X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fx86%2Finsts.lisp;h=720ad62ee83e5cb0abc5a1126ac1b28ae76b16cc;hb=d6f9676ae94419cb5544c45821a8d31adbc1fbe8;hp=f58b42a506270890f08b1c62a67fc532e4ee1de6;hpb=5de74c72e5a9522c7fdd3dbb31a39641e9de8877;p=sbcl.git

diff --git a/src/compiler/x86/insts.lisp b/src/compiler/x86/insts.lisp
index f58b42a..720ad62 100644
--- a/src/compiler/x86/insts.lisp
+++ b/src/compiler/x86/insts.lisp
@@ -40,6 +40,41 @@
 (defparameter *dword-reg-names*
   #(eax ecx edx ebx esp ebp esi edi))
 
+;;; Disassembling x86 code needs to take into account little things
+;;; like instructions that have a byte/word length bit in their
+;;; encoding, prefixes to change the default word length for a single
+;;; instruction, and so on.  Unfortunately, there is no easy way with
+;;; this disassembler framework to handle prefixes that will work
+;;; correctly in all cases, so we copy the x86-64 version which at
+;;; least can handle the code output by the compiler.
+;;;
+;;; Width information for an instruction is stored as an inst-prop on
+;;; the dstate.  The inst-props are cleared automatically after each
+;;; instruction, must be set by prefilters, and contain a single bit
+;;; of data each (presence/absence).  As such, each instruction that
+;;; can emit an operand-size prefix (x66 prefix) needs to have a set
+;;; of printers declared for both the prefixed and non-prefixed
+;;; encodings.
+
+;;; Return the operand size based on the prefixes and width bit from
+;;; the dstate.
+(defun inst-operand-size (dstate)
+  (declare (type sb!disassem:disassem-state dstate))
+  (cond ((sb!disassem:dstate-get-inst-prop dstate 'operand-size-8)
+         :byte)
+        ((sb!disassem:dstate-get-inst-prop dstate 'operand-size-16)
+         :word)
+        (t
+         +default-operand-size+)))
+
+;;; Return the operand size for a "word-sized" operand based on the
+;;; prefixes from the dstate.
+(defun inst-word-operand-size (dstate)
+  (declare (type sb!disassem:disassem-state dstate))
+  (if (sb!disassem:dstate-get-inst-prop dstate 'operand-size-16)
+      :word
+      :dword))
+
 (defun print-reg-with-width (value width stream dstate)
   (declare (ignore dstate))
   (princ (aref (ecase width
@@ -56,7 +91,7 @@
            (type stream stream)
            (type sb!disassem:disassem-state dstate))
   (print-reg-with-width value
-                        (sb!disassem:dstate-get-prop dstate 'width)
+                        (inst-operand-size dstate)
                         stream
                         dstate))
 
@@ -65,8 +100,7 @@
            (type stream stream)
            (type sb!disassem:disassem-state dstate))
   (print-reg-with-width value
-                        (or (sb!disassem:dstate-get-prop dstate 'word-width)
-                            +default-operand-size+)
+                        (inst-word-operand-size dstate)
                         stream
                         dstate))
 
@@ -170,18 +204,19 @@
 ;;; This is a sort of bogus prefilter that just stores the info globally for
 ;;; other people to use; it probably never gets printed.
 (defun prefilter-width (value dstate)
-  (setf (sb!disassem:dstate-get-prop dstate 'width)
-        (if (zerop value)
-            :byte
-            (let ((word-width
-                   ;; set by a prefix instruction
-                   (or (sb!disassem:dstate-get-prop dstate 'word-width)
-                       +default-operand-size+)))
-              (when (not (eql word-width +default-operand-size+))
-                ;; Reset it.
-                (setf (sb!disassem:dstate-get-prop dstate 'word-width)
-                      +default-operand-size+))
-              word-width))))
+  (declare (type bit value)
+           (type sb!disassem:disassem-state dstate))
+  (when (zerop value)
+    (sb!disassem:dstate-put-inst-prop dstate 'operand-size-8))
+  value)
+
+;;; This prefilter is used solely for its side effect, namely to put
+;;; the property OPERAND-SIZE-16 into the DSTATE.
+(defun prefilter-x66 (value dstate)
+  (declare (type (eql #x66) value)
+           (ignore value)
+           (type sb!disassem:disassem-state dstate))
+  (sb!disassem:dstate-put-inst-prop dstate 'operand-size-16))
 
 (defun read-address (value dstate)
   (declare (ignore value))              ; always nil anyway
@@ -237,13 +272,13 @@
   :prefilter (lambda (value dstate)
                (declare (ignore value)) ; always nil anyway
                (sb!disassem:read-suffix
-                (width-bits (sb!disassem:dstate-get-prop dstate 'width))
+                (width-bits (inst-operand-size dstate))
                 dstate)))
 
 (sb!disassem:define-arg-type signed-imm-data
   :prefilter (lambda (value dstate)
                (declare (ignore value)) ; always nil anyway
-               (let ((width (sb!disassem:dstate-get-prop dstate 'width)))
+               (let ((width (inst-operand-size dstate)))
                  (sb!disassem:read-signed-suffix (width-bits width) dstate))))
 
 (sb!disassem:define-arg-type signed-imm-byte
@@ -259,17 +294,13 @@
 (sb!disassem:define-arg-type imm-word
   :prefilter (lambda (value dstate)
                (declare (ignore value)) ; always nil anyway
-               (let ((width
-                      (or (sb!disassem:dstate-get-prop dstate 'word-width)
-                          +default-operand-size+)))
+               (let ((width (inst-word-operand-size dstate)))
                  (sb!disassem:read-suffix (width-bits width) dstate))))
 
 (sb!disassem:define-arg-type signed-imm-word
   :prefilter (lambda (value dstate)
                (declare (ignore value)) ; always nil anyway
-               (let ((width
-                      (or (sb!disassem:dstate-get-prop dstate 'word-width)
-                          +default-operand-size+)))
+               (let ((width (inst-word-operand-size dstate)))
                  (sb!disassem:read-signed-suffix (width-bits width) dstate))))
 
