alias = ir.get_name(id);
+ if (alias.empty())
+ return join("_", id);
+ else
+ return alias;
+}
+
+bool Compiler::function_is_pure(const SPIRFunction &func)
+{
+ for (auto block : func.blocks)
+ {
+ if (!block_is_pure(get<SPIRBlock>(block)))
+ {
+ //fprintf(stderr, "Function %s is impure!\n", to_name(func.self).c_str());
+ return false;
+ }
+ }
+
+ //fprintf(stderr, "Function %s is pure!\n", to_name(func.self).c_str());
+ return true;
+}
+
+void Compiler::register_global_read_dependencies(const SPIRBlock &block, uint32_t id)
+{
+ for (auto &i : block.ops)
+ {
+ auto ops = stream(i);
+ auto op = static_cast<Op>(i.op);
+
+ switch (op)
+ {
+ case OpFunctionCall:
+ {
+ uint32_t func = ops[2];
+ register_global_read_dependencies(get<SPIRFunction>(func), id);
+ break;
+ }
+
+ case OpLoad:
+ case OpImageRead:
+ {
+ // If we're in a storage class which does not get invalidated, adding dependencies here is no big deal.
+ auto *var = maybe_get_backing_variable(ops[2]);
+ if (var && var->storage != StorageClassFunction)
+ {
+ auto &type = get<SPIRType>(var->basetype);
+
+ // InputTargets are immutable.
+ if (type.basetype != SPIRType::Image && type.image.dim != DimSubpassData)
+ var->dependees.push_back(id);
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+ }
+}
+
+void Compiler::register_global_read_dependencies(const SPIRFunction &func, uint32_t id)
+{
+ for (auto block : func.blocks)
+ register_global_read_dependencies(get<SPIRBlock>(block), id);
+}
+
+SPIRVariable *Compiler::maybe_get_backing_variable(uint32_t chain)
+{
+ auto *var = maybe_get<SPIRVariable>(chain);
+ if (!var)
+ {
+ auto *cexpr = maybe_get<SPIRExpression>(chain);
+ if (cexpr)
+ var = maybe_get<SPIRVariable>(cexpr->loaded_from);
+
+ auto *access_chain = maybe_get<SPIRAccessChain>(chain);
+ if (access_chain)
+ var = maybe_get<SPIRVariable>(access_chain->loaded_from);
+ }
+
+ return var;
+}
+
+void Compiler::register_read(uint32_t expr, uint32_t chain, bool forwarded)
+{
+ auto &e = get<SPIRExpression>(expr);
+ auto *var = maybe_get_backing_variable(chain);
+
+ if (var)
+ {
+ e.loaded_from = var->self;
+
+ // If the backing variable is immutable, we do not need to depend on the variable.
+ if (forwarded && !is_immutable(var->self))
+ var->dependees.push_back(e.self);
+
+ // If we load from a parameter, make sure we create "inout" if we also write to the parameter.
+ // The default is "in" however, so we never invalidate our compilation by reading.
+ if (var && var->parameter)
+ var->parameter->read_count++;
+ }
+}
+
+void Compiler::register_write(uint32_t chain)
+{
+ auto *var = maybe_get<SPIRVariable>(chain);
+ if (!var)
+ {
+ // If we're storing through an access chain, invalidate the backing variable instead.
+ auto *expr = maybe_get<SPIRExpression>(chain);
+ if (expr && expr->loaded_from)
+ var = maybe_get<SPIRVariable>(expr->loaded_from);
+
+ auto *access_chain = maybe_get<SPIRAccessChain>(chain);
+ if (access_chain && access_chain->loaded_from)
+ var = maybe_get<SPIRVariable>(access_chain->loaded_from);
+ }
+
+ if (var)
+ {
+ // If our variable is in a storage class which can alias with other buffers,
+ // invalidate all variables which depend on aliased variables. And if this is a
+ // variable pointer, then invalidate all variables regardless.
+ if (get_variable_data_type(*var).pointer)
+ flush_all_active_variables();
+ if (variable_storage_is_aliased(*var))
+ flush_all_aliased_variables();
+ else if (var)
+ flush_dependees(*var);
+
+ // We tried to write to a parameter which is not marked with out qualifier, force a recompile.
+ if (var->parameter && var->parameter->write_count == 0)
+ {
+ var->parameter->write_count++;
+ force_recompile = true;
+ }
+ }
+ else
+ {
+ // If we stored through a variable pointer, then we don't know which
+ // variable we stored to. So *all* expressions after this point need to
+ // be invalidated.
+ // FIXME: If we can prove that the variable pointer will point to
+ // only certain variables, we can invalidate only those.
+ flush_all_active_variables();
+ }
+}
+
+void Compiler::flush_dependees(SPIRVariable &var)
+{
+ for (auto expr : var.dependees)
+ invalid_expressions.insert(expr);
+ var.dependees.clear();
+}
+
+void Compiler::flush_all_aliased_variables()
+{
+ for (auto aliased : aliased_variables)
+ flush_dependees(get<SPIRVariable>(aliased));
+}
+
+void Compiler::flush_all_atomic_capable_variables()
+{
+ for (auto global : global_variables)
+ flush_dependees(get<SPIRVariable>(global));
+ flush_all_aliased_variables();
+}
+
+void Compiler::flush_control_dependent_expressions(uint32_t block_id)
+{
+ auto &block = get<SPIRBlock>(block_id);
+ for (auto &expr : block.invalidate_expressions)
+ invalid_expressions.insert(expr);
+ block.invalidate_expressions.clear();
+}
+
+void Compiler::flush_all_active_variables()
+{
+ // Invalidate all temporaries we read from variables in this block since they were forwarded.
+ // Invalidate all temporaries we read from globals.
+ for (auto &v : current_function->local_variables)
+ flush_dependees(get<SPIRVariable>(v));
+ for (auto &arg : current_function->arguments)
+ flush_dependees(get<SPIRVariable>(arg.id));
+ for (auto global : global_variables)
+ flush_dependees(get<SPIRVariable>(global));
+
+ flush_all_aliased_variables();
+}
+
+uint32_t Compiler::expression_type_id(uint32_t id) const
+{
+ switch (ir.ids[id].get_type())
+ {
+ case TypeVariable:
+ return get<SPIRVariable>(id).basetype;
+
+ case TypeExpression:
+ return get<SPIRExpression>(id).expression_type;
+
+ case TypeConstant:
+ return get<SPIRConstant>(id).constant_type;
+
+ case TypeConstantOp:
+ return get<SPIRConstantOp>(id).basetype;
+
+ case TypeUndef:
+ return get<SPIRUndef>(id).basetype;
+
+ case TypeCombinedImageSampler:
+ return get<SPIRCombinedImageSampler>(id).combined_type;
+
+ case TypeAccessChain:
+ return get<SPIRAccessChain>(id).basetype;
+
+ default:
+ SPIRV_CROSS_THROW("Cannot resolve expression type.");
+ }
+}
+
+const SPIRType &Compiler::expression_type(uint32_t id) const
+{
+ return get<SPIRType>(expression_type_id(id));
+}
+
+bool Compiler::expression_is_lvalue(uint32_t id) const
+{
+ auto &type = expression_type(id);
+ switch (type.basetype)
+ {
+ case SPIRType::SampledImage:
+ case SPIRType::Image:
+ case SPIRType::Sampler:
+ return false;
+
+ default:
+ return true;
+ }
+}
+
+bool Compiler::is_immutable(uint32_t id) const
+{
+ if (ir.ids[id].get_type() == TypeVariable)
+ {
+ auto &var = get<SPIRVariable>(id);
+
+ // Anything we load from the UniformConstant address space is guaranteed to be immutable.
+ bool pointer_to_const = var.storage == StorageClassUniformConstant;
+ return pointer_to_const || var.phi_variable || !expression_is_lvalue(id);
+ }
+ else if (ir.ids[id].get_type() == TypeAccessChain)
+ return get<SPIRAccessChain>(id).immutable;
+ else if (ir.ids[id].get_type() == TypeExpression)
+ return get<SPIRExpression>(id).immutable;
+ else if (ir.ids[id].get_type() == TypeConstant || ir.ids[id].get_type() == TypeConstantOp ||
+ ir.ids[id].get_type() == TypeUndef)
+ return true;
+ else
+ return false;
+}
+
+static inline bool storage_class_is_interface(spv::StorageClass storage)
+{
+ switch (storage)
+ {
+ case StorageClassInput:
+ case StorageClassOutput:
+ case StorageClassUniform:
+ case StorageClassUniformConstant:
+ case StorageClassAtomicCounter:
+ case StorageClassPushConstant:
+ case StorageClassStorageBuffer:
+ return true;
+
+ default:
+ return false;
+ }
+}
+
+bool Compiler::is_hidden_variable(const SPIRVariable &var, bool include_builtins) const
+{
+ if ((is_builtin_variable(var) && !include_builtins) || var.remapped_variable)
+ return true;
+
+ // Combined image samplers are always considered active as they are "magic" variables.
+ if (find_if(begin(combined_image_samplers), end(combined_image_samplers), [&var](const CombinedImageSampler &samp) {
+ return samp.combined_id == var.self;
+ }) != end(combined_image_samplers))
+ {
+ return false;
+ }
+
+ bool hidden = false;
+ if (check_active_interface_variables && storage_class_is_interface(var.storage))
+ hidden = active_interface_variables.find(var.self) == end(active_interface_variables);
+ return hidden;
+}
+
+bool Compiler::is_builtin_type(const SPIRType &type) const
+{
+ auto *type_meta = ir.find_meta(type.self);
+
+ // We can have builtin structs as well. If one member of a struct is builtin, the struct must also be builtin.
+ if (type_meta)
+ for (auto &m : type_meta->members)
+ if (m.builtin)
+ return true;
+
+ return false;
+}
+
+bool Compiler::is_builtin_variable(const SPIRVariable &var) const
+{
+ auto *m = ir.find_meta(var.self);
+
+ if (var.compat_builtin || (m && m->decoration.builtin))
+ return true;
+ else
+ return is_builtin_type(get<SPIRType>(var.basetype));
+}
+
+bool Compiler::is_member_builtin(const SPIRType &type, uint32_t index, BuiltIn *builtin) const
+{
+ auto *type_meta = ir.find_meta(type.self);
+
+ if (type_meta)
+ {
+ auto &memb = type_meta->members;
+ if (index < memb.size() && memb[index].builtin)
+ {
+ if (builtin)
+ *builtin = memb[index].builtin_type;
+ return true;
+ }
+ }
+
+ return false;
+}
+
+bool Compiler::is_scalar(const SPIRType &type) const
+{
+ return type.basetype != SPIRType::Struct && type.vecsize == 1 && type.columns == 1;
+}
+
+bool Compiler::is_vector(const SPIRType &type) const
+{
+ return type.vecsize > 1 && type.columns == 1;
+}
+
+bool Compiler::is_matrix(const SPIRType &type) const
+{
+ return type.vecsize > 1 && type.columns > 1;
+}
+
+bool Compiler::is_array(const SPIRType &type) const
+{
+ return !type.array.empty();
+}
+
+ShaderResources Compiler::get_shader_resources() const
+{
+ return get_shader_resources(nullptr);
+}
+
+ShaderResources Compiler::get_shader_resources(const unordered_set<uint32_t> &active_variables) const
+{
+ return get_shader_resources(&active_variables);
+}
+
+bool Compiler::InterfaceVariableAccessHandler::handle(Op opcode, const uint32_t *args, uint32_t length)
+{
+ uint32_t variable = 0;
+ switch (opcode)
+ {
+ // Need this first, otherwise, GCC complains about unhandled switch statements.
+ default:
+ break;
+
+ case OpFunctionCall:
+ {
+ // Invalid SPIR-V.
+ if (length < 3)
+ return false;
+
+ uint32_t count = length - 3;
+ args += 3;
+ for (uint32_t i = 0; i < count; i++)
+ {
+ auto *var = compiler.maybe_get<SPIRVariable>(args[i]);
+ if (var && storage_class_is_interface(var->storage))
+ variables.insert(args[i]);
+ }
+ break;
+ }
+
+ case OpSelect:
+ {
+ // Invalid SPIR-V.
+ if (length < 5)
+ return false;
+
+ uint32_t count = length - 3;
+ args += 3;
+ for (uint32_t i = 0; i < count; i++)
+ {
+ auto *var = compiler.maybe_get<SPIRVariable>(args[i]);
+ if (var && storage_class_is_interface(var->storage))
+ variables.insert(args[i]);
+ }
+ break;
+ }
+
+ case OpPhi:
+ {
+ // Invalid SPIR-V.
+ if (length < 2)
+ return false;
+
+ uint32_t count = length - 2;
+ args += 2;
+ for (uint32_t i = 0; i < count; i += 2)
+ {
+ auto *var = compiler.maybe_get<SPIRVariable>(args[i]);
+ if (var && storage_class_is_interface(var->storage))
+ variables.insert(args[i]);
+ }
+ break;
+ }
+
+ case OpAtomicStore:
+ case OpStore:
+ // Invalid SPIR-V.
+ if (length < 1)
+ return false;
+ variable = args[0];
+ break;
+
+ case OpCopyMemory:
+ {
+ if (length < 2)
+ return false;
+
+ auto *var = compiler.maybe_get<SPIRVariable>(args[0]);
+ if (var && storage_class_is_interface(var->storage))
+ variables.insert(variable);
+
+ var = compiler.maybe_get<SPIRVariable>(args[1]);
+ if (var && storage_class_is_interface(var->storage))
+ variables.insert(variable);
+ break;
+ }
+
+ case OpExtInst:
+ {
+ if (length < 5)
+ return false;
+ uint32_t extension_set = args[2];
+ if (compiler.get<SPIRExtension>(extension_set).ext == SPIRExtension::SPV_AMD_shader_explicit_vertex_parameter)
+ {
+ enum AMDShaderExplicitVertexParameter
+ {
+ InterpolateAtVertexAMD = 1
+ };
+
+ auto op = static_cast<AMDShaderExplicitVertexParameter>(args[3]);
+
+ switch (op)
+ {
+ case InterpolateAtVertexAMD:
+ {
+ auto *var = compiler.maybe_get<SPIRVariable>(args[4]);
+ if (var && storage_class_is_interface(var->storage))
+ variables.insert(args[4]);
+ break;
+ }
+
+ default:
+ break;
+ }
+ }
+ break;
+ }
+
+ case OpAccessChain:
+ case OpInBoundsAccessChain:
+ case OpPtrAccessChain:
+ case OpLoad:
+ case OpCopyObject:
+ case OpImageTexelPointer:
+ case OpAtomicLoad:
+ case OpAtomicExchange:
+ case OpAtomicCompareExchange:
+ case OpAtomicCompareExchangeWeak:
+ case OpAtomicIIncrement:
+ case OpAtomicIDecrement:
+ case OpAtomicIAdd:
+ case OpAtomicISub:
+ case OpAtomicSMin:
+ case OpAtomicUMin:
+ case OpAtomicSMax:
+ case OpAtomicUMax:
+ case OpAtomicAnd:
+ case OpAtomicOr:
+ case OpAtomicXor:
+ // Invalid SPIR-V.
+ if (length < 3)
+ return false;
+ variable = args[2];
+ break;
+ }
+
+ if (variable)
+ {
+ auto *var = compiler.maybe_get<SPIRVariable>(variable);
+ if (var && storage_class_is_interface(var->storage))
+ variables.insert(variable);
+ }
+ return true;
+}
+
+unordered_set<uint32_t> Compiler::get_active_interface_variables() const
+{
+ // Traverse the call graph and find all interface variables which are in use.
+ unordered_set<uint32_t> variables;
+ InterfaceVariableAccessHandler handler(*this, variables);
+ traverse_all_reachable_opcodes(get<SPIRFunction>(ir.default_entry_point), handler);
+
+ // Make sure we preserve output variables which are only initialized, but never accessed by any code.
+ ir.for_each_typed_id<SPIRVariable>([&](uint32_t, const SPIRVariable &var) {
+ if (var.storage == StorageClassOutput && var.initializer != 0)
+ variables.insert(var.self);
+ });
+
+ // If we needed to create one, we'll need it.
+ if (dummy_sampler_id)
+ variables.insert(dummy_sampler_id);
+
+ return variables;
+}
+
+void Compiler::set_enabled_interface_variables(std::unordered_set<uint32_t> active_variables)
+{
+ active_interface_variables = move(active_variables);
+ check_active_interface_variables = true;
+}
+
+ShaderResources Compiler::get_shader_resources(const unordered_set<uint32_t> *active_variables) const
+{
+ ShaderResources res;
+
+ ir.for_each_typed_id<SPIRVariable>([&](uint32_t, const SPIRVariable &var) {
+ auto &type = this->get<SPIRType>(var.basetype);
+
+ // It is possible for uniform storage classes to be passed as function parameters, so detect
+ // that. To detect function parameters, check of StorageClass of variable is function scope.
