A traditional table-based DFA implementation looks like this:
uint8_t table[NUM_STATES][256]
uint8_t run(const uint8_t *start, const uint8_t *end, uint8_t state) {
for (const uint8_t *s = start; s != end; s++)
state = table[state][*s];
return state;
}
| #define RUN_ME /* | |
| exec cc -g -ggdb -O2 -W -Wall -std=c99 $0 -o "$(basename $0 .c)" | |
| */ | |
| /* | |
| * Copyright 2020 Paul Khuong | |
| * SPDX-License-Identifier: BSD-2-Clause | |
| * | |
| * Redistribution and use in source and binary forms, with or without | |
| * modification, are permitted provided that the following conditions |
| # If you, like me, have all of your various source-code-like projects in ~/src/ | |
| # this is how to give yourself per-project shell history. | |
| # | |
| # I wish I'd done this years ago. | |
| # | |
| # First, in your .bashrc file, you redefine the cd, pushd and popd builtins to be "do the builtin bit, | |
| # then do one other thing (set_src_history.sh, below) like so: | |
| cd () { |
This document was originally written several years ago. At the time I was working as an execution core verification engineer at Arm. The following points are coloured heavily by working in and around the execution cores of various processors. Apply a pinch of salt; points contain varying degrees of opinion.
It is still my opinion that RISC-V could be much better designed; though I will also say that if I was building a 32 or 64-bit CPU today I'd likely implement the architecture to benefit from the existing tooling.
Mostly based upon the RISC-V ISA spec v2.0. Some updates have been made for v2.2
The RISC-V ISA has pursued minimalism to a fault. There is a large emphasis on minimizing instruction count, normalizing encoding, etc. This pursuit of minimalism has resulted in false orthogonalities (such as reusing the same instruction for branches, calls and returns) and a requirement for superfluous instructions which impacts code density both in terms of size and
| #include <stdio.h> | |
| #define STR2(x) #x | |
| #define STR(x) STR2(x) | |
| #ifdef _WIN32 | |
| #define INCBIN_SECTION ".rdata, \"dr\"" | |
| #else | |
| #define INCBIN_SECTION ".rodata" | |
| #endif |