 ;;; needed for the ret imm16 instruction
@@ -310,15 +341,13 @@
 (sb!disassem:define-arg-type width
   :prefilter #'prefilter-width
   :printer (lambda (value stream dstate)
-             (if;; (zerop value)
-                 (or (null value)
-                     (and (numberp value) (zerop value))) ; zzz jrd
-                 (princ 'b stream)
-                 (let ((word-width
-                        ;; set by a prefix instruction
-                        (or (sb!disassem:dstate-get-prop dstate 'word-width)
-                            +default-operand-size+)))
-                   (princ (schar (symbol-name word-width) 0) stream)))))
+             (declare (ignore value))
+             (princ (schar (symbol-name (inst-operand-size dstate)) 0)
+                    stream)))
+
+;;; Used to capture the effect of the #x66 operand size override prefix.
+(sb!disassem:define-arg-type x66
+  :prefilter #'prefilter-x66)
 
 (eval-when (:compile-toplevel :load-toplevel :execute)
 (defparameter *conditions*
@@ -378,11 +407,27 @@
   (accum :type 'accum)
   (imm))
 
+(sb!disassem:define-instruction-format (x66-simple 16)
+  (x66   :field (byte 8 0) :type 'x66 :value #x66)
+  (op    :field (byte 7 9))
+  (width :field (byte 1 8) :type 'width)
+  ;; optional fields
+  (accum :type 'accum)
+  (imm))
+
+(sb!disassem:define-instruction-format (two-bytes 16
+                                        :default-printer '(:name))
+  (op :fields (list (byte 8 0) (byte 8 8))))
+
 ;;; Same as simple, but with direction bit
 (sb!disassem:define-instruction-format (simple-dir 8 :include 'simple)
   (op :field (byte 6 2))
   (dir :field (byte 1 1)))
 
+(sb!disassem:define-instruction-format (x66-simple-dir 16 :include 'x66-simple)
+  (op :field (byte 6 10))
+  (dir :field (byte 1 9)))
+
 ;;; Same as simple, but with the immediate value occurring by default,
 ;;; and with an appropiate printer.
 (sb!disassem:define-instruction-format (accum-imm 8
@@ -391,6 +436,12 @@
                                                         :tab accum ", " imm))
   (imm :type 'imm-data))
 
+(sb!disassem:define-instruction-format (x66-accum-imm 16
+                                     :include 'x66-simple
+                                     :default-printer '(:name
+                                                        :tab accum ", " imm))
+  (imm :type 'imm-data))
+
 (sb!disassem:define-instruction-format (reg-no-width 8
                                      :default-printer '(:name :tab reg))
   (op    :field (byte 5 3))
@@ -399,6 +450,15 @@
   (accum :type 'word-accum)
   (imm))
 
+(sb!disassem:define-instruction-format (x66-reg-no-width 16
+                                     :default-printer '(:name :tab reg))
+  (x66   :field (byte 8 0) :type 'x66 :value #x66)
+  (op    :field (byte 5 11))
+  (reg   :field (byte 3 8) :type 'word-reg)
+  ;; optional fields
+  (accum :type 'word-accum)
+  (imm))
+
 ;;; adds a width field to reg-no-width
 (sb!disassem:define-instruction-format (reg 8
                                         :default-printer '(:name :tab reg))
@@ -410,6 +470,17 @@
   (imm)
   )
 
+(sb!disassem:define-instruction-format (x66-reg 16
+                                        :default-printer '(:name :tab reg))
+  (x66   :field (byte 8 0) :type 'x66 :value #x66)
+  (op    :field (byte 4 12))
+  (width :field (byte 1 11) :type 'width)
+  (reg   :field (byte 3 8) :type 'reg)
+  ;; optional fields
+  (accum :type 'accum)
+  (imm)
+  )
+
 ;;; Same as reg, but with direction bit
 (sb!disassem:define-instruction-format (reg-dir 8 :include 'reg)
   (op  :field (byte 3 5))
@@ -430,6 +501,18 @@
   ;; optional fields
   (imm))
 
+(sb!disassem:define-instruction-format (x66-reg-reg/mem 24
+                                        :default-printer
+                                        `(:name :tab reg ", " reg/mem))
+  (x66   :field (byte 8 0) :type 'x66 :value #x66)
+  (op      :field (byte 7 9))
+  (width   :field (byte 1 8)    :type 'width)
+  (reg/mem :fields (list (byte 2 22) (byte 3 16))
+                                :type 'reg/mem)
+  (reg     :field (byte 3 19)   :type 'reg)
+  ;; optional fields
+  (imm))
+
 ;;; same as reg-reg/mem, but with direction bit
 (sb!disassem:define-instruction-format (reg-reg/mem-dir 16
                                         :include 'reg-reg/mem
@@ -440,6 +523,15 @@
   (op  :field (byte 6 2))
   (dir :field (byte 1 1)))
 
+(sb!disassem:define-instruction-format (x66-reg-reg/mem-dir 24
+                                        :include 'x66-reg-reg/mem
+                                        :default-printer
+                                        `(:name
+                                          :tab
+                                          ,(swap-if 'dir 'reg/mem ", " 'reg)))
+  (op  :field (byte 6 10))
+  (dir :field (byte 1 9)))
+
 ;;; Same as reg-rem/mem, but uses the reg field as a second op code.
 (sb!disassem:define-instruction-format (reg/mem 16
                                         :default-printer '(:name :tab reg/mem))
@@ -450,6 +542,16 @@
   ;; optional fields
   (imm))
 
+(sb!disassem:define-instruction-format (x66-reg/mem 24
+                                        :default-printer '(:name :tab reg/mem))
+  (x66   :field (byte 8 0) :type 'x66 :value #x66)
+  (op      :fields (list (byte 7 9) (byte 3 19)))
+  (width   :field (byte 1 8)    :type 'width)
+  (reg/mem :fields (list (byte 2 22) (byte 3 16))
+                                :type 'sized-reg/mem)
+  ;; optional fields
+  (imm))
+
 ;;; Same as reg/mem, but with the immediate value occurring by default,
 ;;; and with an appropiate printer.
 (sb!disassem:define-instruction-format (reg/mem-imm 16
@@ -459,6 +561,13 @@
   (reg/mem :type 'sized-reg/mem)
   (imm     :type 'imm-data))
 