+ if (var.storage == StorageClassFunction || !type.pointer || is_builtin_variable(var))
+ return;
+
+ if (active_variables && active_variables->find(var.self) == end(*active_variables))
+ return;
+
+ // Input
+ if (var.storage == StorageClassInput && interface_variable_exists_in_entry_point(var.self))
+ {
+ if (has_decoration(type.self, DecorationBlock))
+ {
+ res.stage_inputs.push_back(
+ { var.self, var.basetype, type.self, get_remapped_declared_block_name(var.self) });
+ }
+ else
+ res.stage_inputs.push_back({ var.self, var.basetype, type.self, get_name(var.self) });
+ }
+ // Subpass inputs
+ else if (var.storage == StorageClassUniformConstant && type.image.dim == DimSubpassData)
+ {
+ res.subpass_inputs.push_back({ var.self, var.basetype, type.self, get_name(var.self) });
+ }
+ // Outputs
+ else if (var.storage == StorageClassOutput && interface_variable_exists_in_entry_point(var.self))
+ {
+ if (has_decoration(type.self, DecorationBlock))
+ {
+ res.stage_outputs.push_back(
+ { var.self, var.basetype, type.self, get_remapped_declared_block_name(var.self) });
+ }
+ else
+ res.stage_outputs.push_back({ var.self, var.basetype, type.self, get_name(var.self) });
+ }
+ // UBOs
+ else if (type.storage == StorageClassUniform && has_decoration(type.self, DecorationBlock))
+ {
+ res.uniform_buffers.push_back(
+ { var.self, var.basetype, type.self, get_remapped_declared_block_name(var.self) });
+ }
+ // Old way to declare SSBOs.
+ else if (type.storage == StorageClassUniform && has_decoration(type.self, DecorationBufferBlock))
+ {
+ res.storage_buffers.push_back(
+ { var.self, var.basetype, type.self, get_remapped_declared_block_name(var.self) });
+ }
+ // Modern way to declare SSBOs.
+ else if (type.storage == StorageClassStorageBuffer)
+ {
+ res.storage_buffers.push_back(
+ { var.self, var.basetype, type.self, get_remapped_declared_block_name(var.self) });
+ }
+ // Push constant blocks
+ else if (type.storage == StorageClassPushConstant)
+ {
+ // There can only be one push constant block, but keep the vector in case this restriction is lifted
+ // in the future.
+ res.push_constant_buffers.push_back({ var.self, var.basetype, type.self, get_name(var.self) });
+ }
+ // Images
+ else if (type.storage == StorageClassUniformConstant && type.basetype == SPIRType::Image &&
+ type.image.sampled == 2)
+ {
+ res.storage_images.push_back({ var.self, var.basetype, type.self, get_name(var.self) });
+ }
+ // Separate images
+ else if (type.storage == StorageClassUniformConstant && type.basetype == SPIRType::Image &&
+ type.image.sampled == 1)
+ {
+ res.separate_images.push_back({ var.self, var.basetype, type.self, get_name(var.self) });
+ }
+ // Separate samplers
+ else if (type.storage == StorageClassUniformConstant && type.basetype == SPIRType::Sampler)
+ {
+ res.separate_samplers.push_back({ var.self, var.basetype, type.self, get_name(var.self) });
+ }
+ // Textures
+ else if (type.storage == StorageClassUniformConstant && type.basetype == SPIRType::SampledImage)
+ {
+ res.sampled_images.push_back({ var.self, var.basetype, type.self, get_name(var.self) });
+ }
+ // Atomic counters
+ else if (type.storage == StorageClassAtomicCounter)
+ {
+ res.atomic_counters.push_back({ var.self, var.basetype, type.self, get_name(var.self) });
+ }
+ // Acceleration structures
+ else if (type.storage == StorageClassUniformConstant && type.basetype == SPIRType::AccelerationStructureNV)
+ {
+ res.acceleration_structures.push_back({ var.self, var.basetype, type.self, get_name(var.self) });
+ }
+ });
+
+ return res;
+}
+
+bool Compiler::type_is_block_like(const SPIRType &type) const
+{
+ if (type.basetype != SPIRType::Struct)
+ return false;
+
+ if (has_decoration(type.self, DecorationBlock) || has_decoration(type.self, DecorationBufferBlock))
+ {
+ return true;
+ }
+
+ // Block-like types may have Offset decorations.
+ for (uint32_t i = 0; i < uint32_t(type.member_types.size()); i++)
+ if (has_member_decoration(type.self, i, DecorationOffset))
+ return true;
+
+ return false;
+}
+
+void Compiler::fixup_type_alias()
+{
+ // Due to how some backends work, the "master" type of type_alias must be a block-like type if it exists.
+ // FIXME: Multiple alias types which are both block-like will be awkward, for now, it's best to just drop the type
+ // alias if the slave type is a block type.
+ ir.for_each_typed_id<SPIRType>([&](uint32_t self, SPIRType &type) {
+ if (type.type_alias && type_is_block_like(type))
+ {
+ // Become the master.
+ ir.for_each_typed_id<SPIRType>([&](uint32_t other_id, SPIRType &other_type) {
+ if (other_id == type.self)
+ return;
+
+ if (other_type.type_alias == type.type_alias)
+ other_type.type_alias = type.self;
+ });
+
+ this->get<SPIRType>(type.type_alias).type_alias = self;
+ type.type_alias = 0;
+ }
+ });
+
+ ir.for_each_typed_id<SPIRType>([&](uint32_t, SPIRType &type) {
+ if (type.type_alias && type_is_block_like(type))
+ {
+ // This is not allowed, drop the type_alias.
+ type.type_alias = 0;
+ }
+ });
+
+ // Reorder declaration of types so that the master of the type alias is always emitted first.
+ // We need this in case a type B depends on type A (A must come before in the vector), but A is an alias of a type Abuffer, which
+ // means declaration of A doesn't happen (yet), and order would be B, ABuffer and not ABuffer, B. Fix this up here.
+ auto &type_ids = ir.ids_for_type[TypeType];
+ for (auto alias_itr = begin(type_ids); alias_itr != end(type_ids); ++alias_itr)
+ {
+ auto &type = get<SPIRType>(*alias_itr);
+ if (type.type_alias != 0 && !has_extended_decoration(type.type_alias, SPIRVCrossDecorationPacked))
+ {
+ // We will skip declaring this type, so make sure the type_alias type comes before.
+ auto master_itr = find(begin(type_ids), end(type_ids), type.type_alias);
+ assert(master_itr != end(type_ids));
+
+ if (alias_itr < master_itr)
+ {
+ // Must also swap the type order for the constant-type joined array.
+ auto &joined_types = ir.ids_for_constant_or_type;
+ auto alt_alias_itr = find(begin(joined_types), end(joined_types), *alias_itr);
+ auto alt_master_itr = find(begin(joined_types), end(joined_types), *master_itr);
+ assert(alt_alias_itr != end(joined_types));
+ assert(alt_master_itr != end(joined_types));
+
+ swap(*alias_itr, *master_itr);
+ swap(*alt_alias_itr, *alt_master_itr);
+ }
+ }
+ }
+}
+
+void Compiler::parse_fixup()
+{
+ // Figure out specialization constants for work group sizes.
+ for (auto id_ : ir.ids_for_constant_or_variable)
+ {
+ auto &id = ir.ids[id_];
+
+ if (id.get_type() == TypeConstant)
+ {
+ auto &c = id.get<SPIRConstant>();
+ if (ir.meta[c.self].decoration.builtin && ir.meta[c.self].decoration.builtin_type == BuiltInWorkgroupSize)
+ {
+ // In current SPIR-V, there can be just one constant like this.
+ // All entry points will receive the constant value.
+ for (auto &entry : ir.entry_points)
+ {
+ entry.second.workgroup_size.constant = c.self;
+ entry.second.workgroup_size.x = c.scalar(0, 0);
+ entry.second.workgroup_size.y = c.scalar(0, 1);
+ entry.second.workgroup_size.z = c.scalar(0, 2);
+ }
+ }
+ }
+ else if (id.get_type() == TypeVariable)
+ {
+ auto &var = id.get<SPIRVariable>();
+ if (var.storage == StorageClassPrivate || var.storage == StorageClassWorkgroup ||
+ var.storage == StorageClassOutput)
+ global_variables.push_back(var.self);
+ if (variable_storage_is_aliased(var))
+ aliased_variables.push_back(var.self);
+ }
+ }
+
+ fixup_type_alias();
+}
+
+void Compiler::update_name_cache(unordered_set<string> &cache_primary, const unordered_set<string> &cache_secondary,
+ string &name)
+{
+ if (name.empty())
+ return;
+
+ const auto find_name = [&](const string &n) -> bool {
+ if (cache_primary.find(n) != end(cache_primary))
+ return true;
+
+ if (&cache_primary != &cache_secondary)
+ if (cache_secondary.find(n) != end(cache_secondary))
+ return true;
+
+ return false;
+ };
+
+ const auto insert_name = [&](const string &n) { cache_primary.insert(n); };
+
+ if (!find_name(name))
+ {
+ insert_name(name);
+ return;
+ }
+
+ uint32_t counter = 0;
+ auto tmpname = name;
+
+ bool use_linked_underscore = true;
+
+ if (tmpname == "_")
+ {
+ // We cannot just append numbers, as we will end up creating internally reserved names.
+ // Make it like _0_<counter> instead.
+ tmpname += "0";
+ }
+ else if (tmpname.back() == '_')
+ {
+ // The last_character is an underscore, so we don't need to link in underscore.
+ // This would violate double underscore rules.
+ use_linked_underscore = false;
+ }
+
+ // If there is a collision (very rare),
+ // keep tacking on extra identifier until it's unique.
+ do
+ {
+ counter++;
+ name = tmpname + (use_linked_underscore ? "_" : "") + convert_to_string(counter);
+ } while (find_name(name));
+ insert_name(name);
+}
+
+void Compiler::update_name_cache(unordered_set<string> &cache, string &name)
+{
+ update_name_cache(cache, cache, name);
+}
+
+void Compiler::set_name(uint32_t id, const std::string &name)
+{
+ ir.set_name(id, name);
+}
+
+const SPIRType &Compiler::get_type(uint32_t id) const
+{
+ return get<SPIRType>(id);
+}
+
+const SPIRType &Compiler::get_type_from_variable(uint32_t id) const
+{
+ return get<SPIRType>(get<SPIRVariable>(id).basetype);
+}
+
+uint32_t Compiler::get_pointee_type_id(uint32_t type_id) const
+{
+ auto *p_type = &get<SPIRType>(type_id);
+ if (p_type->pointer)
+ {
+ assert(p_type->parent_type);
+ type_id = p_type->parent_type;
+ }
+ return type_id;
+}
+
+const SPIRType &Compiler::get_pointee_type(const SPIRType &type) const
+{
+ auto *p_type = &type;
+ if (p_type->pointer)
+ {
+ assert(p_type->parent_type);
+ p_type = &get<SPIRType>(p_type->parent_type);
+ }
+ return *p_type;
+}
+
+const SPIRType &Compiler::get_pointee_type(uint32_t type_id) const
+{
+ return get_pointee_type(get<SPIRType>(type_id));
+}
+
+uint32_t Compiler::get_variable_data_type_id(const SPIRVariable &var) const
+{
+ if (var.phi_variable)
+ return var.basetype;
+ return get_pointee_type_id(var.basetype);
+}
+
+SPIRType &Compiler::get_variable_data_type(const SPIRVariable &var)
+{
+ return get<SPIRType>(get_variable_data_type_id(var));
+}
+
+const SPIRType &Compiler::get_variable_data_type(const SPIRVariable &var) const
+{
+ return get<SPIRType>(get_variable_data_type_id(var));
+}
+
+SPIRType &Compiler::get_variable_element_type(const SPIRVariable &var)
+{
+ SPIRType *type = &get_variable_data_type(var);
+ if (is_array(*type))
+ type = &get<SPIRType>(type->parent_type);
+ return *type;
+}
+
+const SPIRType &Compiler::get_variable_element_type(const SPIRVariable &var) const
+{
+ const SPIRType *type = &get_variable_data_type(var);
+ if (is_array(*type))
+ type = &get<SPIRType>(type->parent_type);
+ return *type;
+}
+
+bool Compiler::is_sampled_image_type(const SPIRType &type)
+{
+ return (type.basetype == SPIRType::Image || type.basetype == SPIRType::SampledImage) && type.image.sampled == 1 &&
+ type.image.dim != DimBuffer;
+}
+
+void Compiler::set_member_decoration_string(uint32_t id, uint32_t index, spv::Decoration decoration,
+ const std::string &argument)
+{
+ ir.set_member_decoration_string(id, index, decoration, argument);
+}
+
+void Compiler::set_member_decoration(uint32_t id, uint32_t index, Decoration decoration, uint32_t argument)
+{
+ ir.set_member_decoration(id, index, decoration, argument);
+}
+
+void Compiler::set_member_name(uint32_t id, uint32_t index, const std::string &name)
+{
+ ir.set_member_name(id, index, name);
+}
+
+const std::string &Compiler::get_member_name(uint32_t id, uint32_t index) const
+{
+ return ir.get_member_name(id, index);
+}
+
+void Compiler::set_qualified_name(uint32_t id, const string &name)
+{
+ ir.meta[id].decoration.qualified_alias = name;
+}
+
+void Compiler::set_member_qualified_name(uint32_t type_id, uint32_t index, const std::string &name)
+{
+ ir.meta[type_id].members.resize(max(ir.meta[type_id].members.size(), size_t(index) + 1));
+ ir.meta[type_id].members[index].qualified_alias = name;
+}
+
+const string &Compiler::get_member_qualified_name(uint32_t type_id, uint32_t index) const
+{
+ auto *m = ir.find_meta(type_id);
+ if (m && index < m->members.size())
+ return m->members[index].qualified_alias;
+ else
+ return ir.get_empty_string();
+}
+
+uint32_t Compiler::get_member_decoration(uint32_t id, uint32_t index, Decoration decoration) const
+{
+ return ir.get_member_decoration(id, index, decoration);
+}
+
+const Bitset &Compiler::get_member_decoration_bitset(uint32_t id, uint32_t index) const
+{
+ return ir.get_member_decoration_bitset(id, index);
+}
+
+bool Compiler::has_member_decoration(uint32_t id, uint32_t index, Decoration decoration) const
+{
+ return ir.has_member_decoration(id, index, decoration);
+}
+
+void Compiler::unset_member_decoration(uint32_t id, uint32_t index, Decoration decoration)
+{
+ ir.unset_member_decoration(id, index, decoration);
+}
+
+void Compiler::set_decoration_string(uint32_t id, spv::Decoration decoration, const std::string &argument)
+{
+ ir.set_decoration_string(id, decoration, argument);
+}
+
+void Compiler::set_decoration(uint32_t id, Decoration decoration, uint32_t argument)
+{
+ ir.set_decoration(id, decoration, argument);
+}
+
+void Compiler::set_extended_decoration(uint32_t id, ExtendedDecorations decoration, uint32_t value)
+{
+ auto &dec = ir.meta[id].decoration;
+ switch (decoration)
+ {
+ case SPIRVCrossDecorationPacked:
+ dec.extended.packed = true;
+ break;
+
+ case SPIRVCrossDecorationPackedType:
+ dec.extended.packed_type = value;
+ break;
+
+ case SPIRVCrossDecorationInterfaceMemberIndex:
+ dec.extended.ib_member_index = value;
+ break;
+
+ case SPIRVCrossDecorationInterfaceOrigID:
+ dec.extended.ib_orig_id = value;
+ break;
+
+ case SPIRVCrossDecorationArgumentBufferID:
+ dec.extended.argument_buffer_id = value;
+ break;
+ }
+}
+
+void Compiler::set_extended_member_decoration(uint32_t type, uint32_t index, ExtendedDecorations decoration,
+ uint32_t value)
+{
+ ir.meta[type].members.resize(max(ir.meta[type].members.size(), size_t(index) + 1));
+ auto &dec = ir.meta[type].members[index];
+
+ switch (decoration)
+ {
+ case SPIRVCrossDecorationPacked:
+ dec.extended.packed = true;
+ break;
+
+ case SPIRVCrossDecorationPackedType:
