diff options
Diffstat (limited to 'clang/lib/CodeGen/Targets/SPIR.cpp')
| -rw-r--r-- | clang/lib/CodeGen/Targets/SPIR.cpp | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/Targets/SPIR.cpp b/clang/lib/CodeGen/Targets/SPIR.cpp index 4aa6314..3f6d4e0 100644 --- a/clang/lib/CodeGen/Targets/SPIR.cpp +++ b/clang/lib/CodeGen/Targets/SPIR.cpp @@ -61,6 +61,9 @@ public: QualType SampledType, CodeGenModule &CGM) const; void setOCLKernelStubCallingConvention(const FunctionType *&FT) const override; + llvm::Constant *getNullPointer(const CodeGen::CodeGenModule &CGM, + llvm::PointerType *T, + QualType QT) const override; }; class SPIRVTargetCodeGenInfo : public CommonSPIRTargetCodeGenInfo { public: @@ -240,6 +243,29 @@ void CommonSPIRTargetCodeGenInfo::setOCLKernelStubCallingConvention( FT, FT->getExtInfo().withCallingConv(CC_SpirFunction)); } +// LLVM currently assumes a null pointer has the bit pattern 0, but some GPU +// targets use a non-zero encoding for null in certain address spaces. +// Because SPIR(-V) is a generic target and the bit pattern of null in +// non-generic AS is unspecified, materialize null in non-generic AS via an +// addrspacecast from null in generic AS. This allows later lowering to +// substitute the target's real sentinel value. +llvm::Constant * +CommonSPIRTargetCodeGenInfo::getNullPointer(const CodeGen::CodeGenModule &CGM, + llvm::PointerType *PT, + QualType QT) const { + LangAS AS = QT->getUnqualifiedDesugaredType()->isNullPtrType() + ? LangAS::Default + : QT->getPointeeType().getAddressSpace(); + if (AS == LangAS::Default || AS == LangAS::opencl_generic) + return llvm::ConstantPointerNull::get(PT); + + auto &Ctx = CGM.getContext(); + auto NPT = llvm::PointerType::get( + PT->getContext(), Ctx.getTargetAddressSpace(LangAS::opencl_generic)); + return llvm::ConstantExpr::getAddrSpaceCast( + llvm::ConstantPointerNull::get(NPT), PT); +} + LangAS SPIRVTargetCodeGenInfo::getGlobalVarAddressSpace(CodeGenModule &CGM, const VarDecl *D) const { |