+(sb!disassem:define-instruction-format (x66-reg/mem-imm 24
+                                        :include 'x66-reg/mem
+                                        :default-printer
+                                        '(:name :tab reg/mem ", " imm))
+  (reg/mem :type 'sized-reg/mem)
+  (imm     :type 'imm-data))
+
 ;;; Same as reg/mem, but with using the accumulator in the default printer
 (sb!disassem:define-instruction-format
     (accum-reg/mem 16
@@ -466,6 +575,13 @@
   (reg/mem :type 'reg/mem)              ; don't need a size
   (accum :type 'accum))
 
+(sb!disassem:define-instruction-format (x66-accum-reg/mem 24
+                                        :include 'x66-reg/mem
+                                        :default-printer
+                                        '(:name :tab accum ", " reg/mem))
+  (reg/mem :type 'reg/mem)              ; don't need a size
+  (accum :type 'accum))
+
 ;;; Same as reg-reg/mem, but with a prefix of #b00001111
 (sb!disassem:define-instruction-format (ext-reg-reg/mem 24
                                         :default-printer
@@ -479,6 +595,26 @@
   ;; optional fields
   (imm))
 
+(sb!disassem:define-instruction-format (x66-ext-reg-reg/mem 32
+                                        :default-printer
+                                        `(:name :tab reg ", " reg/mem))
+  (x66   :field (byte 8 0) :type 'x66 :value #x66)
+  (prefix  :field (byte 8 8)    :value #b00001111)
+  (op      :field (byte 7 17))
+  (width   :field (byte 1 16)    :type 'width)
+  (reg/mem :fields (list (byte 2 30) (byte 3 24))
+                                :type 'reg/mem)
+  (reg     :field (byte 3 27)   :type 'reg)
+  ;; optional fields
+  (imm))
+
+;;; reg-no-width with #x0f prefix
+(sb!disassem:define-instruction-format (ext-reg-no-width 16
+                                        :default-printer '(:name :tab reg))
+  (prefix  :field (byte 8 0)    :value #b00001111)
+  (op    :field (byte 5 11))
+  (reg   :field (byte 3 8) :type 'reg))
+
 ;;; Same as reg/mem, but with a prefix of #b00001111
 (sb!disassem:define-instruction-format (ext-reg/mem 24
                                         :default-printer '(:name :tab reg/mem))
@@ -490,11 +626,28 @@
   ;; optional fields
   (imm))
 
+(sb!disassem:define-instruction-format (x66-ext-reg/mem 32
+                                        :default-printer '(:name :tab reg/mem))
+  (x66     :field (byte 8 0)    :type 'x66 :value #x66)
+  (prefix  :field (byte 8 8)    :value #b00001111)
+  (op      :fields (list (byte 7 17) (byte 3 27)))
+  (width   :field (byte 1 16)    :type 'width)
+  (reg/mem :fields (list (byte 2 30) (byte 3 22))
+                                :type 'sized-reg/mem)
+  ;; optional fields
+  (imm))
+
 (sb!disassem:define-instruction-format (ext-reg/mem-imm 24
                                         :include 'ext-reg/mem
                                         :default-printer
                                         '(:name :tab reg/mem ", " imm))
   (imm :type 'imm-data))
+
+(sb!disassem:define-instruction-format (x66-ext-reg/mem-imm 32
+                                        :include 'x66-ext-reg/mem
+                                        :default-printer
+                                        '(:name :tab reg/mem ", " imm))
+  (imm :type 'imm-data))
 
 ;;;; This section was added by jrd, for fp instructions.
 
@@ -555,6 +708,10 @@
                                      :include 'simple
                                      :default-printer '(:name width)))
 
+(sb!disassem:define-instruction-format (x66-string-op 16
+                                     :include 'x66-simple
+                                     :default-printer '(:name width)))
+
 (sb!disassem:define-instruction-format (short-cond-jump 16)
   (op    :field (byte 4 4))
   (cc    :field (byte 4 0) :type 'condition-code)
@@ -606,6 +763,17 @@
                                 :type 'reg/mem)
   (reg     :field (byte 3 19)   :type 'reg))
 
+(sb!disassem:define-instruction-format (x66-cond-move 32
+                                     :default-printer
+                                        '('cmov cc :tab reg ", " reg/mem))
+  (x66   :field (byte 8 0) :type 'x66 :value #x66)
+  (prefix  :field (byte 8 8)    :value #b00001111)
+  (op      :field (byte 4 20)   :value #b0100)
+  (cc      :field (byte 4 16)    :type 'condition-code)
+  (reg/mem :fields (list (byte 2 30) (byte 3 24))
+                                :type 'reg/mem)
+  (reg     :field (byte 3 27)   :type 'reg))
+
 (sb!disassem:define-instruction-format (enter-format 32
                                      :default-printer '(:name
                                                         :tab disp
@@ -632,8 +800,8 @@
 ;;; Two byte instruction with an immediate byte argument.
 ;;;
 (sb!disassem:define-instruction-format (word-imm 24
-                                                 :default-printer '(:name :tab code))
-    (op :field (byte 16 0))
+                                     :default-printer '(:name :tab code))
+  (op :field (byte 16 0))
   (code :field (byte 8 16)))
 