+ dec.extended.packed_type = value;
+ break;
+
+ case SPIRVCrossDecorationInterfaceMemberIndex:
+ dec.extended.ib_member_index = value;
+ break;
+
+ case SPIRVCrossDecorationInterfaceOrigID:
+ dec.extended.ib_orig_id = value;
+ break;
+
+ case SPIRVCrossDecorationArgumentBufferID:
+ dec.extended.argument_buffer_id = value;
+ break;
+ }
+}
+
+uint32_t Compiler::get_extended_decoration(uint32_t id, ExtendedDecorations decoration) const
+{
+ auto *m = ir.find_meta(id);
+ if (!m)
+ return 0;
+
+ auto &dec = m->decoration;
+ switch (decoration)
+ {
+ case SPIRVCrossDecorationPacked:
+ return uint32_t(dec.extended.packed);
+
+ case SPIRVCrossDecorationPackedType:
+ return dec.extended.packed_type;
+
+ case SPIRVCrossDecorationInterfaceMemberIndex:
+ return dec.extended.ib_member_index;
+
+ case SPIRVCrossDecorationInterfaceOrigID:
+ return dec.extended.ib_orig_id;
+
+ case SPIRVCrossDecorationArgumentBufferID:
+ return dec.extended.argument_buffer_id;
+ }
+
+ return 0;
+}
+
+uint32_t Compiler::get_extended_member_decoration(uint32_t type, uint32_t index, ExtendedDecorations decoration) const
+{
+ auto *m = ir.find_meta(type);
+ if (!m)
+ return 0;
+
+ if (index >= m->members.size())
+ return 0;
+
+ auto &dec = m->members[index];
+ switch (decoration)
+ {
+ case SPIRVCrossDecorationPacked:
+ return uint32_t(dec.extended.packed);
+
+ case SPIRVCrossDecorationPackedType:
+ return dec.extended.packed_type;
+
+ case SPIRVCrossDecorationInterfaceMemberIndex:
+ return dec.extended.ib_member_index;
+
+ case SPIRVCrossDecorationInterfaceOrigID:
+ return dec.extended.ib_orig_id;
+
+ case SPIRVCrossDecorationArgumentBufferID:
+ return dec.extended.argument_buffer_id;
+ }
+
+ return 0;
+}
+
+bool Compiler::has_extended_decoration(uint32_t id, ExtendedDecorations decoration) const
+{
+ auto *m = ir.find_meta(id);
+ if (!m)
+ return false;
+
+ auto &dec = m->decoration;
+ switch (decoration)
+ {
+ case SPIRVCrossDecorationPacked:
+ return dec.extended.packed;
+
+ case SPIRVCrossDecorationPackedType:
+ return dec.extended.packed_type != 0;
+
+ case SPIRVCrossDecorationInterfaceMemberIndex:
+ return dec.extended.ib_member_index != uint32_t(-1);
+
+ case SPIRVCrossDecorationInterfaceOrigID:
+ return dec.extended.ib_orig_id != 0;
+
+ case SPIRVCrossDecorationArgumentBufferID:
+ return dec.extended.argument_buffer_id != 0;
+ }
+
+ return false;
+}
+
+bool Compiler::has_extended_member_decoration(uint32_t type, uint32_t index, ExtendedDecorations decoration) const
+{
+ auto *m = ir.find_meta(type);
+ if (!m)
+ return false;
+
+ if (index >= m->members.size())
+ return false;
+
+ auto &dec = m->members[index];
+ switch (decoration)
+ {
+ case SPIRVCrossDecorationPacked:
+ return dec.extended.packed;
+
+ case SPIRVCrossDecorationPackedType:
+ return dec.extended.packed_type != 0;
+
+ case SPIRVCrossDecorationInterfaceMemberIndex:
+ return dec.extended.ib_member_index != uint32_t(-1);
+
+ case SPIRVCrossDecorationInterfaceOrigID:
+ return dec.extended.ib_orig_id != 0;
+
+ case SPIRVCrossDecorationArgumentBufferID:
+ return dec.extended.argument_buffer_id != uint32_t(-1);
+ }
+
+ return false;
+}
+
+void Compiler::unset_extended_decoration(uint32_t id, ExtendedDecorations decoration)
+{
+ auto &dec = ir.meta[id].decoration;
+ switch (decoration)
+ {
+ case SPIRVCrossDecorationPacked:
+ dec.extended.packed = false;
+ break;
+
+ case SPIRVCrossDecorationPackedType:
+ dec.extended.packed_type = 0;
+ break;
+
+ case SPIRVCrossDecorationInterfaceMemberIndex:
+ dec.extended.ib_member_index = ~(0u);
+ break;
+
+ case SPIRVCrossDecorationInterfaceOrigID:
+ dec.extended.ib_orig_id = 0;
+ break;
+
+ case SPIRVCrossDecorationArgumentBufferID:
+ dec.extended.argument_buffer_id = 0;
+ break;
+ }
+}
+
+void Compiler::unset_extended_member_decoration(uint32_t type, uint32_t index, ExtendedDecorations decoration)
+{
+ ir.meta[type].members.resize(max(ir.meta[type].members.size(), size_t(index) + 1));
+ auto &dec = ir.meta[type].members[index];
+
+ switch (decoration)
+ {
+ case SPIRVCrossDecorationPacked:
+ dec.extended.packed = false;
+ break;
+
+ case SPIRVCrossDecorationPackedType:
+ dec.extended.packed_type = 0;
+ break;
+
+ case SPIRVCrossDecorationInterfaceMemberIndex:
+ dec.extended.ib_member_index = ~(0u);
+ break;
+
+ case SPIRVCrossDecorationInterfaceOrigID:
+ dec.extended.ib_orig_id = 0;
+ break;
+
+ case SPIRVCrossDecorationArgumentBufferID:
+ dec.extended.argument_buffer_id = 0;
+ break;
+ }
+}
+
+StorageClass Compiler::get_storage_class(uint32_t id) const
+{
+ return get<SPIRVariable>(id).storage;
+}
+
+const std::string &Compiler::get_name(uint32_t id) const
+{
+ return ir.get_name(id);
+}
+
+const std::string Compiler::get_fallback_name(uint32_t id) const
+{
+ return join("_", id);
+}
+
+const std::string Compiler::get_block_fallback_name(uint32_t id) const
+{
+ auto &var = get<SPIRVariable>(id);
+ if (get_name(id).empty())
+ return join("_", get<SPIRType>(var.basetype).self, "_", id);
+ else
+ return get_name(id);
+}
+
+const Bitset &Compiler::get_decoration_bitset(uint32_t id) const
+{
+ return ir.get_decoration_bitset(id);
+}
+
+bool Compiler::has_decoration(uint32_t id, Decoration decoration) const
+{
+ return ir.has_decoration(id, decoration);
+}
+
+const string &Compiler::get_decoration_string(uint32_t id, Decoration decoration) const
+{
+ return ir.get_decoration_string(id, decoration);
+}
+
+const string &Compiler::get_member_decoration_string(uint32_t id, uint32_t index, Decoration decoration) const
+{
+ return ir.get_member_decoration_string(id, index, decoration);
+}
+
+uint32_t Compiler::get_decoration(uint32_t id, Decoration decoration) const
+{
+ return ir.get_decoration(id, decoration);
+}
+
+void Compiler::unset_decoration(uint32_t id, Decoration decoration)
+{
+ ir.unset_decoration(id, decoration);
+}
+
+bool Compiler::get_binary_offset_for_decoration(uint32_t id, spv::Decoration decoration, uint32_t &word_offset) const
+{
+ auto *m = ir.find_meta(id);
+ if (!m)
+ return false;
+
+ auto &word_offsets = m->decoration_word_offset;
+ auto itr = word_offsets.find(decoration);
+ if (itr == end(word_offsets))
+ return false;
+
+ word_offset = itr->second;
+ return true;
+}
+
+bool Compiler::block_is_loop_candidate(const SPIRBlock &block, SPIRBlock::Method method) const
+{
+ // Tried and failed.
+ if (block.disable_block_optimization || block.complex_continue)
+ return false;
+
+ if (method == SPIRBlock::MergeToSelectForLoop || method == SPIRBlock::MergeToSelectContinueForLoop)
+ {
+ // Try to detect common for loop pattern
+ // which the code backend can use to create cleaner code.
+ // for(;;) { if (cond) { some_body; } else { break; } }
+ // is the pattern we're looking for.
+ const auto *false_block = maybe_get<SPIRBlock>(block.false_block);
+ const auto *true_block = maybe_get<SPIRBlock>(block.true_block);
+ const auto *merge_block = maybe_get<SPIRBlock>(block.merge_block);
+
+ bool false_block_is_merge = block.false_block == block.merge_block ||
+ (false_block && merge_block && execution_is_noop(*false_block, *merge_block));
+
+ bool true_block_is_merge = block.true_block == block.merge_block ||
+ (true_block && merge_block && execution_is_noop(*true_block, *merge_block));
+
+ bool positive_candidate =
+ block.true_block != block.merge_block && block.true_block != block.self && false_block_is_merge;
+
+ bool negative_candidate =
+ block.false_block != block.merge_block && block.false_block != block.self && true_block_is_merge;
+
+ bool ret = block.terminator == SPIRBlock::Select && block.merge == SPIRBlock::MergeLoop &&
+ (positive_candidate || negative_candidate);
+
+ if (ret && positive_candidate && method == SPIRBlock::MergeToSelectContinueForLoop)
+ ret = block.true_block == block.continue_block;
+ else if (ret && negative_candidate && method == SPIRBlock::MergeToSelectContinueForLoop)
+ ret = block.false_block == block.continue_block;
+
+ // If we have OpPhi which depends on branches which came from our own block,
+ // we need to flush phi variables in else block instead of a trivial break,
+ // so we cannot assume this is a for loop candidate.
+ if (ret)
+ {
+ for (auto &phi : block.phi_variables)
+ if (phi.parent == block.self)
+ return false;
+
+ auto *merge = maybe_get<SPIRBlock>(block.merge_block);
+ if (merge)
+ for (auto &phi : merge->phi_variables)
+ if (phi.parent == block.self)
+ return false;
+ }
+ return ret;
+ }
+ else if (method == SPIRBlock::MergeToDirectForLoop)
+ {
+ // Empty loop header that just sets up merge target
+ // and branches to loop body.
+ bool ret = block.terminator == SPIRBlock::Direct && block.merge == SPIRBlock::MergeLoop && block.ops.empty();
+
+ if (!ret)
+ return false;
+
+ auto &child = get<SPIRBlock>(block.next_block);
+
+ const auto *false_block = maybe_get<SPIRBlock>(child.false_block);
+ const auto *true_block = maybe_get<SPIRBlock>(child.true_block);
+ const auto *merge_block = maybe_get<SPIRBlock>(block.merge_block);
+
+ bool false_block_is_merge = child.false_block == block.merge_block ||
+ (false_block && merge_block && execution_is_noop(*false_block, *merge_block));
+
+ bool true_block_is_merge = child.true_block == block.merge_block ||
+ (true_block && merge_block && execution_is_noop(*true_block, *merge_block));
+
+ bool positive_candidate =
+ child.true_block != block.merge_block && child.true_block != block.self && false_block_is_merge;
+
+ bool negative_candidate =
+ child.false_block != block.merge_block && child.false_block != block.self && true_block_is_merge;
+
+ ret = child.terminator == SPIRBlock::Select && child.merge == SPIRBlock::MergeNone &&
+ (positive_candidate || negative_candidate);
+
+ // If we have OpPhi which depends on branches which came from our own block,
+ // we need to flush phi variables in else block instead of a trivial break,
+ // so we cannot assume this is a for loop candidate.
+ if (ret)
+ {
+ for (auto &phi : block.phi_variables)
+ if (phi.parent == block.self || phi.parent == child.self)
+ return false;
+
+ for (auto &phi : child.phi_variables)
+ if (phi.parent == block.self)
+ return false;
+
+ auto *merge = maybe_get<SPIRBlock>(block.merge_block);
+ if (merge)
+ for (auto &phi : merge->phi_variables)
+ if (phi.parent == block.self || phi.parent == child.false_block)
+ return false;
+ }
+
+ return ret;
+ }
+ else
+ return false;
+}
+
+bool Compiler::block_is_outside_flow_control_from_block(const SPIRBlock &from, const SPIRBlock &to)
+{
+ auto *start = &from;
+
+ if (start->self == to.self)
+ return true;
+
+ // Break cycles.
+ if (is_continue(start->self))
+ return false;
+
+ // If our select block doesn't merge, we must break or continue in these blocks,
+ // so if continues occur branchless within these blocks, consider them branchless as well.
+ // This is typically used for loop control.
+ if (start->terminator == SPIRBlock::Select && start->merge == SPIRBlock::MergeNone &&
+ (block_is_outside_flow_control_from_block(get<SPIRBlock>(start->true_block), to) ||
+ block_is_outside_flow_control_from_block(get<SPIRBlock>(start->false_block), to)))
+ {
+ return true;
+ }
+ else if (start->merge_block && block_is_outside_flow_control_from_block(get<SPIRBlock>(start->merge_block), to))
+ {
+ return true;
+ }
+ else if (start->next_block && block_is_outside_flow_control_from_block(get<SPIRBlock>(start->next_block), to))
+ {
+ return true;
+ }
+ else
+ return false;
+}
+
+bool Compiler::execution_is_noop(const SPIRBlock &from, const SPIRBlock &to) const
+{
+ if (!execution_is_branchless(from, to))
+ return false;
+
+ auto *start = &from;
+ for (;;)
+ {
+ if (start->self == to.self)
+ return true;
+
+ if (!start->ops.empty())
+ return false;
+
+ auto &next = get<SPIRBlock>(start->next_block);
+ // Flushing phi variables does not count as noop.
+ for (auto &phi : next.phi_variables)
+ if (phi.parent == start->self)
+ return false;
+
+ start = &next;
+ }
+}
+
+bool Compiler::execution_is_branchless(const SPIRBlock &from, const SPIRBlock &to) const
+{
+ auto *start = &from;
+ for (;;)
+ {
+ if (start->self == to.self)
+ return true;
+
+ if (start->terminator == SPIRBlock::Direct && start->merge == SPIRBlock::MergeNone)
+ start = &get<SPIRBlock>(start->next_block);
+ else
+ return false;
+ }
+}
+
+SPIRBlock::ContinueBlockType Compiler::continue_block_type(const SPIRBlock &block) const
+{
+ // The block was deemed too complex during code emit, pick conservative fallback paths.
+ if (block.complex_continue)
+ return SPIRBlock::ComplexLoop;
+
+ // In older glslang output continue block can be equal to the loop header.
+ // In this case, execution is clearly branchless, so just assume a while loop header here.
+ if (block.merge == SPIRBlock::MergeLoop)
+ return SPIRBlock::WhileLoop;
+
+ auto &dominator = get<SPIRBlock>(block.loop_dominator);
+
+ if (execution_is_noop(block, dominator))
+ return SPIRBlock::WhileLoop;
+ else if (execution_is_branchless(block, dominator))
+ return SPIRBlock::ForLoop;
+ else
+ {
+ const auto *false_block = maybe_get<SPIRBlock>(block.false_block);
+ const auto *true_block = maybe_get<SPIRBlock>(block.true_block);
+ const auto *merge_block = maybe_get<SPIRBlock>(dominator.merge_block);
+
+ bool positive_do_while = block.true_block == dominator.self &&
+ (block.false_block == dominator.merge_block ||
+ (false_block && merge_block && execution_is_noop(*false_block, *merge_block)));
+
+ bool negative_do_while = block.false_block == dominator.self &&
+ (block.true_block == dominator.merge_block ||
+ (true_block && merge_block && execution_is_noop(*true_block, *merge_block)));
+
+ if (block.merge == SPIRBlock::MergeNone && block.terminator == SPIRBlock::Select &&
+ (positive_do_while || negative_do_while))
+ {
+ return SPIRBlock::DoWhileLoop;
+ }
+ else
+ return SPIRBlock::ComplexLoop;
+ }
+}
+
+bool Compiler::traverse_all_reachable_opcodes(const SPIRBlock &block, OpcodeHandler &handler) const
+{
+ handler.set_current_block(block);
+
+ // Ideally, perhaps traverse the CFG instead of all blocks in order to eliminate dead blocks,
+ // but this shouldn't be a problem in practice unless the SPIR-V is doing insane things like recursing
+ // inside dead blocks ...
