19 ms·

No I mean a disassembler, I can see how an assembler is nice to write in a language like that but I've never seen much byte manipulation examples. For example g

by speps 7y ago

No I mean a disassembler, I can see how an assembler is nice to write in a language like that but I've never seen much byte manipulation examples. For example going from machine code to the list of opcodes for example.

siraben 7y ago
That would be an interesting project. AFAIK Emacs has a bytecode disassembler[0] but I'm not aware of disassemblers for other instruction sets. [0] https://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/emacs-lisp/disass.el https://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/emacs-...
pjmlp 7y ago
There you go, "CHIP-8 in Common Lisp: Disassembly" https://stevelosh.com/blog/2017/01/chip8-disassembly/ https://stevelosh.com/blog/2017/01/chip8-disassembly/
lispm 7y ago
Every Common Lisp has a DISASSEMBLE function built-in. Compile a function and call the disassembler. For example SBCL https://github.com/sbcl/sbcl/blob/master/src/compiler/disassem.lisp https://github.com/sbcl/sbcl/blob/master/src/compiler/disass... and its ARM64 instructions: https://github.com/sbcl/sbcl/blob/master/src/compiler/arm64/insts.lisp https://github.com/sbcl/sbcl/blob/master/src/compiler/arm64/...
- dreamcompiler 7y ago
  Here's the times13 function in CCL on x86-64. (Note that #x68 is 13 shifted left 3 times to allow tag bits in the LS 3 bit positions. Also the below could be optimized a lot more but this is the default compilation.) ? (defun times13 (x) (* 13 x)) TIMES13 ? (disassemble 'times13) ;;; (defun times13 (x) (* 13 x)) (recover-fn-from-rip) ; [0] (cmpl ($ 8) (% nargs)) ; [7] (jne L41) ; [10] (pushq (% rbp)) ; [12] (movq (% rsp) (% rbp)) ; [13] (pushq (% arg_z)) ; [16] ;;; (* 13 x) (movl ($ #x68) (% arg_y.l)) ; [17] (movq (@ -8 (% rbp)) (% arg_z)) ; [22] (movq (% rbp) (% rsp)) ; [26] (popq (% rbp)) ; [29] (jmp (@ .SPBUILTIN-TIMES)) ; [30] ;;; #<no source text> (:align 3) L41 ; [@56] (uuo-error-wrong-number-of-args) ; [41] NIL

by speps 7y ago

siraben 7y ago

That would be an interesting project. AFAIK Emacs has a bytecode disassembler[0] but I'm not aware of disassemblers for other instruction sets. [0] https://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/emacs-lisp/disass.el https://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/emacs-...

pjmlp 7y ago

There you go, "CHIP-8 in Common Lisp: Disassembly" https://stevelosh.com/blog/2017/01/chip8-disassembly/ https://stevelosh.com/blog/2017/01/chip8-disassembly/

lispm 7y ago

Every Common Lisp has a DISASSEMBLE function built-in. Compile a function and call the disassembler. For example SBCL https://github.com/sbcl/sbcl/blob/master/src/compiler/disassem.lisp https://github.com/sbcl/sbcl/blob/master/src/compiler/disass... and its ARM64 instructions: https://github.com/sbcl/sbcl/blob/master/src/compiler/arm64/insts.lisp https://github.com/sbcl/sbcl/blob/master/src/compiler/arm64/...

dreamcompiler 7y ago
Here's the times13 function in CCL on x86-64. (Note that #x68 is 13 shifted left 3 times to allow tag bits in the LS 3 bit positions. Also the below could be optimized a lot more but this is the default compilation.) ? (defun times13 (x) (* 13 x)) TIMES13 ? (disassemble 'times13) ;;; (defun times13 (x) (* 13 x)) (recover-fn-from-rip) ; [0] (cmpl ($ 8) (% nargs)) ; [7] (jne L41) ; [10] (pushq (% rbp)) ; [12] (movq (% rsp) (% rbp)) ; [13] (pushq (% arg_z)) ; [16] ;;; (* 13 x) (movl ($ #x68) (% arg_y.l)) ; [17] (movq (@ -8 (% rbp)) (% arg_z)) ; [22] (movq (% rbp) (% rsp)) ; [26] (popq (% rbp)) ; [29] (jmp (@ .SPBUILTIN-TIMES)) ; [30] ;;; #<no source text> (:align 3) L41 ; [@56] (uuo-error-wrong-number-of-args) ; [41] NIL