SPIRV-Cross/spirv_msl.cpp

3144 строки
94 KiB
C++

/*
* Copyright 2016-2017 The Brenwill Workshop Ltd.
*
* 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_msl.hpp"
#include "GLSL.std.450.h"
#include <algorithm>
#include <cassert>
#include <numeric>
using namespace spv;
using namespace spirv_cross;
using namespace std;
static const uint32_t k_unknown_location = ~0;
CompilerMSL::CompilerMSL(vector<uint32_t> spirv_, vector<MSLVertexAttr> *p_vtx_attrs,
vector<MSLResourceBinding> *p_res_bindings)
: CompilerGLSL(move(spirv_))
{
populate_func_name_overrides();
populate_var_name_overrides();
if (p_vtx_attrs)
for (auto &va : *p_vtx_attrs)
vtx_attrs_by_location[va.location] = &va;
if (p_res_bindings)
for (auto &rb : *p_res_bindings)
resource_bindings.push_back(&rb);
}
CompilerMSL::CompilerMSL(const uint32_t *ir, size_t word_count, MSLVertexAttr *p_vtx_attrs, size_t vtx_attrs_count,
MSLResourceBinding *p_res_bindings, size_t res_bindings_count)
: CompilerGLSL(ir, word_count)
{
populate_func_name_overrides();
populate_var_name_overrides();
if (p_vtx_attrs)
for (size_t i = 0; i < vtx_attrs_count; i++)
vtx_attrs_by_location[p_vtx_attrs[i].location] = &p_vtx_attrs[i];
if (p_res_bindings)
for (size_t i = 0; i < res_bindings_count; i++)
resource_bindings.push_back(&p_res_bindings[i]);
}
// Populate the collection of function names that need to be overridden
void CompilerMSL::populate_func_name_overrides()
{
func_name_overrides["main"] = "main0";
func_name_overrides["saturate"] = "saturate0";
}
void CompilerMSL::populate_var_name_overrides()
{
var_name_overrides["kernel"] = "kernel0";
var_name_overrides["bias"] = "bias0";
}
string CompilerMSL::compile()
{
// Force a classic "C" locale, reverts when function returns
ClassicLocale classic_locale;
// Set main function name if it was explicitly set
if (!options.entry_point_name.empty())
set_name(entry_point, options.entry_point_name);
non_stage_in_input_var_ids.clear();
struct_member_padding.clear();
update_active_builtins();
fixup_image_load_store_access();
set_enabled_interface_variables(get_active_interface_variables());
// Preprocess OpCodes to extract the need to output additional header content
preprocess_op_codes();
// Create structs to hold input, output and uniform variables
qual_pos_var_name = "";
stage_in_var_id = add_interface_block(StorageClassInput);
stage_out_var_id = add_interface_block(StorageClassOutput);
stage_uniforms_var_id = add_interface_block(StorageClassUniformConstant);
// Convert the use of global variables to recursively-passed function parameters
localize_global_variables();
extract_global_variables_from_functions();
// Do not deal with GLES-isms like precision, older extensions and such.
CompilerGLSL::options.vulkan_semantics = true;
CompilerGLSL::options.es = false;
CompilerGLSL::options.version = 120;
backend.float_literal_suffix = false;
backend.uint32_t_literal_suffix = true;
backend.basic_int_type = "int";
backend.basic_uint_type = "uint";
backend.discard_literal = "discard_fragment()";
backend.swizzle_is_function = false;
backend.shared_is_implied = false;
backend.native_row_major_matrix = false;
uint32_t pass_count = 0;
do
{
if (pass_count >= 3)
SPIRV_CROSS_THROW("Over 3 compilation loops detected. Must be a bug!");
reset();
next_metal_resource_index = MSLResourceBinding(); // Start bindings at zero
// Move constructor for this type is broken on GCC 4.9 ...
buffer = unique_ptr<ostringstream>(new ostringstream());
emit_header();
emit_specialization_constants();
emit_resources();
emit_custom_functions();
emit_function(get<SPIRFunction>(entry_point), 0);
pass_count++;
} while (force_recompile);
return buffer->str();
}
string CompilerMSL::compile(vector<MSLVertexAttr> *p_vtx_attrs, vector<MSLResourceBinding> *p_res_bindings)
{
if (p_vtx_attrs)
{
vtx_attrs_by_location.clear();
for (auto &va : *p_vtx_attrs)
vtx_attrs_by_location[va.location] = &va;
}
if (p_res_bindings)
{
resource_bindings.clear();
for (auto &rb : *p_res_bindings)
resource_bindings.push_back(&rb);
}
return compile();
}
string CompilerMSL::compile(MSLConfiguration &msl_cfg, vector<MSLVertexAttr> *p_vtx_attrs,
vector<MSLResourceBinding> *p_res_bindings)
{
options = msl_cfg;
return compile(p_vtx_attrs, p_res_bindings);
}
// Register the need to output any custom functions.
void CompilerMSL::preprocess_op_codes()
{
spv_function_implementations.clear();
OpCodePreprocessor preproc(*this);
traverse_all_reachable_opcodes(get<SPIRFunction>(entry_point), preproc);
if (preproc.suppress_missing_prototypes)
add_pragma_line("#pragma clang diagnostic ignored \"-Wmissing-prototypes\"");
if (preproc.uses_atomics)
{
add_header_line("#include <metal_atomic>");
add_pragma_line("#pragma clang diagnostic ignored \"-Wunused-variable\"");
}
}
// Move the Private global variables to the entry function.
// Non-constant variables cannot have global scope in Metal.
void CompilerMSL::localize_global_variables()
{
auto &entry_func = get<SPIRFunction>(entry_point);
auto iter = global_variables.begin();
while (iter != global_variables.end())
{
uint32_t gv_id = *iter;
auto &gbl_var = get<SPIRVariable>(gv_id);
if (gbl_var.storage == StorageClassPrivate)
{
entry_func.add_local_variable(gv_id);
iter = global_variables.erase(iter);
}
else
iter++;
}
}
// For any global variable accessed directly by a function,
// extract that variable and add it as an argument to that function.
void CompilerMSL::extract_global_variables_from_functions()
{
// Uniforms
unordered_set<uint32_t> global_var_ids;
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
auto &var = id.get<SPIRVariable>();
if (var.storage == StorageClassInput || var.storage == StorageClassUniform ||
var.storage == StorageClassUniformConstant || var.storage == StorageClassPushConstant ||
var.storage == StorageClassStorageBuffer)
{
global_var_ids.insert(var.self);
}
}
}
// Local vars that are declared in the main function and accessed directy by a function
auto &entry_func = get<SPIRFunction>(entry_point);
for (auto &var : entry_func.local_variables)
global_var_ids.insert(var);
std::set<uint32_t> added_arg_ids;
unordered_set<uint32_t> processed_func_ids;
extract_global_variables_from_function(entry_point, added_arg_ids, global_var_ids, processed_func_ids);
}
// MSL does not support the use of global variables for shader input content.
// For any global variable accessed directly by the specified function, extract that variable,
// add it as an argument to that function, and the arg to the added_arg_ids collection.
void CompilerMSL::extract_global_variables_from_function(uint32_t func_id, std::set<uint32_t> &added_arg_ids,
unordered_set<uint32_t> &global_var_ids,
unordered_set<uint32_t> &processed_func_ids)
{
// Avoid processing a function more than once
if (processed_func_ids.find(func_id) != processed_func_ids.end())
{
// Return function global variables
added_arg_ids = function_global_vars[func_id];
return;
}
processed_func_ids.insert(func_id);
auto &func = get<SPIRFunction>(func_id);
// Recursively establish global args added to functions on which we depend.
for (auto block : func.blocks)
{
auto &b = get<SPIRBlock>(block);
for (auto &i : b.ops)
{
auto ops = stream(i);
auto op = static_cast<Op>(i.op);
switch (op)
{
case OpLoad:
case OpAccessChain:
{
uint32_t base_id = ops[2];
if (global_var_ids.find(base_id) != global_var_ids.end())
added_arg_ids.insert(base_id);
break;
}
case OpFunctionCall:
{
uint32_t inner_func_id = ops[2];
std::set<uint32_t> inner_func_args;
extract_global_variables_from_function(inner_func_id, inner_func_args, global_var_ids,
processed_func_ids);
added_arg_ids.insert(inner_func_args.begin(), inner_func_args.end());
break;
}
default:
break;
}
}
}
function_global_vars[func_id] = added_arg_ids;
// Add the global variables as arguments to the function
if (func_id != entry_point)
{
uint32_t next_id = increase_bound_by(uint32_t(added_arg_ids.size()));
for (uint32_t arg_id : added_arg_ids)
{
uint32_t type_id = get<SPIRVariable>(arg_id).basetype;
func.add_parameter(type_id, next_id, true);
set<SPIRVariable>(next_id, type_id, StorageClassFunction);
// Ensure both the existing and new variables have the same name, and the name is valid
string vld_name = ensure_valid_name(to_name(arg_id), "v");
set_name(arg_id, vld_name);
set_name(next_id, vld_name);
meta[next_id].decoration.qualified_alias = meta[arg_id].decoration.qualified_alias;
next_id++;
}
}
}
// If a vertex attribute exists at the location, it is marked as being used by this shader
void CompilerMSL::mark_location_as_used_by_shader(uint32_t location, StorageClass storage)
{
MSLVertexAttr *p_va;
auto &execution = get_entry_point();
if ((execution.model == ExecutionModelVertex) && (storage == StorageClassInput) &&
(p_va = vtx_attrs_by_location[location]))
p_va->used_by_shader = true;
}
// Add an interface structure for the type of storage, which is either StorageClassInput or StorageClassOutput.
// Returns the ID of the newly added variable, or zero if no variable was added.
uint32_t CompilerMSL::add_interface_block(StorageClass storage)
{
// Accumulate the variables that should appear in the interface struct
vector<SPIRVariable *> vars;
bool incl_builtins = (storage == StorageClassOutput);
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
auto &var = id.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
if (var.storage == storage && interface_variable_exists_in_entry_point(var.self) &&
!is_hidden_variable(var, incl_builtins) && type.pointer)
{
vars.push_back(&var);
}
}
}
// If no variables qualify, leave
if (vars.empty())
return 0;
// Add a new typed variable for this interface structure.
// The initializer expression is allocated here, but populated when the function
// declaraion is emitted, because it is cleared after each compilation pass.
uint32_t next_id = increase_bound_by(3);
uint32_t ib_type_id = next_id++;
auto &ib_type = set<SPIRType>(ib_type_id);
ib_type.basetype = SPIRType::Struct;
ib_type.storage = storage;
set_decoration(ib_type_id, DecorationBlock);
uint32_t ib_var_id = next_id++;
auto &var = set<SPIRVariable>(ib_var_id, ib_type_id, storage, 0);
var.initializer = next_id++;
string ib_var_ref;
switch (storage)
{
case StorageClassInput:
ib_var_ref = stage_in_var_name;
break;
case StorageClassOutput:
{
ib_var_ref = stage_out_var_name;
// Add the output interface struct as a local variable to the entry function,
// and force the entry function to return the output interface struct from
// any blocks that perform a function return.
auto &entry_func = get<SPIRFunction>(entry_point);
entry_func.add_local_variable(ib_var_id);
for (auto &blk_id : entry_func.blocks)
{
auto &blk = get<SPIRBlock>(blk_id);
if (blk.terminator == SPIRBlock::Return)
blk.return_value = ib_var_id;
}
break;
}
case StorageClassUniformConstant:
{
ib_var_ref = stage_uniform_var_name;
active_interface_variables.insert(ib_var_id); // Ensure will be emitted
break;
}
default:
break;
}
set_name(ib_type_id, get_entry_point_name() + "_" + ib_var_ref);
set_name(ib_var_id, ib_var_ref);
for (auto p_var : vars)
{
uint32_t type_id = p_var->basetype;
auto &type = get<SPIRType>(type_id);
if (type.basetype == SPIRType::Struct)
{
// Flatten the struct members into the interface struct
uint32_t mbr_idx = 0;
for (auto &mbr_type_id : type.member_types)
{
BuiltIn builtin;
bool is_builtin = is_member_builtin(type, mbr_idx, &builtin);
auto &mbr_type = get<SPIRType>(mbr_type_id);
if (should_move_to_input_buffer(mbr_type, is_builtin, storage))
move_member_to_input_buffer(type, mbr_idx);
else if (!is_builtin || has_active_builtin(builtin, storage))
{
// Add a reference to the member to the interface struct.
