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Add dynamic dispatch support for export functions with pointers to varying data as arguments

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This commit is contained in:
james.brodman
2013-12-05 17:47:58 -05:00
parent a448ccf20c
commit d10c0d9545
3 changed files with 148 additions and 11 deletions
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155
module.cpp
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@@ -599,6 +599,11 @@ lRecursiveCheckValidParamType(const Type *t, bool vectorOk) {
const PointerType *pt = CastType<PointerType>(t);
if (pt != NULL) {
// Only allow exported uniform pointers
// Uniform pointers to varying data, however, are ok.
if (pt->IsVaryingType())
return false;
else
return lRecursiveCheckValidParamType(pt->GetBaseType(), true);
}
@@ -615,6 +620,9 @@ static void
lCheckExportedParameterTypes(const Type *type, const std::string &name,
SourcePos pos) {
if (lRecursiveCheckValidParamType(type, false) == false) {
if (CastType<PointerType>(type))
Error(pos, "Varying pointer type parameter \"%s\" is illegal "
"in an exported function.", name.c_str());
if (CastType<StructType>(type->GetBaseType()))
Error(pos, "Struct parameter \"%s\" with vector typed "
"member(s) is illegal in an exported function.", name.c_str());
@@ -622,7 +630,7 @@ lCheckExportedParameterTypes(const Type *type, const std::string &name,
Error(pos, "Vector-typed parameter \"%s\" is illegal in an exported "
"function.", name.c_str());
else
Error(pos, "\"%s\" is illegal in an exported function.",
Error(pos, "Varying parameter \"%s\" is illegal in an exported function.",
name.c_str());
}
}
@@ -823,8 +831,8 @@ Module::AddFunctionDeclaration(const std::string &name,
// doesn't have any funky stuff going on in it.
// JCB nomosoa - Varying is now a-ok.
if (functionType->isExported) {
lCheckExportedParameterTypes(argType, argName, argPos);
}
lCheckExportedParameterTypes(argType, argName, argPos);
}
// ISPC assumes that no pointers alias. (It should be possible to
// specify when this is not the case, but this should be the
@@ -1784,6 +1792,60 @@ Module::writeHeader(const char *fn) {
}
bool
Module::writeDispatchHeaderSection(FILE *f, unsigned int *flags) {
unsigned int AlreadyDone4 = (*flags) & 4;
unsigned int AlreadyDone8 = (*flags) & 8;
unsigned int AlreadyDone16 = (*flags) & 16;
// Get Target ProgramCount
// If not already done
// {
// ...
// (*flags) = (*flags) | target program count
// }
// else return
fprintf(f, "\n#ifdef __cplusplus\nnamespace ispc { /* namespace */\n#endif // __cplusplus\n");
// Get all of the struct, vector, and enumerant types used as function
// parameters. These vectors may have repeats.
std::vector<const StructType *> exportedStructTypes;
std::vector<const EnumType *> exportedEnumTypes;
std::vector<const VectorType *> exportedVectorTypes;
lGetExportedParamTypes(exportedFuncs, &exportedStructTypes,
&exportedEnumTypes, &exportedVectorTypes);
lGetExportedParamTypes(externCFuncs, &exportedStructTypes,
&exportedEnumTypes, &exportedVectorTypes);
// Go through the explicitly exported types
for (int i = 0; i < (int)exportedTypes.size(); ++i) {
if (const StructType *st = CastType<StructType>(exportedTypes[i].first))
exportedStructTypes.push_back(st->GetAsUniformType());
else if (const EnumType *et = CastType<EnumType>(exportedTypes[i].first))
exportedEnumTypes.push_back(et->GetAsUniformType());
else if (const VectorType *vt = CastType<VectorType>(exportedTypes[i].first))
exportedVectorTypes.push_back(vt->GetAsUniformType());
else
FATAL("Unexpected type in export list");
}
// And print them
lEmitVectorTypedefs(exportedVectorTypes, f);
lEmitEnumDecls(exportedEnumTypes, f);
lEmitStructDecls(exportedStructTypes, f);
// end namespace
fprintf(f, "\n");
fprintf(f, "\n#ifdef __cplusplus\n} /* namespace */\n#endif // __cplusplus\n");
// end guard
fprintf(f, "\n#endif // %s\n", guard.c_str());
return true;
}
void
Module::execPreprocessor(const char *infilename, llvm::raw_string_ostream *ostream) const
{
@@ -1980,13 +2042,16 @@ lSymbolIsExported(const Symbol *s) {
// llvm::Function that were compiled for different compilation target ISAs.
struct FunctionTargetVariants {
FunctionTargetVariants() {
for (int i = 0; i < Target::NUM_ISAS; ++i)
for (int i = 0; i < Target::NUM_ISAS; ++i) {
func[i] = NULL;
FTs[i] = NULL;
}
}
// The func array is indexed with the Target::ISA enumerant. Some
// values may be NULL, indicating that the original function wasn't
// compiled to the corresponding target ISA.
llvm::Function *func[Target::NUM_ISAS];
const FunctionType *FTs[Target::NUM_ISAS];
};
@@ -2001,6 +2066,7 @@ lGetExportedFunctions(SymbolTable *symbolTable,
for (unsigned int i = 0; i < syms.size(); ++i) {
FunctionTargetVariants &ftv = functions[syms[i]->name];
ftv.func[g->target->getISA()] = syms[i]->exportedFunction;
ftv.FTs[g->target->getISA()] = CastType<FunctionType>(syms[i]->type);
}
}
@@ -2107,6 +2173,53 @@ lAddExtractedGlobals(llvm::Module *module,
