slang-type-layout.h
#ifndef SLANG_TYPE_LAYOUT_H
#define SLANG_TYPE_LAYOUT_H
#include "../core/slang-basic.h"
#include "slang-compiler.h"
#include "slang-profile.h"
#include "slang-syntax.h"
#include "../../slang.h"
namespace Slang {
// Forward declarations
enum class BaseType;
class Type;
struct IRLayout;
//
#if 0
enum class LayoutRulesFamily
{
HLSL,
GLSL,
};
#endif
// A "size" that can either be a simple finite size or
// the special case of an infinite/unbounded size.
//
struct LayoutSize
{
typedef size_t RawValue;
LayoutSize()
: raw(0)
{}
LayoutSize(RawValue size)
: raw(size)
{
SLANG_ASSERT(size != RawValue(-1));
}
static LayoutSize fromRaw(RawValue raw)
{
LayoutSize size;
size.raw = raw;
return size;
}
static LayoutSize infinite()
{
LayoutSize result;
result.raw = RawValue(-1);
return result;
}
bool isInfinite() const { return raw == RawValue(-1); }
bool isFinite() const { return raw != RawValue(-1); }
RawValue getFiniteValue() const { SLANG_ASSERT(isFinite()); return raw; }
bool operator==(LayoutSize that) const
{
return raw == that.raw;
}
bool operator!=(LayoutSize that) const
{
return raw != that.raw;
}
void operator+=(LayoutSize right)
{
if( isInfinite() ) {}
else if( right.isInfinite() )
{
*this = LayoutSize::infinite();
}
else
{
*this = LayoutSize(raw + right.raw);
}
}
void operator*=(LayoutSize right)
{
// Deal with zero first, so that anything (even the "infinite" value) times zero is zero.
if( raw == 0 )
{
return;
}
if( right.raw == 0 )
{
raw = 0;
return;
}
// Next we deal with infinite cases, so that infinite times anything non-zero is infinite
if( isInfinite() )
{
return;
}
if( right.isInfinite() )
{
*this = LayoutSize::infinite();
return;
}
// Finally deal with the case where both sides are finite
*this = LayoutSize(raw * right.raw);
}
void operator-=(RawValue right)
{
if( isInfinite() ) {}
else
{
*this = LayoutSize(raw - right);
}
}
void operator/=(RawValue right)
{
if( isInfinite() ) {}
else
{
*this = LayoutSize(raw / right);
}
}
RawValue raw;
};
inline LayoutSize operator+(LayoutSize left, LayoutSize right)
{
LayoutSize result(left);
result += right;
return result;
}
inline LayoutSize operator*(LayoutSize left, LayoutSize right)
{
LayoutSize result(left);
result *= right;
return result;
}
inline LayoutSize operator-(LayoutSize left, LayoutSize::RawValue right)
{
LayoutSize result(left);
result -= right;
return result;
}
inline LayoutSize operator/(LayoutSize left, LayoutSize::RawValue right)
{
LayoutSize result(left);
result /= right;
return result;
}
inline LayoutSize maximum(LayoutSize left, LayoutSize right)
{
if(left.isInfinite() || right.isInfinite())
return LayoutSize::infinite();
return LayoutSize(Math::Max(
left.getFiniteValue(),
right.getFiniteValue()));
}
inline bool operator>(LayoutSize left, LayoutSize::RawValue right)
{
return left.isInfinite() || (left.getFiniteValue() > right);
}
inline bool operator<=(LayoutSize left, LayoutSize::RawValue right)
{
return left.isFinite() && (left.getFiniteValue() <= right);
}
// Layout appropriate to "just memory" scenarios,
// such as laying out the members of a constant buffer.
struct UniformLayoutInfo
{
LayoutSize size;
size_t alignment;
UniformLayoutInfo()
: size(0)
, alignment(1)
{}
UniformLayoutInfo(
LayoutSize size,
size_t alignment)
: size(size)
, alignment(alignment)
{}
};
// Extended information required for an array of uniform data,
// including the "stride" of the array (the space between
// consecutive elements).