uint32_t ib_mbr_idx = uint32_t(ib_type.member_types.size());
ib_type.member_types.push_back(mbr_type_id); // membertype.self is different for array types
// Give the member a name
string mbr_name = ensure_valid_name(to_qualified_member_name(type, mbr_idx), "m");
set_member_name(ib_type_id, ib_mbr_idx, mbr_name);
// Update the original variable reference to include the structure reference
string qual_var_name = ib_var_ref + "." + mbr_name;
set_member_qualified_name(type_id, mbr_idx, qual_var_name);
// Copy the variable location from the original variable to the member
if (has_member_decoration(type_id, mbr_idx, DecorationLocation))
{
uint32_t locn = get_member_decoration(type_id, mbr_idx, DecorationLocation);
set_member_decoration(ib_type_id, ib_mbr_idx, DecorationLocation, locn);
mark_location_as_used_by_shader(locn, storage);
}
else if (has_decoration(p_var->self, DecorationLocation))
{
// The block itself might have a location and in this case, all members of the block
// receive incrementing locations.
uint32_t locn = get_decoration(p_var->self, DecorationLocation) + mbr_idx;
set_member_decoration(ib_type_id, ib_mbr_idx, DecorationLocation, locn);
mark_location_as_used_by_shader(locn, storage);
}
// Mark the member as builtin if needed
if (is_builtin)
{
set_member_decoration(ib_type_id, ib_mbr_idx, DecorationBuiltIn, builtin);
if (builtin == BuiltInPosition)
qual_pos_var_name = qual_var_name;
}
}
mbr_idx++;
}
}
else if (type.basetype == SPIRType::Boolean || type.basetype == SPIRType::Char ||
type.basetype == SPIRType::Int || type.basetype == SPIRType::UInt ||
type.basetype == SPIRType::Int64 || type.basetype == SPIRType::UInt64 ||
type.basetype == SPIRType::Float || type.basetype == SPIRType::Double ||
type.basetype == SPIRType::Boolean)
{
bool is_builtin = is_builtin_variable(*p_var);
BuiltIn builtin = BuiltIn(get_decoration(p_var->self, DecorationBuiltIn));
if (should_move_to_input_buffer(type, is_builtin, storage))
move_to_input_buffer(*p_var);
else if (!is_builtin || has_active_builtin(builtin, storage))
{
// Add a reference to the variable type to the interface struct.
uint32_t ib_mbr_idx = uint32_t(ib_type.member_types.size());
ib_type.member_types.push_back(type_id);
// Give the member a name
string mbr_name = ensure_valid_name(to_expression(p_var->self), "m");
set_member_name(ib_type_id, ib_mbr_idx, mbr_name);
// Update the original variable reference to include the structure reference
string qual_var_name = ib_var_ref + "." + mbr_name;
meta[p_var->self].decoration.qualified_alias = qual_var_name;
// Copy the variable location from the original variable to the member
if (get_decoration_mask(p_var->self) & (1ull << DecorationLocation))
{
uint32_t locn = get_decoration(p_var->self, DecorationLocation);
set_member_decoration(ib_type_id, ib_mbr_idx, DecorationLocation, locn);
mark_location_as_used_by_shader(locn, storage);
}
// Mark the member as builtin if needed
if (is_builtin)
{
set_member_decoration(ib_type_id, ib_mbr_idx, DecorationBuiltIn, builtin);
if (builtin == BuiltInPosition)
qual_pos_var_name = qual_var_name;
}
}
}
}
// Sort the members of the structure by their locations.
// Oddly, Metal handles inputs better if they are sorted in reverse order.
MemberSorter::SortAspect sort_aspect =
(storage == StorageClassInput) ? MemberSorter::LocationReverse : MemberSorter::Location;
MemberSorter member_sorter(ib_type, meta[ib_type_id], sort_aspect);
member_sorter.sort();
return ib_var_id;
}
// Returns whether a variable of type and storage class should be moved from an interface
// block to a secondary input buffer block.
// This is the case for matrixes and arrays that appear in the stage_in interface block
// of a vertex function, and true is returned.
// Other types do not need to move, and false is returned.
// Matrices and arrays are not permitted in the output of a vertex function or the input
// or output of a fragment function, and in those cases, an exception is thrown.
bool CompilerMSL::should_move_to_input_buffer(SPIRType &type, bool is_builtin, StorageClass storage)
{
if ((is_matrix(type) || is_array(type)) && !is_builtin)
{
auto &execution = get_entry_point();
if (execution.model == ExecutionModelVertex)
{
if (storage == StorageClassInput)
return true;
if (storage == StorageClassOutput)
SPIRV_CROSS_THROW("The vertex function output structure may not include a matrix or array.");
}
else if (execution.model == ExecutionModelFragment)
{
if (storage == StorageClassInput)
SPIRV_CROSS_THROW("The fragment function stage_in structure may not include a matrix or array.");
if (storage == StorageClassOutput)
SPIRV_CROSS_THROW("The fragment function output structure may not include a matrix or array.");
}
}
return false;
}
// Excludes the specified variable from an interface block structure.
// Instead, for the variable is added to a block variable corresponding to a secondary MSL buffer.
// The use case for this is when a vertex stage_in variable contains a matrix or array.
void CompilerMSL::move_to_input_buffer(SPIRVariable &var)
{
uint32_t var_id = var.self;
if (!has_decoration(var_id, DecorationLocation))
return;
uint32_t mbr_type_id = var.basetype;
string mbr_name = ensure_valid_name(to_expression(var_id), "m");
uint32_t mbr_locn = get_decoration(var_id, DecorationLocation);
meta[var_id].decoration.qualified_alias = add_input_buffer_block_member(mbr_type_id, mbr_name, mbr_locn);
}
// Excludes the specified type member from the stage_in block structure.
// Instead, for the variable is added to a block variable corresponding to a secondary MSL buffer.
// The use case for this is when a vertex stage_in variable contains a matrix or array.
void CompilerMSL::move_member_to_input_buffer(const SPIRType &type, uint32_t index)
{
uint32_t type_id = type.self;
if (!has_member_decoration(type_id, index, DecorationLocation))
return;
uint32_t mbr_type_id = type.member_types[index];
string mbr_name = ensure_valid_name(to_qualified_member_name(type, index), "m");
uint32_t mbr_locn = get_member_decoration(type_id, index, DecorationLocation);
string qual_name = add_input_buffer_block_member(mbr_type_id, mbr_name, mbr_locn);
set_member_qualified_name(type_id, index, qual_name);
}
// Adds a member to the input buffer block that corresponds to the MTLBuffer used by an attribute location
string CompilerMSL::add_input_buffer_block_member(uint32_t mbr_type_id, string mbr_name, uint32_t mbr_locn)
{
mark_location_as_used_by_shader(mbr_locn, StorageClassInput);
MSLVertexAttr *p_va = vtx_attrs_by_location[mbr_locn];
if (!p_va)
return "";
if (p_va->per_instance)
needs_instance_idx_arg = true;
else
needs_vertex_idx_arg = true;
// The variable that is the block struct.
// Record the stride of this struct in its offset decoration.
uint32_t ib_var_id = get_input_buffer_block_var_id(p_va->msl_buffer);
auto &ib_var = get<SPIRVariable>(ib_var_id);
uint32_t ib_type_id = ib_var.basetype;
auto &ib_type = get<SPIRType>(ib_type_id);
set_decoration(ib_type_id, DecorationOffset, p_va->msl_stride);
// Add a reference to the variable type to the interface struct.
uint32_t ib_mbr_idx = uint32_t(ib_type.member_types.size());
ib_type.member_types.push_back(mbr_type_id);
// Give the member a name
set_member_name(ib_type_id, ib_mbr_idx, mbr_name);
// Set MSL buffer and offset decorations, and indicate no valid attribute location
set_member_decoration(ib_type_id, ib_mbr_idx, DecorationBinding, p_va->msl_buffer);
set_member_decoration(ib_type_id, ib_mbr_idx, DecorationOffset, p_va->msl_offset);
set_member_decoration(ib_type_id, ib_mbr_idx, DecorationLocation, k_unknown_location);
// Update the original variable reference to include the structure and index reference
string idx_var_name =
builtin_to_glsl(p_va->per_instance ? BuiltInInstanceIndex : BuiltInVertexIndex, StorageClassInput);
return get_name(ib_var_id) + "[" + idx_var_name + "]." + mbr_name;
}
// Returns the ID of the input block that will use the specified MSL buffer index,
// lazily creating an input block variable and type if needed.
//
// The use of this block applies only to input variables that have been excluded from the stage_in
// block, which typically only occurs if an attempt to pass a matrix in the stage_in block.
uint32_t CompilerMSL::get_input_buffer_block_var_id(uint32_t msl_buffer)
{
uint32_t ib_var_id = non_stage_in_input_var_ids[msl_buffer];
if (!ib_var_id)
{
// No interface block exists yet. Create a new typed variable for this interface block.
// The initializer expression is allocated here, but populated when the function
// declaraion is emitted, because it is cleared after each compilation pass.
uint32_t next_id = increase_bound_by(3);
uint32_t ib_type_id = next_id++;
auto &ib_type = set<SPIRType>(ib_type_id);
ib_type.basetype = SPIRType::Struct;
ib_type.storage = StorageClassInput;
set_decoration(ib_type_id, DecorationBlock);
ib_var_id = next_id++;
auto &var = set<SPIRVariable>(ib_var_id, ib_type_id, StorageClassInput, 0);
var.initializer = next_id++;
string ib_var_name = stage_in_var_name + convert_to_string(msl_buffer);
set_name(ib_var_id, ib_var_name);
set_name(ib_type_id, get_entry_point_name() + "_" + ib_var_name);
// Add the variable to the map of buffer blocks, accessed by the Metal buffer index.
non_stage_in_input_var_ids[msl_buffer] = ib_var_id;
}
return ib_var_id;
}
// Sort the members of the struct type by offset, and pack and then pad members where needed
// to align MSL members with SPIR-V offsets. The struct members are iterated twice. Packing
// occurs first, followed by padding, because packing a member reduces both its size and its
// natural alignment, possibly requiring a padding member to be added ahead of it.
void CompilerMSL::align_struct(SPIRType &ib_type)
{
uint32_t &ib_type_id = ib_type.self;
// Sort the members of the interface structure by their offset.
// They should already be sorted per SPIR-V spec anyway.
MemberSorter member_sorter(ib_type, meta[ib_type_id], MemberSorter::Offset);
member_sorter.sort();
uint32_t curr_offset = 0;
uint32_t mbr_cnt = uint32_t(ib_type.member_types.size());
// Test the alignment of each member, and if a member should be closer to the previous
// member than the default spacing expects, it is likely that the previous member is in
// a packed format. If so, and the previous member is packable, pack it.
// For example...this applies to any 3-element vector that is followed by a scalar.
for (uint32_t mbr_idx = 0; mbr_idx < mbr_cnt; mbr_idx++)
{
// Align current offset to the current member's default alignment.
size_t align_mask = get_declared_struct_member_alignment(ib_type, mbr_idx) - 1;
curr_offset = uint32_t((curr_offset + align_mask) & ~align_mask);
// Fetch the member offset as declared in the SPIRV.
uint32_t mbr_offset = get_member_decoration(ib_type_id, mbr_idx, DecorationOffset);
if (curr_offset > mbr_offset)
{
uint32_t prev_mbr_idx = mbr_idx - 1;
if (is_member_packable(ib_type, prev_mbr_idx))
set_member_decoration(ib_type_id, prev_mbr_idx, DecorationCPacked);
}
// Increment the current offset to be positioned immediately after the current member.
curr_offset = mbr_offset + uint32_t(get_declared_struct_member_size(ib_type, mbr_idx));
}
// Test the alignment of each member, and if a member is positioned farther than its
// alignment and the end of the previous member, add a dummy padding member that will
// be added before the current member when the delaration of this struct is emitted.
for (uint32_t mbr_idx = 0; mbr_idx < mbr_cnt; mbr_idx++)
{
// Align current offset to the current member's default alignment.
size_t align_mask = get_declared_struct_member_alignment(ib_type, mbr_idx) - 1;
curr_offset = uint32_t((curr_offset + align_mask) & ~align_mask);
// Fetch the member offset as declared in the SPIRV.
uint32_t mbr_offset = get_member_decoration(ib_type_id, mbr_idx, DecorationOffset);
if (mbr_offset > curr_offset)
{
// Since MSL and SPIR-V have slightly different struct member alignment and
// size rules, we'll pad to standard C-packing rules. If the member is farther
// away than C-packing, expects, add an inert padding member before the the member.