+ for (auto &i : block.ops)
+ {
+ auto ops = stream(i);
+ auto op = static_cast<Op>(i.op);
+
+ if (!handler.handle(op, ops, i.length))
+ return false;
+
+ if (op == OpFunctionCall)
+ {
+ auto &func = get<SPIRFunction>(ops[2]);
+ if (handler.follow_function_call(func))
+ {
+ if (!handler.begin_function_scope(ops, i.length))
+ return false;
+ if (!traverse_all_reachable_opcodes(get<SPIRFunction>(ops[2]), handler))
+ return false;
+ if (!handler.end_function_scope(ops, i.length))
+ return false;
+ }
+ }
+ }
+
+ return true;
+}
+
+bool Compiler::traverse_all_reachable_opcodes(const SPIRFunction &func, OpcodeHandler &handler) const
+{
+ for (auto block : func.blocks)
+ if (!traverse_all_reachable_opcodes(get<SPIRBlock>(block), handler))
+ return false;
+
+ return true;
+}
+
+uint32_t Compiler::type_struct_member_offset(const SPIRType &type, uint32_t index) const
+{
+ auto *type_meta = ir.find_meta(type.self);
+ if (type_meta)
+ {
+ // Decoration must be set in valid SPIR-V, otherwise throw.
+ auto &dec = type_meta->members[index];
+ if (dec.decoration_flags.get(DecorationOffset))
+ return dec.offset;
+ else
+ SPIRV_CROSS_THROW("Struct member does not have Offset set.");
+ }
+ else
+ SPIRV_CROSS_THROW("Struct member does not have Offset set.");
+}
+
+uint32_t Compiler::type_struct_member_array_stride(const SPIRType &type, uint32_t index) const
+{
+ auto *type_meta = ir.find_meta(type.member_types[index]);
+ if (type_meta)
+ {
+ // Decoration must be set in valid SPIR-V, otherwise throw.
+ // ArrayStride is part of the array type not OpMemberDecorate.
+ auto &dec = type_meta->decoration;
+ if (dec.decoration_flags.get(DecorationArrayStride))
+ return dec.array_stride;
+ else
+ SPIRV_CROSS_THROW("Struct member does not have ArrayStride set.");
+ }
+ else
+ SPIRV_CROSS_THROW("Struct member does not have Offset set.");
+}
+
+uint32_t Compiler::type_struct_member_matrix_stride(const SPIRType &type, uint32_t index) const
+{
+ auto *type_meta = ir.find_meta(type.self);
+ if (type_meta)
+ {
+ // Decoration must be set in valid SPIR-V, otherwise throw.
+ // MatrixStride is part of OpMemberDecorate.
+ auto &dec = type_meta->members[index];
+ if (dec.decoration_flags.get(DecorationMatrixStride))
+ return dec.matrix_stride;
+ else
+ SPIRV_CROSS_THROW("Struct member does not have MatrixStride set.");
+ }
+ else
+ SPIRV_CROSS_THROW("Struct member does not have MatrixStride set.");
+}
+
+size_t Compiler::get_declared_struct_size(const SPIRType &type) const
+{
+ if (type.member_types.empty())
+ SPIRV_CROSS_THROW("Declared struct in block cannot be empty.");
+
+ uint32_t last = uint32_t(type.member_types.size() - 1);
+ size_t offset = type_struct_member_offset(type, last);
+ size_t size = get_declared_struct_member_size(type, last);
+ return offset + size;
+}
+
+size_t Compiler::get_declared_struct_size_runtime_array(const SPIRType &type, size_t array_size) const
+{
+ if (type.member_types.empty())
+ SPIRV_CROSS_THROW("Declared struct in block cannot be empty.");
+
+ size_t size = get_declared_struct_size(type);
+ auto &last_type = get<SPIRType>(type.member_types.back());
+ if (!last_type.array.empty() && last_type.array_size_literal[0] && last_type.array[0] == 0) // Runtime array
+ size += array_size * type_struct_member_array_stride(type, uint32_t(type.member_types.size() - 1));
+
+ return size;
+}
+
+size_t Compiler::get_declared_struct_member_size(const SPIRType &struct_type, uint32_t index) const
+{
+ if (struct_type.member_types.empty())
+ SPIRV_CROSS_THROW("Declared struct in block cannot be empty.");
+
+ auto &flags = get_member_decoration_bitset(struct_type.self, index);
+ auto &type = get<SPIRType>(struct_type.member_types[index]);
+
+ switch (type.basetype)
+ {
+ case SPIRType::Unknown:
+ case SPIRType::Void:
+ case SPIRType::Boolean: // Bools are purely logical, and cannot be used for externally visible types.
+ case SPIRType::AtomicCounter:
+ case SPIRType::Image:
+ case SPIRType::SampledImage:
+ case SPIRType::Sampler:
+ SPIRV_CROSS_THROW("Querying size for object with opaque size.");
+
+ default:
+ break;
+ }
+
+ if (!type.array.empty())
+ {
+ // For arrays, we can use ArrayStride to get an easy check.
+ bool array_size_literal = type.array_size_literal.back();
+ uint32_t array_size = array_size_literal ? type.array.back() : get<SPIRConstant>(type.array.back()).scalar();
+ return type_struct_member_array_stride(struct_type, index) * array_size;
+ }
+ else if (type.basetype == SPIRType::Struct)
+ {
+ return get_declared_struct_size(type);
+ }
+ else
+ {
+ unsigned vecsize = type.vecsize;
+ unsigned columns = type.columns;
+
+ // Vectors.
+ if (columns == 1)
+ {
+ size_t component_size = type.width / 8;
+ return vecsize * component_size;
+ }
+ else
+ {
+ uint32_t matrix_stride = type_struct_member_matrix_stride(struct_type, index);
+
+ // Per SPIR-V spec, matrices must be tightly packed and aligned up for vec3 accesses.
+ if (flags.get(DecorationRowMajor))
+ return matrix_stride * vecsize;
+ else if (flags.get(DecorationColMajor))
+ return matrix_stride * columns;
+ else
+ SPIRV_CROSS_THROW("Either row-major or column-major must be declared for matrices.");
+ }
+ }
+}
+
+bool Compiler::BufferAccessHandler::handle(Op opcode, const uint32_t *args, uint32_t length)
+{
+ if (opcode != OpAccessChain && opcode != OpInBoundsAccessChain && opcode != OpPtrAccessChain)
+ return true;
+
+ bool ptr_chain = (opcode == OpPtrAccessChain);
+
+ // Invalid SPIR-V.
+ if (length < (ptr_chain ? 5u : 4u))
+ return false;
+
+ if (args[2] != id)
+ return true;
+
+ // Don't bother traversing the entire access chain tree yet.
+ // If we access a struct member, assume we access the entire member.
+ uint32_t index = compiler.get<SPIRConstant>(args[ptr_chain ? 4 : 3]).scalar();
+
+ // Seen this index already.
+ if (seen.find(index) != end(seen))
+ return true;
+ seen.insert(index);
+
+ auto &type = compiler.expression_type(id);
+ uint32_t offset = compiler.type_struct_member_offset(type, index);
+
+ size_t range;
+ // If we have another member in the struct, deduce the range by looking at the next member.
+ // This is okay since structs in SPIR-V can have padding, but Offset decoration must be
+ // monotonically increasing.
+ // Of course, this doesn't take into account if the SPIR-V for some reason decided to add
+ // very large amounts of padding, but that's not really a big deal.
+ if (index + 1 < type.member_types.size())
+ {
+ range = compiler.type_struct_member_offset(type, index + 1) - offset;
+ }
+ else
+ {
+ // No padding, so just deduce it from the size of the member directly.
+ range = compiler.get_declared_struct_member_size(type, index);
+ }
+
+ ranges.push_back({ index, offset, range });
+ return true;
+}
+
+std::vector<BufferRange> Compiler::get_active_buffer_ranges(uint32_t id) const
+{
+ std::vector<BufferRange> ranges;
+ BufferAccessHandler handler(*this, ranges, id);
+ traverse_all_reachable_opcodes(get<SPIRFunction>(ir.default_entry_point), handler);
+ return ranges;
+}
+
+bool Compiler::types_are_logically_equivalent(const SPIRType &a, const SPIRType &b) const
+{
+ if (a.basetype != b.basetype)
+ return false;
+ if (a.width != b.width)
+ return false;
+ if (a.vecsize != b.vecsize)
+ return false;
+ if (a.columns != b.columns)
+ return false;
+ if (a.array.size() != b.array.size())
+ return false;
+
+ size_t array_count = a.array.size();
+ if (array_count && memcmp(a.array.data(), b.array.data(), array_count * sizeof(uint32_t)) != 0)
+ return false;
+
+ if (a.basetype == SPIRType::Image || a.basetype == SPIRType::SampledImage)
+ {
+ if (memcmp(&a.image, &b.image, sizeof(SPIRType::Image)) != 0)
+ return false;
+ }
+
+ if (a.member_types.size() != b.member_types.size())
+ return false;
+
+ size_t member_types = a.member_types.size();
+ for (size_t i = 0; i < member_types; i++)
+ {
+ if (!types_are_logically_equivalent(get<SPIRType>(a.member_types[i]), get<SPIRType>(b.member_types[i])))
+ return false;
+ }
+
+ return true;
+}
+
+const Bitset &Compiler::get_execution_mode_bitset() const
+{
+ return get_entry_point().flags;
+}
+
+void Compiler::set_execution_mode(ExecutionMode mode, uint32_t arg0, uint32_t arg1, uint32_t arg2)
+{
+ auto &execution = get_entry_point();
+
+ execution.flags.set(mode);
+ switch (mode)
+ {
+ case ExecutionModeLocalSize:
+ execution.workgroup_size.x = arg0;
+ execution.workgroup_size.y = arg1;
+ execution.workgroup_size.z = arg2;
+ break;
+
+ case ExecutionModeInvocations:
+ execution.invocations = arg0;
+ break;
+
+ case ExecutionModeOutputVertices:
+ execution.output_vertices = arg0;
+ break;
+
+ default:
+ break;
+ }
+}
+
+void Compiler::unset_execution_mode(ExecutionMode mode)
+{
+ auto &execution = get_entry_point();
+ execution.flags.clear(mode);
+}
+
+uint32_t Compiler::get_work_group_size_specialization_constants(SpecializationConstant &x, SpecializationConstant &y,
+ SpecializationConstant &z) const
+{
+ auto &execution = get_entry_point();
+ x = { 0, 0 };
+ y = { 0, 0 };
+ z = { 0, 0 };
+
+ if (execution.workgroup_size.constant != 0)
+ {
+ auto &c = get<SPIRConstant>(execution.workgroup_size.constant);
+
+ if (c.m.c[0].id[0] != 0)
+ {
+ x.id = c.m.c[0].id[0];
+ x.constant_id = get_decoration(c.m.c[0].id[0], DecorationSpecId);
+ }
+
+ if (c.m.c[0].id[1] != 0)
+ {
+ y.id = c.m.c[0].id[1];
+ y.constant_id = get_decoration(c.m.c[0].id[1], DecorationSpecId);
+ }
+
+ if (c.m.c[0].id[2] != 0)
+ {
+ z.id = c.m.c[0].id[2];
+ z.constant_id = get_decoration(c.m.c[0].id[2], DecorationSpecId);
+ }
+ }
+
+ return execution.workgroup_size.constant;
+}
+
+uint32_t Compiler::get_execution_mode_argument(spv::ExecutionMode mode, uint32_t index) const
+{
+ auto &execution = get_entry_point();
+ switch (mode)
+ {
+ case ExecutionModeLocalSize:
+ switch (index)
+ {
+ case 0:
+ return execution.workgroup_size.x;
+ case 1:
+ return execution.workgroup_size.y;
+ case 2:
+ return execution.workgroup_size.z;
+ default:
+ return 0;
+ }
+
+ case ExecutionModeInvocations:
+ return execution.invocations;
+
+ case ExecutionModeOutputVertices:
+ return execution.output_vertices;
+
+ default:
+ return 0;
+ }
+}
+
+ExecutionModel Compiler::get_execution_model() const
+{
+ auto &execution = get_entry_point();
+ return execution.model;
+}
+
+bool Compiler::is_tessellation_shader(ExecutionModel model)
+{
+ return model == ExecutionModelTessellationControl || model == ExecutionModelTessellationEvaluation;
+}
+
+bool Compiler::is_tessellation_shader() const
+{
+ return is_tessellation_shader(get_execution_model());
+}
+
+void Compiler::set_remapped_variable_state(uint32_t id, bool remap_enable)
+{
+ get<SPIRVariable>(id).remapped_variable = remap_enable;
+}
+
+bool Compiler::get_remapped_variable_state(uint32_t id) const
+{
+ return get<SPIRVariable>(id).remapped_variable;
+}
+
+void Compiler::set_subpass_input_remapped_components(uint32_t id, uint32_t components)
+{
+ get<SPIRVariable>(id).remapped_components = components;
+}
+
+uint32_t Compiler::get_subpass_input_remapped_components(uint32_t id) const
+{
+ return get<SPIRVariable>(id).remapped_components;
+}
+
+void Compiler::add_implied_read_expression(SPIRExpression &e, uint32_t source)
+{
+ auto itr = find(begin(e.implied_read_expressions), end(e.implied_read_expressions), source);
+ if (itr == end(e.implied_read_expressions))
+ e.implied_read_expressions.push_back(source);
+}
+
+void Compiler::add_implied_read_expression(SPIRAccessChain &e, uint32_t source)
+{
+ auto itr = find(begin(e.implied_read_expressions), end(e.implied_read_expressions), source);
+ if (itr == end(e.implied_read_expressions))
+ e.implied_read_expressions.push_back(source);
+}
+
+void Compiler::inherit_expression_dependencies(uint32_t dst, uint32_t source_expression)
+{
+ // Don't inherit any expression dependencies if the expression in dst
+ // is not a forwarded temporary.
+ if (forwarded_temporaries.find(dst) == end(forwarded_temporaries) ||
+ forced_temporaries.find(dst) != end(forced_temporaries))
+ {
+ return;
+ }
+
+ auto &e = get<SPIRExpression>(dst);
+ auto *phi = maybe_get<SPIRVariable>(source_expression);
+ if (phi && phi->phi_variable)
+ {
+ // We have used a phi variable, which can change at the end of the block,
+ // so make sure we take a dependency on this phi variable.
+ phi->dependees.push_back(dst);
+ }
+
+ auto *s = maybe_get<SPIRExpression>(source_expression);
+ if (!s)
+ return;
+
+ auto &e_deps = e.expression_dependencies;
+ auto &s_deps = s->expression_dependencies;
+
+ // If we depend on a expression, we also depend on all sub-dependencies from source.
+ e_deps.push_back(source_expression);
+ e_deps.insert(end(e_deps), begin(s_deps), end(s_deps));
+
+ // Eliminate duplicated dependencies.