 
@@ -728,8 +896,8 @@
         (emit-mod-reg-r/m-byte segment #b11 reg (reg-tn-encoding thing)))
        (stack
         ;; Convert stack tns into an index off of EBP.
-        (let ((disp (- (* (1+ (tn-offset thing)) n-word-bytes))))
-          (cond ((< -128 disp 127)
+        (let ((disp (frame-byte-offset (tn-offset thing))))
+          (cond ((<= -128 disp 127)
                  (emit-mod-reg-r/m-byte segment #b01 reg #b101)
                  (emit-byte segment disp))
                 (t
@@ -761,6 +929,11 @@
             (r/m (cond (index #b100)
                        ((null base) #b101)
                        (t (reg-tn-encoding base)))))
+       (when (and (fixup-p disp)
+                  (label-p (fixup-offset disp)))
+         (aver (null base))
+         (aver (null index))
+         (return-from emit-ea (emit-ea segment disp reg allow-constants)))
        (emit-mod-reg-r/m-byte segment mod reg r/m)
        (when (= r/m #b100)
          (let ((ss (1- (integer-length scale)))
@@ -899,19 +1072,26 @@
 
 ;;;; general data transfer
 
-(define-instruction mov (segment dst src)
+(define-instruction mov (segment dst src &optional prefix)
   ;; immediate to register
   (:printer reg ((op #b1011) (imm nil :type 'imm-data))
             '(:name :tab reg ", " imm))
+  (:printer x66-reg ((op #b1011) (imm nil :type 'imm-data))
+            '(:name :tab reg ", " imm))
   ;; absolute mem to/from accumulator
   (:printer simple-dir ((op #b101000) (imm nil :type 'imm-addr))
             `(:name :tab ,(swap-if 'dir 'accum ", " '("[" imm "]"))))
+  (:printer x66-simple-dir ((op #b101000) (imm nil :type 'imm-addr))
+            `(:name :tab ,(swap-if 'dir 'accum ", " '("[" imm "]"))))
   ;; register to/from register/memory
   (:printer reg-reg/mem-dir ((op #b100010)))
+  (:printer x66-reg-reg/mem-dir ((op #b100010)))
   ;; immediate to register/memory
   (:printer reg/mem-imm ((op '(#b1100011 #b000))))
+  (:printer x66-reg/mem-imm ((op '(#b1100011 #b000))))
 
   (:emitter
+   (emit-prefix segment prefix)
    (let ((size (matching-operand-size dst src)))
      (maybe-emit-operand-size-prefix segment size)
      (cond ((register-p dst)
@@ -976,18 +1156,30 @@
           (emit-ea segment src (reg-tn-encoding dst))))))))
 
 (define-instruction movsx (segment dst src)
-  (:printer ext-reg-reg/mem ((op #b1011111) (reg nil :type 'word-reg)))
+  (:printer ext-reg-reg/mem ((op #b1011111)
+                             (reg nil :type 'word-reg)
+                             (reg/mem nil :type 'sized-reg/mem)))
+  (:printer x66-ext-reg-reg/mem ((op #b1011111)
+                                 (reg nil :type 'word-reg)
+                                 (reg/mem nil :type 'sized-reg/mem)))
   (:emitter (emit-move-with-extension segment dst src #b10111110)))
 
 (define-instruction movzx (segment dst src)
-  (:printer ext-reg-reg/mem ((op #b1011011) (reg nil :type 'word-reg)))
+  (:printer ext-reg-reg/mem ((op #b1011011)
+                             (reg nil :type 'word-reg)
+                             (reg/mem nil :type 'sized-reg/mem)))
+  (:printer x66-ext-reg-reg/mem ((op #b1011011)
+                                 (reg nil :type 'word-reg)
+                                 (reg/mem nil :type 'sized-reg/mem)))
   (:emitter (emit-move-with-extension segment dst src #b10110110)))
 
-(define-instruction push (segment src)
+(define-instruction push (segment src &optional prefix)
   ;; register
   (:printer reg-no-width ((op #b01010)))
+  (:printer x66-reg-no-width ((op #b01010)))
   ;; register/memory
   (:printer reg/mem ((op '(#b1111111 #b110)) (width 1)))
+  (:printer x66-reg/mem ((op '(#b1111111 #b110)) (width 1)))
   ;; immediate
   (:printer byte ((op #b01101010) (imm nil :type 'signed-imm-byte))
             '(:name :tab imm))
@@ -996,6 +1188,7 @@
   ;; ### segment registers?
 
   (:emitter
+   (emit-prefix segment prefix)
    (cond ((integerp src)
           (cond ((<= -128 src 127)
                  (emit-byte segment #b01101010)
@@ -1023,7 +1216,9 @@
    (emit-byte segment #b01100000)))
 
 (define-instruction pop (segment dst)
+  (:printer x66-reg-no-width ((op #b01011)))
   (:printer reg-no-width ((op #b01011)))
+  (:printer x66-reg/mem ((op '(#b1000111 #b000)) (width 1)))
   (:printer reg/mem ((op '(#b1000111 #b000)) (width 1)))
   (:emitter
    (let ((size (operand-size dst)))
@@ -1043,8 +1238,10 @@
 (define-instruction xchg (segment operand1 operand2)
   ;; Register with accumulator.
   (:printer reg-no-width ((op #b10010)) '(:name :tab accum ", " reg))
+  (:printer x66-reg-no-width ((op #b10010)) '(:name :tab accum ", " reg))
   ;; Register/Memory with Register.
   (:printer reg-reg/mem ((op #b1000011)))
+  (:printer x66-reg-reg/mem ((op #b1000011)))
   (:emitter
    (let ((size (matching-operand-size operand1 operand2)))
      (maybe-emit-operand-size-prefix segment size)
@@ -1075,22 +1272,45 @@
    (emit-byte segment #b10001101)
    (emit-ea segment src (reg-tn-encoding dst))))
 
-(define-instruction cmpxchg (segment dst src)
+(define-instruction cmpxchg (segment dst src &optional prefix)
   ;; Register/Memory with Register.
   (:printer ext-reg-reg/mem ((op #b1011000)) '(:name :tab reg/mem ", " reg))
+  (:printer x66-ext-reg-reg/mem ((op #b1011000)) '(:name :tab reg/mem ", " reg))
   (:emitter
    (aver (register-p src))
+   (emit-prefix segment prefix)
    (let ((size (matching-operand-size src dst)))
      (maybe-emit-operand-size-prefix segment size)
      (emit-byte segment #b00001111)
      (emit-byte segment (if (eq size :byte) #b10110000 #b10110001))
      (emit-ea segment dst (reg-tn-encoding src)))))
 