struct UniformArrayLayoutInfo : UniformLayoutInfo
{
size_t elementStride;
UniformArrayLayoutInfo()
: elementStride(0)
{}
UniformArrayLayoutInfo(
LayoutSize size,
size_t alignment,
size_t elementStride)
: UniformLayoutInfo(size, alignment)
, elementStride(elementStride)
{}
};
typedef slang::ParameterCategory LayoutResourceKind;
// Layout information for a value that only consumes
// a single resource kind.
struct SimpleLayoutInfo
{
// What kind of resource should we consume?
LayoutResourceKind kind;
// How many resources of that kind?
LayoutSize size;
// only useful in the uniform case
size_t alignment;
SimpleLayoutInfo()
: kind(LayoutResourceKind::None)
, size(0)
, alignment(1)
{}
SimpleLayoutInfo(
UniformLayoutInfo uniformInfo)
: kind(LayoutResourceKind::Uniform)
, size(uniformInfo.size)
, alignment(uniformInfo.alignment)
{}
SimpleLayoutInfo(LayoutResourceKind kind, LayoutSize size, size_t alignment=1)
: kind(kind)
, size(size)
, alignment(alignment)
{}
// Convert to layout for uniform data
UniformLayoutInfo getUniformLayout()
{
if(kind == LayoutResourceKind::Uniform)
{
return UniformLayoutInfo(size, alignment);
}
else
{
return UniformLayoutInfo(0, 1);
}
}
};
// Only useful in the case of a homogeneous array
struct SimpleArrayLayoutInfo : SimpleLayoutInfo
{
// This field is only useful in the uniform case
size_t elementStride;
// Convert to layout for uniform data
UniformArrayLayoutInfo getUniformLayout()
{
if(kind == LayoutResourceKind::Uniform)
{
return UniformArrayLayoutInfo(size, alignment, elementStride);
}
else
{
return UniformArrayLayoutInfo(0, 1, 0);
}
}
};
struct LayoutRulesImpl;
// Base class for things that store layout info
class Layout : public RefObject
{
};
// A reified representation of a particular laid-out type
class TypeLayout : public Layout
{
public:
// The type that was laid out
RefPtr<Type> type;
Type* getType() { return type.Ptr(); }
// The layout rules that were used to produce this type
LayoutRulesImpl* rules;
struct ResourceInfo
{
// What kind of register was it?
LayoutResourceKind kind = LayoutResourceKind::None;
// How many registers of the above kind did we use?
LayoutSize count;
};
List<ResourceInfo> resourceInfos;
// For uniform data, alignment matters, but not for
// any other resource category, so we don't waste
// the space storing it in the above array
UInt uniformAlignment = 1;
/// The layout for data that is conceptually owned by this type, but which is pending layout.
///
/// When a type contains interface/existential fields (recursively), the
/// actual data referenced by these fields needs to get allocated somewhere,
/// but it cannot go inline at the point where the interface/existential
/// type appears, or else the layout of a composite object would change
/// when the concrete type(s) we plug in change.
///
/// We solve this problem by tracking this data that is "pending" layout,
/// and then "flushing" the pending data at appropriate places during
/// the layout process.
///
RefPtr<TypeLayout> pendingDataTypeLayout;
ResourceInfo* FindResourceInfo(LayoutResourceKind kind)
{
for(auto& rr : resourceInfos)
{
if(rr.kind == kind)
return &rr;
}
return nullptr;
}
ResourceInfo* findOrAddResourceInfo(LayoutResourceKind kind)
{
auto existing = FindResourceInfo(kind);
if(existing) return existing;
ResourceInfo info;
info.kind = kind;
info.count = 0;
resourceInfos.add(info);
return &resourceInfos.getLast();
}
void addResourceUsage(ResourceInfo info)
{
if(info.count == 0) return;
findOrAddResourceInfo(info.kind)->count += info.count;
}
void addResourceUsage(LayoutResourceKind kind, LayoutSize count)
{
ResourceInfo info;
info.kind = kind;
info.count = count;
addResourceUsage(info);
}
void removeResourceUsage(LayoutResourceKind kind);
void addResourceUsageFrom(TypeLayout* otherTypeLayout);
/// "Unwrap" any layers of array-ness from this type layout.
