diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 69c72c52b22..10840a5b173 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,33 @@
+2013-10-02  Pedro Alves  <palves@redhat.com>
+
+	* cp-valprint.c (cp_print_value_fields): Adjust calls to
+	val_print_optimized_out.
+	* jv-valprint.c (java_print_value_fields): Likewise.
+	* p-valprint.c (pascal_object_print_value_fields): Likewise.
+	* dwarf2loc.c (dwarf2_evaluate_loc_desc_full)
+	<DWARF_VALUE_REGISTER>: If the register was not saved, return a
+	new optimized out value.
+	* findvar.c (address_from_register): Likewise.
+	* frame.c (put_frame_register): Tweak error string to say the
+	register was not saved, rather than optimized out.
+	* infcmd.c (default_print_one_register_info): Adjust call to
+	val_print_optimized_out.  Use value_of_register instead of
+	get_frame_register_value.
+	* mi/mi-main.c (output_register): Use value_of_register instead of
+	get_frame_register_value.
+	* valprint.c (valprint_check_validity): Likewise.
+	(val_print_optimized_out): New value parameter.  If the value is
+	lval_register, print <not saved> instead.
+	(value_check_printable, val_print_scalar_formatted): Adjust calls
+	to val_print_optimized_out.
+	* valprint.h (val_print_optimized_out): New value parameter.
+	* value.c (struct value) <optimized_out>: Extend comment.
+	(error_value_optimized_out): New function.
+	(require_not_optimized_out): Use it.  Use a different string for
+	lval_register values.
+	* value.h (error_value_optimized_out): New declaration.
+	* NEWS: Mention <not saved>.
+
 2013-10-02  Joel Brobecker  <brobecker@adacore.com>
 
 	* symtab.c (compare_search_syms): Use FILENAME_CMP instead of
diff --git a/gdb/NEWS b/gdb/NEWS
index b44eb256bcc..5a9f8db69a6 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -15,6 +15,20 @@
 
 * The "catch syscall" command now works on arm*-linux* targets.
 
+* GDB now consistently shows "<not saved>" when printing values of
+  registers the debug info indicates have not been saved in the frame
+  and there's nowhere to retrieve them from
+  (callee-saved/call-clobbered registers):
+
+    (gdb) p $rax
+    $1 = <not saved>
+
+    (gdb) info registers rax
+    rax            <not saved>
+
+  Before, the former would print "<optimized out>", and the latter
+  "*value not available*".
+
 * Python scripting
 
   ** Frame filters and frame decorators have been added.
diff --git a/gdb/cp-valprint.c b/gdb/cp-valprint.c
index e83d9791ee2..1d7147cdd23 100644
--- a/gdb/cp-valprint.c
+++ b/gdb/cp-valprint.c
@@ -298,7 +298,7 @@ cp_print_value_fields (struct type *type, struct type *real_type,
 					  TYPE_FIELD_BITPOS (type, i),
 					  TYPE_FIELD_BITSIZE (type, i)))
 		{
-		  val_print_optimized_out (stream);
+		  val_print_optimized_out (val, stream);
 		}
 	      else
 		{
@@ -334,7 +334,7 @@ cp_print_value_fields (struct type *type, struct type *real_type,
 				      _("<error reading variable: %s>"),
 				      ex.message);
 		  else if (v == NULL)
-		    val_print_optimized_out (stream);
+		    val_print_optimized_out (NULL, stream);
 		  else
 		    cp_print_static_field (TYPE_FIELD_TYPE (type, i),
 					   v, stream, recurse + 1,
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index f5a80d3e78d..705af69599f 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,8 @@
+2013-10-02  Pedro Alves  <palves@redhat.com>
+
+	* gdb.texinfo (Registers): Expand description of saved registers
+	in frames.  Explain <not saved>.
+
 2013-09-25  Doug Evans  <dje@google.com>
 
 	* gdb.texinfo (Debugging Output): Document set/show debug symfile.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 07d5068797d..cf6f7d30a88 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -10031,10 +10031,33 @@ were exited and their saved registers restored.  In order to see the
 true contents of hardware registers, you must select the innermost
 frame (with @samp{frame 0}).
 