MSLStructMemberKey key = get_struct_member_key(ib_type_id, mbr_idx);
struct_member_padding[key] = mbr_offset - curr_offset;
}
// Increment the current offset to be positioned immediately after the current member.
curr_offset = mbr_offset + uint32_t(get_declared_struct_member_size(ib_type, mbr_idx));
}
}
// Returns whether the specified struct member supports a packable type
// variation that is smaller than the unpacked variation of that type.
bool CompilerMSL::is_member_packable(SPIRType &ib_type, uint32_t index)
{
uint32_t mbr_type_id = ib_type.member_types[index];
auto &mbr_type = get<SPIRType>(mbr_type_id);
// 3-element vectors (char3, uchar3, short3, ushort3, int3, uint3, half3, float3)
if (mbr_type.vecsize == 3 && mbr_type.columns == 1)
return true;
return false;
}
// Returns a combination of type ID and member index for use as hash key
MSLStructMemberKey CompilerMSL::get_struct_member_key(uint32_t type_id, uint32_t index)
{
MSLStructMemberKey k = type_id;
k <<= 32;
k += index;
return k;
}
// Converts the format of the current expression from packed to unpacked,
// by wrapping the expression in a constructor of the appropriate type.
string CompilerMSL::unpack_expression_type(string expr_str, const SPIRType &type)
{
return join(type_to_glsl(type), "(", expr_str, ")");
}
// Emits the file header info
void CompilerMSL::emit_header()
{
for (auto &header : pragma_lines)
statement(header);
if (!pragma_lines.empty())
statement("");
statement("#include <metal_stdlib>");
statement("#include <simd/simd.h>");
for (auto &header : header_lines)
statement(header);
statement("");
statement("using namespace metal;");
statement("");
}
void CompilerMSL::add_pragma_line(const string &line)
{
pragma_lines.push_back(line);
}
// Emits any needed custom function bodies.
void CompilerMSL::emit_custom_functions()
{
for (auto &spv_func : spv_function_implementations)
{
switch (spv_func)
{
case SPVFuncImplMod:
statement("// Implementation of the GLSL mod() function, which is slightly different than Metal fmod()");
statement("template<typename Tx, typename Ty>");
statement("Tx mod(Tx x, Ty y)");
begin_scope();
statement("return x - y * floor(x / y);");
end_scope();
statement("");
break;
case SPVFuncImplRadians:
statement("// Implementation of the GLSL radians() function");
statement("template<typename T>");
statement("T radians(T d)");
begin_scope();
statement("return d * 0.01745329251;");
end_scope();
statement("");
break;
case SPVFuncImplDegrees:
statement("// Implementation of the GLSL degrees() function");
statement("template<typename T>");
statement("T degrees(T r)");
begin_scope();
statement("return r * 57.2957795131;");
end_scope();
statement("");
break;
case SPVFuncImplFindILsb:
statement("// Implementation of the GLSL findLSB() function");
statement("template<typename T>");
statement("T findLSB(T x)");
begin_scope();
statement("return select(ctz(x), -1, x == 0);");
end_scope();
statement("");
break;
case SPVFuncImplFindUMsb:
statement("// Implementation of the unsigned GLSL findMSB() function");
statement("template<typename T>");
statement("T findUMSB(T x)");
begin_scope();
statement("return select(clz(0) - (clz(x) + 1), -1, x == 0);");
end_scope();
statement("");
break;
case SPVFuncImplFindSMsb:
statement("// Implementation of the signed GLSL findMSB() function");
statement("template<typename T>");
statement("T findSMSB(T x)");
begin_scope();
statement("T v = select(x, -1 - x, x < 0);");
statement("return select(clz(0) - (clz(v) + 1), -1, v == 0);");
end_scope();
statement("");
break;
case SPVFuncImplInverse4x4:
statement("// Returns the determinant of a 2x2 matrix.");
statement("inline float spvDet2x2(float a1, float a2, float b1, float b2)");
begin_scope();
statement("return a1 * b2 - b1 * a2;");
end_scope();
statement("");
statement("// Returns the determinant of a 3x3 matrix.");
statement("inline float spvDet3x3(float a1, float a2, float a3, float b1, float b2, float b3, float c1, "
"float c2, float c3)");
begin_scope();
statement("return a1 * spvDet2x2(b2, b3, c2, c3) - b1 * spvDet2x2(a2, a3, c2, c3) + c1 * spvDet2x2(a2, a3, "
"b2, b3);");
end_scope();
statement("");
statement("// Returns the inverse of a matrix, by using the algorithm of calculating the classical");
statement("// adjoint and dividing by the determinant. The contents of the matrix are changed.");
statement("float4x4 spvInverse4x4(float4x4 m)");
begin_scope();
statement("float4x4 adj; // The adjoint matrix (inverse after dividing by determinant)");
statement("");
statement("// Create the transpose of the cofactors, as the classical adjoint of the matrix.");
statement("adj[0][0] = spvDet3x3(m[1][1], m[1][2], m[1][3], m[2][1], m[2][2], m[2][3], m[3][1], m[3][2], "
"m[3][3]);");
statement("adj[0][1] = -spvDet3x3(m[0][1], m[0][2], m[0][3], m[2][1], m[2][2], m[2][3], m[3][1], m[3][2], "
"m[3][3]);");
statement("adj[0][2] = spvDet3x3(m[0][1], m[0][2], m[0][3], m[1][1], m[1][2], m[1][3], m[3][1], m[3][2], "
"m[3][3]);");
statement("adj[0][3] = -spvDet3x3(m[0][1], m[0][2], m[0][3], m[1][1], m[1][2], m[1][3], m[2][1], m[2][2], "
"m[2][3]);");
statement("");
statement("adj[1][0] = -spvDet3x3(m[1][0], m[1][2], m[1][3], m[2][0], m[2][2], m[2][3], m[3][0], m[3][2], "
"m[3][3]);");
statement("adj[1][1] = spvDet3x3(m[0][0], m[0][2], m[0][3], m[2][0], m[2][2], m[2][3], m[3][0], m[3][2], "
"m[3][3]);");
statement("adj[1][2] = -spvDet3x3(m[0][0], m[0][2], m[0][3], m[1][0], m[1][2], m[1][3], m[3][0], m[3][2], "
"m[3][3]);");
statement("adj[1][3] = spvDet3x3(m[0][0], m[0][2], m[0][3], m[1][0], m[1][2], m[1][3], m[2][0], m[2][2], "
"m[2][3]);");
statement("");
statement("adj[2][0] = spvDet3x3(m[1][0], m[1][1], m[1][3], m[2][0], m[2][1], m[2][3], m[3][0], m[3][1], "
"m[3][3]);");
statement("adj[2][1] = -spvDet3x3(m[0][0], m[0][1], m[0][3], m[2][0], m[2][1], m[2][3], m[3][0], m[3][1], "
"m[3][3]);");
statement("adj[2][2] = spvDet3x3(m[0][0], m[0][1], m[0][3], m[1][0], m[1][1], m[1][3], m[3][0], m[3][1], "
"m[3][3]);");
statement("adj[2][3] = -spvDet3x3(m[0][0], m[0][1], m[0][3], m[1][0], m[1][1], m[1][3], m[2][0], m[2][1], "
"m[2][3]);");
statement("");
statement("adj[3][0] = -spvDet3x3(m[1][0], m[1][1], m[1][2], m[2][0], m[2][1], m[2][2], m[3][0], m[3][1], "
"m[3][2]);");
statement("adj[3][1] = spvDet3x3(m[0][0], m[0][1], m[0][2], m[2][0], m[2][1], m[2][2], m[3][0], m[3][1], "
"m[3][2]);");
statement("adj[3][2] = -spvDet3x3(m[0][0], m[0][1], m[0][2], m[1][0], m[1][1], m[1][2], m[3][0], m[3][1], "
"m[3][2]);");
statement("adj[3][3] = spvDet3x3(m[0][0], m[0][1], m[0][2], m[1][0], m[1][1], m[1][2], m[2][0], m[2][1], "
"m[2][2]);");
statement("");
statement("// Calculate the determinant as a combination of the cofactors of the first row.");
statement("float det = (adj[0][0] * m[0][0]) + (adj[0][1] * m[1][0]) + (adj[0][2] * m[2][0]) + (adj[0][3] "
"* m[3][0]);");
statement("");
statement("// Divide the classical adjoint matrix by the determinant.");
statement("// If determinant is zero, matrix is not invertable, so leave it unchanged.");
statement("return (det != 0.0f) ? (adj * (1.0f / det)) : m;");
end_scope();
statement("");
break;
case SPVFuncImplInverse3x3:
statement("// Returns the determinant of a 2x2 matrix.");
statement("inline float spvDet2x2(float a1, float a2, float b1, float b2)");
begin_scope();
statement("return a1 * b2 - b1 * a2;");
end_scope();
statement("");
statement("// Returns the inverse of a matrix, by using the algorithm of calculating the classical");
statement("// adjoint and dividing by the determinant. The contents of the matrix are changed.");
statement("float3x3 spvInverse3x3(float3x3 m)");
begin_scope();
statement("float3x3 adj; // The adjoint matrix (inverse after dividing by determinant)");
statement("");
statement("// Create the transpose of the cofactors, as the classical adjoint of the matrix.");
statement("adj[0][0] = spvDet2x2(m[1][1], m[1][2], m[2][1], m[2][2]);");
statement("adj[0][1] = -spvDet2x2(m[0][1], m[0][2], m[2][1], m[2][2]);");
statement("adj[0][2] = spvDet2x2(m[0][1], m[0][2], m[1][1], m[1][2]);");
statement("");
statement("adj[1][0] = -spvDet2x2(m[1][0], m[1][2], m[2][0], m[2][2]);");
statement("adj[1][1] = spvDet2x2(m[0][0], m[0][2], m[2][0], m[2][2]);");
statement("adj[1][2] = -spvDet2x2(m[0][0], m[0][2], m[1][0], m[1][2]);");
statement("");
statement("adj[2][0] = spvDet2x2(m[1][0], m[1][1], m[2][0], m[2][1]);");
statement("adj[2][1] = -spvDet2x2(m[0][0], m[0][1], m[2][0], m[2][1]);");
statement("adj[2][2] = spvDet2x2(m[0][0], m[0][1], m[1][0], m[1][1]);");
statement("");
statement("// Calculate the determinant as a combination of the cofactors of the first row.");
statement("float det = (adj[0][0] * m[0][0]) + (adj[0][1] * m[1][0]) + (adj[0][2] * m[2][0]);");
statement("");
statement("// Divide the classical adjoint matrix by the determinant.");
statement("// If determinant is zero, matrix is not invertable, so leave it unchanged.");
statement("return (det != 0.0f) ? (adj * (1.0f / det)) : m;");
end_scope();
statement("");
break;
case SPVFuncImplInverse2x2:
statement("// Returns the inverse of a matrix, by using the algorithm of calculating the classical");
statement("// adjoint and dividing by the determinant. The contents of the matrix are changed.");
statement("float2x2 spvInverse2x2(float2x2 m)");
begin_scope();
statement("float2x2 adj; // The adjoint matrix (inverse after dividing by determinant)");
statement("");
statement("// Create the transpose of the cofactors, as the classical adjoint of the matrix.");
statement("adj[0][0] = m[1][1];");
statement("adj[0][1] = -m[0][1];");
statement("");
statement("adj[1][0] = -m[1][0];");
statement("adj[1][1] = m[0][0];");
statement("");
statement("// Calculate the determinant as a combination of the cofactors of the first row.");
statement("float det = (adj[0][0] * m[0][0]) + (adj[0][1] * m[1][0]);");
statement("");
statement("// Divide the classical adjoint matrix by the determinant.");
statement("// If determinant is zero, matrix is not invertable, so leave it unchanged.");
statement("return (det != 0.0f) ? (adj * (1.0f / det)) : m;");
end_scope();
statement("");
break;
default:
break;
}
}
}
void CompilerMSL::emit_resources()
{
// Output all basic struct types which are not Block or BufferBlock as these are declared inplace
// when such variables are instantiated.
