SPV: Flatten structs for copy when they are GLSL type aliases.
Addresses issue #304 and issue #307 by replacing unmatched type OpStores with
per-member copies. Covers assignment statements and most argument passing, but
does not yet cover r-value-based argument passing.
diff --git a/SPIRV/GlslangToSpv.cpp b/SPIRV/GlslangToSpv.cpp
index ddad636..84c9e73 100755
--- a/SPIRV/GlslangToSpv.cpp
+++ b/SPIRV/GlslangToSpv.cpp
@@ -130,6 +130,7 @@
spv::Id makeArraySizeId(const glslang::TArraySizes&, int dim);
spv::Id accessChainLoad(const glslang::TType& type);
void accessChainStore(const glslang::TType& type, spv::Id rvalue);
+ void multiTypeStore(const glslang::TType&, spv::Id rValue);
glslang::TLayoutPacking getExplicitLayout(const glslang::TType& type) const;
int getArrayStride(const glslang::TType& arrayType, glslang::TLayoutPacking, glslang::TLayoutMatrix);
int getMatrixStride(const glslang::TType& matrixType, glslang::TLayoutPacking, glslang::TLayoutMatrix);
@@ -188,7 +189,7 @@
std::unordered_map<const char*, spv::Id> extBuiltinMap;
std::unordered_map<int, spv::Id> symbolValues;
- std::unordered_set<int> constReadOnlyParameters; // set of formal function parameters that have glslang qualifier constReadOnly, so we know they are not local function "const" that are write-once
+ std::unordered_set<int> rValueParameters; // set of formal function parameters passed as rValues, rather than a pointer
std::unordered_map<std::string, spv::Function*> functionMap;
std::unordered_map<const glslang::TTypeList*, spv::Id> structMap[glslang::ElpCount][glslang::ElmCount];
std::unordered_map<const glslang::TTypeList*, std::vector<int> > memberRemapper; // for mapping glslang block indices to spv indices (e.g., due to hidden members)
@@ -897,13 +898,12 @@
// For now, we consider all user variables as being in memory, so they are pointers,
// except for
- // A) "const in" arguments to a function, which are an intermediate object.
+ // A) R-Value arguments to a function, which are an intermediate object.
// See comments in handleUserFunctionCall().
- // B) Specialization constants (normal constant don't even come in as a variable),
+ // B) Specialization constants (normal constants don't even come in as a variable),
// These are also pure R-values.
glslang::TQualifier qualifier = symbol->getQualifier();
- if ((qualifier.storage == glslang::EvqConstReadOnly && constReadOnlyParameters.find(symbol->getId()) != constReadOnlyParameters.end()) ||
- qualifier.isSpecConstant())
+ if (qualifier.isSpecConstant() || rValueParameters.find(symbol->getId()) != rValueParameters.end())
builder.setAccessChainRValue(id);
else
builder.setAccessChainLValue(id);
@@ -965,16 +965,7 @@
// store the result
builder.setAccessChain(lValue);
- if (builder.isStructType(builder.getTypeId(rValue))) {
- //spv::Id lType = builder.getContainedTypeId(builder.getTypeId(builder.accessChainGetLValue()));
- //spv::Id rType = builder.getTypeId(rValue);
- //if (lType != rType) {
- // TODO: do member-wise copy instead, this is current issue
- // https://github.com/KhronosGroup/glslang/issues/304
- //} else
- accessChainStore(node->getType(), rValue);
- } else
- accessChainStore(node->getType(), rValue);
+ multiTypeStore(node->getType(), rValue);
// assignments are expressions having an rValue after they are evaluated...
builder.clearAccessChain();
@@ -2248,6 +2239,8 @@
// Wrap the builder's accessChainStore to:
// - do conversion of concrete to abstract type
+//
+// Implicitly uses the existing builder.accessChain as the storage target.
void TGlslangToSpvTraverser::accessChainStore(const glslang::TType& type, spv::Id rvalue)
{
// Need to convert to abstract types when necessary
@@ -2277,6 +2270,57 @@
builder.accessChainStore(rvalue);
}
+// For storing when types match at the glslang level, but not might match at the
+// SPIR-V level.
+//
+// This especially happens when a single glslang type expands to multiple
+// SPIR-V types, like a struct that is used in an member-undecorated way as well
+// as in a member-decorated way.
+//
+// NOTE: This function can handle any store request; if it's not special it
+// simplifies to a simple OpStore.