///
/// If this is an `ArrayTypeLayout`, returns the result of unwrapping the element type layout.
/// Otherwise, returns this type layout.
///
RefPtr<TypeLayout> unwrapArray();
};
typedef unsigned int VarLayoutFlags;
enum VarLayoutFlag : VarLayoutFlags
{
HasSemantic = 1 << 0
};
// A reified layout for a particular variable, field, etc.
class VarLayout : public Layout
{
public:
// The variable we are laying out
DeclRef<VarDeclBase> varDecl;
VarDeclBase* getVariable() { return varDecl.getDecl(); }
Name* getName() { return getVariable()->getName(); }
// The result of laying out the variable's type
RefPtr<TypeLayout> typeLayout;
TypeLayout* getTypeLayout() { return typeLayout.Ptr(); }
// Additional flags
VarLayoutFlags flags = 0;
// System-value semantic (and index) if this is a system value
String systemValueSemantic;
int systemValueSemanticIndex;
// General case semantic name and index
// TODO: this and the system-value field are redundant
// TODO: the `VarLayout` type is getting bloated; we need to not store this
// information unless actually required.
String semanticName;
int semanticIndex;
// The stage this variable belongs to, in case it is
// stage-specific.
// TODO: This is wasteful to be storing on every single
// variable layout.
Stage stage = Stage::Unknown;
// The start register(s) for any resources
struct ResourceInfo
{
// What kind of register was it?
LayoutResourceKind kind = LayoutResourceKind::None;
// What binding space (HLSL) or set (Vulkan) are we placed in?
UInt space;
// What is our starting register in that space?
//
// (In the case of uniform data, this is a byte offset)
UInt index;
};
List<ResourceInfo> resourceInfos;
ResourceInfo* FindResourceInfo(LayoutResourceKind kind)
{
for(auto& rr : resourceInfos)
{
if(rr.kind == kind)
return &rr;
}
return nullptr;
}
ResourceInfo* AddResourceInfo(LayoutResourceKind kind)
{
ResourceInfo info;
info.kind = kind;
info.space = 0;
info.index = 0;
resourceInfos.add(info);
return &resourceInfos.getLast();
}
ResourceInfo* findOrAddResourceInfo(LayoutResourceKind kind)
{
auto existing = FindResourceInfo(kind);
if(existing) return existing;
return AddResourceInfo(kind);
}
RefPtr<VarLayout> pendingVarLayout;
};
// type layout for a variable that has a constant-buffer type
class ParameterGroupTypeLayout : public TypeLayout
{
public:
// The layout of the "container" part itself.
// E.g., for a constant buffer, this would reflect
// the resource usage of the container, without
// the element type factored in. All of the offsets
// for this variable should be zero, but it is included
// for completeness.
RefPtr<VarLayout> containerVarLayout;
// A variable layout for the element of the container.
// The offsets of the variable layout will reflect
// the offsets that need to applied to get past the
// container types resource usage, while the actual
// type layout won't have offsets applied (unlike
// `offsetElementTypeLayout` below).
RefPtr<VarLayout> elementVarLayout;
// The layout of the element type, with offsets applied
// so that any fields (if the element type is a `struct`)
// will be offset by the resource usage of the container.
RefPtr<TypeLayout> offsetElementTypeLayout;
};
// type layout for a variable that has a constant-buffer type
class StructuredBufferTypeLayout : public TypeLayout
{
public:
RefPtr<TypeLayout> elementTypeLayout;
};
/// Type layout for a logical sequence type
class SequenceTypeLayout : public TypeLayout
{
public:
/// The layout of the element type.