for (auto &id : ids)
{
if (id.get_type() == TypeType)
{
auto &type = id.get<SPIRType>();
if (type.basetype == SPIRType::Struct && type.array.empty() && !type.pointer &&
!has_decoration(type.self, DecorationBlock) && !has_decoration(type.self, DecorationBufferBlock))
{
emit_struct(type);
}
}
}
// Output Uniform buffers and constants
unordered_set<uint32_t> declared_interface_structs;
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
auto &var = id.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
if (var.storage != StorageClassFunction && type.pointer &&
(type.storage == StorageClassUniform || type.storage == StorageClassUniformConstant ||
type.storage == StorageClassPushConstant || type.storage == StorageClassStorageBuffer) &&
(has_decoration(type.self, DecorationBlock) || has_decoration(type.self, DecorationBufferBlock)) &&
!is_hidden_variable(var))
{
// Avoid declaring the same struct multiple times.
if (declared_interface_structs.count(type.self) == 0)
{
align_struct(type);
emit_struct(type);
declared_interface_structs.insert(type.self);
}
}
}
}
declare_undefined_values();
// Output interface blocks.
emit_interface_block(stage_in_var_id);
for (auto &nsi_var : non_stage_in_input_var_ids)
emit_interface_block(nsi_var.second);
emit_interface_block(stage_out_var_id);
emit_interface_block(stage_uniforms_var_id);
}
// Emit declarations for the specialization Metal function constants
void CompilerMSL::emit_specialization_constants()
{
const vector<SpecializationConstant> spec_consts = get_specialization_constants();
SpecializationConstant wg_x, wg_y, wg_z;
uint32_t workgroup_size_id = get_work_group_size_specialization_constants(wg_x, wg_y, wg_z);
for (auto &sc : spec_consts)
{
// If WorkGroupSize is a specialization constant, it will be declared explicitly below.
if (sc.id == workgroup_size_id)
continue;
auto &type = expression_type(sc.id);
string sc_type_name = type_to_glsl(type);
string sc_name = to_name(sc.id);
string sc_tmp_name = to_name(sc.id) + "_tmp";
if (type.vecsize == 1 && type.columns == 1 && type.basetype != SPIRType::Struct && type.array.empty())
{
// Only scalar, non-composite values can be function constants.
statement("constant ", sc_type_name, " ", sc_tmp_name, " [[function_constant(",
convert_to_string(sc.constant_id), ")]];");
statement("constant ", sc_type_name, " ", sc_name, " = is_function_constant_defined(", sc_tmp_name, ") ? ",
sc_tmp_name, " : ", constant_expression(get<SPIRConstant>(sc.id)), ";");
}
else
{
// Composite specialization constants must be built from other specialization constants.
statement("constant ", sc_type_name, " ", sc_name, " = ", constant_expression(get<SPIRConstant>(sc.id)),
";");
}
}
// TODO: This can be expressed as a [[threads_per_threadgroup]] input semantic, but we need to know
// the work group size at compile time in SPIR-V, and [[threads_per_threadgroup]] would need to be passed around as a global.
// The work group size may be a specialization constant.
if (workgroup_size_id)
statement("constant uint3 gl_WorkGroupSize = ", constant_expression(get<SPIRConstant>(workgroup_size_id)), ";");
if (!spec_consts.empty() || workgroup_size_id)
statement("");
}
// Override for MSL-specific syntax instructions
void CompilerMSL::emit_instruction(const Instruction &instruction)
{
#define BOP(op) emit_binary_op(ops[0], ops[1], ops[2], ops[3], #op)
#define BOP_CAST(op, type) \
emit_binary_op_cast(ops[0], ops[1], ops[2], ops[3], #op, type, opcode_is_sign_invariant(opcode))
#define UOP(op) emit_unary_op(ops[0], ops[1], ops[2], #op)
#define QFOP(op) emit_quaternary_func_op(ops[0], ops[1], ops[2], ops[3], ops[4], ops[5], #op)
#define TFOP(op) emit_trinary_func_op(ops[0], ops[1], ops[2], ops[3], ops[4], #op)
#define BFOP(op) emit_binary_func_op(ops[0], ops[1], ops[2], ops[3], #op)
#define BFOP_CAST(op, type) \
emit_binary_func_op_cast(ops[0], ops[1], ops[2], ops[3], #op, type, opcode_is_sign_invariant(opcode))
#define BFOP(op) emit_binary_func_op(ops[0], ops[1], ops[2], ops[3], #op)
#define UFOP(op) emit_unary_func_op(ops[0], ops[1], ops[2], #op)
auto ops = stream(instruction);
auto opcode = static_cast<Op>(instruction.op);
switch (opcode)
{
// Comparisons
case OpIEqual:
case OpLogicalEqual:
case OpFOrdEqual:
BOP(==);
break;
case OpINotEqual:
case OpLogicalNotEqual:
case OpFOrdNotEqual:
BOP(!=);
break;
case OpUGreaterThan:
case OpSGreaterThan:
case OpFOrdGreaterThan:
BOP(>);
break;
case OpUGreaterThanEqual:
case OpSGreaterThanEqual:
case OpFOrdGreaterThanEqual:
BOP(>=);
break;
case OpULessThan:
case OpSLessThan:
case OpFOrdLessThan:
BOP(<);
break;
case OpULessThanEqual:
case OpSLessThanEqual:
case OpFOrdLessThanEqual:
BOP(<=);
break;
// Derivatives
case OpDPdx:
case OpDPdxFine:
case OpDPdxCoarse:
UFOP(dfdx);
break;
case OpDPdy:
case OpDPdyFine:
case OpDPdyCoarse:
UFOP(dfdy);
break;
// Bitfield
case OpBitFieldInsert:
QFOP(insert_bits);
break;
case OpBitFieldSExtract:
case OpBitFieldUExtract:
TFOP(extract_bits);
break;
case OpBitReverse:
UFOP(reverse_bits);
break;
case OpBitCount:
UFOP(popcount);
break;
// Atomics
case OpAtomicExchange:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t ptr = ops[2];
uint32_t mem_sem = ops[4];
uint32_t val = ops[5];
emit_atomic_func_op(result_type, id, "atomic_exchange_explicit", mem_sem, mem_sem, false, ptr, val);
break;
}
case OpAtomicCompareExchange:
case OpAtomicCompareExchangeWeak:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t ptr = ops[2];
uint32_t mem_sem_pass = ops[4];
uint32_t mem_sem_fail = ops[5];
uint32_t val = ops[6];
uint32_t comp = ops[7];
emit_atomic_func_op(result_type, id, "atomic_compare_exchange_weak_explicit", mem_sem_pass, mem_sem_fail, true,
ptr, comp, true, val);
break;
}
case OpAtomicLoad:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t ptr = ops[2];
uint32_t mem_sem = ops[4];
emit_atomic_func_op(result_type, id, "atomic_load_explicit", mem_sem, mem_sem, false, ptr, 0);
break;
}
case OpAtomicStore:
{
uint32_t result_type = expression_type(ops[0]).self;
uint32_t id = ops[0];
uint32_t ptr = ops[0];
uint32_t mem_sem = ops[2];
uint32_t val = ops[3];
emit_atomic_func_op(result_type, id, "atomic_store_explicit", mem_sem, mem_sem, false, ptr, val);
break;
}
#define AFMOImpl(op, valsrc) \
do \
{ \
uint32_t result_type = ops[0]; \
uint32_t id = ops[1]; \
uint32_t ptr = ops[2]; \
uint32_t mem_sem = ops[4]; \
uint32_t val = valsrc; \
emit_atomic_func_op(result_type, id, "atomic_fetch_" #op "_explicit", mem_sem, mem_sem, false, ptr, val); \
} while (false)
#define AFMO(op) AFMOImpl(op, ops[5])
#define AFMIO(op) AFMOImpl(op, 1)
case OpAtomicIIncrement:
AFMIO(add);
break;
case OpAtomicIDecrement:
AFMIO(sub);
break;
case OpAtomicIAdd:
AFMO(add);
break;
case OpAtomicISub:
AFMO(sub);
break;
case OpAtomicSMin:
case OpAtomicUMin:
AFMO(min);
break;
case OpAtomicSMax:
case OpAtomicUMax:
AFMO(max);
break;
case OpAtomicAnd:
AFMO(and);
break;
case OpAtomicOr:
AFMO(or);
break;
case OpAtomicXor:
AFMO (xor);
break;
// Images
// Reads == Fetches in Metal
case OpImageRead:
{
// Mark that this shader reads from this image
uint32_t img_id = ops[2];
auto *p_var = maybe_get_backing_variable(img_id);
if (p_var)
unset_decoration(p_var->self, DecorationNonReadable);
emit_texture_op(instruction);
break;
}
case OpImageWrite:
{
uint32_t img_id = ops[0];
uint32_t coord_id = ops[1];
uint32_t texel_id = ops[2];
const uint32_t *opt = &ops[3];
uint32_t length = instruction.length - 4;
// Bypass pointers because we need the real image struct
auto &type = expression_type(img_id);
auto &img_type = get<SPIRType>(type.self);
// Ensure this image has been marked as being written to and force a
// recommpile so that the image type output will include write access
auto *p_var = maybe_get_backing_variable(img_id);
if (p_var && has_decoration(p_var->self, DecorationNonWritable))
{
unset_decoration(p_var->self, DecorationNonWritable);
force_recompile = true;
}
bool forward = false;
uint32_t bias = 0;
uint32_t lod = 0;
uint32_t flags = 0;
if (length)
{
flags = *opt++;
length--;
}
auto test = [&](uint32_t &v, uint32_t flag) {
if (length && (flags & flag))
{
v = *opt++;
length--;
}
};
test(bias, ImageOperandsBiasMask);
test(lod, ImageOperandsLodMask);
statement(join(
to_expression(img_id), ".write(", to_expression(texel_id), ", ",
to_function_args(img_id, img_type, true, false, false, coord_id, 0, 0, 0, 0, lod, 0, 0, 0, 0, 0, &forward),
");"));
if (p_var && variable_storage_is_aliased(*p_var))
flush_all_aliased_variables();
break;
}
case OpImageQuerySize:
case OpImageQuerySizeLod:
{
uint32_t rslt_type_id = ops[0];
auto &rslt_type = get<SPIRType>(rslt_type_id);
uint32_t id = ops[1];
uint32_t img_id = ops[2];
string img_exp = to_expression(img_id);
auto &img_type = expression_type(img_id);
Dim img_dim = img_type.image.dim;
bool is_array = img_type.image.arrayed;
if (img_type.basetype != SPIRType::Image)
SPIRV_CROSS_THROW("Invalid type for OpImageQuerySize.");
string lod;
if (opcode == OpImageQuerySizeLod)
{
// LOD index defaults to zero, so don't bother outputing level zero index
string decl_lod = to_expression(ops[3]);
if (decl_lod != "0")
lod = decl_lod;
}
string expr = type_to_glsl(rslt_type) + "(";
expr += img_exp + ".get_width(" + lod + ")";
if (img_dim == Dim2D || img_dim == DimCube || img_dim == Dim3D)
expr += ", " + img_exp + ".get_height(" + lod + ")";
if (img_dim == Dim3D)
expr += ", " + img_exp + ".get_depth(" + lod + ")";
if (is_array)
expr += ", " + img_exp + ".get_array_size()";
expr += ")";
emit_op(rslt_type_id, id, expr, should_forward(img_id));
break;
}
#define ImgQry(qrytype) \
do \
{ \
uint32_t rslt_type_id = ops[0]; \
auto &rslt_type = get<SPIRType>(rslt_type_id); \
uint32_t id = ops[1]; \
uint32_t img_id = ops[2]; \
string img_exp = to_expression(img_id); \
string expr = type_to_glsl(rslt_type) + "(" + img_exp + ".get_num_" #qrytype "())"; \
emit_op(rslt_type_id, id, expr, should_forward(img_id)); \
} while (false)
case OpImageQueryLevels:
ImgQry(mip_levels);
break;
case OpImageQuerySamples:
ImgQry(samples);
break;
// Casting
case OpQuantizeToF16:
{
uint32_t result_type = ops[0];
uint32_t id = ops[1];
uint32_t arg = ops[2];
string exp;
auto &type = get<SPIRType>(result_type);
switch (type.vecsize)
{
case 1:
exp = join("float(half(", to_expression(arg), "))");
break;
case 2:
exp = join("float2(half2(", to_expression(arg), "))");
break;
case 3:
exp = join("float3(half3(", to_expression(arg), "))");
break;
case 4:
exp = join("float4(half4(", to_expression(arg), "))");
break;
default:
SPIRV_CROSS_THROW("Illegal argument to OpQuantizeToF16.");
}
emit_op(result_type, id, exp, should_forward(arg));
break;
}
case OpStore:
{
if (!maybe_emit_input_struct_assignment(ops[0], ops[1]))
CompilerGLSL::emit_instruction(instruction);
break;
}
// OpOuterProduct
default:
CompilerGLSL::emit_instruction(instruction);
break;
}
}
// Since MSL does not allow structs to be nested within the stage_in struct, the original
// input structs are flattened into a single stage_in struct by add_interface_block.
