2010-12-27 Kevin Buettner <kevinb@redhat.com>

            Hui Zhu  <teawater@gmail.com>

	* mips-tedp.c (mips_register_name): Add comments.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 108907828c7c60c4e6439df81012f23bbbbbe5c0..33f2d8f17bee28361f5238737d47515fc977e010 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2010-12-27  Kevin Buettner  <kevinb@redhat.com>
+            Hui Zhu  <teawater@gmail.com>
+
+       * mips-tedp.c (mips_register_name): Add comments.
+
 2010-12-23  Yao Qi  <yao@codesourcery.com>
 
        * arm-tdep.c (thumb_analyze_prologue): Move some code ...

diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c
index 81f2d7de63cce4bda6ba399857b1f54eefe1c034..e6df5f56a6899d6ba69e5af611cf6aa588fb781d 100644 (file)
--- a/gdb/mips-tdep.c
+++ b/gdb/mips-tdep.c
@@ -454,7 +454,16 @@ mips_register_name (struct gdbarch *gdbarch, int regno)
   enum mips_abi abi = mips_abi (gdbarch);
 
   /* Map [gdbarch_num_regs .. 2*gdbarch_num_regs) onto the raw registers, 
-     but then don't make the raw register names visible.  */
+     but then don't make the raw register names visible.  This (upper)
+     range of user visible register numbers are the pseudo-registers.
+
+     This approach was adopted accommodate the following scenario:
+     It is possible to debug a 64-bit device using a 32-bit
+     programming model.  In such instances, the raw registers are
+     configured to be 64-bits wide, while the pseudo registers are
+     configured to be 32-bits wide.  The registers that the user
+     sees - the pseudo registers - match the users expectations
+     given the programming model being used.  */
   int rawnum = regno % gdbarch_num_regs (gdbarch);
   if (regno < gdbarch_num_regs (gdbarch))
     return "";