Robert Neil Faiman

US Patent:

58360140, Nov 10, 1998

Filed:

May 16, 1994

Appl. No.:

8/243560

Inventors:

Robert Neil Faiman - Wilton NH

Assignee:

Digital Equipment Corporation - Maynard MA

International Classification:

G06F 945

US Classification:

395707

Abstract:

A compiler framework comprises a generic compiler back end which may be used by a plurality of front ends to generate object code for a target computer system. Each front end scans and parses a source module containing source code for a programming language, and generates an intermediate language representation that describes the source code. The intermediate language representation is input to the generic compiler back end which performs optimization and code generation for a plurality of target computer systems. "Constant folding" optimization is performed by the generic compiler back end, and comprises finding occurrences of expressions that can be reduced to a constant and calculated at compile time rather than at runtime. One mechanism for performing constant folding, also referred to as K-folding, uses a KFOLD routine that is built by the compiler framework. The KFOLD routine is constructed using a special front end that produces an intermediate language representation of the KFOLD routine which may be used by the generic back end to produce a corresponding object file for one of a plurality of target computer systems.

US Patent:

56597533, Aug 19, 1997

Filed:

Dec 27, 1994

Appl. No.:

8/364437

Inventors:

Dennis Joseph Murphy - Westford MA
Robert Neil Faiman - Wilton NH

Assignee:

Digital Equipment Corporation - Maynard MA

International Classification:

G06F 945

US Classification:

395705

Abstract:

A compiler framework uses a generic "shell" and a generic back end (where the code generator is target-specific). The generic back end provides the functions of optimization, register and memory allocation, and code generation. The code generation function of the back end may be targeted for any of a number of computer architectures. A front end is tailored for each different source language, such as Cobol, Fortran, Pascal, C, C++, etc. The front end scans and parses the source code modules, and generates from them an intermediate language representation of the source code programs expressed in the source code. The intermediate language represents any of the source code languages in a universal manner, so the interface between the front end and back end is of a standard format, and need not be rewritten for each language-specific front end. A feature is the type definition (TD) mechanism, referred to a the TD module. This module provides mechanisms used by the front end and the compiler of the back end in constructing program "type-information" to be incorporated in an object module for use by a linker or debugger.