// As a result, if the LHS and RHS represent an assignment of an entire input struct,
// we must perform this member-by-member, mapping to the flattened stage_in struct.
// Returns whether the struct assignment was emitted.
bool CompilerMSL::maybe_emit_input_struct_assignment(uint32_t id_lhs, uint32_t id_rhs)
{
auto *p_v_lhs = maybe_get_backing_variable(id_lhs);
auto *p_v_rhs = maybe_get_backing_variable(id_rhs);
if (p_v_lhs && p_v_rhs && p_v_rhs->storage == StorageClassInput)
{
uint32_t tid_lhs = p_v_lhs->basetype;
uint32_t tid_rhs = p_v_rhs->basetype;
auto &t_lhs = get<SPIRType>(tid_lhs);
auto &t_rhs = get<SPIRType>(tid_rhs);
if (t_lhs.basetype == SPIRType::Struct && t_rhs.basetype == SPIRType::Struct)
{
size_t mbr_cnt = t_rhs.member_types.size();
assert(t_lhs.member_types.size() == mbr_cnt);
flush_variable_declaration(p_v_lhs->self);
for (uint32_t mbr_idx = 0; mbr_idx < mbr_cnt; mbr_idx++)
{
string expr;
//LHS
expr += to_name(id_lhs);
expr += ".";
expr += to_member_name(t_lhs, mbr_idx);
expr += " = ";
//RHS
string qual_mbr_name = get_member_qualified_name(tid_rhs, mbr_idx);
if (qual_mbr_name.empty())
{
expr += to_name(id_rhs);
expr += ".";
expr += to_member_name(t_rhs, mbr_idx);
}
else
expr += qual_mbr_name;
statement(expr, ";");
}
return true;
}
}
return false;
}
// Emits one of the atomic functions. In MSL, the atomic functions operate on pointers
void CompilerMSL::emit_atomic_func_op(uint32_t result_type, uint32_t result_id, const char *op, uint32_t mem_order_1,
uint32_t mem_order_2, bool has_mem_order_2, uint32_t obj, uint32_t op1,
bool op1_is_pointer, uint32_t op2)
{
forced_temporaries.insert(result_id);
bool fwd_obj = should_forward(obj);
bool fwd_op1 = op1 ? should_forward(op1) : true;
bool fwd_op2 = op2 ? should_forward(op2) : true;
bool forward = fwd_obj && fwd_op1 && fwd_op2;
string exp = string(op) + "(";
auto &type = expression_type(obj);
exp += "(volatile ";
exp += "device";
exp += " atomic_";
exp += type_to_glsl(type);
exp += "*)";
exp += "&(";
exp += to_expression(obj);
exp += ")";
if (op1)
{
if (op1_is_pointer)
{
statement(declare_temporary(expression_type(op2).self, op1), to_expression(op1), ";");
exp += ", &(" + to_name(op1) + ")";
}
else
exp += ", " + to_expression(op1);
}
if (op2)
exp += ", " + to_expression(op2);
exp += string(", ") + get_memory_order(mem_order_1);
if (has_mem_order_2)
exp += string(", ") + get_memory_order(mem_order_2);
exp += ")";
emit_op(result_type, result_id, exp, forward);
inherit_expression_dependencies(result_id, obj);
if (op1)
inherit_expression_dependencies(result_id, op1);
if (op2)
inherit_expression_dependencies(result_id, op2);
flush_all_atomic_capable_variables();
}
// Metal only supports relaxed memory order for now
const char *CompilerMSL::get_memory_order(uint32_t)
{
return "memory_order_relaxed";
}
// Override for MSL-specific extension syntax instructions
void CompilerMSL::emit_glsl_op(uint32_t result_type, uint32_t id, uint32_t eop, const uint32_t *args, uint32_t count)
{
GLSLstd450 op = static_cast<GLSLstd450>(eop);
switch (op)
{
case GLSLstd450Atan2:
emit_binary_func_op(result_type, id, args[0], args[1], "atan2");
break;
case GLSLstd450InverseSqrt:
emit_unary_func_op(result_type, id, args[0], "rsqrt");
break;
case GLSLstd450RoundEven:
emit_unary_func_op(result_type, id, args[0], "rint");
break;
case GLSLstd450FindSMsb:
emit_unary_func_op(result_type, id, args[0], "findSMSB");
break;
case GLSLstd450FindUMsb:
emit_unary_func_op(result_type, id, args[0], "findUMSB");
break;
case GLSLstd450PackSnorm4x8:
emit_unary_func_op(result_type, id, args[0], "pack_float_to_snorm4x8");
break;
case GLSLstd450PackUnorm4x8:
emit_unary_func_op(result_type, id, args[0], "pack_float_to_unorm4x8");
break;
case GLSLstd450PackSnorm2x16:
emit_unary_func_op(result_type, id, args[0], "pack_float_to_snorm2x16");
break;
case GLSLstd450PackUnorm2x16:
emit_unary_func_op(result_type, id, args[0], "pack_float_to_unorm2x16");
break;
case GLSLstd450PackHalf2x16:
emit_unary_func_op(result_type, id, args[0], "pack_half_to_snorm2x16");
break;
case GLSLstd450UnpackSnorm4x8:
emit_unary_func_op(result_type, id, args[0], "unpack_snorm4x8_to_float");
break;
case GLSLstd450UnpackUnorm4x8:
emit_unary_func_op(result_type, id, args[0], "unpack_unorm4x8_to_float");
break;
case GLSLstd450UnpackSnorm2x16:
emit_unary_func_op(result_type, id, args[0], "unpack_snorm2x16_to_float");
break;
case GLSLstd450UnpackUnorm2x16:
emit_unary_func_op(result_type, id, args[0], "unpack_unorm2x16_to_float");
break;
case GLSLstd450UnpackHalf2x16:
emit_unary_func_op(result_type, id, args[0], "unpack_snorm2x16_to_half");
break;
case GLSLstd450PackDouble2x32:
emit_unary_func_op(result_type, id, args[0], "unsupported_GLSLstd450PackDouble2x32"); // Currently unsupported
break;
case GLSLstd450UnpackDouble2x32:
emit_unary_func_op(result_type, id, args[0], "unsupported_GLSLstd450UnpackDouble2x32"); // Currently unsupported
break;
case GLSLstd450MatrixInverse:
{
auto &mat_type = get<SPIRType>(result_type);
switch (mat_type.columns)
{
case 2:
emit_unary_func_op(result_type, id, args[0], "spvInverse2x2");
break;
case 3:
emit_unary_func_op(result_type, id, args[0], "spvInverse3x3");
break;
case 4:
emit_unary_func_op(result_type, id, args[0], "spvInverse4x4");
break;
default:
break;
}
break;
}
// TODO:
// GLSLstd450InterpolateAtCentroid (centroid_no_perspective qualifier)
// GLSLstd450InterpolateAtSample (sample_no_perspective qualifier)
// GLSLstd450InterpolateAtOffset
default:
CompilerGLSL::emit_glsl_op(result_type, id, eop, args, count);
break;
}
}
// Emit a structure declaration for the specified interface variable.
void CompilerMSL::emit_interface_block(uint32_t ib_var_id)
{
if (ib_var_id)
{
auto &ib_var = get<SPIRVariable>(ib_var_id);
auto &ib_type = get<SPIRType>(ib_var.basetype);
auto &m = meta.at(ib_type.self);
if (m.members.size() > 0)
emit_struct(ib_type);
}
}
// Emits the declaration signature of the specified function.
// If this is the entry point function, Metal-specific return value and function arguments are added.
void CompilerMSL::emit_function_prototype(SPIRFunction &func, uint64_t)
{
local_variable_names = resource_names;
string decl;
processing_entry_point = (func.self == entry_point);
auto &type = get<SPIRType>(func.return_type);
decl += func_type_decl(type);
decl += " ";
decl += clean_func_name(to_name(func.self));
decl += "(";
if (processing_entry_point)
{
decl += entry_point_args(!func.arguments.empty());
// If entry point function has a output interface struct, set its initializer.
// This is done at this late stage because the initialization expression is
// cleared after each compilation pass.
if (stage_out_var_id)
{
auto &so_var = get<SPIRVariable>(stage_out_var_id);
auto &so_type = get<SPIRType>(so_var.basetype);
set<SPIRExpression>(so_var.initializer, "{}", so_type.self, true);
}
}
for (auto &arg : func.arguments)
{
add_local_variable_name(arg.id);
string address_space = "thread";
auto *var = maybe_get<SPIRVariable>(arg.id);
if (var)
{
var->parameter = &arg; // Hold a pointer to the parameter so we can invalidate the readonly field if needed.
address_space = get_argument_address_space(*var);
}
decl += address_space + " ";
decl += argument_decl(arg);
// Manufacture automatic sampler arg for SampledImage texture
auto &arg_type = get<SPIRType>(arg.type);
if (arg_type.basetype == SPIRType::SampledImage)
decl += ", thread const sampler& " + to_sampler_expression(arg.id);
if (&arg != &func.arguments.back())
decl += ", ";
}
decl += ")";
statement(decl);
}
// Returns the texture sampling function string for the specified image and sampling characteristics.
string CompilerMSL::to_function_name(uint32_t img, const SPIRType &, bool is_fetch, bool is_gather, bool, bool, bool,
bool, bool has_dref, uint32_t)
{
// Texture reference
string fname = to_expression(img) + ".";
// Texture function and sampler
if (is_fetch)
fname += "read";
else if (is_gather)
fname += "gather";
else
fname += "sample";
if (has_dref)
fname += "_compare";
return fname;
}
// Returns the function args for a texture sampling function for the specified image and sampling characteristics.
string CompilerMSL::to_function_args(uint32_t img, const SPIRType &imgtype, bool is_fetch, bool, bool is_proj,
uint32_t coord, uint32_t, uint32_t dref, uint32_t grad_x, uint32_t grad_y,
uint32_t lod, uint32_t coffset, uint32_t offset, uint32_t bias, uint32_t comp,
uint32_t sample, bool *p_forward)
{
string farg_str;
if (!is_fetch)
farg_str += to_sampler_expression(img);
// Texture coordinates
bool forward = should_forward(coord);
auto coord_expr = to_enclosed_expression(coord);
auto &coord_type = expression_type(coord);
bool coord_is_fp = (coord_type.basetype == SPIRType::Float) || (coord_type.basetype == SPIRType::Double);
bool is_cube_fetch = false;
string tex_coords = coord_expr;
const char *alt_coord = "";
switch (imgtype.image.dim)
{
case Dim1D:
if (coord_type.vecsize > 1)
tex_coords += ".x";
if (is_fetch)
tex_coords = "uint(" + round_fp_tex_coords(tex_coords, coord_is_fp) + ")";
alt_coord = ".y";
break;
case DimBuffer:
if (coord_type.vecsize > 1)
tex_coords += ".x";
if (is_fetch)
tex_coords = "uint2(" + round_fp_tex_coords(tex_coords, coord_is_fp) + ", 0)"; // Metal textures are 2D
alt_coord = ".y";
break;
case Dim2D:
if (coord_type.vecsize > 2)
tex_coords += ".xy";
if (is_fetch)
tex_coords = "uint2(" + round_fp_tex_coords(tex_coords, coord_is_fp) + ")";
alt_coord = ".z";
break;
case Dim3D:
if (coord_type.vecsize > 3)
tex_coords += ".xyz";
if (is_fetch)
tex_coords = "uint3(" + round_fp_tex_coords(tex_coords, coord_is_fp) + ")";
alt_coord = ".w";
break;
case DimCube:
if (is_fetch)
{
is_cube_fetch = true;
tex_coords += ".xy";
tex_coords = "uint2(" + round_fp_tex_coords(tex_coords, coord_is_fp) + ")";
}
else
{
if (coord_type.vecsize > 3)
tex_coords += ".xyz";
}
alt_coord = ".w";
break;
default:
break;
}
// If projection, use alt coord as divisor
if (is_proj)
tex_coords += " / " + coord_expr + alt_coord;
if (!farg_str.empty())
farg_str += ", ";
farg_str += tex_coords;
// If fetch from cube, add face explicitly
if (is_cube_fetch)
farg_str += ", uint(" + round_fp_tex_coords(coord_expr + ".z", coord_is_fp) + ")";
// If array, use alt coord
if (imgtype.image.arrayed)
farg_str += ", uint(" + round_fp_tex_coords(coord_expr + alt_coord, coord_is_fp) + ")";
// Depth compare reference value
if (dref)
{
forward = forward && should_forward(dref);
farg_str += ", ";
farg_str += to_expression(dref);
}
// LOD Options
if (bias)
{
forward = forward && should_forward(bias);
farg_str += ", bias(" + to_expression(bias) + ")";
}
if (lod)
{
forward = forward && should_forward(lod);
if (is_fetch)
{
farg_str += ", " + to_expression(lod);
}
else
{
farg_str += ", level(" + to_expression(lod) + ")";
}
}
if (grad_x || grad_y)
{
forward = forward && should_forward(grad_x);
forward = forward && should_forward(grad_y);
string grad_opt;
switch (imgtype.image.dim)
{
case Dim2D:
grad_opt = "2d";
break;
case Dim3D:
grad_opt = "3d";
break;
case DimCube:
grad_opt = "cube";
break;
default:
grad_opt = "unsupported_gradient_dimension";
break;
}
farg_str += ", gradient" + grad_opt + "(" + to_expression(grad_x) + ", " + to_expression(grad_y) + ")";
}
// Add offsets
string offset_expr;
if (coffset)
{
forward = forward && should_forward(coffset);
offset_expr = to_expression(coffset);
}
else if (offset)
{
forward = forward && should_forward(offset);
offset_expr = to_expression(offset);
}
if (!offset_expr.empty())
{
switch (imgtype.image.dim)
{
case Dim2D:
if (coord_type.vecsize > 2)
offset_expr += ".xy";
farg_str += ", " + offset_expr;
break;
case Dim3D:
if (coord_type.vecsize > 3)
offset_expr += ".xyz";
farg_str += ", " + offset_expr;
break;
default:
break;
}
}
if (comp)
{
forward = forward && should_forward(comp);
farg_str += ", " + to_component_argument(comp);
}
if (sample)
{
farg_str += ", ";
farg_str += to_expression(sample);
}
*p_forward = forward;
return farg_str;
}
// If the texture coordinates are floating point, invokes MSL round() function to round them.