+(define-instruction pause (segment)
+  (:printer two-bytes ((op '(#xf3 #x90))))
+  (:emitter
+   (emit-byte segment #xf3)
+   (emit-byte segment #x90)))
 
+(defun emit-prefix (segment name)
+  (ecase name
+    ((nil))
+    (:lock
+     #!+sb-thread
+     (emit-byte segment #xf0))
+    (:fs
+     (emit-byte segment #x64))
+    (:gs
+     (emit-byte segment #x65))))
 
 (define-instruction fs-segment-prefix (segment)
+  (:printer byte ((op #b01100100)))
+  (:emitter
+   (bug "FS emitted as a separate instruction!")))
+
+(define-instruction gs-segment-prefix (segment)
+  (:printer byte ((op #b01100101)))
   (:emitter
-   (emit-byte segment #x64)))
+   (bug "GS emitted as a separate instruction!")))
 
 ;;;; flag control instructions
 
@@ -1163,7 +1383,7 @@
 ;;;; arithmetic
 
 (defun emit-random-arith-inst (name segment dst src opcode
-                                    &optional allow-constants)
+                               &optional allow-constants)
   (let ((size (matching-operand-size dst src)))
     (maybe-emit-operand-size-prefix segment size)
     (cond
@@ -1202,37 +1422,50 @@
 (eval-when (:compile-toplevel :execute)
   (defun arith-inst-printer-list (subop)
     `((accum-imm ((op ,(dpb subop (byte 3 2) #b0000010))))
+      (x66-accum-imm ((op ,(dpb subop (byte 3 2) #b0000010))))
       (reg/mem-imm ((op (#b1000000 ,subop))))
+      (x66-reg/mem-imm ((op (#b1000000 ,subop))))
       (reg/mem-imm ((op (#b1000001 ,subop))
                     (imm nil :type signed-imm-byte)))
-      (reg-reg/mem-dir ((op ,(dpb subop (byte 3 1) #b000000))))))
+      (x66-reg/mem-imm ((op (#b1000001 ,subop))
+                        (imm nil :type signed-imm-byte)))
+      (reg-reg/mem-dir ((op ,(dpb subop (byte 3 1) #b000000))))
+      (x66-reg-reg/mem-dir ((op ,(dpb subop (byte 3 1) #b000000))))))
   )
 
-(define-instruction add (segment dst src)
+(define-instruction add (segment dst src &optional prefix)
   (:printer-list (arith-inst-printer-list #b000))
-  (:emitter (emit-random-arith-inst "ADD" segment dst src #b000)))
+  (:emitter
+   (emit-prefix segment prefix)
+   (emit-random-arith-inst "ADD" segment dst src #b000)))
 
 (define-instruction adc (segment dst src)
   (:printer-list (arith-inst-printer-list #b010))
   (:emitter (emit-random-arith-inst "ADC" segment dst src #b010)))
 
-(define-instruction sub (segment dst src)
+(define-instruction sub (segment dst src &optional prefix)
   (:printer-list (arith-inst-printer-list #b101))
-  (:emitter (emit-random-arith-inst "SUB" segment dst src #b101)))
+  (:emitter
+   (emit-prefix segment prefix)
+   (emit-random-arith-inst "SUB" segment dst src #b101)))
 
 (define-instruction sbb (segment dst src)
   (:printer-list (arith-inst-printer-list #b011))
   (:emitter (emit-random-arith-inst "SBB" segment dst src #b011)))
 
-(define-instruction cmp (segment dst src)
+(define-instruction cmp (segment dst src &optional prefix)
   (:printer-list (arith-inst-printer-list #b111))
-  (:emitter (emit-random-arith-inst "CMP" segment dst src #b111 t)))
+  (:emitter
+   (emit-prefix segment prefix)
+   (emit-random-arith-inst "CMP" segment dst src #b111 t)))
 
 (define-instruction inc (segment dst)
   ;; Register.
   (:printer reg-no-width ((op #b01000)))
+  (:printer x66-reg-no-width ((op #b01000)))
   ;; Register/Memory
   (:printer reg/mem ((op '(#b1111111 #b000))))
+  (:printer x66-reg/mem ((op '(#b1111111 #b000))))
   (:emitter
    (let ((size (operand-size dst)))
      (maybe-emit-operand-size-prefix segment size)
@@ -1245,8 +1478,10 @@
 (define-instruction dec (segment dst)
   ;; Register.
   (:printer reg-no-width ((op #b01001)))
+  (:printer x66-reg-no-width ((op #b01001)))
   ;; Register/Memory
   (:printer reg/mem ((op '(#b1111111 #b001))))
+  (:printer x66-reg/mem ((op '(#b1111111 #b001))))
   (:emitter
    (let ((size (operand-size dst)))
      (maybe-emit-operand-size-prefix segment size)
@@ -1258,6 +1493,7 @@
 
 (define-instruction neg (segment dst)
   (:printer reg/mem ((op '(#b1111011 #b011))))
+  (:printer x66-reg/mem ((op '(#b1111011 #b011))))
   (:emitter
    (let ((size (operand-size dst)))
      (maybe-emit-operand-size-prefix segment size)
@@ -1286,6 +1522,7 @@
 
 (define-instruction mul (segment dst src)
   (:printer accum-reg/mem ((op '(#b1111011 #b100))))
+  (:printer x66-accum-reg/mem ((op '(#b1111011 #b100))))
   (:emitter
    (let ((size (matching-operand-size dst src)))
      (aver (accumulator-p dst))
@@ -1295,13 +1532,21 @@
 
