SCM

6.4: Improvements To Make

• Prefix and make more uniform all C function, variable, and constant names. Provide a file full of #define's to provide backward compatability.
• lgcd() needs to generate at most one bignum, but currently generates more.
• divide() could use shifts instead of multiply and divide when scaling.
• If an open fails because there are no unused file handles, GC should be done so that file handles which are no longer used can be collected.
• Currently, dumping an executable does not preserve ports. When loading a dumped executable, disk files could be reopened to the same file and position as they had when the executable was dumped.
• Compaction could be done to malloced objects by freeing and reallocing all the malloc objects encountered in a scan of the heap. Whether compactions would actually occur is system depenedent.
• Copying all of the stack is wasteful of storage. Any time a call-with-current-continuation is called the stack could be re-rooted with a frame which calls the contin just created. This in combination with checking stack depth could also be used to allow stacks deeper than 64K on the IBM PC.
• The must- or make- routines need some sort of C macros or conditionalization so that they check:
  • that the LENGTH field fits into a size_t (as is checked now) for platforms with (sizeof(size_t) < sizeof(SCM)).
  • that the LENGTH field fits into 24 (or 56) bits on machines where size_t is 32 bits or more.

  This is trickier than it first looks because the must_malloc() routine is also used for allocating heap segments, which do not have the LENGTH field restriction. Putting the 24 bit test into must_malloc() should be tested for speed impact.