///
/// This layout may include adjustments to make lookups in elements
/// of the array Just Work, and may not be the same as the layout
/// of the element type when used in a non-array context.
///
RefPtr<TypeLayout> elementTypeLayout;
/// The stride in bytes between elements.
size_t uniformStride = 0;
};
/// Type layout for an array type
class ArrayTypeLayout : public SequenceTypeLayout
{
public:
/// The original layout of the element type.
///
/// This layout does not include any adjustments that
/// were made to the element type in order to make
/// lookup into array elements Just Work.
///
RefPtr<TypeLayout> originalElementTypeLayout;
};
// type layout for a variable with stream-output type
class StreamOutputTypeLayout : public TypeLayout
{
public:
RefPtr<TypeLayout> elementTypeLayout;
};
class VectorTypeLayout : public SequenceTypeLayout
{
public:
};
class MatrixTypeLayout : public SequenceTypeLayout
{
public:
/// Is this matrix laid out as row-major or column-major?
///
/// Note that this does *not* affect the interpretation
/// of the `elementTypeLayout` field, which always represents
/// the logical elements of the matrix type, which are its
/// rows.
///
MatrixLayoutMode mode;
};
// Specific case of type layout for a struct
class StructTypeLayout : public TypeLayout
{
public:
// An ordered list of layouts for the known fields
List<RefPtr<VarLayout>> fields;
// Map a variable to its layout directly.
//
// Note that in the general case, there may be entries
// in the `fields` array that came from multiple
// translation units, and in cases where there are
// multiple declarations of the same parameter, only
// one will appear in `fields`, while all of
// them will be reflected in `mapVarToLayout`.
//
// TODO: This should map from a declaration to the *index*
// in the array above, rather than to the actual pointer,
// so that we
Dictionary<VarDeclBase*, RefPtr<VarLayout>> mapVarToLayout;
};
class GenericParamTypeLayout : public TypeLayout
{
public:
RefPtr<GlobalGenericParamDecl> getGlobalGenericParamDecl();
Index paramIndex = 0;
};
/// Layout information for a tagged union type.
class TaggedUnionTypeLayout : public TypeLayout
{
public:
/// The layouts of each of the case types.
///
/// The order of entries in this array matches
/// the order of case types on the original
/// `TaggedUnionType`, and the index of a case
/// type is also the tag value for that case.
///
List<RefPtr<TypeLayout>> caseTypeLayouts;
/// The byte offset for the tag field.
///
/// The tag field will always be allocated as
/// a `uint`, so we don't store a separate layout
/// for it.
///
LayoutSize tagOffset;
};
/// Layout information for a type with existential (sub-)field types specialized.
class ExistentialSpecializedTypeLayout : public TypeLayout
{
public:
RefPtr<TypeLayout> baseTypeLayout;
RefPtr<VarLayout> pendingDataVarLayout;
};
/// Layout for a scoped entity like a program, module, or entry point
class ScopeLayout : public Layout
{
public:
// The layout for the parameters of this entity.
//
RefPtr<VarLayout> parametersLayout;
};
StructTypeLayout* getScopeStructLayout(
ScopeLayout* programLayout);
// Layout information for a single shader entry point
// within a program
//
// Treated as a subclass of `StructTypeLayout` because
// it needs to include computed layout information
// for the parameters of the entry point.