 (define-instruction imul (segment dst &optional src1 src2)
   (:printer accum-reg/mem ((op '(#b1111011 #b101))))
+  (:printer x66-accum-reg/mem ((op '(#b1111011 #b101))))
   (:printer ext-reg-reg/mem ((op #b1010111)))
+  (:printer x66-ext-reg-reg/mem ((op #b1010111)))
   (:printer reg-reg/mem ((op #b0110100) (width 1)
                          (imm nil :type 'signed-imm-word))
             '(:name :tab reg ", " reg/mem ", " imm))
+  (:printer x66-reg-reg/mem ((op #b0110100) (width 1)
+                             (imm nil :type 'signed-imm-word))
+            '(:name :tab reg ", " reg/mem ", " imm))
   (:printer reg-reg/mem ((op #b0110101) (width 1)
                          (imm nil :type 'signed-imm-byte))
             '(:name :tab reg ", " reg/mem ", " imm))
+  (:printer x66-reg-reg/mem ((op #b0110101) (width 1)
+                             (imm nil :type 'signed-imm-byte))
+            '(:name :tab reg ", " reg/mem ", " imm))
   (:emitter
    (flet ((r/m-with-immed-to-reg (reg r/m immed)
             (let* ((size (matching-operand-size reg r/m))
@@ -1330,6 +1575,7 @@
 
 (define-instruction div (segment dst src)
   (:printer accum-reg/mem ((op '(#b1111011 #b110))))
+  (:printer x66-accum-reg/mem ((op '(#b1111011 #b110))))
   (:emitter
    (let ((size (matching-operand-size dst src)))
      (aver (accumulator-p dst))
@@ -1339,6 +1585,7 @@
 
 (define-instruction idiv (segment dst src)
   (:printer accum-reg/mem ((op '(#b1111011 #b111))))
+  (:printer x66-accum-reg/mem ((op '(#b1111011 #b111))))
   (:emitter
    (let ((size (matching-operand-size dst src)))
      (aver (accumulator-p dst))
@@ -1358,20 +1605,29 @@
    (emit-byte segment #b11010100)
    (emit-byte segment #b00001010)))
 
+(define-instruction bswap (segment dst)
+  (:printer ext-reg-no-width ((op #b11001)))
+  (:emitter
+   (emit-byte segment #x0f)
+   (emit-byte-with-reg segment #b11001 (reg-tn-encoding dst))))
+
 ;;; CBW -- Convert Byte to Word. AX <- sign_xtnd(AL)
 (define-instruction cbw (segment)
+  (:printer two-bytes ((op '(#b01100110 #b10011000))))
   (:emitter
    (maybe-emit-operand-size-prefix segment :word)
    (emit-byte segment #b10011000)))
 
 ;;; CWDE -- Convert Word To Double Word Extened. EAX <- sign_xtnd(AX)
 (define-instruction cwde (segment)
+  (:printer byte ((op #b10011000)))
   (:emitter
    (maybe-emit-operand-size-prefix segment :dword)
    (emit-byte segment #b10011000)))
 
 ;;; CWD -- Convert Word to Double Word. DX:AX <- sign_xtnd(AX)
 (define-instruction cwd (segment)
+  (:printer two-bytes ((op '(#b01100110 #b10011001))))
   (:emitter
    (maybe-emit-operand-size-prefix segment :word)
    (emit-byte segment #b10011001)))
@@ -1383,11 +1639,13 @@
    (maybe-emit-operand-size-prefix segment :dword)
    (emit-byte segment #b10011001)))
 
-(define-instruction xadd (segment dst src)
+(define-instruction xadd (segment dst src &optional prefix)
   ;; Register/Memory with Register.
   (:printer ext-reg-reg/mem ((op #b1100000)) '(:name :tab reg/mem ", " reg))
+  (:printer x66-ext-reg-reg/mem ((op #b1100000)) '(:name :tab reg/mem ", " reg))
   (:emitter
    (aver (register-p src))
+   (emit-prefix segment prefix)
    (let ((size (matching-operand-size src dst)))
      (maybe-emit-operand-size-prefix segment size)
      (emit-byte segment #b00001111)
@@ -1415,10 +1673,16 @@
   (defun shift-inst-printer-list (subop)
     `((reg/mem ((op (#b1101000 ,subop)))
                (:name :tab reg/mem ", 1"))
+      (x66-reg/mem ((op (#b1101000 ,subop)))
+                   (:name :tab reg/mem ", 1"))
       (reg/mem ((op (#b1101001 ,subop)))
                (:name :tab reg/mem ", " 'cl))
+      (x66-reg/mem ((op (#b1101001 ,subop)))
+                   (:name :tab reg/mem ", " 'cl))
       (reg/mem-imm ((op (#b1100000 ,subop))
-                    (imm nil :type signed-imm-byte))))))
+                    (imm nil :type signed-imm-byte)))
+      (x66-reg/mem-imm ((op (#b1100000 ,subop))
+                        (imm nil :type signed-imm-byte))))))
 
 (define-instruction rol (segment dst amount)
   (:printer-list
@@ -1482,6 +1746,8 @@
       (ext-reg-reg/mem-imm ((op ,(logior op #b10))
                             (imm nil :type signed-imm-byte)))
       (ext-reg-reg/mem ((op ,(logior op #b10)))
+         (:name :tab reg/mem ", " reg ", " 'cl))
+      (x66-ext-reg-reg/mem ((op ,(logior op #b10)))
          (:name :tab reg/mem ", " reg ", " 'cl)))))
 
 (define-instruction shld (segment dst src amt)
@@ -1504,8 +1770,11 @@
 
 (define-instruction test (segment this that)
   (:printer accum-imm ((op #b1010100)))
+  (:printer x66-accum-imm ((op #b1010100)))
   (:printer reg/mem-imm ((op '(#b1111011 #b000))))
+  (:printer x66-reg/mem-imm ((op '(#b1111011 #b000))))
   (:printer reg-reg/mem ((op #b1000010)))
+  (:printer x66-reg-reg/mem ((op #b1000010)))
   (:emitter
    (let ((size (matching-operand-size this that)))
      (maybe-emit-operand-size-prefix segment size)
@@ -1533,20 +1802,47 @@
              (t
               (error "bogus operands for TEST: ~S and ~S" this that)))))))
 