+ sort(begin(e_deps), end(e_deps));
+ e_deps.erase(unique(begin(e_deps), end(e_deps)), end(e_deps));
+}
+
+vector<EntryPoint> Compiler::get_entry_points_and_stages() const
+{
+ vector<EntryPoint> entries;
+ for (auto &entry : ir.entry_points)
+ entries.push_back({ entry.second.orig_name, entry.second.model });
+ return entries;
+}
+
+void Compiler::rename_entry_point(const std::string &old_name, const std::string &new_name, spv::ExecutionModel model)
+{
+ auto &entry = get_entry_point(old_name, model);
+ entry.orig_name = new_name;
+ entry.name = new_name;
+}
+
+void Compiler::set_entry_point(const std::string &name, spv::ExecutionModel model)
+{
+ auto &entry = get_entry_point(name, model);
+ ir.default_entry_point = entry.self;
+}
+
+SPIREntryPoint &Compiler::get_first_entry_point(const std::string &name)
+{
+ auto itr = find_if(
+ begin(ir.entry_points), end(ir.entry_points),
+ [&](const std::pair<uint32_t, SPIREntryPoint> &entry) -> bool { return entry.second.orig_name == name; });
+
+ if (itr == end(ir.entry_points))
+ SPIRV_CROSS_THROW("Entry point does not exist.");
+
+ return itr->second;
+}
+
+const SPIREntryPoint &Compiler::get_first_entry_point(const std::string &name) const
+{
+ auto itr = find_if(
+ begin(ir.entry_points), end(ir.entry_points),
+ [&](const std::pair<uint32_t, SPIREntryPoint> &entry) -> bool { return entry.second.orig_name == name; });
+
+ if (itr == end(ir.entry_points))
+ SPIRV_CROSS_THROW("Entry point does not exist.");
+
+ return itr->second;
+}
+
+SPIREntryPoint &Compiler::get_entry_point(const std::string &name, ExecutionModel model)
+{
+ auto itr = find_if(begin(ir.entry_points), end(ir.entry_points),
+ [&](const std::pair<uint32_t, SPIREntryPoint> &entry) -> bool {
+ return entry.second.orig_name == name && entry.second.model == model;
+ });
+
+ if (itr == end(ir.entry_points))
+ SPIRV_CROSS_THROW("Entry point does not exist.");
+
+ return itr->second;
+}
+
+const SPIREntryPoint &Compiler::get_entry_point(const std::string &name, ExecutionModel model) const
+{
+ auto itr = find_if(begin(ir.entry_points), end(ir.entry_points),
+ [&](const std::pair<uint32_t, SPIREntryPoint> &entry) -> bool {
+ return entry.second.orig_name == name && entry.second.model == model;
+ });
+
+ if (itr == end(ir.entry_points))
+ SPIRV_CROSS_THROW("Entry point does not exist.");
+
+ return itr->second;
+}
+
+const string &Compiler::get_cleansed_entry_point_name(const std::string &name, ExecutionModel model) const
+{
+ return get_entry_point(name, model).name;
+}
+
+const SPIREntryPoint &Compiler::get_entry_point() const
+{
+ return ir.entry_points.find(ir.default_entry_point)->second;
+}
+
+SPIREntryPoint &Compiler::get_entry_point()
+{
+ return ir.entry_points.find(ir.default_entry_point)->second;
+}
+
+bool Compiler::interface_variable_exists_in_entry_point(uint32_t id) const
+{
+ auto &var = get<SPIRVariable>(id);
+ if (var.storage != StorageClassInput && var.storage != StorageClassOutput &&
+ var.storage != StorageClassUniformConstant)
+ SPIRV_CROSS_THROW("Only Input, Output variables and Uniform constants are part of a shader linking interface.");
+
+ // This is to avoid potential problems with very old glslang versions which did
+ // not emit input/output interfaces properly.
+ // We can assume they only had a single entry point, and single entry point
+ // shaders could easily be assumed to use every interface variable anyways.
+ if (ir.entry_points.size() <= 1)
+ return true;
+
+ auto &execution = get_entry_point();
+ return find(begin(execution.interface_variables), end(execution.interface_variables), id) !=
+ end(execution.interface_variables);
+}
+
+void Compiler::CombinedImageSamplerHandler::push_remap_parameters(const SPIRFunction &func, const uint32_t *args,
+ uint32_t length)
+{
+ // If possible, pipe through a remapping table so that parameters know
+ // which variables they actually bind to in this scope.
+ unordered_map<uint32_t, uint32_t> remapping;
+ for (uint32_t i = 0; i < length; i++)
+ remapping[func.arguments[i].id] = remap_parameter(args[i]);
+ parameter_remapping.push(move(remapping));
+}
+
+void Compiler::CombinedImageSamplerHandler::pop_remap_parameters()
+{
+ parameter_remapping.pop();
+}
+
+uint32_t Compiler::CombinedImageSamplerHandler::remap_parameter(uint32_t id)
+{
+ auto *var = compiler.maybe_get_backing_variable(id);
+ if (var)
+ id = var->self;
+
+ if (parameter_remapping.empty())
+ return id;
+
+ auto &remapping = parameter_remapping.top();
+ auto itr = remapping.find(id);
+ if (itr != end(remapping))
+ return itr->second;
+ else
+ return id;
+}
+
+bool Compiler::CombinedImageSamplerHandler::begin_function_scope(const uint32_t *args, uint32_t length)
+{
+ if (length < 3)
+ return false;
+
+ auto &callee = compiler.get<SPIRFunction>(args[2]);
+ args += 3;
+ length -= 3;
+ push_remap_parameters(callee, args, length);
+ functions.push(&callee);
+ return true;
+}
+
+bool Compiler::CombinedImageSamplerHandler::end_function_scope(const uint32_t *args, uint32_t length)
+{
+ if (length < 3)
+ return false;
+
+ auto &callee = compiler.get<SPIRFunction>(args[2]);
+ args += 3;
+
+ // There are two types of cases we have to handle,
+ // a callee might call sampler2D(texture2D, sampler) directly where
+ // one or more parameters originate from parameters.
+ // Alternatively, we need to provide combined image samplers to our callees,
+ // and in this case we need to add those as well.
+
+ pop_remap_parameters();
+
+ // Our callee has now been processed at least once.
+ // No point in doing it again.
+ callee.do_combined_parameters = false;
+
+ auto &params = functions.top()->combined_parameters;
+ functions.pop();
+ if (functions.empty())
+ return true;
+
+ auto &caller = *functions.top();
+ if (caller.do_combined_parameters)
+ {
+ for (auto &param : params)
+ {
+ uint32_t image_id = param.global_image ? param.image_id : args[param.image_id];
+ uint32_t sampler_id = param.global_sampler ? param.sampler_id : args[param.sampler_id];
+
+ auto *i = compiler.maybe_get_backing_variable(image_id);
+ auto *s = compiler.maybe_get_backing_variable(sampler_id);
+ if (i)
+ image_id = i->self;
+ if (s)
+ sampler_id = s->self;
+
+ register_combined_image_sampler(caller, image_id, sampler_id, param.depth);
+ }
+ }
+
+ return true;
+}
+
+void Compiler::CombinedImageSamplerHandler::register_combined_image_sampler(SPIRFunction &caller, uint32_t image_id,
+ uint32_t sampler_id, bool depth)
+{
+ // We now have a texture ID and a sampler ID which will either be found as a global
+ // or a parameter in our own function. If both are global, they will not need a parameter,
+ // otherwise, add it to our list.
+ SPIRFunction::CombinedImageSamplerParameter param = {
+ 0u, image_id, sampler_id, true, true, depth,
+ };
+
+ auto texture_itr = find_if(begin(caller.arguments), end(caller.arguments),
+ [image_id](const SPIRFunction::Parameter &p) { return p.id == image_id; });
+ auto sampler_itr = find_if(begin(caller.arguments), end(caller.arguments),
+ [sampler_id](const SPIRFunction::Parameter &p) { return p.id == sampler_id; });
+
+ if (texture_itr != end(caller.arguments))
+ {
+ param.global_image = false;
+ param.image_id = uint32_t(texture_itr - begin(caller.arguments));
+ }
+
+ if (sampler_itr != end(caller.arguments))
+ {
+ param.global_sampler = false;
+ param.sampler_id = uint32_t(sampler_itr - begin(caller.arguments));
+ }
+
+ if (param.global_image && param.global_sampler)
+ return;
+
+ auto itr = find_if(begin(caller.combined_parameters), end(caller.combined_parameters),
+ [&param](const SPIRFunction::CombinedImageSamplerParameter &p) {
+ return param.image_id == p.image_id && param.sampler_id == p.sampler_id &&
+ param.global_image == p.global_image && param.global_sampler == p.global_sampler;
+ });
+
+ if (itr == end(caller.combined_parameters))
+ {
+ uint32_t id = compiler.ir.increase_bound_by(3);
+ auto type_id = id + 0;
+ auto ptr_type_id = id + 1;
+ auto combined_id = id + 2;
+ auto &base = compiler.expression_type(image_id);
+ auto &type = compiler.set<SPIRType>(type_id);
+ auto &ptr_type = compiler.set<SPIRType>(ptr_type_id);
+
+ type = base;
+ type.self = type_id;
+ type.basetype = SPIRType::SampledImage;
+ type.pointer = false;
+ type.storage = StorageClassGeneric;
+ type.image.depth = depth;
+
+ ptr_type = type;
+ ptr_type.pointer = true;
+ ptr_type.storage = StorageClassUniformConstant;
+ ptr_type.parent_type = type_id;
+
+ // Build new variable.
+ compiler.set<SPIRVariable>(combined_id, ptr_type_id, StorageClassFunction, 0);
+
+ // Inherit RelaxedPrecision (and potentially other useful flags if deemed relevant).
+ auto &new_flags = compiler.ir.meta[combined_id].decoration.decoration_flags;
+ auto &old_flags = compiler.ir.meta[sampler_id].decoration.decoration_flags;
+ new_flags.reset();
+ if (old_flags.get(DecorationRelaxedPrecision))
+ new_flags.set(DecorationRelaxedPrecision);
+
+ param.id = combined_id;
+
+ compiler.set_name(combined_id,
+ join("SPIRV_Cross_Combined", compiler.to_name(image_id), compiler.to_name(sampler_id)));
+
+ caller.combined_parameters.push_back(param);
+ caller.shadow_arguments.push_back({ ptr_type_id, combined_id, 0u, 0u, true });
+ }
+}
+
+bool Compiler::DummySamplerForCombinedImageHandler::handle(Op opcode, const uint32_t *args, uint32_t length)
+{
+ if (need_dummy_sampler)
+ {
+ // No need to traverse further, we know the result.
+ return false;
+ }
+
+ switch (opcode)
+ {
+ case OpLoad:
+ {
+ if (length < 3)
+ return false;
+
+ uint32_t result_type = args[0];
+
+ auto &type = compiler.get<SPIRType>(result_type);
+ bool separate_image =
+ type.basetype == SPIRType::Image && type.image.sampled == 1 && type.image.dim != DimBuffer;
+
+ // If not separate image, don't bother.
+ if (!separate_image)
+ return true;
+
+ uint32_t id = args[1];
+ uint32_t ptr = args[2];
+ compiler.set<SPIRExpression>(id, "", result_type, true);
+ compiler.register_read(id, ptr, true);
+ break;
+ }
+
+ case OpImageFetch:
+ case OpImageQuerySizeLod:
+ case OpImageQuerySize:
+ case OpImageQueryLevels:
+ case OpImageQuerySamples:
+ {
+ // If we are fetching or querying LOD from a plain OpTypeImage, we must pre-combine with our dummy sampler.
+ auto *var = compiler.maybe_get_backing_variable(args[2]);
+ if (var)
+ {
+ auto &type = compiler.get<SPIRType>(var->basetype);
+ if (type.basetype == SPIRType::Image && type.image.sampled == 1 && type.image.dim != DimBuffer)
+ need_dummy_sampler = true;
+ }
+
+ break;
+ }
+
+ case OpInBoundsAccessChain:
+ case OpAccessChain:
+ case OpPtrAccessChain:
+ {
+ if (length < 3)
+ return false;
+
+ uint32_t result_type = args[0];
+ auto &type = compiler.get<SPIRType>(result_type);
+ bool separate_image =
+ type.basetype == SPIRType::Image && type.image.sampled == 1 && type.image.dim != DimBuffer;
+ if (!separate_image)
+ return true;
+
+ uint32_t id = args[1];
+ uint32_t ptr = args[2];
+ compiler.set<SPIRExpression>(id, "", result_type, true);
+ compiler.register_read(id, ptr, true);
+
+ // Other backends might use SPIRAccessChain for this later.
+ compiler.ir.ids[id].set_allow_type_rewrite();
+ break;
+ }
+
+ default:
+ break;
+ }
+
+ return true;
+}
+
+bool Compiler::CombinedImageSamplerHandler::handle(Op opcode, const uint32_t *args, uint32_t length)
+{
+ // We need to figure out where samplers and images are loaded from, so do only the bare bones compilation we need.
+ bool is_fetch = false;
+
+ switch (opcode)
+ {
+ case OpLoad:
+ {
+ if (length < 3)
+ return false;
+
+ uint32_t result_type = args[0];
+
+ auto &type = compiler.get<SPIRType>(result_type);
+ bool separate_image = type.basetype == SPIRType::Image && type.image.sampled == 1;
+ bool separate_sampler = type.basetype == SPIRType::Sampler;
+
+ // If not separate image or sampler, don't bother.
+ if (!separate_image && !separate_sampler)
+ return true;
+
+ uint32_t id = args[1];
+ uint32_t ptr = args[2];
+ compiler.set<SPIRExpression>(id, "", result_type, true);
+ compiler.register_read(id, ptr, true);
+ return true;
+ }
+
+ case OpInBoundsAccessChain:
+ case OpAccessChain:
+ case OpPtrAccessChain:
+ {
+ if (length < 3)
+ return false;
+
+ // Technically, it is possible to have arrays of textures and arrays of samplers and combine them, but this becomes essentially
+ // impossible to implement, since we don't know which concrete sampler we are accessing.
+ // One potential way is to create a combinatorial explosion where N textures and M samplers are combined into N * M sampler2Ds,
+ // but this seems ridiculously complicated for a problem which is easy to work around.
+ // Checking access chains like this assumes we don't have samplers or textures inside uniform structs, but this makes no sense.
+
+ uint32_t result_type = args[0];
+
+ auto &type = compiler.get<SPIRType>(result_type);
+ bool separate_image = type.basetype == SPIRType::Image && type.image.sampled == 1;
+ bool separate_sampler = type.basetype == SPIRType::Sampler;
+ if (separate_sampler)
+ SPIRV_CROSS_THROW(
+ "Attempting to use arrays or structs of separate samplers. This is not possible to statically "
+ "remap to plain GLSL.");
+
+ if (separate_image)
+ {
+ uint32_t id = args[1];
+ uint32_t ptr = args[2];
+ compiler.set<SPIRExpression>(id, "", result_type, true);
+ compiler.register_read(id, ptr, true);
+ }
+ return true;
+ }
+
+ case OpImageFetch:
+ case OpImageQuerySizeLod:
+ case OpImageQuerySize:
+ case OpImageQueryLevels:
+ case OpImageQuerySamples:
+ {
+ // If we are fetching from a plain OpTypeImage or querying LOD, we must pre-combine with our dummy sampler.
+ auto *var = compiler.maybe_get_backing_variable(args[2]);
+ if (!var)
+ return true;
+
+ auto &type = compiler.get<SPIRType>(var->basetype);
+ if (type.basetype == SPIRType::Image && type.image.sampled == 1 && type.image.dim != DimBuffer)
+ {
+ if (compiler.dummy_sampler_id == 0)
+ SPIRV_CROSS_THROW("texelFetch without sampler was found, but no dummy sampler has been created with "
+ "build_dummy_sampler_for_combined_images().");
+
+ // Do it outside.
+ is_fetch = true;
+ break;
+ }
+
+ return true;
+ }
+
+ case OpSampledImage:
+ // Do it outside.
+ break;
+
+ default:
+ return true;
+ }
+
+ // Registers sampler2D calls used in case they are parameters so
+ // that their callees know which combined image samplers to propagate down the call stack.
+ if (!functions.empty())
+ {
+ auto &callee = *functions.top();
+ if (callee.do_combined_parameters)
+ {
+ uint32_t image_id = args[2];
+
+ auto *image = compiler.maybe_get_backing_variable(image_id);
+ if (image)
+ image_id = image->self;
+
+ uint32_t sampler_id = is_fetch ? compiler.dummy_sampler_id : args[3];
+ auto *sampler = compiler.maybe_get_backing_variable(sampler_id);
+ if (sampler)
+ sampler_id = sampler->self;
+
+ auto &combined_type = compiler.get<SPIRType>(args[0]);
+ register_combined_image_sampler(callee, image_id, sampler_id, combined_type.image.depth);
+ }
+ }
+
+ // For function calls, we need to remap IDs which are function parameters into global variables.
+ // This information is statically known from the current place in the call stack.
+ // Function parameters are not necessarily pointers, so if we don't have a backing variable, remapping will know
+ // which backing variable the image/sample came from.
+ uint32_t image_id = remap_parameter(args[2]);
+ uint32_t sampler_id = is_fetch ? compiler.dummy_sampler_id : remap_parameter(args[3]);
+
+ auto itr = find_if(begin(compiler.combined_image_samplers), end(compiler.combined_image_samplers),
+ [image_id, sampler_id](const CombinedImageSampler &combined) {
+ return combined.image_id == image_id && combined.sampler_id == sampler_id;
+ });
+
+ if (itr == end(compiler.combined_image_samplers))
+ {
+ uint32_t sampled_type;
+ if (is_fetch)
+ {
+ // Have to invent the sampled image type.
+ sampled_type = compiler.ir.increase_bound_by(1);
+ auto &type = compiler.set<SPIRType>(sampled_type);
+ type = compiler.expression_type(args[2]);
+ type.self = sampled_type;
+ type.basetype = SPIRType::SampledImage;
+ type.image.depth = false;
+ }
+ else
+ {
+ sampled_type = args[0];
+ }
+
+ auto id = compiler.ir.increase_bound_by(2);
+ auto type_id = id + 0;
+ auto combined_id = id + 1;
+
+ // Make a new type, pointer to OpTypeSampledImage, so we can make a variable of this type.
