Auto push constant blocks (#2764)
* add ability to upgrade uniform block to push constants assuming it fits within the size limit imposed by the caller
* allow selecting the packing for the auto push constants
* check the size using the potential layout packing of the push constants
diff --git a/glslang/Include/Types.h b/glslang/Include/Types.h
index a6bf191..f4f3f34 100644
--- a/glslang/Include/Types.h
+++ b/glslang/Include/Types.h
@@ -741,6 +741,16 @@
}
}
+ bool isUniform() const
+ {
+ switch (storage) {
+ case EvqUniform:
+ return true;
+ default:
+ return false;
+ }
+ }
+
bool isIo() const
{
switch (storage) {
diff --git a/glslang/MachineIndependent/iomapper.cpp b/glslang/MachineIndependent/iomapper.cpp
index 7e12864..3486ea6 100644
--- a/glslang/MachineIndependent/iomapper.cpp
+++ b/glslang/MachineIndependent/iomapper.cpp
@@ -1633,6 +1633,37 @@
return TVarEntryInfo::TOrderByPriority()(p1.second, p2.second);
});
resolver->endResolve(EShLangCount);
+ if (autoPushConstantBlockName.length()) {
+ bool upgraded = false;
+ for (size_t stage = 0; stage < EShLangCount; stage++) {
+ if (intermediates[stage] != nullptr) {
+ TVarLiveMap** pUniformVarMap = uniformResolve.uniformVarMap;
+ auto at = pUniformVarMap[stage]->find(autoPushConstantBlockName);
+ if (at == pUniformVarMap[stage]->end())
+ continue;
+ TQualifier& qualifier = at->second.symbol->getQualifier();
+ if (!qualifier.isUniform())
+ continue;
+ TType& t = at->second.symbol->getWritableType();
+ int size, stride;
+ TIntermediate::getBaseAlignment(t, size, stride, autoPushConstantBlockPacking,
+ qualifier.layoutMatrix == ElmRowMajor);
+ if (size <= int(autoPushConstantMaxSize)) {
+ qualifier.setBlockStorage(EbsPushConstant);
+ qualifier.layoutPacking = autoPushConstantBlockPacking;
+ upgraded = true;
+ }
+ }
+ }
+ // If it's been upgraded to push_constant, then remove it from the uniformVector
+ // so it doesn't get a set/binding assigned to it.
+ if (upgraded) {
+ auto at = std::find_if(uniformVector.begin(), uniformVector.end(),
+ [this](const TVarLivePair& p) { return p.first == autoPushConstantBlockName; });
+ if (at != uniformVector.end())
+ uniformVector.erase(at);
+ }
+ }
for (size_t stage = 0; stage < EShLangCount; stage++) {
if (intermediates[stage] != nullptr) {
// traverse each stage, set new location to each input/output and unifom symbol, set new binding to
diff --git a/glslang/MachineIndependent/iomapper.h b/glslang/MachineIndependent/iomapper.h
index 07357c2..843ea73 100644
--- a/glslang/MachineIndependent/iomapper.h
+++ b/glslang/MachineIndependent/iomapper.h
@@ -291,7 +291,7 @@
bool virtual doMap(TIoMapResolver*, TInfoSink&) { return true; }
};
-// I/O mapper for OpenGL
+// I/O mapper for GLSL
class TGlslIoMapper : public TIoMapper {
public:
TGlslIoMapper() {
@@ -301,6 +301,8 @@
memset(intermediates, 0, sizeof(TIntermediate*) * (EShLangCount + 1));
profile = ENoProfile;
version = 0;
+ autoPushConstantMaxSize = 128;
+ autoPushConstantBlockPacking = ElpStd430;
}
virtual ~TGlslIoMapper() {
for (size_t stage = 0; stage < EShLangCount; stage++) {
@@ -320,6 +322,13 @@
intermediates[stage] = nullptr;
}
}
+ // If set, the uniform block with the given name will be changed to be backed by
+ // push_constant if it's size is <= maxSize
+ void setAutoPushConstantBlock(const char* name, unsigned int maxSize, TLayoutPacking packing) {
+ autoPushConstantBlockName = name;
+ autoPushConstantMaxSize = maxSize;
+ autoPushConstantBlockPacking = packing;
+ }
// grow the reflection stage by stage
bool addStage(EShLanguage, TIntermediate&, TInfoSink&, TIoMapResolver*) override;
bool doMap(TIoMapResolver*, TInfoSink&) override;
@@ -329,6 +338,11 @@
bool hadError = false;
EProfile profile;
int version;
+
+private:
+ TString autoPushConstantBlockName;
+ unsigned int autoPushConstantMaxSize;
+ TLayoutPacking autoPushConstantBlockPacking;
};
} // end namespace glslang
diff --git a/glslang/MachineIndependent/linkValidate.cpp b/glslang/MachineIndependent/linkValidate.cpp
index 4a68130..4edd2a9 100644
--- a/glslang/MachineIndependent/linkValidate.cpp
+++ b/glslang/MachineIndependent/linkValidate.cpp
@@ -1934,7 +1934,7 @@
}
// rule 9
- if (type.getBasicType() == EbtStruct) {
+ if (type.getBasicType() == EbtStruct || type.getBasicType() == EbtBlock) {
const TTypeList& memberList = *type.getStruct();
size = 0;