string CompilerMSL::round_fp_tex_coords(string tex_coords, bool coord_is_fp)
{
return coord_is_fp ? ("round(" + tex_coords + ")") : tex_coords;
}
// Returns a string to use in an image sampling function argument.
// The ID must be a scalar constant.
string CompilerMSL::to_component_argument(uint32_t id)
{
if (ids[id].get_type() != TypeConstant)
{
SPIRV_CROSS_THROW("ID " + to_string(id) + " is not an OpConstant.");
return "component::x";
}
uint32_t component_index = get<SPIRConstant>(id).scalar();
switch (component_index)
{
case 0:
return "component::x";
case 1:
return "component::y";
case 2:
return "component::z";
case 3:
return "component::w";
default:
SPIRV_CROSS_THROW("The value (" + to_string(component_index) + ") of OpConstant ID " + to_string(id) +
" is not a valid Component index, which must be one of 0, 1, 2, or 3.");
return "component::x";
}
}
// Establish sampled image as expression object and assign the sampler to it.
void CompilerMSL::emit_sampled_image_op(uint32_t result_type, uint32_t result_id, uint32_t image_id, uint32_t samp_id)
{
set<SPIRExpression>(result_id, to_expression(image_id), result_type, true);
meta[result_id].sampler = samp_id;
}
// Returns a string representation of the ID, usable as a function arg.
// Manufacture automatic sampler arg for SampledImage texture.
string CompilerMSL::to_func_call_arg(uint32_t id)
{
string arg_str = CompilerGLSL::to_func_call_arg(id);
// Manufacture automatic sampler arg if the arg is a SampledImage texture.
Variant &id_v = ids[id];
if (id_v.get_type() == TypeVariable)
{
auto &var = id_v.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
if (type.basetype == SPIRType::SampledImage)
arg_str += ", " + to_sampler_expression(id);
}
return arg_str;
}
// If the ID represents a sampled image that has been assigned a sampler already,
// generate an expression for the sampler, otherwise generate a fake sampler name
// by appending a suffix to the expression constructed from the ID.
string CompilerMSL::to_sampler_expression(uint32_t id)
{
uint32_t samp_id = meta[id].sampler;
return samp_id ? to_expression(samp_id) : to_expression(id) + sampler_name_suffix;
}
// Called automatically at the end of the entry point function
void CompilerMSL::emit_fixup()
{
auto &execution = get_entry_point();
if ((execution.model == ExecutionModelVertex) && stage_out_var_id && !qual_pos_var_name.empty())
{
if (CompilerGLSL::options.vertex.fixup_clipspace)
{
statement(qual_pos_var_name, ".z = (", qual_pos_var_name, ".z + ", qual_pos_var_name,
".w) * 0.5; // Adjust clip-space for Metal");
}
if (CompilerGLSL::options.vertex.flip_vert_y)
statement(qual_pos_var_name, ".y = -(", qual_pos_var_name, ".y);", " // Invert Y-axis for Metal");
}
}
// Emit a structure member, padding and packing to maintain the correct memeber alignments.
void CompilerMSL::emit_struct_member(const SPIRType &type, uint32_t member_type_id, uint32_t index,
const string &qualifier)
{
auto &membertype = get<SPIRType>(member_type_id);
// If this member requires padding to maintain alignment, emit a dummy padding member.
MSLStructMemberKey key = get_struct_member_key(type.self, index);
uint32_t pad_len = struct_member_padding[key];
if (pad_len > 0)
statement("char pad", to_string(index), "[", to_string(pad_len), "];");
// If this member is packed, mark it as so.
string pack_pfx = member_is_packed_type(type, index) ? "packed_" : "";
statement(pack_pfx, type_to_glsl(membertype), " ", qualifier, to_member_name(type, index),
member_attribute_qualifier(type, index), type_to_array_glsl(membertype), ";");
}
// Return a MSL qualifier for the specified function attribute member
string CompilerMSL::member_attribute_qualifier(const SPIRType &type, uint32_t index)
{
auto &execution = get_entry_point();
uint32_t mbr_type_id = type.member_types[index];
auto &mbr_type = get<SPIRType>(mbr_type_id);
BuiltIn builtin;
bool is_builtin = is_member_builtin(type, index, &builtin);
// Vertex function inputs
if (execution.model == ExecutionModelVertex && type.storage == StorageClassInput)
{
if (is_builtin)
{
switch (builtin)
{
case BuiltInVertexId:
case BuiltInVertexIndex:
case BuiltInInstanceId:
case BuiltInInstanceIndex:
return string(" [[") + builtin_qualifier(builtin) + "]]";
default:
return "";
}
}
uint32_t locn = get_ordered_member_location(type.self, index);
if (locn != k_unknown_location)
return string(" [[attribute(") + convert_to_string(locn) + ")]]";
}
// Vertex function outputs
if (execution.model == ExecutionModelVertex && type.storage == StorageClassOutput)
{
if (is_builtin)
{
switch (builtin)
{
case BuiltInPointSize:
// Only mark the PointSize builtin if really rendering points.
// Some shaders may include a PointSize builtin even when used to render
// non-point topologies, and Metal will reject this builtin when compiling
// the shader into a render pipeline that uses a non-point topology.
return options.enable_point_size_builtin ? (string(" [[") + builtin_qualifier(builtin) + "]]") : "";
case BuiltInPosition:
case BuiltInLayer:
case BuiltInClipDistance:
return string(" [[") + builtin_qualifier(builtin) + "]]" + (mbr_type.array.empty() ? "" : " ");
default:
return "";
}
}
uint32_t locn = get_ordered_member_location(type.self, index);
if (locn != k_unknown_location)
return string(" [[user(locn") + convert_to_string(locn) + ")]]";
}
// Fragment function inputs
if (execution.model == ExecutionModelFragment && type.storage == StorageClassInput)
{
if (is_builtin)
{
switch (builtin)
{
case BuiltInFrontFacing:
case BuiltInPointCoord:
case BuiltInFragCoord:
case BuiltInSampleId:
case BuiltInSampleMask:
case BuiltInLayer:
return string(" [[") + builtin_qualifier(builtin) + "]]";
default:
return "";
}
}
uint32_t locn = get_ordered_member_location(type.self, index);
if (locn != k_unknown_location)
return string(" [[user(locn") + convert_to_string(locn) + ")]]";
}
// Fragment function outputs
if (execution.model == ExecutionModelFragment && type.storage == StorageClassOutput)
{
if (is_builtin)
{
switch (builtin)
{
case BuiltInSampleMask:
case BuiltInFragDepth:
return string(" [[") + builtin_qualifier(builtin) + "]]";
default:
return "";
}
}
uint32_t locn = get_ordered_member_location(type.self, index);
if (locn != k_unknown_location)
return string(" [[color(") + convert_to_string(locn) + ")]]";
}
// Compute function inputs
if (execution.model == ExecutionModelGLCompute && type.storage == StorageClassInput)
{
if (is_builtin)
{
switch (builtin)
{
case BuiltInGlobalInvocationId:
case BuiltInWorkgroupId:
case BuiltInNumWorkgroups:
case BuiltInLocalInvocationId:
case BuiltInLocalInvocationIndex:
return string(" [[") + builtin_qualifier(builtin) + "]]";
default:
return "";
}
}
}
return "";
}
// Returns the location decoration of the member with the specified index in the specified type.
// If the location of the member has been explicitly set, that location is used. If not, this
// function assumes the members are ordered in their location order, and simply returns the
// index as the location.
uint32_t CompilerMSL::get_ordered_member_location(uint32_t type_id, uint32_t index)
{
auto &m = meta.at(type_id);
if (index < m.members.size())
{
auto &dec = m.members[index];
if (dec.decoration_flags & (1ull << DecorationLocation))
return dec.location;
}
return index;
}
string CompilerMSL::constant_expression(const SPIRConstant &c)
{
if (!c.subconstants.empty())
{
// Handles Arrays and structures.
string res = "{";
for (auto &elem : c.subconstants)
{
res += constant_expression(get<SPIRConstant>(elem));
if (&elem != &c.subconstants.back())
res += ", ";
}
res += "}";
return res;
}
else if (c.columns() == 1)
{
return constant_expression_vector(c, 0);
}
else
{
string res = type_to_glsl(get<SPIRType>(c.constant_type)) + "(";
for (uint32_t col = 0; col < c.columns(); col++)
{
res += constant_expression_vector(c, col);
if (col + 1 < c.columns())
res += ", ";
}
res += ")";
return res;
}
}
// Returns the type declaration for a function, including the
// entry type if the current function is the entry point function
string CompilerMSL::func_type_decl(SPIRType &type)
{
auto &execution = get_entry_point();
// The regular function return type. If not processing the entry point function, that's all we need
string return_type = type_to_glsl(type);
if (!processing_entry_point)
return return_type;
// If an outgoing interface block has been defined, override the entry point return type
if (stage_out_var_id)
{
auto &so_var = get<SPIRVariable>(stage_out_var_id);
auto &so_type = get<SPIRType>(so_var.basetype);
return_type = type_to_glsl(so_type);
}
// Prepend a entry type, based on the execution model
string entry_type;
switch (execution.model)
{
case ExecutionModelVertex:
entry_type = "vertex";
break;
case ExecutionModelFragment:
entry_type = (execution.flags & (1ull << ExecutionModeEarlyFragmentTests)) ?
"fragment [[ early_fragment_tests ]]" :
"fragment";
break;
case ExecutionModelGLCompute:
case ExecutionModelKernel:
entry_type = "kernel";
break;
default:
entry_type = "unknown";
break;
}
return entry_type + " " + return_type;
}
// Ensures the function name is not "main", which is illegal in MSL
string CompilerMSL::clean_func_name(string func_name)
{
auto iter = func_name_overrides.find(func_name);
return (iter != func_name_overrides.end()) ? iter->second : func_name;
}
// In MSL address space qualifiers are required for all pointer or reference arguments
string CompilerMSL::get_argument_address_space(const SPIRVariable &argument)
{
const auto &type = get<SPIRType>(argument.basetype);
if ((type.basetype == SPIRType::Struct) &&
(type.storage == StorageClassUniform || type.storage == StorageClassUniformConstant ||
type.storage == StorageClassPushConstant || type.storage == StorageClassStorageBuffer))
{
if (type.storage == StorageClassStorageBuffer)
return "device";
else
{
return ((meta[type.self].decoration.decoration_flags & (1ull << DecorationBufferBlock)) != 0 &&
(meta[argument.self].decoration.decoration_flags & (1ull << DecorationNonWritable)) == 0) ?