+ // We will probably have this type lying around, but it doesn't hurt to make duplicates for internal purposes.
+ auto &type = compiler.set<SPIRType>(type_id);
+ auto &base = compiler.get<SPIRType>(sampled_type);
+ type = base;
+ type.pointer = true;
+ type.storage = StorageClassUniformConstant;
+ type.parent_type = type_id;
+
+ // Build new variable.
+ compiler.set<SPIRVariable>(combined_id, type_id, StorageClassUniformConstant, 0);
+
+ // Inherit RelaxedPrecision (and potentially other useful flags if deemed relevant).
+ auto &new_flags = compiler.ir.meta[combined_id].decoration.decoration_flags;
+ // Fetch inherits precision from the image, not sampler (there is no sampler).
+ auto &old_flags = compiler.ir.meta[is_fetch ? image_id : sampler_id].decoration.decoration_flags;
+ new_flags.reset();
+ if (old_flags.get(DecorationRelaxedPrecision))
+ new_flags.set(DecorationRelaxedPrecision);
+
+ // Propagate the array type for the original image as well.
+ auto *var = compiler.maybe_get_backing_variable(image_id);
+ if (var)
+ {
+ auto &parent_type = compiler.get<SPIRType>(var->basetype);
+ type.array = parent_type.array;
+ type.array_size_literal = parent_type.array_size_literal;
+ }
+
+ compiler.combined_image_samplers.push_back({ combined_id, image_id, sampler_id });
+ }
+
+ return true;
+}
+
+uint32_t Compiler::build_dummy_sampler_for_combined_images()
+{
+ DummySamplerForCombinedImageHandler handler(*this);
+ traverse_all_reachable_opcodes(get<SPIRFunction>(ir.default_entry_point), handler);
+ if (handler.need_dummy_sampler)
+ {
+ uint32_t offset = ir.increase_bound_by(3);
+ auto type_id = offset + 0;
+ auto ptr_type_id = offset + 1;
+ auto var_id = offset + 2;
+
+ SPIRType sampler_type;
+ auto &sampler = set<SPIRType>(type_id);
+ sampler.basetype = SPIRType::Sampler;
+
+ auto &ptr_sampler = set<SPIRType>(ptr_type_id);
+ ptr_sampler = sampler;
+ ptr_sampler.self = type_id;
+ ptr_sampler.storage = StorageClassUniformConstant;
+ ptr_sampler.pointer = true;
+ ptr_sampler.parent_type = type_id;
+
+ set<SPIRVariable>(var_id, ptr_type_id, StorageClassUniformConstant, 0);
+ set_name(var_id, "SPIRV_Cross_DummySampler");
+ dummy_sampler_id = var_id;
+ return var_id;
+ }
+ else
+ return 0;
+}
+
+void Compiler::build_combined_image_samplers()
+{
+ ir.for_each_typed_id<SPIRFunction>([&](uint32_t, SPIRFunction &func) {
+ func.combined_parameters.clear();
+ func.shadow_arguments.clear();
+ func.do_combined_parameters = true;
+ });
+
+ combined_image_samplers.clear();
+ CombinedImageSamplerHandler handler(*this);
+ traverse_all_reachable_opcodes(get<SPIRFunction>(ir.default_entry_point), handler);
+}
+
+vector<SpecializationConstant> Compiler::get_specialization_constants() const
+{
+ vector<SpecializationConstant> spec_consts;
+ ir.for_each_typed_id<SPIRConstant>([&](uint32_t, const SPIRConstant &c) {
+ if (c.specialization && has_decoration(c.self, DecorationSpecId))
+ spec_consts.push_back({ c.self, get_decoration(c.self, DecorationSpecId) });
+ });
+ return spec_consts;
+}
+
+SPIRConstant &Compiler::get_constant(uint32_t id)
+{
+ return get<SPIRConstant>(id);
+}
+
+const SPIRConstant &Compiler::get_constant(uint32_t id) const
+{
+ return get<SPIRConstant>(id);
+}
+
+static bool exists_unaccessed_path_to_return(const CFG &cfg, uint32_t block, const unordered_set<uint32_t> &blocks)
+{
+ // This block accesses the variable.
+ if (blocks.find(block) != end(blocks))
+ return false;
+
+ // We are at the end of the CFG.
+ if (cfg.get_succeeding_edges(block).empty())
+ return true;
+
+ // If any of our successors have a path to the end, there exists a path from block.
+ for (auto &succ : cfg.get_succeeding_edges(block))
+ if (exists_unaccessed_path_to_return(cfg, succ, blocks))
+ return true;
+
+ return false;
+}
+
+void Compiler::analyze_parameter_preservation(
+ SPIRFunction &entry, const CFG &cfg, const unordered_map<uint32_t, unordered_set<uint32_t>> &variable_to_blocks,
+ const unordered_map<uint32_t, unordered_set<uint32_t>> &complete_write_blocks)
+{
+ for (auto &arg : entry.arguments)
+ {
+ // Non-pointers are always inputs.
+ auto &type = get<SPIRType>(arg.type);
+ if (!type.pointer)
+ continue;
+
+ // Opaque argument types are always in
+ bool potential_preserve;
+ switch (type.basetype)
+ {
+ case SPIRType::Sampler:
+ case SPIRType::Image:
+ case SPIRType::SampledImage:
+ case SPIRType::AtomicCounter:
+ potential_preserve = false;
+ break;
+
+ default:
+ potential_preserve = true;
+ break;
+ }
+
+ if (!potential_preserve)
+ continue;
+
+ auto itr = variable_to_blocks.find(arg.id);
+ if (itr == end(variable_to_blocks))
+ {
+ // Variable is never accessed.
+ continue;
+ }
+
+ // We have accessed a variable, but there was no complete writes to that variable.
+ // We deduce that we must preserve the argument.
+ itr = complete_write_blocks.find(arg.id);
+ if (itr == end(complete_write_blocks))
+ {
+ arg.read_count++;
+ continue;
+ }
+
+ // If there is a path through the CFG where no block completely writes to the variable, the variable will be in an undefined state
+ // when the function returns. We therefore need to implicitly preserve the variable in case there are writers in the function.
+ // Major case here is if a function is
+ // void foo(int &var) { if (cond) var = 10; }
+ // Using read/write counts, we will think it's just an out variable, but it really needs to be inout,
+ // because if we don't write anything whatever we put into the function must return back to the caller.
+ if (exists_unaccessed_path_to_return(cfg, entry.entry_block, itr->second))
+ arg.read_count++;
+ }
+}
+
+Compiler::AnalyzeVariableScopeAccessHandler::AnalyzeVariableScopeAccessHandler(Compiler &compiler_,
+ SPIRFunction &entry_)
+ : compiler(compiler_)
+ , entry(entry_)
+{
+}
+
+bool Compiler::AnalyzeVariableScopeAccessHandler::follow_function_call(const SPIRFunction &)
+{
+ // Only analyze within this function.
+ return false;
+}
+
+void Compiler::AnalyzeVariableScopeAccessHandler::set_current_block(const SPIRBlock &block)
+{
+ current_block = &block;
+
+ // If we're branching to a block which uses OpPhi, in GLSL
+ // this will be a variable write when we branch,
+ // so we need to track access to these variables as well to
+ // have a complete picture.
+ const auto test_phi = [this, &block](uint32_t to) {
+ auto &next = compiler.get<SPIRBlock>(to);
+ for (auto &phi : next.phi_variables)
+ {
+ if (phi.parent == block.self)
+ {
+ accessed_variables_to_block[phi.function_variable].insert(block.self);
+ // Phi variables are also accessed in our target branch block.
+ accessed_variables_to_block[phi.function_variable].insert(next.self);
+
+ notify_variable_access(phi.local_variable, block.self);
+ }
+ }
+ };
+
+ switch (block.terminator)
+ {
+ case SPIRBlock::Direct:
+ notify_variable_access(block.condition, block.self);
+ test_phi(block.next_block);
+ break;
+
+ case SPIRBlock::Select:
+ notify_variable_access(block.condition, block.self);
+ test_phi(block.true_block);
+ test_phi(block.false_block);
+ break;
+
+ case SPIRBlock::MultiSelect:
+ notify_variable_access(block.condition, block.self);
+ for (auto &target : block.cases)
+ test_phi(target.block);
+ if (block.default_block)
+ test_phi(block.default_block);
+ break;
+
+ default:
+ break;
+ }
+}
+
+void Compiler::AnalyzeVariableScopeAccessHandler::notify_variable_access(uint32_t id, uint32_t block)
+{
+ if (id_is_phi_variable(id))
+ accessed_variables_to_block[id].insert(block);
+ else if (id_is_potential_temporary(id))
+ accessed_temporaries_to_block[id].insert(block);
+}
+
+bool Compiler::AnalyzeVariableScopeAccessHandler::id_is_phi_variable(uint32_t id) const
+{
+ if (id >= compiler.get_current_id_bound())
+ return false;
+ auto *var = compiler.maybe_get<SPIRVariable>(id);
+ return var && var->phi_variable;
+}
+
+bool Compiler::AnalyzeVariableScopeAccessHandler::id_is_potential_temporary(uint32_t id) const
+{
+ if (id >= compiler.get_current_id_bound())
+ return false;
+
+ // Temporaries are not created before we start emitting code.
+ return compiler.ir.ids[id].empty() || (compiler.ir.ids[id].get_type() == TypeExpression);
+}
+
+bool Compiler::AnalyzeVariableScopeAccessHandler::handle(spv::Op op, const uint32_t *args, uint32_t length)
+{
+ // Keep track of the types of temporaries, so we can hoist them out as necessary.
+ uint32_t result_type, result_id;
+ if (compiler.instruction_to_result_type(result_type, result_id, op, args, length))
+ result_id_to_type[result_id] = result_type;
+
+ switch (op)
+ {
+ case OpStore:
+ {
+ if (length < 2)
+ return false;
+
+ uint32_t ptr = args[0];
+ auto *var = compiler.maybe_get_backing_variable(ptr);
+
+ // If we store through an access chain, we have a partial write.
+ if (var)
+ {
+ accessed_variables_to_block[var->self].insert(current_block->self);
+ if (var->self == ptr)
+ complete_write_variables_to_block[var->self].insert(current_block->self);
+ else
+ partial_write_variables_to_block[var->self].insert(current_block->self);
+ }
+
+ // Might try to store a Phi variable here.
+ notify_variable_access(args[1], current_block->self);
+ break;
+ }
+
+ case OpAccessChain:
+ case OpInBoundsAccessChain:
+ case OpPtrAccessChain:
+ {
+ if (length < 3)
+ return false;
+
+ uint32_t ptr = args[2];
+ auto *var = compiler.maybe_get<SPIRVariable>(ptr);
+ if (var)
+ accessed_variables_to_block[var->self].insert(current_block->self);
+
+ for (uint32_t i = 3; i < length; i++)
+ notify_variable_access(args[i], current_block->self);
+
+ // The result of an access chain is a fixed expression and is not really considered a temporary.
+ auto &e = compiler.set<SPIRExpression>(args[1], "", args[0], true);
+ auto *backing_variable = compiler.maybe_get_backing_variable(ptr);
+ e.loaded_from = backing_variable ? backing_variable->self : 0;
+
+ // Other backends might use SPIRAccessChain for this later.
+ compiler.ir.ids[args[1]].set_allow_type_rewrite();
+ break;
+ }
+
+ case OpCopyMemory:
+ {
+ if (length < 2)
+ return false;
+
+ uint32_t lhs = args[0];
+ uint32_t rhs = args[1];
+ auto *var = compiler.maybe_get_backing_variable(lhs);
+
+ // If we store through an access chain, we have a partial write.
+ if (var)
+ {
+ accessed_variables_to_block[var->self].insert(current_block->self);
+ if (var->self == lhs)
+ complete_write_variables_to_block[var->self].insert(current_block->self);
+ else
+ partial_write_variables_to_block[var->self].insert(current_block->self);
+ }
+
+ var = compiler.maybe_get_backing_variable(rhs);
+ if (var)
+ accessed_variables_to_block[var->self].insert(current_block->self);
+ break;
+ }
+
+ case OpCopyObject:
+ {
+ if (length < 3)
+ return false;
+
+ auto *var = compiler.maybe_get_backing_variable(args[2]);
+ if (var)
+ accessed_variables_to_block[var->self].insert(current_block->self);
+
+ // Might try to copy a Phi variable here.
+ notify_variable_access(args[2], current_block->self);
+ break;
+ }
+
+ case OpLoad:
+ {
+ if (length < 3)
+ return false;
+ uint32_t ptr = args[2];
+ auto *var = compiler.maybe_get_backing_variable(ptr);
+ if (var)
+ accessed_variables_to_block[var->self].insert(current_block->self);
+
+ // Loaded value is a temporary.
+ notify_variable_access(args[1], current_block->self);
+ break;
+ }
+
+ case OpFunctionCall:
+ {
+ if (length < 3)
+ return false;
+
+ length -= 3;
+ args += 3;
+
+ for (uint32_t i = 0; i < length; i++)
+ {
+ auto *var = compiler.maybe_get_backing_variable(args[i]);
+ if (var)
+ {
+ accessed_variables_to_block[var->self].insert(current_block->self);
+ // Assume we can get partial writes to this variable.
+ partial_write_variables_to_block[var->self].insert(current_block->self);
+ }
+
+ // Cannot easily prove if argument we pass to a function is completely written.
+ // Usually, functions write to a dummy variable,
+ // which is then copied to in full to the real argument.
+
+ // Might try to copy a Phi variable here.
+ notify_variable_access(args[i], current_block->self);
+ }
+
+ // Return value may be a temporary.
+ notify_variable_access(args[1], current_block->self);
+ break;
+ }
+
+ case OpExtInst:
+ {
+ for (uint32_t i = 4; i < length; i++)
+ notify_variable_access(args[i], current_block->self);
+ notify_variable_access(args[1], current_block->self);
+ break;
+ }
+
+ case OpArrayLength:
+ // Uses literals, but cannot be a phi variable or temporary, so ignore.
+ break;
+
+ // Atomics shouldn't be able to access function-local variables.
+ // Some GLSL builtins access a pointer.
+
+ case OpCompositeInsert:
+ case OpVectorShuffle:
+ // Specialize for opcode which contains literals.
+ for (uint32_t i = 1; i < 4; i++)
+ notify_variable_access(args[i], current_block->self);
+ break;
+
+ case OpCompositeExtract:
+ // Specialize for opcode which contains literals.
+ for (uint32_t i = 1; i < 3; i++)
+ notify_variable_access(args[i], current_block->self);
+ break;
+
+ case OpImageWrite:
+ for (uint32_t i = 0; i < length; i++)
+ {
+ // Argument 3 is a literal.
+ if (i != 3)
+ notify_variable_access(args[i], current_block->self);
+ }
+ break;
+
+ case OpImageSampleImplicitLod:
+ case OpImageSampleExplicitLod:
+ case OpImageSparseSampleImplicitLod:
+ case OpImageSparseSampleExplicitLod:
+ case OpImageSampleProjImplicitLod:
+ case OpImageSampleProjExplicitLod:
+ case OpImageSparseSampleProjImplicitLod:
+ case OpImageSparseSampleProjExplicitLod:
+ case OpImageFetch:
+ case OpImageSparseFetch:
+ case OpImageRead:
+ case OpImageSparseRead:
+ for (uint32_t i = 1; i < length; i++)
+ {
+ // Argument 4 is a literal.
+ if (i != 4)
+ notify_variable_access(args[i], current_block->self);
+ }
+ break;
+
+ case OpImageSampleDrefImplicitLod:
+ case OpImageSampleDrefExplicitLod:
+ case OpImageSparseSampleDrefImplicitLod:
+ case OpImageSparseSampleDrefExplicitLod:
+ case OpImageSampleProjDrefImplicitLod:
+ case OpImageSampleProjDrefExplicitLod:
+ case OpImageSparseSampleProjDrefImplicitLod:
+ case OpImageSparseSampleProjDrefExplicitLod:
+ case OpImageGather:
+ case OpImageSparseGather:
+ case OpImageDrefGather:
+ case OpImageSparseDrefGather:
+ for (uint32_t i = 1; i < length; i++)
+ {
+ // Argument 5 is a literal.
+ if (i != 5)
+ notify_variable_access(args[i], current_block->self);
+ }
+ break;
+
+ default:
+ {
+ // Rather dirty way of figuring out where Phi variables are used.
+ // As long as only IDs are used, we can scan through instructions and try to find any evidence that
+ // the ID of a variable has been used.
