Re: [commit] mep-tdep.c: prologue analyzer update

[Kevin Buettner <kevinb@redhat.com>]

> The comment might want to mention why we should only do this for
> forward branches.  :)

Thanks for the feedback!  I've updated the comment as follows...

	* mep-tdep.c (mep_analyze_prologue): Update comment for BRA
	instruction case.

Index: mep-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/mep-tdep.c,v
retrieving revision 1.6
diff -u -p -r1.6 mep-tdep.c
--- mep-tdep.c	13 Jul 2007 00:00:15 -0000	1.6
+++ mep-tdep.c	14 Jul 2007 00:14:16 -0000
@@ -1812,13 +1812,24 @@ mep_analyze_prologue (CORE_ADDR start_pc
         }
       else if (IS_BRA (insn) && BRA_DISP (insn) > 0)
 	{
-	  /* When a loop appears as the first statement as a function
+	  /* When a loop appears as the first statement of a function
 	     body, gcc 4.x will use a BRA instruction to branch to the
 	     loop condition checking code.  This BRA instruction is
 	     marked as part of the prologue.  We therefore set next_pc
 	     to this branch target and also stop the prologue scan. 
 	     The instructions at and beyond the branch target should
-	     no longer be associated with the prologue.  */
+	     no longer be associated with the prologue.
+	     
+	     Note that we only consider forward branches here.  We
+	     presume that a forward branch is being used to skip over
+	     a loop body.
+	     
+	     A backwards branch is covered by the default case below.
+	     If we were to encounter a backwards branch, that would
+	     most likely mean that we've scanned through a loop body.
+	     We definitely want to stop the prologue scan when this
+	     happens and that is precisely what is done by the default
+	     case below.  */
 	  next_pc = pc + BRA_DISP (insn);
 	  after_last_frame_setup_insn = next_pc;
 	  break;