//
// TODO: where to store layout info for the return
// type of the function?
class EntryPointLayout : public ScopeLayout
{
public:
// The corresponding function declaration
DeclRef<FuncDecl> entryPoint;
DeclRef<FuncDecl> getFuncDeclRef() { return entryPoint; }
FuncDecl* getFuncDecl() { return entryPoint.getDecl(); }
// The shader profile that was used to compile the entry point
Profile profile;
// The name of the entry point. Always available even if entryPoint is nullptr (for example when it came from a library)
Name* name = nullptr;
// Layout for any results of the entry point
RefPtr<VarLayout> resultLayout;
enum Flag : unsigned
{
usesAnySampleRateInput = 0x1,
};
unsigned flags = 0;
// EntryPointLayout* getAbsoluteLayout(VarLayout* parentLayout);
// RefPtr<EntryPointLayout> m_absoluteLayout;
};
/// Reflection/layout information about a specialization parameter
class SpecializationParamLayout : public Layout
{
public:
Index index;
};
/// Reflection/layout information about a generic specialization parameter
class GenericSpecializationParamLayout : public SpecializationParamLayout
{
public:
/// The declaration of the generic parameter.
///
/// Could be any subclass of `Decl` that represents a generic value or type parameter.
RefPtr<Decl> decl;
};
/// Reflection/layout information about an existential/interface specialization parameter.
class ExistentialSpecializationParamLayout : public SpecializationParamLayout
{
public:
/// The type that needs to be specialized.
///
/// Currently, this will be an `interface` type that any concrete
/// type argument getting plugged in must conform to.
///
RefPtr<Type> type;
};
// Layout information for the global scope of a program
class ProgramLayout : public ScopeLayout
{
public:
/*
// We store a layout for the declarations at the global
// scope. Note that this will *either* be a single
// `StructTypeLayout` with the fields stored directly,
// or it will be a single `ParameterGroupTypeLayout`,
// where the global-scope fields are the members of
// that constant buffer.
//
// The `struct` case will be used if there are no
// "naked" global-scope uniform variables, and the
// constant-buffer case will be used if there are
// (since a constant buffer will have to be allocated
// to store them).
//
RefPtr<VarLayout> globalScopeLayout;
*/
/// The target and program for which layout was computed
TargetProgram* targetProgram;
TargetProgram* getTargetProgram() { return targetProgram; }
TargetRequest* getTargetReq() { return targetProgram->getTargetReq(); }
ComponentType* getProgram() { return targetProgram->getProgram(); }
// We catalog the requested entry points here,
// and any entry-point-specific parameter data
// will (eventually) belong there...
List<RefPtr<EntryPointLayout>> entryPoints;
/// Reflection information on (unspecialized) specialization parameters.
List<RefPtr<SpecializationParamLayout>> specializationParams;
/// Concrete argument values that were provided to specific global generic parameters.
///
/// Not useful for reflection, but valuable for code generation.
///
Dictionary<GlobalGenericParamDecl*, RefPtr<Val>> globalGenericArgs;
/// Layouts for all tagged union types required by this program
///
/// These are any tagged union types used by the specialization
/// arguments that have been used to specialize the program.
///
List<RefPtr<TypeLayout>> taggedUnionTypeLayouts;
};
StructTypeLayout* getGlobalStructLayout(
ProgramLayout* programLayout);
struct LayoutRulesFamilyImpl;
// A delineation of shader parameter types into fine-grained
// categories that can then be mapped down to actual resources
// by a given set of rules.
//
// TODO(tfoley): `SlangParameterCategory` and `slang::ParameterCategory`
// are badly named, and need to be revised so they can't be confused
// with this concept.
enum class ShaderParameterKind
{
ConstantBuffer,
TextureUniformBuffer,
ShaderStorageBuffer,
StructuredBuffer,
MutableStructuredBuffer,
RawBuffer,
MutableRawBuffer,
Buffer,
MutableBuffer,
Texture,
MutableTexture,
TextureSampler,
MutableTextureSampler,
InputRenderTarget,
SamplerState,
Image,
MutableImage,
RegisterSpace,
};
struct SimpleLayoutRulesImpl
{
// Get size and alignment for a single value of base type.
