2011-09-14 Pedro Alves <pedro@codesourcery.com>

	* infrun.c (prepare_for_detach, wait_for_inferior)
	(fetch_inferior_event): Don't flush the register cache.
	* remote.c (struct stop_reply) <regcache>: Add comment.

3 files changed, 10 insertions, 33 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 34e8eb0..00188e6 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2011-09-14  Pedro Alves  <pedro@codesourcery.com>
+
+	* infrun.c (prepare_for_detach, wait_for_inferior)
+	(fetch_inferior_event): Don't flush the register cache.
+	* remote.c (struct stop_reply) <regcache>: Add comment.
+
 2011-09-13  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
 	Remove excessive DWARF expressions memory duplication.
diff --git a/gdb/infrun.c b/gdb/infrun.c
index 2b4f6db..c72b05d 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -2580,14 +2580,6 @@ prepare_for_detach (void)
 
       overlay_cache_invalid = 1;
 
-      /* We have to invalidate the registers BEFORE calling
-	 target_wait because they can be loaded from the target while
-	 in target_wait.  This makes remote debugging a bit more
-	 efficient for those targets that provide critical registers
-	 as part of their normal status mechanism.  */
-
-      registers_changed ();
-
       if (deprecated_target_wait_hook)
 	ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
       else
@@ -2657,14 +2649,7 @@ wait_for_inferior (void)
     {
       struct cleanup *old_chain;
 
-      /* We have to invalidate the registers BEFORE calling target_wait
-	 because they can be loaded from the target while in target_wait.
-	 This makes remote debugging a bit more efficient for those
-	 targets that provide critical registers as part of their normal
-	 status mechanism.  */
-
       overlay_cache_invalid = 1;
-      registers_changed ();
 
       if (deprecated_target_wait_hook)
 	ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
@@ -2734,26 +2719,8 @@ fetch_inferior_event (void *client_data)
        running any breakpoint commands.  */
     make_cleanup_restore_current_thread ();
 
-  /* We have to invalidate the registers BEFORE calling target_wait
-     because they can be loaded from the target while in target_wait.
-     This makes remote debugging a bit more efficient for those
-     targets that provide critical registers as part of their normal
-     status mechanism.  */
-
   overlay_cache_invalid = 1;
 
-  /* But don't do it if the current thread is already stopped (hence
-     this is either a delayed event that will result in
-     TARGET_WAITKIND_IGNORE, or it's an event for another thread (and
-     we always clear the register and frame caches when the user
-     switches threads anyway).  If we didn't do this, a spurious
-     delayed event in all-stop mode would make the user lose the
-     selected frame.  */
-  if (non_stop
-      || (!ptid_equal (inferior_ptid, null_ptid)
-	  && is_executing (inferior_ptid)))
-    registers_changed ();
-
   make_cleanup_restore_integer (&execution_direction);
   execution_direction = target_execution_direction ();
 
diff --git a/gdb/remote.c b/gdb/remote.c
index 1535fb6..1c9e965 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -4898,6 +4898,10 @@ struct stop_reply
 
   struct target_waitstatus ws;
 
+  /* Expedited registers.  This makes remote debugging a bit more
+     efficient for those targets that provide critical registers as
+     part of their normal status mechanism (as another roundtrip to
+     fetch them is avoided).  */
   VEC(cached_reg_t) *regcache;
 
   int stopped_by_watchpoint_p;