* mep-tdep.c (IS_BRA, BRA_DISP): New macros.

	(mep_analyze_prologue): Add case for BRA instruction.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 75fee36..de167a6 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2007-07-12  Kevin Buettner  <kevinb@redhat.com>
+
+       * mep-tdep.c (IS_BRA, BRA_DISP): New macros.
+       (mep_analyze_prologue): Add case for BRA instruction.
+
 2007-07-12  Ulrich Weigand  <uweigand@de.ibm.com>
 
        * solib-svr4.c (LM_ADDR_CHECK): Relax prelink recognition heuristic.

diff --git a/gdb/mep-tdep.c b/gdb/mep-tdep.c
index b42b02c..5d60437 100644 (file)
--- a/gdb/mep-tdep.c
+++ b/gdb/mep-tdep.c
@@ -1578,6 +1578,10 @@ mep_get_insn (CORE_ADDR pc, long *insn)
 #define MOV_TARGET(i)        (FIELD (i, 24, 4))
 #define MOV_SOURCE(i)        (FIELD (i, 20, 4))
 
+/* BRA disp12.align2         1011_dddd_dddd_ddd0 xxxx_xxxx_xxxx_xxxx */
+#define IS_BRA(i)            (((i) & 0xf0010000) == 0xb0000000)
+#define BRA_DISP(i)           (SFIELD (i, 17, 11) << 1)
+
 
 /* This structure holds the results of a prologue analysis.  */
 struct mep_prologue
@@ -1806,6 +1810,19 @@ mep_analyze_prologue (CORE_ADDR start_pc, CORE_ADDR limit_pc,
 
           reg[rn] = pv_area_fetch (stack, addr, 4);
         }
+      else if (IS_BRA (insn) && BRA_DISP (insn) > 0)
+       {
+         /* When a loop appears as the first statement as 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.  */
+         next_pc = pc + BRA_DISP (insn);
+         after_last_frame_setup_insn = next_pc;
+         break;
+       }
       else
         /* We've hit some instruction we don't know how to simulate.
            Strictly speaking, we should set every value we're