virtual SimpleLayoutInfo GetScalarLayout(BaseType baseType) = 0;
// Get size and alignment for an array of elements
virtual SimpleArrayLayoutInfo GetArrayLayout(SimpleLayoutInfo elementInfo, LayoutSize elementCount) = 0;
// Get layout for a vector or matrix type
virtual SimpleLayoutInfo GetVectorLayout(SimpleLayoutInfo elementInfo, size_t elementCount) = 0;
virtual SimpleArrayLayoutInfo GetMatrixLayout(SimpleLayoutInfo elementInfo, size_t rowCount, size_t columnCount) = 0;
// Begin doing layout on a `struct` type
virtual UniformLayoutInfo BeginStructLayout() = 0;
// Add a field to a `struct` type, and return the offset for the field
virtual LayoutSize AddStructField(UniformLayoutInfo* ioStructInfo, UniformLayoutInfo fieldInfo) = 0;
// End layout for a struct, and finalize its size/alignment.
virtual void EndStructLayout(UniformLayoutInfo* ioStructInfo) = 0;
};
struct ObjectLayoutRulesImpl
{
// Compute layout info for an object type
virtual SimpleLayoutInfo GetObjectLayout(ShaderParameterKind kind) = 0;
};
struct LayoutRulesImpl
{
LayoutRulesFamilyImpl* family;
SimpleLayoutRulesImpl* simpleRules;
ObjectLayoutRulesImpl* objectRules;
// Forward `SimpleLayoutRulesImpl` interface
SimpleLayoutInfo GetScalarLayout(BaseType baseType)
{
return simpleRules->GetScalarLayout(baseType);
}
SimpleArrayLayoutInfo GetArrayLayout(SimpleLayoutInfo elementInfo, LayoutSize elementCount)
{
return simpleRules->GetArrayLayout(elementInfo, elementCount);
}
SimpleLayoutInfo GetVectorLayout(SimpleLayoutInfo elementInfo, size_t elementCount)
{
return simpleRules->GetVectorLayout(elementInfo, elementCount);
}
SimpleArrayLayoutInfo GetMatrixLayout(SimpleLayoutInfo elementInfo, size_t rowCount, size_t columnCount)
{
return simpleRules->GetMatrixLayout(elementInfo, rowCount, columnCount);
}
UniformLayoutInfo BeginStructLayout()
{
return simpleRules->BeginStructLayout();
}
LayoutSize AddStructField(UniformLayoutInfo* ioStructInfo, UniformLayoutInfo fieldInfo)
{
return simpleRules->AddStructField(ioStructInfo, fieldInfo);
}
void EndStructLayout(UniformLayoutInfo* ioStructInfo)
{
return simpleRules->EndStructLayout(ioStructInfo);
}
// Forward `ObjectLayoutRulesImpl` interface
SimpleLayoutInfo GetObjectLayout(ShaderParameterKind kind)
{
return objectRules->GetObjectLayout(kind);
}
//
LayoutRulesFamilyImpl* getLayoutRulesFamily() { return family; }
};
struct LayoutRulesFamilyImpl
{
virtual LayoutRulesImpl* getConstantBufferRules() = 0;
virtual LayoutRulesImpl* getPushConstantBufferRules() = 0;
virtual LayoutRulesImpl* getTextureBufferRules() = 0;
virtual LayoutRulesImpl* getVaryingInputRules() = 0;
virtual LayoutRulesImpl* getVaryingOutputRules() = 0;
virtual LayoutRulesImpl* getSpecializationConstantRules()= 0;
virtual LayoutRulesImpl* getShaderStorageBufferRules() = 0;
virtual LayoutRulesImpl* getParameterBlockRules() = 0;
virtual LayoutRulesImpl* getRayPayloadParameterRules() = 0;
virtual LayoutRulesImpl* getCallablePayloadParameterRules() = 0;
virtual LayoutRulesImpl* getHitAttributesParameterRules()= 0;
virtual LayoutRulesImpl* getShaderRecordConstantBufferRules() = 0;
virtual LayoutRulesImpl* getStructuredBufferRules() = 0;
};
struct TypeLayoutContext
{
// The layout rules to use (e.g., we compute
// layout differently in a `cbuffer` vs. the
// parameter list of a fragment shader).
