rrh@june.cs.washington.edu (Robert R. Henry) (06/15/89)
I am interested in readers' experiences with self-modifying code. Specifically, I'm interested in knowing of 'standard' programming tricks that have been used in conjunction with self modifying code, and in what kinds of programs and on what kinds of architectures self modifying or self generating code has proven to be useful. I'm interested in any of these three kinds of self-modifications, although for the moment I'm focusing on fine-grain modifications: *fine-grain shape-preserving self modifications (such as changing an instruction every time through a loop) *medium/coarse-grain shape-preserving self modifications (similar to relinking code prior to executing it) *shape-altering modifications via on-the-fly code generation (this is used in some bit-blit kernels, and in some interpreters for lisp and smalltalk) Please don't flame me about system's level issues. I'm perfectly aware that self-modifying code is not reentrant; is not sharable; it can't reside in a ROM; it must be paged; it leads to serious cache coherency problems; it isn't easy to understand; it is architecture and perhaps implementation dependent. Please send mail directly to me, and I'll (eventually) post a summary. Thanks, Robert R. Henry Computer Science Department University of Washington