-(define-instruction or (segment dst src)
+;;; Emit the most compact form of the test immediate instruction,
+;;; using an 8 bit test when the immediate is only 8 bits and the
+;;; value is one of the four low registers (eax, ebx, ecx, edx) or the
+;;; control stack.
+(defun emit-optimized-test-inst (x y)
+  (typecase y
+    ((unsigned-byte 7)
+     (let ((offset (tn-offset x)))
+       (cond ((and (sc-is x any-reg descriptor-reg)
+                   (or (= offset eax-offset) (= offset ebx-offset)
+                       (= offset ecx-offset) (= offset edx-offset)))
+              (inst test (make-random-tn :kind :normal
+                                         :sc (sc-or-lose 'byte-reg)
+                                         :offset offset)
+                    y))
+             ((sc-is x control-stack)
+              (inst test (make-ea :byte :base ebp-tn
+                                  :disp (frame-byte-offset offset))
+                    y))
+             (t
+              (inst test x y)))))
+    (t
+     (inst test x y))))
+
+(define-instruction or (segment dst src &optional prefix)
   (:printer-list
    (arith-inst-printer-list #b001))
   (:emitter
+   (emit-prefix segment prefix)
    (emit-random-arith-inst "OR" segment dst src #b001)))
 
-(define-instruction xor (segment dst src)
+(define-instruction xor (segment dst src &optional prefix)
   (:printer-list
    (arith-inst-printer-list #b110))
   (:emitter
+   (emit-prefix segment prefix)
    (emit-random-arith-inst "XOR" segment dst src #b110)))
 
 (define-instruction not (segment dst)
   (:printer reg/mem ((op '(#b1111011 #b010))))
+  (:printer x66-reg/mem ((op '(#b1111011 #b010))))
   (:emitter
    (let ((size (operand-size dst)))
      (maybe-emit-operand-size-prefix segment size)
@@ -1557,12 +1853,14 @@
 
 (define-instruction cmps (segment size)
   (:printer string-op ((op #b1010011)))
+  (:printer x66-string-op ((op #b1010011)))
   (:emitter
    (maybe-emit-operand-size-prefix segment size)
    (emit-byte segment (if (eq size :byte) #b10100110 #b10100111))))
 
 (define-instruction ins (segment acc)
   (:printer string-op ((op #b0110110)))
+  (:printer x66-string-op ((op #b0110110)))
   (:emitter
    (let ((size (operand-size acc)))
      (aver (accumulator-p acc))
@@ -1571,6 +1869,7 @@
 
 (define-instruction lods (segment acc)
   (:printer string-op ((op #b1010110)))
+  (:printer x66-string-op ((op #b1010110)))
   (:emitter
    (let ((size (operand-size acc)))
      (aver (accumulator-p acc))
@@ -1579,12 +1878,14 @@
 
 (define-instruction movs (segment size)
   (:printer string-op ((op #b1010010)))
+  (:printer x66-string-op ((op #b1010010)))
   (:emitter
    (maybe-emit-operand-size-prefix segment size)
    (emit-byte segment (if (eq size :byte) #b10100100 #b10100101))))
 
 (define-instruction outs (segment acc)
   (:printer string-op ((op #b0110111)))
+  (:printer x66-string-op ((op #b0110111)))
   (:emitter
    (let ((size (operand-size acc)))
      (aver (accumulator-p acc))
@@ -1593,6 +1894,7 @@
 
 (define-instruction scas (segment acc)
   (:printer string-op ((op #b1010111)))
+  (:printer x66-string-op ((op #b1010111)))
   (:emitter
    (let ((size (operand-size acc)))
      (aver (accumulator-p acc))
@@ -1601,6 +1903,7 @@
 
 (define-instruction stos (segment acc)
   (:printer string-op ((op #b1010101)))
+  (:printer x66-string-op ((op #b1010101)))
   (:emitter
    (let ((size (operand-size acc)))
      (aver (accumulator-p acc))
@@ -1614,7 +1917,7 @@
 
 (define-instruction rep (segment)
   (:emitter
-   (emit-byte segment #b11110010)))
+   (emit-byte segment #b11110011)))
 
 (define-instruction repe (segment)
   (:printer byte ((op #b11110011)))
@@ -1631,6 +1934,7 @@
 
 (define-instruction bsf (segment dst src)
   (:printer ext-reg-reg/mem ((op #b1011110) (width 0)))
+  (:printer x66-ext-reg-reg/mem ((op #b1011110) (width 0)))
   (:emitter
    (let ((size (matching-operand-size dst src)))
      (when (eq size :byte)
@@ -1642,6 +1946,7 @@
 
 (define-instruction bsr (segment dst src)
   (:printer ext-reg-reg/mem ((op #b1011110) (width 1)))
+  (:printer x66-ext-reg-reg/mem ((op #b1011110) (width 1)))
   (:emitter
    (let ((size (matching-operand-size dst src)))
      (when (eq size :byte)
@@ -1671,9 +1976,16 @@
                         (reg/mem nil :type word-reg/mem)
                         (imm nil :type imm-data)
                         (width 0)))
+      (x66-ext-reg/mem-imm ((op (#b1011101 ,subop))
+                            (reg/mem nil :type word-reg/mem)
+                            (imm nil :type imm-data)
+                            (width 0)))
       (ext-reg-reg/mem ((op ,(dpb subop (byte 3 2) #b1000001))
                         (width 1))
-                       (:name :tab reg/mem ", " reg)))))
+                       (:name :tab reg/mem ", " reg))
+      (x66-ext-reg-reg/mem ((op ,(dpb subop (byte 3 2) #b1000001))
+                            (width 1))
+                           (:name :tab reg/mem ", " reg)))))
 