+//
+// Implicitly uses the existing builder.accessChain as the storage target.
+void TGlslangToSpvTraverser::multiTypeStore(const glslang::TType& type, spv::Id rValue)
+{
+ // we only do the complex path here if it's a structure
+ if (! type.isStruct()) {
+ accessChainStore(type, rValue);
+ return;
+ }
+
+ // and, it has to be a case of structure type aliasing
+ spv::Id rType = builder.getTypeId(rValue);
+ spv::Id lValue = builder.accessChainGetLValue();
+ spv::Id lType = builder.getContainedTypeId(builder.getTypeId(lValue));
+ if (lType == rType) {
+ accessChainStore(type, rValue);
+ return;
+ }
+
+ // Recursively (as needed) copy a struct type to a different struct type,
+ // where the two types were the same type in GLSL. This requires member
+ // by member copy, recursively.
+
+ // loop over members
+ const glslang::TTypeList& members = *type.getStruct();
+ for (int m = 0; m < (int)members.size(); ++m) {
+ const glslang::TType& glslangMemberType = *members[m].type;
+
+ // get the source member
+ spv::Id memberRType = builder.getContainedTypeId(rType, m);
+ spv::Id memberRValue = builder.createCompositeExtract(rValue, memberRType, m);
+
+ // set up the target storage
+ builder.clearAccessChain();
+ builder.setAccessChainLValue(lValue);
+ builder.accessChainPush(builder.makeIntConstant(m));
+
+ // store the member
+ multiTypeStore(glslangMemberType, memberRValue);
+ }
+}
+
// Decide whether or not this type should be
// decorated with offsets and strides, and if so
// whether std140 or std430 rules should be applied.
@@ -2403,19 +2447,18 @@
continue;
// We're on a user function. Set up the basic interface for the function now,
- // so that it's available to call.
- // Translating the body will happen later.
+ // so that it's available to call. Translating the body will happen later.
//
// Typically (except for a "const in" parameter), an address will be passed to the
// function. What it is an address of varies:
//
- // - "in" parameters not marked as "const" can be written to without modifying the argument,
- // so that write needs to be to a copy, hence the address of a copy works.
+ // - "in" parameters not marked as "const" can be written to without modifying the calling
+ // argument so that write needs to be to a copy, hence the address of a copy works.
//
// - "const in" parameters can just be the r-value, as no writes need occur.
//
- // - "out" and "inout" arguments can't be done as direct pointers, because GLSL has
- // copy-in/copy-out semantics. They can be handled though with a pointer to a copy.
+ // - "out" and "inout" arguments can't be done as pointers to the calling argument, because
+ // GLSL has copy-in/copy-out semantics. They can be handled though with a pointer to a copy.
std::vector<spv::Id> paramTypes;
std::vector<spv::Decoration> paramPrecisions;
@@ -2429,7 +2472,7 @@
else if (paramType.getQualifier().storage != glslang::EvqConstReadOnly)
typeId = builder.makePointer(spv::StorageClassFunction, typeId);
else
- constReadOnlyParameters.insert(parameters[p]->getAsSymbolNode()->getId());
+ rValueParameters.insert(parameters[p]->getAsSymbolNode()->getId());
paramPrecisions.push_back(TranslatePrecisionDecoration(paramType));
paramTypes.push_back(typeId);
}
@@ -2914,7 +2957,9 @@
// need to copy the input into output space
builder.setAccessChain(lValues[lValueCount]);
spv::Id copy = accessChainLoad(*argTypes[a]);
- builder.createStore(copy, arg);
+ builder.clearAccessChain();
+ builder.setAccessChainLValue(arg);
+ multiTypeStore(paramType, copy);
}
++lValueCount;
} else {
@@ -2931,11 +2976,12 @@
// 4. Copy back out an "out" arguments.
lValueCount = 0;
for (int a = 0; a < (int)glslangArgs.size(); ++a) {
+ const glslang::TType& paramType = glslangArgs[a]->getAsTyped()->getType();
if (qualifiers[a] != glslang::EvqConstReadOnly) {
if (qualifiers[a] == glslang::EvqOut || qualifiers[a] == glslang::EvqInOut) {
spv::Id copy = builder.createLoad(spvArgs[a]);
builder.setAccessChain(lValues[lValueCount]);
- accessChainStore(glslangArgs[a]->getAsTyped()->getType(), copy);
+ multiTypeStore(paramType, copy);
}
++lValueCount;
}