Raymond Toy pushed to branch issue-97-define-ud2-inst at cmucl / cmucl

Commits:

• 9c5cdf07
  by Raymond Toy at 2021-05-20T21:18:44-07:00

  Define separate int and int3 instructions.
  
  Note that `(inst int 3)` is two bytes long and is not converted to an
  int3 instruction that is one byte long.
  
  Tested by looking at the output of
  `disassem::print-backend-inst-space` and also by inserting a
  function-start breakpoint in `#'kernel:%sqrt` and disassembling the
  function.  We see the `int3` instruction, and it is exactly one byte
  long.
  

1 changed file:

• src/compiler/x86/insts.lisp

Changes:

 (define-instruction int (segment number)

   (:declare (type (unsigned-byte 8) number))

   (:printer byte-imm ((op #b11001101)))

-  (:printer byte ((op #b11001100))

-	    `(:name 3))

-  (:emitter

-   (etypecase number

-     ((member 3)

-      (emit-byte segment #b11001100))

-     ((unsigned-byte 8)

-      (emit-byte segment #b11001101)

-      (emit-byte segment number)))))

+  (:emitter

+   (emit-byte segment #b11001101)

+   (emit-byte segment number)))

+

+(define-instruction int3 (segment)

+  (:printer byte ((op #b11001100)))

+  (:emitter

+   (emit-byte segment #b11001100)))

 (define-instruction into (segment)

   (:printer byte ((op #b11001110)))