Displaying 1 result from an estimated 1 matches for "w37mfnu_ag8".
2016 Feb 12
3
Experimental 6502 backend; memory operand folding problem
...sk for help as I'm stuck on one particularly sticky problem.
I'll describe the problem shortly.
Occasionally, the topic of a 6502 backend comes up on this mailing list. Here
is an old thread talking about some of the challenges involved:
<https://groups.google.com/forum/#!topic/llvm-dev/w37MfNU_Ag8>.
The 6502 has only three 8-bit registers: A, X and Y, and 256 bytes of hardware-
supported stack. Generating code for such a constrained system pushes LLVM to
its limits.
For one thing, LLVM couldn't figure out how to lower an ADD instruction that
added a reg to a reg. The 6502's ADD...