+ // There are potential false positives here where a literal is used in-place of an ID,
+ // but worst case, it does not affect the correctness of the compile.
+ // Exhaustive analysis would be better here, but it's not worth it for now.
+ for (uint32_t i = 0; i < length; i++)
+ notify_variable_access(args[i], current_block->self);
+ break;
+ }
+ }
+ return true;
+}
+
+Compiler::StaticExpressionAccessHandler::StaticExpressionAccessHandler(Compiler &compiler_, uint32_t variable_id_)
+ : compiler(compiler_)
+ , variable_id(variable_id_)
+{
+}
+
+bool Compiler::StaticExpressionAccessHandler::follow_function_call(const SPIRFunction &)
+{
+ return false;
+}
+
+bool Compiler::StaticExpressionAccessHandler::handle(spv::Op op, const uint32_t *args, uint32_t length)
+{
+ switch (op)
+ {
+ case OpStore:
+ if (length < 2)
+ return false;
+ if (args[0] == variable_id)
+ {
+ static_expression = args[1];
+ write_count++;
+ }
+ break;
+
+ case OpLoad:
+ if (length < 3)
+ return false;
+ if (args[2] == variable_id && static_expression == 0) // Tried to read from variable before it was initialized.
+ return false;
+ break;
+
+ case OpAccessChain:
+ case OpInBoundsAccessChain:
+ case OpPtrAccessChain:
+ if (length < 3)
+ return false;
+ if (args[2] == variable_id) // If we try to access chain our candidate variable before we store to it, bail.
+ return false;
+ break;
+
+ default:
+ break;
+ }
+
+ return true;
+}
+
+void Compiler::find_function_local_luts(SPIRFunction &entry, const AnalyzeVariableScopeAccessHandler &handler,
+ bool single_function)
+{
+ auto &cfg = *function_cfgs.find(entry.self)->second;
+
+ // For each variable which is statically accessed.
+ for (auto &accessed_var : handler.accessed_variables_to_block)
+ {
+ auto &blocks = accessed_var.second;
+ auto &var = get<SPIRVariable>(accessed_var.first);
+ auto &type = expression_type(accessed_var.first);
+
+ // Only consider function local variables here.
+ // If we only have a single function in our CFG, private storage is also fine,
+ // since it behaves like a function local variable.
+ bool allow_lut = var.storage == StorageClassFunction || (single_function && var.storage == StorageClassPrivate);
+ if (!allow_lut)
+ continue;
+
+ // We cannot be a phi variable.
+ if (var.phi_variable)
+ continue;
+
+ // Only consider arrays here.
+ if (type.array.empty())
+ continue;
+
+ // If the variable has an initializer, make sure it is a constant expression.
+ uint32_t static_constant_expression = 0;
+ if (var.initializer)
+ {
+ if (ir.ids[var.initializer].get_type() != TypeConstant)
+ continue;
+ static_constant_expression = var.initializer;
+
+ // There can be no stores to this variable, we have now proved we have a LUT.
+ if (handler.complete_write_variables_to_block.count(var.self) != 0 ||
+ handler.partial_write_variables_to_block.count(var.self) != 0)
+ continue;
+ }
+ else
+ {
+ // We can have one, and only one write to the variable, and that write needs to be a constant.
+
+ // No partial writes allowed.
+ if (handler.partial_write_variables_to_block.count(var.self) != 0)
+ continue;
+
+ auto itr = handler.complete_write_variables_to_block.find(var.self);
+
+ // No writes?
+ if (itr == end(handler.complete_write_variables_to_block))
+ continue;
+
+ // We write to the variable in more than one block.
+ auto &write_blocks = itr->second;
+ if (write_blocks.size() != 1)
+ continue;
+
+ // The write needs to happen in the dominating block.
+ DominatorBuilder builder(cfg);
+ for (auto &block : blocks)
+ builder.add_block(block);
+ uint32_t dominator = builder.get_dominator();
+
+ // The complete write happened in a branch or similar, cannot deduce static expression.
+ if (write_blocks.count(dominator) == 0)
+ continue;
+
+ // Find the static expression for this variable.
+ StaticExpressionAccessHandler static_expression_handler(*this, var.self);
+ traverse_all_reachable_opcodes(get<SPIRBlock>(dominator), static_expression_handler);
+
+ // We want one, and exactly one write
+ if (static_expression_handler.write_count != 1 || static_expression_handler.static_expression == 0)
+ continue;
+
+ // Is it a constant expression?
+ if (ir.ids[static_expression_handler.static_expression].get_type() != TypeConstant)
+ continue;
+
+ // We found a LUT!
+ static_constant_expression = static_expression_handler.static_expression;
+ }
+
+ get<SPIRConstant>(static_constant_expression).is_used_as_lut = true;
+ var.static_expression = static_constant_expression;
+ var.statically_assigned = true;
+ var.remapped_variable = true;
+ }
+}
+
+void Compiler::analyze_variable_scope(SPIRFunction &entry, AnalyzeVariableScopeAccessHandler &handler)
+{
+ // First, we map out all variable access within a function.
+ // Essentially a map of block -> { variables accessed in the basic block }
+ traverse_all_reachable_opcodes(entry, handler);
+
+ auto &cfg = *function_cfgs.find(entry.self)->second;
+
+ // Analyze if there are parameters which need to be implicitly preserved with an "in" qualifier.
+ analyze_parameter_preservation(entry, cfg, handler.accessed_variables_to_block,
+ handler.complete_write_variables_to_block);
+
+ unordered_map<uint32_t, uint32_t> potential_loop_variables;
+
+ // For each variable which is statically accessed.
+ for (auto &var : handler.accessed_variables_to_block)
+ {
+ // Only deal with variables which are considered local variables in this function.
+ if (find(begin(entry.local_variables), end(entry.local_variables), var.first) == end(entry.local_variables))
+ continue;
+
+ DominatorBuilder builder(cfg);
+ auto &blocks = var.second;
+ auto &type = expression_type(var.first);
+
+ // Figure out which block is dominating all accesses of those variables.
+ for (auto &block : blocks)
+ {
+ // If we're accessing a variable inside a continue block, this variable might be a loop variable.
+ // We can only use loop variables with scalars, as we cannot track static expressions for vectors.
+ if (is_continue(block))
+ {
+ // Potentially awkward case to check for.
+ // We might have a variable inside a loop, which is touched by the continue block,
+ // but is not actually a loop variable.
+ // The continue block is dominated by the inner part of the loop, which does not make sense in high-level
+ // language output because it will be declared before the body,
+ // so we will have to lift the dominator up to the relevant loop header instead.
+ builder.add_block(ir.continue_block_to_loop_header[block]);
+
+ // Arrays or structs cannot be loop variables.
+ if (type.vecsize == 1 && type.columns == 1 && type.basetype != SPIRType::Struct && type.array.empty())
+ {
+ // The variable is used in multiple continue blocks, this is not a loop
+ // candidate, signal that by setting block to -1u.
+ auto &potential = potential_loop_variables[var.first];
+
+ if (potential == 0)
+ potential = block;
+ else
+ potential = ~(0u);
+ }
+ }
+ builder.add_block(block);
+ }
+
+ builder.lift_continue_block_dominator();
+
+ // Add it to a per-block list of variables.
+ uint32_t dominating_block = builder.get_dominator();
+
+ // If all blocks here are dead code, this will be 0, so the variable in question
+ // will be completely eliminated.
+ if (dominating_block)
+ {
+ auto &block = get<SPIRBlock>(dominating_block);
+ block.dominated_variables.push_back(var.first);
+ get<SPIRVariable>(var.first).dominator = dominating_block;
+ }
+ }
+
+ for (auto &var : handler.accessed_temporaries_to_block)
+ {
+ auto itr = handler.result_id_to_type.find(var.first);
+
+ if (itr == end(handler.result_id_to_type))
+ {
+ // We found a false positive ID being used, ignore.
+ // This should probably be an assert.
+ continue;
+ }
+
+ // There is no point in doing domination analysis for opaque types.
+ auto &type = get<SPIRType>(itr->second);
+ if (type_is_opaque_value(type))
+ continue;
+
+ DominatorBuilder builder(cfg);
+ bool force_temporary = false;
+
+ // Figure out which block is dominating all accesses of those temporaries.
+ auto &blocks = var.second;
+ for (auto &block : blocks)
+ {
+ builder.add_block(block);
+
+ // If a temporary is used in more than one block, we might have to lift continue block
+ // access up to loop header like we did for variables.
+ if (blocks.size() != 1 && is_continue(block))
+ builder.add_block(ir.continue_block_to_loop_header[block]);
+ else if (blocks.size() != 1 && is_single_block_loop(block))
+ {
+ // Awkward case, because the loop header is also the continue block.
+ force_temporary = true;
+ }
+ }
+
+ uint32_t dominating_block = builder.get_dominator();
+ if (dominating_block)
+ {
+ // If we touch a variable in the dominating block, this is the expected setup.
+ // SPIR-V normally mandates this, but we have extra cases for temporary use inside loops.
+ bool first_use_is_dominator = blocks.count(dominating_block) != 0;
+
+ if (!first_use_is_dominator || force_temporary)
+ {
+ // This should be very rare, but if we try to declare a temporary inside a loop,
+ // and that temporary is used outside the loop as well (spirv-opt inliner likes this)
+ // we should actually emit the temporary outside the loop.
+ hoisted_temporaries.insert(var.first);
+ forced_temporaries.insert(var.first);
+
+ auto &block_temporaries = get<SPIRBlock>(dominating_block).declare_temporary;
+ block_temporaries.emplace_back(handler.result_id_to_type[var.first], var.first);
+ }
+ else if (blocks.size() > 1)
+ {
+ // Keep track of the temporary as we might have to declare this temporary.
+ // This can happen if the loop header dominates a temporary, but we have a complex fallback loop.
+ // In this case, the header is actually inside the for (;;) {} block, and we have problems.
+ // What we need to do is hoist the temporaries outside the for (;;) {} block in case the header block
+ // declares the temporary.
+ auto &block_temporaries = get<SPIRBlock>(dominating_block).potential_declare_temporary;
+ block_temporaries.emplace_back(handler.result_id_to_type[var.first], var.first);
+ }
+ }
+ }
+
+ unordered_set<uint32_t> seen_blocks;
+
+ // Now, try to analyze whether or not these variables are actually loop variables.
+ for (auto &loop_variable : potential_loop_variables)
+ {
+ auto &var = get<SPIRVariable>(loop_variable.first);
+ auto dominator = var.dominator;
+ auto block = loop_variable.second;
+
+ // The variable was accessed in multiple continue blocks, ignore.
+ if (block == ~(0u) || block == 0)
+ continue;
+
+ // Dead code.
+ if (dominator == 0)
+ continue;
+
+ uint32_t header = 0;
+
+ // Find the loop header for this block if we are a continue block.
+ {
+ auto itr = ir.continue_block_to_loop_header.find(block);
+ if (itr != end(ir.continue_block_to_loop_header))
+ {
+ header = itr->second;
+ }
+ else if (get<SPIRBlock>(block).continue_block == block)
+ {
+ // Also check for self-referential continue block.
+ header = block;
+ }
+ }
+
+ assert(header);
+ auto &header_block = get<SPIRBlock>(header);
+ auto &blocks = handler.accessed_variables_to_block[loop_variable.first];
+
+ // If a loop variable is not used before the loop, it's probably not a loop variable.
+ bool has_accessed_variable = blocks.count(header) != 0;
+
+ // Now, there are two conditions we need to meet for the variable to be a loop variable.
+ // 1. The dominating block must have a branch-free path to the loop header,
+ // this way we statically know which expression should be part of the loop variable initializer.
+
+ // Walk from the dominator, if there is one straight edge connecting
+ // dominator and loop header, we statically know the loop initializer.
+ bool static_loop_init = true;
+ while (dominator != header)
+ {
+ if (blocks.count(dominator) != 0)
+ has_accessed_variable = true;
+
+ auto &succ = cfg.get_succeeding_edges(dominator);
+ if (succ.size() != 1)
+ {
+ static_loop_init = false;
+ break;
+ }
+
+ auto &pred = cfg.get_preceding_edges(succ.front());
+ if (pred.size() != 1 || pred.front() != dominator)
+ {
+ static_loop_init = false;
+ break;
+ }
+
+ dominator = succ.front();
+ }
+
+ if (!static_loop_init || !has_accessed_variable)
+ continue;
+
+ // The second condition we need to meet is that no access after the loop
+ // merge can occur. Walk the CFG to see if we find anything.
+
+ seen_blocks.clear();
+ cfg.walk_from(seen_blocks, header_block.merge_block, [&](uint32_t walk_block) {
+ // We found a block which accesses the variable outside the loop.
+ if (blocks.find(walk_block) != end(blocks))
+ static_loop_init = false;
+ });
+
+ if (!static_loop_init)
+ continue;
+
+ // We have a loop variable.
+ header_block.loop_variables.push_back(loop_variable.first);
+ // Need to sort here as variables come from an unordered container, and pushing stuff in wrong order
+ // will break reproducability in regression runs.
+ sort(begin(header_block.loop_variables), end(header_block.loop_variables));
+ get<SPIRVariable>(loop_variable.first).loop_variable = true;
+ }
+}
+
+Bitset Compiler::get_buffer_block_flags(uint32_t id) const
+{
+ return ir.get_buffer_block_flags(get<SPIRVariable>(id));
+}
+
+bool Compiler::get_common_basic_type(const SPIRType &type, SPIRType::BaseType &base_type)
+{
+ if (type.basetype == SPIRType::Struct)
+ {
+ base_type = SPIRType::Unknown;
+ for (auto &member_type : type.member_types)
+ {
+ SPIRType::BaseType member_base;
+ if (!get_common_basic_type(get<SPIRType>(member_type), member_base))
+ return false;
+
+ if (base_type == SPIRType::Unknown)
+ base_type = member_base;
+ else if (base_type != member_base)
+ return false;
+ }
+ return true;
+ }
+ else
+ {
+ base_type = type.basetype;
+ return true;
+ }
+}
+
+void Compiler::ActiveBuiltinHandler::handle_builtin(const SPIRType &type, BuiltIn builtin,
+ const Bitset &decoration_flags)
+{
+ // If used, we will need to explicitly declare a new array size for these builtins.
+
+ if (builtin == BuiltInClipDistance)
+ {
+ if (!type.array_size_literal[0])
+ SPIRV_CROSS_THROW("Array size for ClipDistance must be a literal.");
+ uint32_t array_size = type.array[0];
+ if (array_size == 0)
+ SPIRV_CROSS_THROW("Array size for ClipDistance must not be unsized.");
+ compiler.clip_distance_count = array_size;
+ }
+ else if (builtin == BuiltInCullDistance)
+ {
+ if (!type.array_size_literal[0])
+ SPIRV_CROSS_THROW("Array size for CullDistance must be a literal.");
+ uint32_t array_size = type.array[0];
+ if (array_size == 0)
+ SPIRV_CROSS_THROW("Array size for CullDistance must not be unsized.");
+ compiler.cull_distance_count = array_size;
+ }
+ else if (builtin == BuiltInPosition)
+ {
+ if (decoration_flags.get(DecorationInvariant))
+ compiler.position_invariant = true;
+ }
+}
+
+bool Compiler::ActiveBuiltinHandler::handle(spv::Op opcode, const uint32_t *args, uint32_t length)
+{
+ const auto add_if_builtin = [&](uint32_t id) {
+ // Only handles variables here.
+ // Builtins which are part of a block are handled in AccessChain.
+ auto *var = compiler.maybe_get<SPIRVariable>(id);
+ auto &decorations = compiler.ir.meta[id].decoration;
+ if (var && decorations.builtin)
+ {
+ auto &type = compiler.get<SPIRType>(var->basetype);
+ auto &flags =
+ type.storage == StorageClassInput ? compiler.active_input_builtins : compiler.active_output_builtins;
+ flags.set(decorations.builtin_type);
+ handle_builtin(type, decorations.builtin_type, decorations.decoration_flags);
+ }
+ };
+
+ switch (opcode)
+ {
+ case OpStore:
+ if (length < 1)
+ return false;
+
+ add_if_builtin(args[0]);
+ break;
+
+ case OpCopyMemory:
+ if (length < 2)
+ return false;
+
+ add_if_builtin(args[0]);
+ add_if_builtin(args[1]);
+ break;
+
+ case OpCopyObject:
+ case OpLoad:
+ if (length < 3)
+ return false;
+
+ add_if_builtin(args[2]);
+ break;
+
+ case OpSelect:
+ if (length < 5)
+ return false;
+
+ add_if_builtin(args[3]);
+ add_if_builtin(args[4]);
+ break;
+
+ case OpPhi:
+ {
+ if (length < 2)
+ return false;
+
+ uint32_t count = length - 2;
+ args += 2;
+ for (uint32_t i = 0; i < count; i += 2)
+ add_if_builtin(args[i]);
+ break;
+ }
+
+ case OpFunctionCall:
+ {
+ if (length < 3)
+ return false;
+
+ uint32_t count = length - 3;
+ args += 3;
+ for (uint32_t i = 0; i < count; i++)
+ add_if_builtin(args[i]);
+ break;
+ }
+
+ case OpAccessChain:
+ case OpInBoundsAccessChain:
+ case OpPtrAccessChain:
+ {
+ if (length < 4)
+ return false;
+
+ // Only consider global variables, cannot consider variables in functions yet, or other
+ // access chains as they have not been created yet.
