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SPV: rationalize parameter handling for "original" and "writable" parameters.

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This commit is contained in:
John Kessenich 2017-09-10 15:21:05 -06:00 committed by GregF
parent bed4e4f7e4
commit d41993d9d2
2 changed files with 31 additions and 28 deletions
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57
SPIRV/GlslangToSpv.cpp
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@ -158,6 +158,8 @@ protected:
void declareUseOfStructMember(const glslang::TTypeList& members, int glslangMember);
bool isShaderEntryPoint(const glslang::TIntermAggregate* node);
bool writableParam(glslang::TStorageQualifier);
bool originalParam(glslang::TStorageQualifier, const glslang::TType&, bool implicitThisParam);
void makeFunctions(const glslang::TIntermSequence&);
void makeGlobalInitializers(const glslang::TIntermSequence&);
void visitFunctions(const glslang::TIntermSequence&);
@ -2969,6 +2971,24 @@ bool TGlslangToSpvTraverser::isShaderEntryPoint(const glslang::TIntermAggregate*
return node->getName().compare(glslangIntermediate->getEntryPointMangledName().c_str()) == 0;
}
// Does parameter need a place to keep writes, separate from the original?
bool TGlslangToSpvTraverser::writableParam(glslang::TStorageQualifier qualifier)
{
return qualifier != glslang::EvqConstReadOnly;
}
// Is parameter pass-by-original?
bool TGlslangToSpvTraverser::originalParam(glslang::TStorageQualifier qualifier, const glslang::TType& paramType,
bool implicitThisParam)
{
if (implicitThisParam) // implicit this
return true;
if (glslangIntermediate->getSource() == glslang::EShSourceHlsl)
return false;
return paramType.containsOpaque() || // sampler, etc.
(paramType.getBasicType() == glslang::EbtBlock && qualifier == glslang::EvqBuffer); // SSBO
}
// Make all the functions, skeletally, without actually visiting their bodies.
void TGlslangToSpvTraverser::makeFunctions(const glslang::TIntermSequence& glslFunctions)
{
@ -3005,23 +3025,13 @@ void TGlslangToSpvTraverser::makeFunctions(const glslang::TIntermSequence& glslF
bool implicitThis = (int)parameters.size() > 0 && parameters[0]->getAsSymbolNode()->getName() ==
glslangIntermediate->implicitThisName;
const auto canPassOriginal = [&](const glslang::TType& paramType, bool firstParam) -> bool {
if (glslangIntermediate->getSource() == glslang::EShSourceHlsl)
return firstParam && implicitThis;
else
return paramType.containsOpaque() || // sampler, etc.
(paramType.getBasicType() == glslang::EbtBlock &&
paramType.getQualifier().storage == glslang::EvqBuffer) || // SSBO
(firstParam && implicitThis); // implicit 'this'
};
paramDecorations.resize(parameters.size());
for (int p = 0; p < (int)parameters.size(); ++p) {
const glslang::TType& paramType = parameters[p]->getAsTyped()->getType();
spv::Id typeId = convertGlslangToSpvType(paramType);
if (canPassOriginal(paramType, p == 0))
if (originalParam(paramType.getQualifier().storage, paramType, implicitThis && p == 0))
typeId = builder.makePointer(TranslateStorageClass(paramType), typeId);
else if (paramType.getQualifier().storage != glslang::EvqConstReadOnly)
else if (writableParam(paramType.getQualifier().storage))
typeId = builder.makePointer(spv::StorageClassFunction, typeId);
else
rValueParameters.insert(parameters[p]->getAsSymbolNode()->getId());
@ -3581,13 +3591,6 @@ spv::Id TGlslangToSpvTraverser::handleUserFunctionCall(const glslang::TIntermAgg
const glslang::TIntermSequence& glslangArgs = node->getSequence();
const glslang::TQualifierList& qualifiers = node->getQualifierList();
// Encapsulate lvalue logic, used in multiple places below, for safety.
const auto isLValue = [&](int qualifier, const glslang::TType& paramType) -> bool {
if (glslangIntermediate->getSource() == glslang::EShSourceHlsl)
return qualifier != glslang::EvqConstReadOnly;
return qualifier != glslang::EvqConstReadOnly || paramType.containsOpaque();
};
// See comments in makeFunctions() for details about the semantics for parameter passing.
//
// These imply we need a four step process:
@ -3606,8 +3609,9 @@ spv::Id TGlslangToSpvTraverser::handleUserFunctionCall(const glslang::TIntermAgg
builder.clearAccessChain();
glslangArgs[a]->traverse(this);
argTypes.push_back(&paramType);
// keep outputs and opaque objects as l-values, evaluate input-only as r-values
if (isLValue(qualifiers[a], paramType)) {
// keep outputs and pass-by-originals as l-values, evaluate others as r-values
if (writableParam(qualifiers[a]) ||
originalParam(qualifiers[a], paramType, function->hasImplicitThis() && a == 0)) {
// save l-value
lValues.push_back(builder.getAccessChain());
} else {
@ -3626,14 +3630,11 @@ spv::Id TGlslangToSpvTraverser::handleUserFunctionCall(const glslang::TIntermAgg
for (int a = 0; a < (int)glslangArgs.size(); ++a) {
const glslang::TType& paramType = glslangArgs[a]->getAsTyped()->getType();
spv::Id arg;
if ((a == 0 && function->hasImplicitThis()) ||
(glslangIntermediate->getSource() != glslang::EShSourceHlsl &&
(paramType.containsOpaque() ||
(paramType.getBasicType() == glslang::EbtBlock && qualifiers[a] == glslang::EvqBuffer)))) {
if (originalParam(qualifiers[a], paramType, function->hasImplicitThis() && a == 0)) {
builder.setAccessChain(lValues[lValueCount]);
arg = builder.accessChainGetLValue();
++lValueCount;
} else if (isLValue(qualifiers[a], paramType)) {
} else if (writableParam(qualifiers[a])) {
// need space to hold the copy
arg = builder.createVariable(spv::StorageClassFunction, convertGlslangToSpvType(paramType), "param");
if (qualifiers[a] == glslang::EvqIn || qualifiers[a] == glslang::EvqInOut) {
@ -3660,7 +3661,9 @@ spv::Id TGlslangToSpvTraverser::handleUserFunctionCall(const glslang::TIntermAgg
lValueCount = 0;
for (int a = 0; a < (int)glslangArgs.size(); ++a) {
const glslang::TType& paramType = glslangArgs[a]->getAsTyped()->getType();
if (isLValue(qualifiers[a], paramType)) {
if (originalParam(qualifiers[a], paramType, function->hasImplicitThis() && a == 0))
++lValueCount;
else if (writableParam(qualifiers[a])) {
if (qualifiers[a] == glslang::EvqOut || qualifiers[a] == glslang::EvqInOut) {
spv::Id copy = builder.createLoad(spvArgs[a]);
builder.setAccessChain(lValues[lValueCount]);

2
glslang/Include/intermediate.h
View File

@ -1286,7 +1286,7 @@ protected:
};
typedef TVector<TIntermNode*> TIntermSequence;
typedef TVector<int> TQualifierList;
typedef TVector<TStorageQualifier> TQualifierList;
//
// Nodes that operate on an arbitrary sized set of children.
//