"device" :
"constant";
}
}
return "thread";
}
// Returns a string containing a comma-delimited list of args for the entry point function
string CompilerMSL::entry_point_args(bool append_comma)
{
string ep_args;
// Stage-in structure
if (stage_in_var_id)
{
auto &var = get<SPIRVariable>(stage_in_var_id);
auto &type = get<SPIRType>(var.basetype);
if (!ep_args.empty())
ep_args += ", ";
ep_args += type_to_glsl(type) + " " + to_name(var.self) + " [[stage_in]]";
}
// Non-stage-in vertex attribute structures
for (auto &nsi_var : non_stage_in_input_var_ids)
{
auto &var = get<SPIRVariable>(nsi_var.second);
auto &type = get<SPIRType>(var.basetype);
if (!ep_args.empty())
ep_args += ", ";
ep_args += "device " + type_to_glsl(type) + "* " + to_name(var.self) + " [[buffer(" +
convert_to_string(nsi_var.first) + ")]]";
}
// Uniforms
for (auto &id : ids)
{
if (id.get_type() == TypeVariable)
{
auto &var = id.get<SPIRVariable>();
auto &type = get<SPIRType>(var.basetype);
uint32_t var_id = var.self;
if ((var.storage == StorageClassUniform || var.storage == StorageClassUniformConstant ||
var.storage == StorageClassPushConstant || var.storage == StorageClassStorageBuffer) &&
!is_hidden_variable(var))
{
switch (type.basetype)
{
case SPIRType::Struct:
{
auto &m = meta.at(type.self);
if (m.members.size() == 0)
break;
if (!ep_args.empty())
ep_args += ", ";
ep_args += get_argument_address_space(var) + " " + type_to_glsl(type) + "& " + to_name(var_id);
ep_args += " [[buffer(" + convert_to_string(get_metal_resource_index(var, type.basetype)) + ")]]";
break;
}
case SPIRType::Sampler:
if (!ep_args.empty())
ep_args += ", ";
ep_args += type_to_glsl(type) + " " + to_name(var_id);
ep_args += " [[sampler(" + convert_to_string(get_metal_resource_index(var, type.basetype)) + ")]]";
break;
case SPIRType::Image:
if (!ep_args.empty())
ep_args += ", ";
ep_args += type_to_glsl(type, var_id) + " " + to_name(var_id);
ep_args += " [[texture(" + convert_to_string(get_metal_resource_index(var, type.basetype)) + ")]]";
break;
case SPIRType::SampledImage:
if (!ep_args.empty())
ep_args += ", ";
ep_args += type_to_glsl(type, var_id) + " " + to_name(var_id);
ep_args +=
" [[texture(" + convert_to_string(get_metal_resource_index(var, SPIRType::Image)) + ")]]";
if (type.image.dim != DimBuffer)
{
ep_args += ", sampler " + to_sampler_expression(var_id);
ep_args +=
" [[sampler(" + convert_to_string(get_metal_resource_index(var, SPIRType::Sampler)) + ")]]";
}
break;
default:
break;
}
}
if (var.storage == StorageClassInput && is_builtin_variable(var))
{
if (!ep_args.empty())
ep_args += ", ";
BuiltIn bi_type = meta[var_id].decoration.builtin_type;
ep_args += builtin_type_decl(bi_type) + " " + to_expression(var_id);
ep_args += " [[" + builtin_qualifier(bi_type) + "]]";
}
}
}
// Vertex and instance index built-ins
if (needs_vertex_idx_arg)
ep_args += built_in_func_arg(BuiltInVertexIndex, !ep_args.empty());
if (needs_instance_idx_arg)
ep_args += built_in_func_arg(BuiltInInstanceIndex, !ep_args.empty());
if (!ep_args.empty() && append_comma)
ep_args += ", ";
return ep_args;
}
// Returns the Metal index of the resource of the specified type as used by the specified variable.
uint32_t CompilerMSL::get_metal_resource_index(SPIRVariable &var, SPIRType::BaseType basetype)
{
auto &execution = get_entry_point();
auto &var_dec = meta[var.self].decoration;
uint32_t var_desc_set = (var.storage == StorageClassPushConstant) ? kPushConstDescSet : var_dec.set;
uint32_t var_binding = (var.storage == StorageClassPushConstant) ? kPushConstBinding : var_dec.binding;
// If a matching binding has been specified, find and use it
for (auto p_res_bind : resource_bindings)
{
if (p_res_bind->stage == execution.model && p_res_bind->desc_set == var_desc_set &&
p_res_bind->binding == var_binding)
{
p_res_bind->used_by_shader = true;
switch (basetype)
{
case SPIRType::Struct:
return p_res_bind->msl_buffer;
case SPIRType::Image:
return p_res_bind->msl_texture;
case SPIRType::Sampler:
return p_res_bind->msl_sampler;
default:
return 0;
}
}
}
// If a binding has not been specified, revert to incrementing resource indices
switch (basetype)
{
case SPIRType::Struct:
return next_metal_resource_index.msl_buffer++;
case SPIRType::Image:
return next_metal_resource_index.msl_texture++;
case SPIRType::Sampler:
return next_metal_resource_index.msl_sampler++;
default:
return 0;
}
}
// Returns the name of the entry point of this shader
string CompilerMSL::get_entry_point_name()
{
return clean_func_name(to_name(entry_point));
}
string CompilerMSL::argument_decl(const SPIRFunction::Parameter &arg)
{
auto &type = expression_type(arg.id);
bool constref = !arg.alias_global_variable && (!type.pointer || arg.write_count == 0);
// TODO: Check if this arg is an uniform pointer
bool pointer = type.storage == StorageClassUniformConstant;
auto &var = get<SPIRVariable>(arg.id);
return join(constref ? "const " : "", type_to_glsl(type), pointer ? " " : "& ", to_name(var.self),
type_to_array_glsl(type));
}
// If we're currently in the entry point function, and the object
// has a qualified name, use it, otherwise use the standard name.
string CompilerMSL::to_name(uint32_t id, bool allow_alias) const
{
if (current_function && (current_function->self == entry_point))
{
string qual_name = meta.at(id).decoration.qualified_alias;
if (!qual_name.empty())
return qual_name;
}
return Compiler::to_name(id, allow_alias);
}
// Returns a name that combines the name of the struct with the name of the member, except for Builtins
string CompilerMSL::to_qualified_member_name(const SPIRType &type, uint32_t index)
{
// Don't qualify Builtin names because they are unique and are treated as such when building expressions
BuiltIn builtin;
if (is_member_builtin(type, index, &builtin))
return builtin_to_glsl(builtin, type.storage);
// Strip any underscore prefix from member name
string mbr_name = to_member_name(type, index);
size_t startPos = mbr_name.find_first_not_of("_");
mbr_name = (startPos != string::npos) ? mbr_name.substr(startPos) : "";
return join(to_name(type.self), "_", mbr_name);
}
// Ensures that the specified name is permanently usable by prepending a prefix
// if the first chars are _ and a digit, which indicate a transient name.
string CompilerMSL::ensure_valid_name(string name, string pfx)
{
if (name.size() >= 2 && name[0] == '_' && isdigit(name[1]))
{
return join(pfx, name);
}
else
{
auto iter = var_name_overrides.find(name);
return (iter != var_name_overrides.end()) ? iter->second : name;
}
}
// The optional id parameter indicates the object whose type we are trying
// to find the description for. It is optional. Most type descriptions do not
// depend on a specific object's use of that type.
string CompilerMSL::type_to_glsl(const SPIRType &type, uint32_t id)
{
// Ignore the pointer type since GLSL doesn't have pointers.
string type_name;
switch (type.basetype)
{
case SPIRType::Struct:
// Need OpName lookup here to get a "sensible" name for a struct.
return to_name(type.self);
case SPIRType::Image:
case SPIRType::SampledImage:
return image_type_glsl(type, id);
case SPIRType::Sampler:
return "sampler";
case SPIRType::Void:
return "void";
case SPIRType::AtomicCounter:
return "atomic_uint";
// Scalars
case SPIRType::Boolean:
type_name = "bool";
break;
case SPIRType::Char:
type_name = "char";
break;
case SPIRType::Int:
type_name = (type.width == 16 ? "short" : "int");
break;
case SPIRType::UInt:
type_name = (type.width == 16 ? "ushort" : "uint");
break;
case SPIRType::Int64:
type_name = "long"; // Currently unsupported
break;
case SPIRType::UInt64:
type_name = "size_t";
break;
case SPIRType::Float:
type_name = (type.width == 16 ? "half" : "float");
break;
case SPIRType::Double:
type_name = "double"; // Currently unsupported
break;
default:
return "unknown_type";
}
// Matrix?
if (type.columns > 1)
type_name += to_string(type.columns) + "x";
// Vector or Matrix?
if (type.vecsize > 1)
type_name += to_string(type.vecsize);
return type_name;
}
// Returns an MSL string describing the SPIR-V image type
string CompilerMSL::image_type_glsl(const SPIRType &type, uint32_t id)
{
string img_type_name;
// Bypass pointers because we need the real image struct
auto &img_type = get<SPIRType>(type.self).image;
if (img_type.depth)
{
switch (img_type.dim)
{
case Dim1D:
img_type_name += "depth1d_unsupported_by_metal";
break;
case Dim2D:
img_type_name += (img_type.ms ? "depth2d_ms" : (img_type.arrayed ? "depth2d_array" : "depth2d"));
break;
case Dim3D:
img_type_name += "depth3d_unsupported_by_metal";
break;
case DimCube:
img_type_name += (img_type.arrayed ? "depthcube_array" : "depthcube");
break;
default:
img_type_name += "unknown_depth_texture_type";
break;
}
}
else
{
switch (img_type.dim)
{
case Dim1D:
img_type_name += (img_type.arrayed ? "texture1d_array" : "texture1d");
break;
case DimBuffer:
case Dim2D:
img_type_name += (img_type.ms ? "texture2d_ms" : (img_type.arrayed ? "texture2d_array" : "texture2d"));
break;
case Dim3D:
img_type_name += "texture3d";
break;
case DimCube:
img_type_name += (img_type.arrayed ? "texturecube_array" : "texturecube");
break;
default:
img_type_name += "unknown_texture_type";
break;
}
}
// Append the pixel type
img_type_name += "<";
img_type_name += type_to_glsl(get<SPIRType>(img_type.type));
// For unsampled images, append the sample/read/write access qualifier.
// For kernel images, the access qualifier my be supplied directly by SPIR-V.
// Otherwise it may be set based on whether the image is read from or written to within the shader.
if (type.basetype == SPIRType::Image && type.image.sampled == 2)
{
switch (img_type.access)
{
case AccessQualifierReadOnly:
img_type_name += ", access::read";
break;
case AccessQualifierWriteOnly:
img_type_name += ", access::write";
break;
case AccessQualifierReadWrite:
img_type_name += ", access::read_write";
break;
default:
{
auto *p_var = maybe_get_backing_variable(id);
if (p_var && !has_decoration(p_var->self, DecorationNonWritable))
{
img_type_name += ", access::";
if (!has_decoration(p_var->self, DecorationNonReadable))
img_type_name += "read_";
img_type_name += "write";
}
break;
}
}
}
img_type_name += ">";
return img_type_name;
}
string CompilerMSL::bitcast_glsl_op(const SPIRType &out_type, const SPIRType &in_type)
{
if ((out_type.basetype == SPIRType::UInt && in_type.basetype == SPIRType::Int) ||
(out_type.basetype == SPIRType::Int && in_type.basetype == SPIRType::UInt) ||
(out_type.basetype == SPIRType::UInt64 && in_type.basetype == SPIRType::Int64) ||
(out_type.basetype == SPIRType::Int64 && in_type.basetype == SPIRType::UInt64))
return type_to_glsl(out_type);
if ((out_type.basetype == SPIRType::UInt && in_type.basetype == SPIRType::Float) ||
(out_type.basetype == SPIRType::Int && in_type.basetype == SPIRType::Float) ||
(out_type.basetype == SPIRType::Float && in_type.basetype == SPIRType::UInt) ||
(out_type.basetype == SPIRType::Float && in_type.basetype == SPIRType::Int) ||
(out_type.basetype == SPIRType::Int64 && in_type.basetype == SPIRType::Double) ||
(out_type.basetype == SPIRType::UInt64 && in_type.basetype == SPIRType::Double) ||
(out_type.basetype == SPIRType::Double && in_type.basetype == SPIRType::Int64) ||
(out_type.basetype == SPIRType::Double && in_type.basetype == SPIRType::UInt64))
return "as_type<" + type_to_glsl(out_type) + ">";
return "";
}
// Returns an MSL string identifying the name of a SPIR-V builtin.