LayoutRulesImpl* rules;
// The target request that is triggering layout
TargetRequest* targetReq;
// A parent program layout that will establish the ordering
// of all global generic type parameters.
//
ProgramLayout* programLayout;
// Whether to lay out matrices column-major
// or row-major.
MatrixLayoutMode matrixLayoutMode;
// The concrete types (if any) to plug into the currently in-scope
// specialization params.
//
Int specializationArgCount = 0;
ExpandedSpecializationArg const* specializationArgs = nullptr;
LayoutRulesImpl* getRules() { return rules; }
LayoutRulesFamilyImpl* getRulesFamily() const { return rules->getLayoutRulesFamily(); }
TypeLayoutContext with(LayoutRulesImpl* inRules) const
{
TypeLayoutContext result = *this;
result.rules = inRules;
return result;
}
TypeLayoutContext with(MatrixLayoutMode inMatrixLayoutMode) const
{
TypeLayoutContext result = *this;
result.matrixLayoutMode = inMatrixLayoutMode;
return result;
}
TypeLayoutContext withSpecializationArgs(
ExpandedSpecializationArg const* args,
Int argCount) const
{
TypeLayoutContext result = *this;
result.specializationArgCount = argCount;
result.specializationArgs = args;
return result;
}
TypeLayoutContext withSpecializationArgsOffsetBy(
Int offset) const
{
TypeLayoutContext result = *this;
if( specializationArgCount > offset )
{
result.specializationArgCount = specializationArgCount - offset;
result.specializationArgs = specializationArgs + offset;
}
else
{
result.specializationArgCount = 0;
result.specializationArgs = nullptr;
}
return result;
}
};
//
/// A custom tuple to capture the outputs of type layout
struct TypeLayoutResult
{
/// The actual heap-allocated layout object with all the details
RefPtr<TypeLayout> layout;
/// A simplified representation of layout information.
///
/// This information is suitable for the case where a type only
/// consumes a single resource.
///
SimpleLayoutInfo info;
/// Default constructor.
TypeLayoutResult()
{}
/// Construct a result from the given layout object and simple layout info.
TypeLayoutResult(RefPtr<TypeLayout> inLayout, SimpleLayoutInfo const& inInfo)
: layout(inLayout)
, info(inInfo)
{}
};
/// Helper type for building `struct` type layouts
struct StructTypeLayoutBuilder
{
public:
/// Begin the layout process for `type`, using `rules`
void beginLayout(
Type* type,
LayoutRulesImpl* rules);
/// Begin the layout process for `type`, using `rules`, if it hasn't already been begun.
///
/// This functions allows for a `StructTypeLayoutBuilder` to be use lazily,
/// only allocating a type layout object if it is actaully needed.
///
void beginLayoutIfNeeded(
Type* type,
LayoutRulesImpl* rules);
/// Add a field to the struct type layout.
///
/// One of the `beginLayout*()` functions must have been called previously.
///
RefPtr<VarLayout> addField(
DeclRef<VarDeclBase> field,
TypeLayoutResult fieldResult);
/// Add a field to the struct type layout.
///
/// One of the `beginLayout*()` functions must have been called previously.
///
RefPtr<VarLayout> addField(
DeclRef<VarDeclBase> field,
RefPtr<TypeLayout> fieldTypeLayout);
/// Complete layout.
///
/// If layout was begun, ensures that the result of `getTypeLayout()` is usable.
/// If layout was never begin, does nothing.
///
void endLayout();
/// Get the type layout.
///
/// This can be called any time after `beginLayout*()`.
/// In particular, it can be called before `endLayout`.
///
RefPtr<StructTypeLayout> getTypeLayout();
/// The the type layout result.
///
/// This is primarily useful for implementation code in `_createTypeLayout`.
///
TypeLayoutResult getTypeLayoutResult();
UniformLayoutInfo* getStructLayoutInfo() { return &m_info; }
private:
/// The layout rules being used, if layout has begun.
