[Boost-commit] svn:boost r43597 - sandbox/SOC/2006/coroutine/trunk/libs/coroutine/src

From: gpderetta_at_[hidden]
Date: 2008-03-13 18:44:58

Author: giovanni.deretta
Date: 2008-03-13 18:44:57 EDT (Thu, 13 Mar 2008)
New Revision: 43597
URL: http://svn.boost.org/trac/boost/changeset/43597

Log:
updated comment, also cheching if credentials still work
Text files modified: 
   sandbox/SOC/2006/coroutine/trunk/libs/coroutine/src/swapcontext32.cpp |     4 ++++                                    
   1 files changed, 4 insertions(+), 0 deletions(-)

Modified: sandbox/SOC/2006/coroutine/trunk/libs/coroutine/src/swapcontext32.cpp
==============================================================================
--- sandbox/SOC/2006/coroutine/trunk/libs/coroutine/src/swapcontext32.cpp	(original)
+++ sandbox/SOC/2006/coroutine/trunk/libs/coroutine/src/swapcontext32.cpp	2008-03-13 18:44:57 EDT (Thu, 13 Mar 2008)
@@ -62,8 +62,12 @@
    'add $4, %esp'
    'jmp *%ecx'
    really kills performance.
+
    NOTE: popl is slightly better than mov+add to pop registers
    so is pushl rather than mov+sub.
+
+   According to Agner Fog, an always taken indirect branch should preferably
+   be followed by an undefined opcode instruction (the ud2).
    */
 #define BOOST_COROUTINE_swapcontext(name) \
 asm volatile (                            \