// Output builtins are qualified with the name of the stage out structure.
string CompilerMSL::builtin_to_glsl(BuiltIn builtin, StorageClass storage)
{
switch (builtin)
{
// Override GLSL compiler strictness
case BuiltInVertexId:
return "gl_VertexID";
case BuiltInInstanceId:
return "gl_InstanceID";
case BuiltInVertexIndex:
return "gl_VertexIndex";
case BuiltInInstanceIndex:
return "gl_InstanceIndex";
// When used in the entry function, output builtins are qualified with output struct name.
case BuiltInPosition:
case BuiltInPointSize:
case BuiltInClipDistance:
case BuiltInLayer:
case BuiltInFragDepth:
if (current_function && (current_function->self == entry_point))
return stage_out_var_name + "." + CompilerGLSL::builtin_to_glsl(builtin, storage);
else
return CompilerGLSL::builtin_to_glsl(builtin, storage);
default:
return CompilerGLSL::builtin_to_glsl(builtin, storage);
}
}
// Returns an MSL string attribute qualifer for a SPIR-V builtin
string CompilerMSL::builtin_qualifier(BuiltIn builtin)
{
auto &execution = get_entry_point();
switch (builtin)
{
// Vertex function in
case BuiltInVertexId:
return "vertex_id";
case BuiltInVertexIndex:
return "vertex_id";
case BuiltInInstanceId:
return "instance_id";
case BuiltInInstanceIndex:
return "instance_id";
// Vertex function out
case BuiltInClipDistance:
return "clip_distance";
case BuiltInPointSize:
return "point_size";
case BuiltInPosition:
return "position";
case BuiltInLayer:
return "render_target_array_index";
// Fragment function in
case BuiltInFrontFacing:
return "front_facing";
case BuiltInPointCoord:
return "point_coord";
case BuiltInFragCoord:
return "position";
case BuiltInSampleId:
return "sample_id";
case BuiltInSampleMask:
return "sample_mask";
// Fragment function out
case BuiltInFragDepth:
if (execution.flags & (1ull << ExecutionModeDepthGreater))
return "depth(greater)";
else if (execution.flags & (1ull << ExecutionModeDepthLess))
return "depth(less)";
else
return "depth(any)";
// Compute function in
case BuiltInGlobalInvocationId:
return "thread_position_in_grid";
case BuiltInWorkgroupId:
return "threadgroup_position_in_grid";
case BuiltInNumWorkgroups:
return "threadgroups_per_grid";
case BuiltInLocalInvocationId:
return "thread_position_in_threadgroup";
case BuiltInLocalInvocationIndex:
return "thread_index_in_threadgroup";
default:
return "unsupported-built-in";
}
}
// Returns an MSL string type declaration for a SPIR-V builtin
string CompilerMSL::builtin_type_decl(BuiltIn builtin)
{
switch (builtin)
{
// Vertex function in
case BuiltInVertexId:
return "uint";
case BuiltInVertexIndex:
return "uint";
case BuiltInInstanceId:
return "uint";
case BuiltInInstanceIndex:
return "uint";
// Vertex function out
case BuiltInClipDistance:
return "float";
case BuiltInPointSize:
return "float";
case BuiltInPosition:
return "float4";
// Fragment function in
case BuiltInFrontFacing:
return "bool";
case BuiltInPointCoord:
return "float2";
case BuiltInFragCoord:
return "float4";
case BuiltInSampleId:
return "uint";
case BuiltInSampleMask:
return "uint";
// Compute function in
case BuiltInGlobalInvocationId:
case BuiltInLocalInvocationId:
case BuiltInNumWorkgroups:
case BuiltInWorkgroupId:
return "uint3";
case BuiltInLocalInvocationIndex:
return "uint";
default:
return "unsupported-built-in-type";
}
}
// Returns the declaration of a built-in argument to a function
string CompilerMSL::built_in_func_arg(BuiltIn builtin, bool prefix_comma)
{
string bi_arg;
if (prefix_comma)
bi_arg += ", ";
bi_arg += builtin_type_decl(builtin);
assert(builtin == BuiltInVertexIndex || builtin == BuiltInInstanceIndex);
bi_arg += " " + builtin_to_glsl(builtin, StorageClassInput);
bi_arg += " [[" + builtin_qualifier(builtin) + "]]";
return bi_arg;
}
// Returns the byte size of a struct member.
size_t CompilerMSL::get_declared_struct_member_size(const SPIRType &struct_type, uint32_t index) const
{
auto dec_mask = get_member_decoration_mask(struct_type.self, index);
auto &type = get<SPIRType>(struct_type.member_types[index]);
switch (type.basetype)
{
case SPIRType::Unknown:
case SPIRType::Void:
case SPIRType::AtomicCounter:
case SPIRType::Image:
case SPIRType::SampledImage:
case SPIRType::Sampler:
SPIRV_CROSS_THROW("Querying size of opaque object.");
case SPIRType::Struct:
return get_declared_struct_size(type);
default:
{
size_t component_size = type.width / 8;
unsigned vecsize = type.vecsize;
unsigned columns = type.columns;
// For arrays, we can use ArrayStride to get an easy check.
if (!type.array.empty())
return type_struct_member_array_stride(struct_type, index) * type.array.back();
if (columns == 1) // An unpacked 3-element vector is the same size as a 4-element vector.
{
if (!(dec_mask & (1ull << DecorationCPacked)))
{
if (vecsize == 3)
vecsize = 4;
}
}
else // For matrices, a 3-element column is the same size as a 4-element column.
{
if (dec_mask & (1ull << DecorationColMajor))
{
if (vecsize == 3)
vecsize = 4;
}
else if (dec_mask & (1ull << DecorationRowMajor))
{
if (columns == 3)
columns = 4;
}
}
return vecsize * columns * component_size;
}
}
}
// Returns the byte alignment of a struct member.
size_t CompilerMSL::get_declared_struct_member_alignment(const SPIRType &struct_type, uint32_t index) const
{
auto &type = get<SPIRType>(struct_type.member_types[index]);
switch (type.basetype)
{
case SPIRType::Unknown:
case SPIRType::Void:
case SPIRType::AtomicCounter:
case SPIRType::Image:
case SPIRType::SampledImage:
case SPIRType::Sampler:
SPIRV_CROSS_THROW("Querying alignment of opaque object.");
case SPIRType::Struct:
return 16; // Per Vulkan spec section 14.5.4
default:
{
// Alignment of packed type is the same as the underlying component size.
// Alignment of unpacked type is the same as the type size (or one matrix column).
auto dec_mask = get_member_decoration_mask(struct_type.self, index);
if (dec_mask & (1ull << DecorationCPacked))
return type.width / 8;
else
return get_declared_struct_member_size(struct_type, index) / type.columns;
}
}
}
bool CompilerMSL::skip_argument(uint32_t) const
{
return false;
}
bool CompilerMSL::OpCodePreprocessor::handle(Op opcode, const uint32_t *args, uint32_t /*length*/)
{
// Since MSL exists in a single execution scope, function prototype declarations are not
// needed, and clutter the output. If secondary functions are output (either as a SPIR-V
// function implementation or as indicated by the presence of OpFunctionCall), then set
// suppress_missing_prototypes to suppress compiler warnings of missing function prototypes.
// Mark if the input requires the implementation of an SPIR-V function that does not exist in Metal.
SPVFuncImpl spv_func = compiler.get_spv_func_impl(opcode, args);
if (spv_func != SPVFuncImplNone)
{
compiler.spv_function_implementations.insert(spv_func);
suppress_missing_prototypes = true;
return true;
}
switch (opcode)
{
case OpFunctionCall:
suppress_missing_prototypes = true;
break;
case OpAtomicExchange:
case OpAtomicCompareExchange:
case OpAtomicCompareExchangeWeak:
case OpAtomicLoad:
case OpAtomicIIncrement:
case OpAtomicIDecrement:
case OpAtomicIAdd:
case OpAtomicISub:
case OpAtomicSMin:
case OpAtomicUMin:
case OpAtomicSMax:
case OpAtomicUMax:
case OpAtomicAnd:
case OpAtomicOr:
case OpAtomicXor:
uses_atomics = true;
break;
default:
break;
}
return true;
}
// Returns an enumeration of a SPIR-V function that needs to be output for certain Op codes.
CompilerMSL::SPVFuncImpl CompilerMSL::get_spv_func_impl(Op opcode, const uint32_t *args)
{
switch (opcode)
{
case OpFMod:
return SPVFuncImplMod;
case OpExtInst:
{
uint32_t extension_set = args[2];
if (get<SPIRExtension>(extension_set).ext == SPIRExtension::GLSL)
{
GLSLstd450 op_450 = static_cast<GLSLstd450>(args[3]);
switch (op_450)
{
case GLSLstd450Radians:
return SPVFuncImplRadians;
case GLSLstd450Degrees:
return SPVFuncImplDegrees;
case GLSLstd450FindILsb:
return SPVFuncImplFindILsb;
case GLSLstd450FindSMsb:
return SPVFuncImplFindSMsb;
case GLSLstd450FindUMsb:
return SPVFuncImplFindUMsb;
case GLSLstd450MatrixInverse:
{
auto &mat_type = get<SPIRType>(args[0]);
switch (mat_type.columns)
{
case 2:
return SPVFuncImplInverse2x2;
case 3:
return SPVFuncImplInverse3x3;
case 4:
return SPVFuncImplInverse4x4;
default:
break;
}
break;
}
default:
break;
}
}
break;
}
default:
break;
}
return SPVFuncImplNone;
}
// Sort both type and meta member content based on builtin status (put builtins at end),
// then by the required sorting aspect.
void CompilerMSL::MemberSorter::sort()
{
// Create a temporary array of consecutive member indices and sort it based on how
// the members should be reordered, based on builtin and sorting aspect meta info.
size_t mbr_cnt = type.member_types.size();
vector<uint32_t> mbr_idxs(mbr_cnt);
iota(mbr_idxs.begin(), mbr_idxs.end(), 0); // Fill with consecutive indices
std::sort(mbr_idxs.begin(), mbr_idxs.end(), *this); // Sort member indices based on sorting aspect
// Move type and meta member info to the order defined by the sorted member indices.
// This is done by creating temporary copies of both member types and meta, and then
// copying back to the original content at the sorted indices.
auto mbr_types_cpy = type.member_types;
auto mbr_meta_cpy = meta.members;
for (uint32_t mbr_idx = 0; mbr_idx < mbr_cnt; mbr_idx++)
{
type.member_types[mbr_idx] = mbr_types_cpy[mbr_idxs[mbr_idx]];
meta.members[mbr_idx] = mbr_meta_cpy[mbr_idxs[mbr_idx]];
}
}
// Sort first by builtin status (put builtins at end), then by the sorting aspect.
bool CompilerMSL::MemberSorter::operator()(uint32_t mbr_idx1, uint32_t mbr_idx2)
{
auto &mbr_meta1 = meta.members[mbr_idx1];
auto &mbr_meta2 = meta.members[mbr_idx2];
if (mbr_meta1.builtin != mbr_meta2.builtin)
return mbr_meta2.builtin;
else
switch (sort_aspect)
{
case Location:
return mbr_meta1.location < mbr_meta2.location;
case LocationReverse:
return mbr_meta1.location > mbr_meta2.location;
case Offset:
return mbr_meta1.offset < mbr_meta2.offset;
case OffsetThenLocationReverse:
return (mbr_meta1.offset < mbr_meta2.offset) ||
((mbr_meta1.offset == mbr_meta2.offset) && (mbr_meta1.location > mbr_meta2.location));
case Alphabetical:
return mbr_meta1.alias < mbr_meta2.alias;
default:
return false;
}
}
CompilerMSL::MemberSorter::MemberSorter(SPIRType &t, Meta &m, SortAspect sa)
: type(t)
, meta(m)
, sort_aspect(sa)
{
// Ensure enough meta info is available
meta.members.resize(max(type.member_types.size(), meta.members.size()));
}