Abstract: A process for transforming source code into efficient shared library executable code in which global offset table address values are computed only when needed by a function. A condition register and current global offset table address register are added to the code by the compiler. The condition register controls recalculation of the global offset table address. The current global offset table register is saved and the condition register is invalidated by the calling function prior to branching to the new function. The new function calculates the global offset address value only if it is needed. The intermediate code generated by the compiler includes specific routines to process local function calls, function calls by pointer, and external function calls. The system efficiency is improved whenever the actual global offset table access is infrequent compared to function calls across module boundaries.

Abstract: A process for compiling shared library source code into libraries in which the global offset table location is calculated only when a cross module boundary function call is made. The compiler process allocates a single global offset table pointer and then pre-appends a word to each function entry point containing the offset from that function entry point to the global offset table pointer. A calling module accesses the global offset table pointer and loads a global offset table register based on the offset and function entry point. Pointer logic instructions are inserted before pointer based branches using instruction cycles that would otherwise be lost to a pipeline stall in the preferred architecture.

Abstract: A system and method for resolving external references in single address space operating systems using client context based external reference resolution. The source code of a shared library module is analyzed during compilation and external references (exported variables and functions) identified. The compiler adds code to resolve the external reference based on a Global Offset Table (GOT) for each client instance of that library. The client instance maintains a global context area address register (GCR) that is combined with a library module offset value to define a real address in the single address space. Only the offset resolution code is fixed by the loader at load-time. The remaining module code is unchanged by the loader. The loader constructs a global context area for each client process as it is loaded and loads the address of that area into the Global Context Register for that process.