LayoutRulesImpl* m_rules = nullptr;
/// The type layout being computed, if layout has begun.
RefPtr<StructTypeLayout> m_typeLayout;
/// Uniform offset/alignment statte used when computing offset for uniform fields.
UniformLayoutInfo m_info;
};
//
// Get an appropriate set of layout rules (packaged up
// as a `TypeLayoutContext`) to perform type layout
// for the given target.
//
// The provided `programLayout` is used to establish
// the ordering of all global generic type paramters.
//
TypeLayoutContext getInitialLayoutContextForTarget(
TargetRequest* targetReq,
ProgramLayout* programLayout);
/// Direction(s) of a varying shader parameter
typedef unsigned int EntryPointParameterDirectionMask;
enum
{
kEntryPointParameterDirection_Input = 0x1,
kEntryPointParameterDirection_Output = 0x2,
};
/// Get layout information for a simple varying parameter type.
///
/// A simple varying parameter is a scalar, vector, or matrix.
///
RefPtr<TypeLayout> getSimpleVaryingParameterTypeLayout(
TypeLayoutContext const& context,
Type* type,
EntryPointParameterDirectionMask directionMask);
// Create a full type-layout object for a type,
// according to the layout rules in `context`.
RefPtr<TypeLayout> createTypeLayout(
TypeLayoutContext const& context,
Type* type);
//
/// Create a layout for a parameter-group type (a `ConstantBuffer` or `ParameterBlock`).
RefPtr<TypeLayout> createParameterGroupTypeLayout(
TypeLayoutContext const& context,
RefPtr<ParameterGroupType> parameterGroupType);
/// Create a wrapper constant buffer type layout, if needed.
///
/// When dealing with entry-point `uniform` and global-scope parameters,
/// we want to create a wrapper constant buffer for all the parameters
/// if and only if there exist some parameters that use "ordinary" data
/// (`LayoutResourceKind::Uniform`).
///
/// This function determines whether such a wrapper is needed, based
/// on the `elementTypeLayout` given, and either creates and returns
/// the layout for the wrapper, or the unmodified `elementTypeLayout`.
///
RefPtr<TypeLayout> createConstantBufferTypeLayoutIfNeeded(
TypeLayoutContext const& context,
RefPtr<TypeLayout> elementTypeLayout);
// Create a type layout for a structured buffer type.
RefPtr<StructuredBufferTypeLayout>
createStructuredBufferTypeLayout(
TypeLayoutContext const& context,
ShaderParameterKind kind,
RefPtr<Type> structuredBufferType,
RefPtr<Type> elementType);
/// Create a type layout for an unspecialized `globalGenericParamDecl`.
RefPtr<TypeLayout> createTypeLayoutForGlobalGenericTypeParam(
TypeLayoutContext const& context,
Type* type,
GlobalGenericParamDecl* globalGenericParamDecl);
/// Find the concrete type (if any) that was plugged in for the global generic type parameter `decl`.
RefPtr<Type> findGlobalGenericSpecializationArg(
TypeLayoutContext const& context,
GlobalGenericParamDecl* decl);
// Given an existing type layout `oldTypeLayout`, apply offsets
// to any contained fields based on the resource infos in `offsetVarLayout`.
RefPtr<TypeLayout> applyOffsetToTypeLayout(
RefPtr<TypeLayout> oldTypeLayout,
RefPtr<VarLayout> offsetVarLayout);
struct IRBuilder;
struct IRTypeLayout;
struct IRVarLayout;
IRTypeLayout* applyOffsetToTypeLayout(
IRBuilder* irBuilder,
IRTypeLayout* oldTypeLayout,
IRVarLayout* offsetVarLayout);
/// Create a layout like `baseLayout`, but offset by `offsetLayout`
IRVarLayout* applyOffsetToVarLayout(
IRBuilder* irBuilder,
IRVarLayout* baseLayout,
IRVarLayout* offsetLayout);
}
#endif