-However, @value{GDBN} must deduce where registers are saved, from the machine
-code generated by your compiler.  If some registers are not saved, or if
-@value{GDBN} is unable to locate the saved registers, the selected stack
-frame makes no difference.
+@cindex caller-saved registers
+@cindex call-clobbered registers
+@cindex volatile registers
+@cindex <not saved> values
+Usually ABIs reserve some registers as not needed to be saved by the
+callee (a.k.a.: ``caller-saved'', ``call-clobbered'' or ``volatile''
+registers).  It may therefore not be possible for @value{GDBN} to know
+the value a register had before the call (in other words, in the outer
+frame), if the register value has since been changed by the callee.
+@value{GDBN} tries to deduce where the inner frame saved
+(``callee-saved'') registers, from the debug info, unwind info, or the
+machine code generated by your compiler.  If some register is not
+saved, and @value{GDBN} knows the register is ``caller-saved'' (via
+its own knowledge of the ABI, or because the debug/unwind info
+explicitly says the register's value is undefined), @value{GDBN}
+displays @w{@samp{<not saved>}} as the register's value.  With targets
+that @value{GDBN} has no knowledge of the register saving convention,
+if a register was not saved by the callee, then its value and location
+in the outer frame are assumed to be the same of the inner frame.
+This is usually harmless, because if the register is call-clobbered,
+the caller either does not care what is in the register after the
+call, or has code to restore the value that it does care about.  Note,
+however, that if you change such a register in the outer frame, you
+may also be affecting the inner frame.  Also, the more ``outer'' the
+frame is you're looking at, the more likely a call-clobbered
+register's value is to be wrong, in the sense that it doesn't actually
+represent the value the register had just before the call.
 
 @node Floating Point Hardware
 @section Floating Point Hardware
diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c
index c875d3a4afa..8242dca93b8 100644
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -2290,11 +2290,21 @@ dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
 	    if (byte_offset != 0)
 	      error (_("cannot use offset on synthetic pointer to register"));
 	    do_cleanups (value_chain);
-	    if (gdb_regnum != -1)
-	      retval = value_from_register (type, gdb_regnum, frame);
-	    else
+	   if (gdb_regnum == -1)
 	      error (_("Unable to access DWARF register number %d"),
 		     dwarf_regnum);
+	   retval = value_from_register (type, gdb_regnum, frame);
+	   if (value_optimized_out (retval))
+	     {
+	       /* This means the register has undefined value / was
+		  not saved.  As we're computing the location of some
+		  variable etc. in the program, not a value for
+		  inspecting a register ($pc, $sp, etc.), return a
+		  generic optimized out value instead, so that we show
+		  <optimized out> instead of <not saved>.  */
+	       do_cleanups (value_chain);
+	       retval = allocate_optimized_out_value (type);
+	     }
 	  }
 	  break;
 
diff --git a/gdb/findvar.c b/gdb/findvar.c
index 25242bea71a..c3550b43f8f 100644
--- a/gdb/findvar.c
+++ b/gdb/findvar.c
@@ -757,6 +757,15 @@ address_from_register (struct type *type, int regnum, struct frame_info *frame)
   value = value_from_register (type, regnum, frame);
   gdb_assert (value);
 
+  if (value_optimized_out (value))
+    {
+      /* This function is used while computing a location expression.
+	 Complain about the value being optimized out, rather than
+	 letting value_as_address complain about some random register
+	 the expression depends on not being saved.  */
+      error_value_optimized_out ();
+    }
+
   result = value_as_address (value);
   release_value (value);
   value_free (value);
diff --git a/gdb/frame.c b/gdb/frame.c
index eace738903f..59e31db692c 100644
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -1143,7 +1143,7 @@ put_frame_register (struct frame_info *frame, int regnum,
   frame_register (frame, regnum, &optim, &unavail,
 		  &lval, &addr, &realnum, NULL);
   if (optim)
-    error (_("Attempt to assign to a value that was optimized out."));
+    error (_("Attempt to assign to a register that was not saved."));
   switch (lval)
     {
     case lval_memory:
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 06596052816..20f88570697 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -2035,7 +2035,7 @@ default_print_one_register_info (struct ui_file *file,
     }
   else if (value_optimized_out (val))
     {
-      val_print_optimized_out (file);
+      val_print_optimized_out (val, file);
       fprintf_filtered (file, "\n");
       return;
     }
@@ -2142,7 +2142,7 @@ default_print_registers_info (struct gdbarch *gdbarch,
 
       default_print_one_register_info (file,
 				       gdbarch_register_name (gdbarch, i),
-				       get_frame_register_value (frame, i));
+				       value_of_register (i, frame));
     }
 }
 
diff --git a/gdb/jv-valprint.c b/gdb/jv-valprint.c
index 3b90e54fec3..cb89a854008 100644
--- a/gdb/jv-valprint.c
+++ b/gdb/jv-valprint.c
@@ -395,7 +395,7 @@ java_print_value_fields (struct type *type, const gdb_byte *valaddr,
 	      else if (!value_bits_valid (val, TYPE_FIELD_BITPOS (type, i),
 					  TYPE_FIELD_BITSIZE (type, i)))
 		{
-		  val_print_optimized_out (stream);
+		  val_print_optimized_out (val, stream);
 		}
 	      else
 		{
@@ -420,7 +420,7 @@ java_print_value_fields (struct type *type, const gdb_byte *valaddr,
 		  struct value *v = value_static_field (type, i);
 
