1.0.15.36: fix bug 423

[sbcl.git] / src / compiler / x86 / insts.lisp

diff --git a/src/compiler/x86/insts.lisp b/src/compiler/x86/insts.lisp
index 132224e..c51745c 100644 (file)
--- a/src/compiler/x86/insts.lisp
+++ b/src/compiler/x86/insts.lisp
@@ -378,6 +378,10 @@
   (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))
@@ -896,6 +900,23 @@
      (emit-word segment value))
     (:dword
      (emit-dword segment value))))
+
+(defun toggle-word-width (chunk inst stream dstate)
+  (declare (ignore chunk inst stream))
+  (let ((word-width (or (sb!disassem:dstate-get-prop dstate 'word-width)
+                        +default-operand-size+)))
+    (setf (sb!disassem:dstate-get-prop dstate 'word-width)
+          (ecase word-width
+            (:word :dword)
+            (:dword :word)))))
+
+;;; This is a "prefix" instruction, which means that it modifies the
+;;; following instruction in some way without having an actual
+;;; mnemonic of its own.
+(define-instruction operand-size-prefix (segment)
+  (:printer byte ((op +operand-size-prefix-byte+))
+            nil                         ; don't actually print it
+            :control #'toggle-word-width))
 \f
 ;;;; general data transfer
 
@@ -2714,3 +2735,17 @@
   (: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)))