}
}
static llvm::FunctionType *
lGetVaryingDispatchType(FunctionTargetVariants &funcs) {
llvm::Type *ptrToInt8Ty = llvm::Type::getInt8PtrTy(*g->ctx);
llvm::FunctionType *resultFuncTy = NULL;
for (int i = 0; i < Target::NUM_ISAS; ++i) {
if (funcs.func[i] == NULL) {
continue;
}
else {
bool foundVarying = false;
const FunctionType *ft = funcs.FTs[i];
resultFuncTy = funcs.func[i]->getFunctionType();
int numArgs = ft->GetNumParameters();
llvm::SmallVector<llvm::Type *, 8> ftype;
for (int j = 0; j < numArgs; ++j) {
ftype.push_back(resultFuncTy->getParamType(j));
}
for (int j = 0; j < numArgs; ++j) {
const Type *arg = ft->GetParameterType(j);
if (arg->IsPointerType()) {
const Type *baseType = CastType<PointerType>(arg)->GetBaseType();
// For each varying type pointed to, swap the LLVM pointer type
// with i8 * (as close as we can get to void *)
if (baseType->IsVaryingType()) {
ftype[j] = ptrToInt8Ty;
foundVarying = true;
}
}
}
if (foundVarying) {
resultFuncTy = llvm::FunctionType::get(resultFuncTy->getReturnType(), ftype, false);
}
}
}
// We should've found at least one variant here
// or else something fishy is going on.
Assert(resultFuncTy);
return resultFuncTy;
}
#include <iostream>
/** Create the dispatch function for an exported ispc function.
This function checks to see which vector ISAs the system the
@@ -2134,11 +2247,12 @@ lCreateDispatchFunction(llvm::Module *module, llvm::Function *setISAFunc,
// we'll start by generating an 'extern' declaration of each one that
// we have in the current module so that we can then call out to that.
llvm::Function *targetFuncs[Target::NUM_ISAS];
llvm::FunctionType *ftype = NULL;
llvm::FunctionType *ftypes[Target::NUM_ISAS];
for (int i = 0; i < Target::NUM_ISAS; ++i) {
if (funcs.func[i] == NULL) {
targetFuncs[i] = NULL;
ftypes[i] = NULL;
continue;
}
@@ -2149,14 +2263,23 @@ lCreateDispatchFunction(llvm::Module *module, llvm::Function *setISAFunc,
// because we only allow uniform stuff to pass through the
// export'ed function layer, they should all have the same memory
// layout, so this is benign..
if (ftype == NULL)
ftype = funcs.func[i]->getFunctionType();
// JCB nomosoa - not anymore...
// add a helper to see if this type has any varying thingies?
// might be hard to detect....
// If so, return a new type with the pointers to those replaced
// by i8 *'s.
// if (ftype == NULL)
ftypes[i] = funcs.func[i]->getFunctionType();
targetFuncs[i] =
llvm::Function::Create(ftype, llvm::GlobalValue::ExternalLinkage,
llvm::Function::Create(ftypes[i], llvm::GlobalValue::ExternalLinkage,
funcs.func[i]->getName(), module);
}
// New helper function checks to see if we need to rewrite the
// type for the dispatch function in case of pointers to varyings
llvm::FunctionType *ftype = lGetVaryingDispatchType(funcs);
bool voidReturn = ftype->getReturnType()->isVoidTy();
// Now we can emit the definition of the dispatch function..
@@ -2201,8 +2324,21 @@ lCreateDispatchFunction(llvm::Module *module, llvm::Function *setISAFunc,
// the target-specific function.
std::vector<llvm::Value *> args;
llvm::Function::arg_iterator argIter = dispatchFunc->arg_begin();
for (; argIter != dispatchFunc->arg_end(); ++argIter)
llvm::Function::arg_iterator targsIter = targetFuncs[i]->arg_begin();
for (; argIter != dispatchFunc->arg_end(); ++argIter, ++targsIter) {
// Check to see if we rewrote any types in the dispatch function.
// If so, create bitcasts for the appropriate pointer types.
if (argIter->getType() == targsIter->getType()) {
args.push_back(argIter);
}
else {
llvm::CastInst *argCast =
llvm::CastInst::CreatePointerCast(argIter, targsIter->getType(),
"dpatch_arg_bitcast", callBBlock);
args.push_back(argCast);
}
}
if (voidReturn) {
llvm::CallInst::Create(targetFuncs[i], args, "", callBBlock);
llvm::ReturnInst::Create(*g->ctx, callBBlock);
@@ -2239,7 +2375,6 @@ lCreateDispatchFunction(llvm::Module *module, llvm::Function *setISAFunc,
}
}
// Given a map that holds the mapping from each of the 'export'ed functions
// in the ispc program to the target-specific variants of the function,
// create a llvm::Module that has a dispatch function for each exported

2
module.h
View File

@@ -181,6 +181,8 @@ private:
llvm::Module *module, OutputType outputType,
const char *outFileName);
static bool writeBitcode(llvm::Module *module, const char *outFileName);
static bool writeDispatchHeader(const char *dispatchHeaderFileName);
bool writeDispatchHeaderSection(FILE *file, unsigned int *flags);
void execPreprocessor(const char *infilename, llvm::raw_string_ostream* ostream) const;
};

2
type.cpp
View File

@@ -459,7 +459,7 @@ AtomicType::GetCDeclaration(const std::string &name) const {
if (variability == Variability::Varying ||
variability == Variability::SOA) {
char buf[32];
// get program count
// get program count
// g->mangleFunctionsNamesWithTarget - hack check for void *
int vWidth = (variability == Variability::Varying) ?
g->target->getVectorWidth() :