 		  if (v == NULL)
-		    val_print_optimized_out (stream);
+		    val_print_optimized_out (NULL, stream);
 		  else
 		    {
 		      struct value_print_options opts;
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index a8405799d9b..ea31367a825 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -1161,7 +1161,7 @@ output_register (struct frame_info *frame, int regnum, int format,
 {
   struct gdbarch *gdbarch = get_frame_arch (frame);
   struct ui_out *uiout = current_uiout;
-  struct value *val = get_frame_register_value (frame, regnum);
+  struct value *val = value_of_register (regnum, frame);
   struct cleanup *tuple_cleanup;
   struct value_print_options opts;
   struct ui_file *stb;
diff --git a/gdb/p-valprint.c b/gdb/p-valprint.c
index 05d4c6f821b..e6d4b91c3ad 100644
--- a/gdb/p-valprint.c
+++ b/gdb/p-valprint.c
@@ -629,7 +629,7 @@ pascal_object_print_value_fields (struct type *type, const gdb_byte *valaddr,
 	      else if (!value_bits_valid (val, TYPE_FIELD_BITPOS (type, i),
 					  TYPE_FIELD_BITSIZE (type, i)))
 		{
-		  val_print_optimized_out (stream);
+		  val_print_optimized_out (val, stream);
 		}
 	      else
 		{
@@ -657,7 +657,7 @@ pascal_object_print_value_fields (struct type *type, const gdb_byte *valaddr,
 		  v = value_field_bitfield (type, i, valaddr, offset, val);
 
 		  if (v == NULL)
-		    val_print_optimized_out (stream);
+		    val_print_optimized_out (NULL, stream);
 		  else
 		    pascal_object_print_static_field (v, stream, recurse + 1,
 						      options);
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 3acc52180cd..1eef53025e9 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2013-10-02  Pedro Alves  <palves@redhat.com>
+
+	* gdb.dwarf2/dw2-reg-undefined.exp <pattern_rax_rbx_rcx_print,
+	pattern_rax_rbx_rcx_info>: Set to "<not saved>".
+	* gdb.mi/mi-reg-undefined.exp (opt_out_pattern): Delete.
+	(not_saved_pattern): New.
+	Replace use of the former with the latter.
+
 2013-10-02  Pedro Alves  <palves@redhat.com>
 
 	* README (Board Settings): Document "exit_is_reliable".
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-reg-undefined.exp b/gdb/testsuite/gdb.dwarf2/dw2-reg-undefined.exp
index 468664827a9..44bf8e9e193 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-reg-undefined.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-reg-undefined.exp
@@ -45,8 +45,8 @@ for {set f 0} {$f < 3} {incr f} {
 	set pattern_r8_r9_print "$hex"
 	set pattern_r8_r9_info "$hex\\s+$decimal"
     } else {
-	set pattern_rax_rbx_rcx_print "<optimized out>"
-	set pattern_rax_rbx_rcx_info "<optimized out>"
+	set pattern_rax_rbx_rcx_print "<not saved>"
+	set pattern_rax_rbx_rcx_info "<not saved>"
 	set pattern_r8_r9_print "$hex"
 	set pattern_r8_r9_info "$hex\\s+$decimal"
     }
diff --git a/gdb/testsuite/gdb.mi/mi-reg-undefined.exp b/gdb/testsuite/gdb.mi/mi-reg-undefined.exp
index 8bcbb21dbf2..cb3a71615b5 100644
--- a/gdb/testsuite/gdb.mi/mi-reg-undefined.exp
+++ b/gdb/testsuite/gdb.mi/mi-reg-undefined.exp
@@ -52,13 +52,13 @@ mi_gdb_test "111-stack-list-frames" \
     "111\\^done,stack=\\\[frame=\{level=\"0\",addr=\"$hex\",func=\"stop_frame\",.*\},frame=\{level=\"1\",addr=\"$hex\",func=\"first_frame\",.*\},frame=\{level=\"2\",addr=\"$hex\",func=\"main\",.*\}\\\]" \
     "stack frame listing"
 
