From bff256a1c266cbe1ca43637c16361cde6fc7a670 Mon Sep 17 00:00:00 2001
From: Douglas Katzman <dougk@google.com>
Date: Mon, 3 Apr 2017 11:34:19 -0400
Subject: [PATCH] Teach x86 disassembler the 0F1F nop encoding.

Clang uses the forms "nop [eax]" and "nop [eax+eax]",
so we'd lose sync when disassembling a C runtime function.
---
 src/compiler/x86/insts.lisp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/compiler/x86/insts.lisp b/src/compiler/x86/insts.lisp
index b8344a7c4..f4d170b12 100644
--- a/src/compiler/x86/insts.lisp
+++ b/src/compiler/x86/insts.lisp
@@ -1883,6 +1883,7 @@
 
 (define-instruction nop (segment)
   (:printer byte ((op #b10010000)))
+  (:printer ext-reg/mem-no-width ((op '(#x1F 0))))
   (:emitter
    (emit-byte segment #b10010000)))
 
-- 
2.11.4.GIT