 (define-instruction bt (segment src index)
   (:printer-list (bit-test-inst-printer-list #b100))
@@ -1789,7 +2101,7 @@
   (:printer byte ((op #b11000010) (imm nil :type 'imm-word-16))
             '(:name :tab imm))
   (:emitter
-   (cond (stack-delta
+   (cond ((and stack-delta (not (zerop stack-delta)))
           (emit-byte segment #b11000010)
           (emit-word segment stack-delta))
          (t
@@ -1822,6 +2134,7 @@
 ;;;; conditional move
 (define-instruction cmov (segment cond dst src)
   (:printer cond-move ())
+  (:printer x66-cond-move ())
   (:emitter
    (aver (register-p dst))
    (let ((size (matching-operand-size dst src)))
@@ -1941,7 +2254,8 @@
     ;; Lisp (with (DESCRIBE 'BYTE-IMM-CODE)) than to definitively deduce
     ;; from first principles whether it's defined in some way that genesis
     ;; can't grok.
-    (case (byte-imm-code chunk dstate)
+    (case #!-ud2-breakpoints (byte-imm-code chunk dstate)
+          #!+ud2-breakpoints (word-imm-code chunk dstate)
       (#.error-trap
        (nt "error trap")
        (sb!disassem:handle-break-args #'snarf-error-junk stream dstate))
@@ -1959,17 +2273,17 @@
 
 (define-instruction break (segment code)
   (:declare (type (unsigned-byte 8) code))
-  #-darwin (:printer byte-imm ((op #b11001100)) '(:name :tab code)
-                     :control #'break-control)
-  #+darwin (:printer word-imm ((op #b0000101100001111)) '(:name :tab code)
-                     :control #'break-control)
+  #!-ud2-breakpoints (:printer byte-imm ((op #b11001100)) '(:name :tab code)
+                               :control #'break-control)
+  #!+ud2-breakpoints (:printer word-imm ((op #b0000101100001111)) '(:name :tab code)
+                               :control #'break-control)
   (:emitter
-   #-darwin (emit-byte segment #b11001100)
+   #!-ud2-breakpoints (emit-byte segment #b11001100)
    ;; On darwin, trap handling via SIGTRAP is unreliable, therefore we
    ;; throw a sigill with 0x0b0f instead and check for this in the
    ;; SIGILL handler and pass it on to the sigtrap handler if
    ;; appropriate
-   #+darwin (emit-word segment #b0000101100001111)
+   #!+ud2-breakpoints (emit-word segment #b0000101100001111)
    (emit-byte segment code)))
 
 (define-instruction int (segment number)
@@ -2019,10 +2333,12 @@
   (:emitter
    (emit-byte segment #b10011011)))
 
+;;; FIXME: It would be better to make the disassembler understand the prefix as part
+;;; of the instructions...
 (define-instruction lock (segment)
   (:printer byte ((op #b11110000)))
   (:emitter
-   (emit-byte segment #b11110000)))
+   (bug "LOCK prefix used as a standalone instruction")))
 
 ;;;; miscellaneous hackery
 
@@ -2344,9 +2660,8 @@
 (define-instruction fxch (segment source)
   (:printer floating-point-fp ((op '(#b001 #b001))))
   (:emitter
-    (unless (and (tn-p source)
-                 (eq (sb-name (sc-sb (tn-sc source))) 'float-registers))
-      (cl:break))
+    (aver (and (tn-p source)
+               (eq (sb-name (sc-sb (tn-sc source))) 'float-registers)))
     (emit-byte segment #b11011001)
     (emit-fp-op segment source #b001)))
 
@@ -2683,3 +2998,78 @@
   (:emitter
    (emit-byte segment #b11011001)
    (emit-byte segment #b11101101)))
+
+;;;; Miscellany
+
+(define-instruction cpuid (segment)
+  (:printer two-bytes ((op '(#b00001111 #b10100010))))
+  (:emitter
+   (emit-byte segment #b00001111)
+   (emit-byte segment #b10100010)))
+
+(define-instruction rdtsc (segment)
+  (:printer two-bytes ((op '(#b00001111 #b00110001))))
+  (:emitter
+   (emit-byte segment #b00001111)
+   (emit-byte segment #b00110001)))
+
+;;;; Late VM definitions
+(defun canonicalize-inline-constant (constant)
+  (let ((first (car constant)))
+    (typecase first
+      (single-float (setf constant (list :single-float first)))
+      (double-float (setf constant (list :double-float first)))))
+  (destructuring-bind (type value) constant
+    (ecase type
+      ((:byte :word :dword)
+         (aver (integerp value))
+         (cons type value))
+      ((:base-char)
+         (aver (base-char-p value))
+         (cons :byte (char-code value)))
+      ((:character)
+         (aver (characterp value))
+         (cons :dword (char-code value)))
+      ((:single-float)
+         (aver (typep value 'single-float))
+         (cons :dword (ldb (byte 32 0) (single-float-bits value))))
+      ((:double-float-bits)
+         (aver (integerp value))
+         (cons :double-float (ldb (byte 64 0) value)))
+      ((:double-float)
+         (aver (typep value 'double-float))
+         (cons :double-float
+               (ldb (byte 64 0) (logior (ash (double-float-high-bits value) 32)
+                                        (double-float-low-bits value))))))))
+
+(defun inline-constant-value (constant)
+  (let ((label (gen-label))
+        (size  (ecase (car constant)
+                 ((:byte :word :dword) (car constant))
+                 (:double-float :dword))))
+    (values label (make-ea size
+                           :disp (make-fixup nil :code-object label)))))
+
+(defun emit-constant-segment-header (constants optimize)
+  (declare (ignore constants))
+  (loop repeat (if optimize 64 16) do (inst byte #x90)))
+
+(defun size-nbyte (size)
+  (ecase size
+    (:byte  1)
+    (:word  2)
+    (:dword 4)
+    (:double-float 8)))
+
+(defun sort-inline-constants (constants)
+  (stable-sort constants #'> :key (lambda (constant)
+                                    (size-nbyte (caar constant)))))
+
+(defun emit-inline-constant (constant label)
+  (let ((size (size-nbyte (car constant))))
+    (emit-alignment (integer-length (1- size)))
+    (emit-label label)
+    (let ((val (cdr constant)))
+      (loop repeat size
+            do (inst byte (ldb (byte 8 0) val))
+               (setf val (ash val -8))))))