Raymond Toy pushed to branch issue-97-define-ud2-inst at cmucl / cmucl Commits: cfb35624 by Raymond Toy at 2021-04-09T16:14:44-07:00 Modify UD1 inst so it prints out registers correctly Hack the definition of the ud1 instruction format so that the reg/mem field is really a word register. This then makes the pending interrupt trap print out as "ud1 ecx, ecx" instead of "ud1 ecx, cl". I don't know why the printer wanted to print cl, but `print-reg` was passing `:byte` as the size (from the dstate `'width`). This works around the issue. - - - - - 1 changed file: - src/compiler/x86/insts.lisp Changes: ===================================== src/compiler/x86/insts.lisp ===================================== @@ -2062,13 +2062,20 @@ (code :field (byte 8 8))) +;; The UD1 instruction. The mod bits of the mod r/m byte MUST be #b11 +;; so that the reg/mem field is actually a register. This is a hack +;; to allow us to print out the reg/mem reg as a 32 reg. Using just +;; reg/mem, the register sometimes printed out as a byte reg and I +;; (toy.raymond) don't know why. (disassem:define-instruction-format (ud1 24 :default-printer '(:name :tab reg ", " reg/mem)) (prefix :field (byte 8 0) :value #b00001111) (op :field (byte 8 8) :value #b10111001) - (reg/mem :fields (list (byte 2 22) (byte 3 16)) - :type 'reg/mem) - (reg :field (byte 3 19) :type 'word-reg)) + ;; The mod bits ensure that the reg/mem field is interpreted as a + ;; register, not memory. + (reg/mem :field (byte 3 16) :type 'word-reg) + (reg :field (byte 3 19) :type 'word-reg) + (mod :field (byte 2 22) :value #b11)) (defun snarf-error-junk (sap offset &optional length-only) (let* ((length (system:sap-ref-8 sap offset)) @@ -2125,7 +2132,7 @@ ;; We just want the trap code in the third byte of the instruction. (define-instruction ud1 (segment code) (:declare (type (unsigned-byte 8) code)) - (:printer ud1 ((op #b10111001)) + (:printer ud1 ((op #b10111001) (reg nil :type 'word-reg)) :default :control #'ud1-control) (:emitter View it on GitLab: https://gitlab.common-lisp.net/cmucl/cmucl/-/commit/cfb35624edee9113a81d9000... -- View it on GitLab: https://gitlab.common-lisp.net/cmucl/cmucl/-/commit/cfb35624edee9113a81d9000... You're receiving this email because of your account on gitlab.common-lisp.net.