-set opt_out_pattern "<optimized out>"
+set not_saved_pattern "<not saved>"
 
 for {set f 0} {$f < 3} {incr f} {
     if {${f} == 0} {
 	set pattern_0_1_2 ${hex}
     } else {
-	set pattern_0_1_2 ${opt_out_pattern}
+	set pattern_0_1_2 ${not_saved_pattern}
     }
 
     mi_gdb_test "22${f}-data-list-register-values --thread 1 --frame ${f} x  0 1 2 8 9" \
diff --git a/gdb/valprint.c b/gdb/valprint.c
index 0f6d65ef362..61492ccba97 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -314,7 +314,7 @@ valprint_check_validity (struct ui_file *stream,
       if (!value_bits_valid (val, TARGET_CHAR_BIT * embedded_offset,
 			     TARGET_CHAR_BIT * TYPE_LENGTH (type)))
 	{
-	  val_print_optimized_out (stream);
+	  val_print_optimized_out (val, stream);
 	  return 0;
 	}
 
@@ -336,9 +336,12 @@ valprint_check_validity (struct ui_file *stream,
 }
 
 void
-val_print_optimized_out (struct ui_file *stream)
+val_print_optimized_out (const struct value *val, struct ui_file *stream)
 {
-  fprintf_filtered (stream, _("<optimized out>"));
+  if (val != NULL && value_lval_const (val) == lval_register)
+    fprintf_filtered (stream, _("<not saved>"));
+  else
+    fprintf_filtered (stream, _("<optimized out>"));
 }
 
 void
@@ -805,7 +808,7 @@ value_check_printable (struct value *val, struct ui_file *stream,
       if (options->summary && !val_print_scalar_type_p (value_type (val)))
 	fprintf_filtered (stream, "...");
       else
-	val_print_optimized_out (stream);
+	val_print_optimized_out (val, stream);
       return 0;
     }
 
@@ -966,7 +969,7 @@ val_print_scalar_formatted (struct type *type,
      printed, because all bits contribute to its representation.  */
   if (!value_bits_valid (val, TARGET_CHAR_BIT * embedded_offset,
 			      TARGET_CHAR_BIT * TYPE_LENGTH (type)))
-    val_print_optimized_out (stream);
+    val_print_optimized_out (val, stream);
   else if (!value_bytes_available (val, embedded_offset, TYPE_LENGTH (type)))
     val_print_unavailable (stream);
   else
diff --git a/gdb/valprint.h b/gdb/valprint.h
index e7073b6dfb4..1d86ed73da8 100644
--- a/gdb/valprint.h
+++ b/gdb/valprint.h
@@ -160,7 +160,8 @@ extern int read_string (CORE_ADDR addr, int len, int width,
 			enum bfd_endian byte_order, gdb_byte **buffer,
 			int *bytes_read);
 
-extern void val_print_optimized_out (struct ui_file *stream);
+extern void val_print_optimized_out (const struct value *val,
+				     struct ui_file *stream);
 
 extern void val_print_unavailable (struct ui_file *stream);
 
diff --git a/gdb/value.c b/gdb/value.c
index bc1239d05aa..d96d285cbdd 100644
--- a/gdb/value.c
+++ b/gdb/value.c
@@ -197,8 +197,13 @@ struct value
      reset, be sure to consider this use as well!  */
   unsigned int lazy : 1;
 
-  /* If nonzero, this is the value of a variable which does not
-     actually exist in the program.  */
+  /* If nonzero, this is the value of a variable that does not
+     actually exist in the program.  If nonzero, and LVAL is
+     lval_register, this is a register ($pc, $sp, etc., never a
+     program variable) that has not been saved in the frame.  All
+     optimized-out values are treated pretty much the same, except
+     registers have a different string representation and related
+     error strings.  */
   unsigned int optimized_out : 1;
 
   /* If value is a variable, is it initialized or not.  */
@@ -902,11 +907,22 @@ value_actual_type (struct value *value, int resolve_simple_types,
   return result;
 }
 
+void
+error_value_optimized_out (void)
+{
+  error (_("value has been optimized out"));
+}
+
 static void
 require_not_optimized_out (const struct value *value)
 {
   if (value->optimized_out)
-    error (_("value has been optimized out"));
+    {
+      if (value->lval == lval_register)
+	error (_("register has not been saved in frame"));
+      else
+	error_value_optimized_out ();
+    }
 }
 
 static void
diff --git a/gdb/value.h b/gdb/value.h
index 98dbadf3681..db964e36e83 100644
--- a/gdb/value.h
+++ b/gdb/value.h
@@ -273,6 +273,11 @@ extern void set_value_lazy (struct value *value, int val);
 extern int value_stack (struct value *);
 extern void set_value_stack (struct value *value, int val);
 
+/* Throw an error complaining that the value has been optimized
+   out.  */
+
+extern void error_value_optimized_out (void);
+
 /* value_contents() and value_contents_raw() both return the address
    of the gdb buffer used to hold a copy of the contents of the lval.
    value_contents() is used when the contents of the buffer are needed