[PATCH V7 8/8] Add MPX feature description to GDB manual.

[Walfred Tedeschi <walfred.tedeschi@intel.com>]

Describes MPX feature registers including bnd0raw ... bnd3raw, bnd0 ... bnd3
bndstatus and bndcfgu. News adds the section for Intel(R) Architecture
Instructions Extensions and mention the MPX support.

2013-08-30  Walfred Tedeschi  <walfred.tedeschi>

	* NEWS: Add section for Intel(R) Architecture Instructions
	Extesions mentioning MPX.
doc/
	* gdb.texinfo (i386 Features): Add MPX feature.

---
 gdb/NEWS            |    2 ++
 gdb/doc/gdb.texinfo |   25 +++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/gdb/NEWS b/gdb/NEWS
index 8114fb1..ef6592f 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -5522,3 +5522,5 @@ GDB now handles cross debugging.  If you are remotely debugging between
 two different machines, type ``./configure host -target=targ''.
 Host is the machine where GDB will run; targ is the machine
 where the program that you are debugging will run.
+
+ *  GDB now supports access to Intel(R) MPX registers on GNU/Linux.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index e196658..d787050 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -42740,6 +42740,31 @@ describe the upper 128 bits of @sc{ymm} registers:
 @samp{ymm0h} through @samp{ymm15h} for amd64
 @end itemize
 
+The @samp{org.gnu.gdb.i386.mpx} is an optional feature representing Intel(R)
+Memory Protection Extension (MPX).  MPX adds the bound registers @samp{BND0}
+@footnote{Capital letters were used to distinguish between architecture
+registers and pseudo registers.  A set of pseudo register for the bound
+registers were created to simplify the display.} through @samp{BND3}.  Bound
+registers store a pair of 64-bit values which are the lower bound and upper
+bound.  Bounds are effective addresses or memory locations.  The upper bounds
+are architecturally represented in 1's complement form.  A bound having lower
+bound = 0, and upper bound = 0 (1's complement of all bits set) will allow
+access to the entire address space.
+
+In order to take the upper bound complement
+of one into account the @samp{BND0} through @samp{BND3} are described in GDB
+as @samp{bnd0raw} through @samp{bnd3raw}.  Pseudo registers @samp{bnd0} through
+@samp{bnd3} display the upper bound performing the complement of one operation,
+i.e.@ when upper bound in @samp{bnd0raw} is 0 in the GDB @samp{bnd0} it will be
+@code{0xfff...}.  The feature adds the following registers:
+
+@itemize @minus
+@item
+@samp{bnd0raw} through @samp{bnd3raw} for i386, amd64 and x32.
+@item
+@samp{bndcfgu} and @samp{bndstatus} for i386, amd64 and x32.
+@end itemize
+
 The @samp{org.gnu.gdb.i386.linux} feature is optional.  It should
 describe a single register, @samp{orig_eax}.
 
-- 
1.7.10.4