+ auto *var = compiler.maybe_get<SPIRVariable>(args[2]);
+ if (!var)
+ break;
+
+ // Required if we access chain into builtins like gl_GlobalInvocationID.
+ add_if_builtin(args[2]);
+
+ // Start traversing type hierarchy at the proper non-pointer types.
+ auto *type = &compiler.get_variable_data_type(*var);
+
+ auto &flags =
+ var->storage == StorageClassInput ? compiler.active_input_builtins : compiler.active_output_builtins;
+
+ uint32_t count = length - 3;
+ args += 3;
+ for (uint32_t i = 0; i < count; i++)
+ {
+ // Pointers
+ if (opcode == OpPtrAccessChain && i == 0)
+ {
+ type = &compiler.get<SPIRType>(type->parent_type);
+ continue;
+ }
+
+ // Arrays
+ if (!type->array.empty())
+ {
+ type = &compiler.get<SPIRType>(type->parent_type);
+ }
+ // Structs
+ else if (type->basetype == SPIRType::Struct)
+ {
+ uint32_t index = compiler.get<SPIRConstant>(args[i]).scalar();
+
+ if (index < uint32_t(compiler.ir.meta[type->self].members.size()))
+ {
+ auto &decorations = compiler.ir.meta[type->self].members[index];
+ if (decorations.builtin)
+ {
+ flags.set(decorations.builtin_type);
+ handle_builtin(compiler.get<SPIRType>(type->member_types[index]), decorations.builtin_type,
+ decorations.decoration_flags);
+ }
+ }
+
+ type = &compiler.get<SPIRType>(type->member_types[index]);
+ }
+ else
+ {
+ // No point in traversing further. We won't find any extra builtins.
+ break;
+ }
+ }
+ break;
+ }
+
+ default:
+ break;
+ }
+
+ return true;
+}
+
+void Compiler::update_active_builtins()
+{
+ active_input_builtins.reset();
+ active_output_builtins.reset();
+ cull_distance_count = 0;
+ clip_distance_count = 0;
+ ActiveBuiltinHandler handler(*this);
+ traverse_all_reachable_opcodes(get<SPIRFunction>(ir.default_entry_point), handler);
+}
+
+// Returns whether this shader uses a builtin of the storage class
+bool Compiler::has_active_builtin(BuiltIn builtin, StorageClass storage)
+{
+ const Bitset *flags;
+ switch (storage)
+ {
+ case StorageClassInput:
+ flags = &active_input_builtins;
+ break;
+ case StorageClassOutput:
+ flags = &active_output_builtins;
+ break;
+
+ default:
+ return false;
+ }
+ return flags->get(builtin);
+}
+
+void Compiler::analyze_image_and_sampler_usage()
+{
+ CombinedImageSamplerDrefHandler dref_handler(*this);
+ traverse_all_reachable_opcodes(get<SPIRFunction>(ir.default_entry_point), dref_handler);
+
+ CombinedImageSamplerUsageHandler handler(*this, dref_handler.dref_combined_samplers);
+ traverse_all_reachable_opcodes(get<SPIRFunction>(ir.default_entry_point), handler);
+ comparison_ids = move(handler.comparison_ids);
+ need_subpass_input = handler.need_subpass_input;
+
+ // Forward information from separate images and samplers into combined image samplers.
+ for (auto &combined : combined_image_samplers)
+ if (comparison_ids.count(combined.sampler_id))
+ comparison_ids.insert(combined.combined_id);
+}
+
+bool Compiler::CombinedImageSamplerDrefHandler::handle(spv::Op opcode, const uint32_t *args, uint32_t)
+{
+ // Mark all sampled images which are used with Dref.
+ switch (opcode)
+ {
+ case OpImageSampleDrefExplicitLod:
+ case OpImageSampleDrefImplicitLod:
+ case OpImageSampleProjDrefExplicitLod:
+ case OpImageSampleProjDrefImplicitLod:
+ case OpImageSparseSampleProjDrefImplicitLod:
+ case OpImageSparseSampleDrefImplicitLod:
+ case OpImageSparseSampleProjDrefExplicitLod:
+ case OpImageSparseSampleDrefExplicitLod:
+ case OpImageDrefGather:
+ case OpImageSparseDrefGather:
+ dref_combined_samplers.insert(args[2]);
+ return true;
+
+ default:
+ break;
+ }
+
+ return true;
+}
+
+void Compiler::build_function_control_flow_graphs_and_analyze()
+{
+ CFGBuilder handler(*this);
+ handler.function_cfgs[ir.default_entry_point].reset(new CFG(*this, get<SPIRFunction>(ir.default_entry_point)));
+ traverse_all_reachable_opcodes(get<SPIRFunction>(ir.default_entry_point), handler);
+ function_cfgs = move(handler.function_cfgs);
+ bool single_function = function_cfgs.size() <= 1;
+
+ for (auto &f : function_cfgs)
+ {
+ auto &func = get<SPIRFunction>(f.first);
+ AnalyzeVariableScopeAccessHandler scope_handler(*this, func);
+ analyze_variable_scope(func, scope_handler);
+ find_function_local_luts(func, scope_handler, single_function);
+
+ // Check if we can actually use the loop variables we found in analyze_variable_scope.
+ // To use multiple initializers, we need the same type and qualifiers.
+ for (auto block : func.blocks)
+ {
+ auto &b = get<SPIRBlock>(block);
+ if (b.loop_variables.size() < 2)
+ continue;
+
+ auto &flags = get_decoration_bitset(b.loop_variables.front());
+ uint32_t type = get<SPIRVariable>(b.loop_variables.front()).basetype;
+ bool invalid_initializers = false;
+ for (auto loop_variable : b.loop_variables)
+ {
+ if (flags != get_decoration_bitset(loop_variable) ||
+ type != get<SPIRVariable>(b.loop_variables.front()).basetype)
+ {
+ invalid_initializers = true;
+ break;
+ }
+ }
+
+ if (invalid_initializers)
+ {
+ for (auto loop_variable : b.loop_variables)
+ get<SPIRVariable>(loop_variable).loop_variable = false;
+ b.loop_variables.clear();
+ }
+ }
+ }
+}
+
+Compiler::CFGBuilder::CFGBuilder(spirv_cross::Compiler &compiler_)
+ : compiler(compiler_)
+{
+}
+
+bool Compiler::CFGBuilder::handle(spv::Op, const uint32_t *, uint32_t)
+{
+ return true;
+}
+
+bool Compiler::CFGBuilder::follow_function_call(const SPIRFunction &func)
+{
+ if (function_cfgs.find(func.self) == end(function_cfgs))
+ {
+ function_cfgs[func.self].reset(new CFG(compiler, func));
+ return true;
+ }
+ else
+ return false;
+}
+
+bool Compiler::CombinedImageSamplerUsageHandler::begin_function_scope(const uint32_t *args, uint32_t length)
+{
+ if (length < 3)
+ return false;
+
+ auto &func = compiler.get<SPIRFunction>(args[2]);
+ const auto *arg = &args[3];
+ length -= 3;
+
+ for (uint32_t i = 0; i < length; i++)
+ {
+ auto &argument = func.arguments[i];
+ dependency_hierarchy[argument.id].insert(arg[i]);
+ }
+
+ return true;
+}
+
+void Compiler::CombinedImageSamplerUsageHandler::add_hierarchy_to_comparison_ids(uint32_t id)
+{
+ // Traverse the variable dependency hierarchy and tag everything in its path with comparison ids.
+ comparison_ids.insert(id);
+ for (auto &dep_id : dependency_hierarchy[id])
+ add_hierarchy_to_comparison_ids(dep_id);
+}
+
+bool Compiler::CombinedImageSamplerUsageHandler::handle(Op opcode, const uint32_t *args, uint32_t length)
+{
+ switch (opcode)
+ {
+ case OpAccessChain:
+ case OpInBoundsAccessChain:
+ case OpPtrAccessChain:
+ case OpLoad:
+ {
+ if (length < 3)
+ return false;
+ dependency_hierarchy[args[1]].insert(args[2]);
+
+ // Ideally defer this to OpImageRead, but then we'd need to track loaded IDs.
+ // If we load an image, we're going to use it and there is little harm in declaring an unused gl_FragCoord.
+ auto &type = compiler.get<SPIRType>(args[0]);
+ if (type.image.dim == DimSubpassData)
+ need_subpass_input = true;
+
+ // If we load a SampledImage and it will be used with Dref, propagate the state up.
+ if (dref_combined_samplers.count(args[1]) != 0)
+ add_hierarchy_to_comparison_ids(args[1]);
+ break;
+ }
+
+ case OpSampledImage:
+ {
+ if (length < 4)
+ return false;
+
+ uint32_t result_type = args[0];
+ uint32_t result_id = args[1];
+ auto &type = compiler.get<SPIRType>(result_type);
+ if (type.image.depth || dref_combined_samplers.count(result_id) != 0)
+ {
+ // This image must be a depth image.
+ uint32_t image = args[2];
+ add_hierarchy_to_comparison_ids(image);
+
+ // This sampler must be a SamplerComparisonState, and not a regular SamplerState.
+ uint32_t sampler = args[3];
+ add_hierarchy_to_comparison_ids(sampler);
+
+ // Mark the OpSampledImage itself as being comparison state.
+ comparison_ids.insert(result_id);
+ }
+ return true;
+ }
+
+ default:
+ break;
+ }
+
+ return true;
+}
+
+bool Compiler::buffer_is_hlsl_counter_buffer(uint32_t id) const
+{
+ auto *m = ir.find_meta(id);
+ return m && m->hlsl_is_magic_counter_buffer;
+}
+
+bool Compiler::buffer_get_hlsl_counter_buffer(uint32_t id, uint32_t &counter_id) const
+{
+ auto *m = ir.find_meta(id);
+
+ // First, check for the proper decoration.
+ if (m && m->hlsl_magic_counter_buffer != 0)
+ {
+ counter_id = m->hlsl_magic_counter_buffer;
+ return true;
+ }
+ else
+ return false;
+}
+
+void Compiler::make_constant_null(uint32_t id, uint32_t type)
+{
+ auto &constant_type = get<SPIRType>(type);
+
+ if (constant_type.pointer)
+ {
+ auto &constant = set<SPIRConstant>(id, type);
+ constant.make_null(constant_type);
+ }
+ else if (!constant_type.array.empty())
+ {
+ assert(constant_type.parent_type);
+ uint32_t parent_id = ir.increase_bound_by(1);
+ make_constant_null(parent_id, constant_type.parent_type);
+
+ if (!constant_type.array_size_literal.back())
+ SPIRV_CROSS_THROW("Array size of OpConstantNull must be a literal.");
+
+ vector<uint32_t> elements(constant_type.array.back());
+ for (uint32_t i = 0; i < constant_type.array.back(); i++)
+ elements[i] = parent_id;
+ set<SPIRConstant>(id, type, elements.data(), uint32_t(elements.size()), false);
+ }
+ else if (!constant_type.member_types.empty())
+ {
+ uint32_t member_ids = ir.increase_bound_by(uint32_t(constant_type.member_types.size()));
+ vector<uint32_t> elements(constant_type.member_types.size());
+ for (uint32_t i = 0; i < constant_type.member_types.size(); i++)
+ {
+ make_constant_null(member_ids + i, constant_type.member_types[i]);
+ elements[i] = member_ids + i;
+ }
+ set<SPIRConstant>(id, type, elements.data(), uint32_t(elements.size()), false);
+ }
+ else
+ {
+ auto &constant = set<SPIRConstant>(id, type);
+ constant.make_null(constant_type);
+ }
+}
+
+const std::vector<spv::Capability> &Compiler::get_declared_capabilities() const
+{
+ return ir.declared_capabilities;
+}
+
+const std::vector<std::string> &Compiler::get_declared_extensions() const
+{
+ return ir.declared_extensions;
+}
+
+std::string Compiler::get_remapped_declared_block_name(uint32_t id) const
+{
+ auto itr = declared_block_names.find(id);
+ if (itr != end(declared_block_names))
+ return itr->second;
+ else
+ {
+ auto &var = get<SPIRVariable>(id);
+ auto &type = get<SPIRType>(var.basetype);
+
+ auto *type_meta = ir.find_meta(type.self);
+ auto *block_name = type_meta ? &type_meta->decoration.alias : nullptr;
+ return (!block_name || block_name->empty()) ? get_block_fallback_name(id) : *block_name;
+ }
+}
+
+bool Compiler::instruction_to_result_type(uint32_t &result_type, uint32_t &result_id, spv::Op op, const uint32_t *args,
+ uint32_t length)
+{
+ // Most instructions follow the pattern of <result-type> <result-id> <arguments>.
+ // There are some exceptions.
+ switch (op)
+ {
+ case OpStore:
+ case OpCopyMemory:
+ case OpCopyMemorySized:
+ case OpImageWrite:
+ case OpAtomicStore:
+ case OpAtomicFlagClear:
+ case OpEmitStreamVertex:
+ case OpEndStreamPrimitive:
+ case OpControlBarrier:
+ case OpMemoryBarrier:
+ case OpGroupWaitEvents:
+ case OpRetainEvent:
+ case OpReleaseEvent:
+ case OpSetUserEventStatus:
+ case OpCaptureEventProfilingInfo:
+ case OpCommitReadPipe:
+ case OpCommitWritePipe:
+ case OpGroupCommitReadPipe:
+ case OpGroupCommitWritePipe:
+ return false;
+
+ default:
+ if (length > 1 && maybe_get<SPIRType>(args[0]) != nullptr)
+ {
+ result_type = args[0];
+ result_id = args[1];
+ return true;
+ }
+ else
+ return false;
+ }
+}
+
+Bitset Compiler::combined_decoration_for_member(const SPIRType &type, uint32_t index) const
+{
+ Bitset flags;
+ auto *type_meta = ir.find_meta(type.self);
+
+ if (type_meta)
+ {
+ auto &memb = type_meta->members;
+ if (index >= memb.size())
+ return flags;
+ auto &dec = memb[index];
+
+ // If our type is a struct, traverse all the members as well recursively.
+ flags.merge_or(dec.decoration_flags);
+ for (uint32_t i = 0; i < type.member_types.size(); i++)
+ flags.merge_or(combined_decoration_for_member(get<SPIRType>(type.member_types[i]), i));
+ }
+
+ return flags;
+}
+
+bool Compiler::is_desktop_only_format(spv::ImageFormat format)
+{
+ switch (format)
+ {
+ // Desktop-only formats
+ case ImageFormatR11fG11fB10f:
+ case ImageFormatR16f:
+ case ImageFormatRgb10A2:
+ case ImageFormatR8:
+ case ImageFormatRg8:
+ case ImageFormatR16:
+ case ImageFormatRg16:
+ case ImageFormatRgba16:
+ case ImageFormatR16Snorm:
+ case ImageFormatRg16Snorm:
+ case ImageFormatRgba16Snorm:
+ case ImageFormatR8Snorm:
+ case ImageFormatRg8Snorm:
+ case ImageFormatR8ui:
+ case ImageFormatRg8ui:
+ case ImageFormatR16ui:
+ case ImageFormatRgb10a2ui:
+ case ImageFormatR8i:
+ case ImageFormatRg8i:
+ case ImageFormatR16i:
+ return true;
+ default:
+ break;
+ }
+
+ return false;
+}
+
+bool Compiler::image_is_comparison(const spirv_cross::SPIRType &type, uint32_t id) const
+{
+ return type.image.depth || (comparison_ids.count(id) != 0);
+}
+
+bool Compiler::type_is_opaque_value(const spirv_cross::SPIRType &type) const
+{
+ return !type.pointer && (type.basetype == SPIRType::SampledImage || type.basetype == SPIRType::Image ||
+ type.basetype == SPIRType::Sampler);
+}