ternary operator, update comment

Author: wenju-he

clang/lib/CodeGen/Targets/SPIR.cpp

@@ -245,19 +245,17 @@ void CommonSPIRTargetCodeGenInfo::setOCLKernelStubCallingConvention(
 
 // 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 virtual target and the bit pattern of a non-generic
-// null is unspecified, materialize non-generic null via an addrspacecast from
-// the generic null.
-// This allows later lowering to substitute the target’s real sentinel value.
+// 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;
-  if (QT->getUnqualifiedDesugaredType()->isNullPtrType())
-    AS = LangAS::Default;
-  else
-    AS = QT->getPointeeType().getAddressSpace();
+  LangAS AS = QT->getUnqualifiedDesugaredType()->isNullPtrType()
+                  ? LangAS::Default
+                  : QT->getPointeeType().getAddressSpace();
   if (AS == LangAS::Default || AS == LangAS::opencl_generic)
     return llvm::ConstantPointerNull::get(PT);