From 24c6fbe30c4524a0fc92a1f6810971c502ca277b Mon Sep 17 00:00:00 2001
From: drow <drow>
Date: Sun, 7 Mar 2004 20:03:11 +0000
Subject: [PATCH] 	* arm-tdep.c (thumb_get_next_pc): Handle BX. 
 (arm_get_next_pc): Handle BX and BLX.

---
 gdb/ChangeLog  |  5 +++++
 gdb/arm-tdep.c | 29 +++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ded5f74f55..a6a71604b5 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2004-03-07  Daniel Jacobowitz  <drow@mvista.com>
+
+	* arm-tdep.c (thumb_get_next_pc): Handle BX.
+	(arm_get_next_pc): Handle BX and BLX.
+
 2004-03-07  Andrew Cagney  <cagney@redhat.com>
 
 	* hppa-tdep.c: Replace DEPRECATED_FP_REGNUM with HPPA_FP_REGNUM,
diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index 9d53facf12..06bfcb612e 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -1657,6 +1657,17 @@ thumb_get_next_pc (CORE_ADDR pc)
       offset = (sbits (inst1, 0, 10) << 12) + (bits (inst2, 0, 10) << 1);
       nextpc = pc_val + offset;
     }
+  else if ((inst1 & 0xff80) == 0x4700)	/* branch and exchange (bx) */
+    {
+      if (bits (inst1, 3, 6) == 0x0f)
+	nextpc = pc_val;
+      else
+	nextpc = read_register (bits (inst1, 3, 6));
+
+      nextpc = ADDR_BITS_REMOVE (nextpc);
+      if (nextpc == pc)
+	error ("Infinite loop detected");
+    }
 
   return nextpc;
 }
@@ -1697,6 +1708,20 @@ arm_get_next_pc (CORE_ADDR pc)
 		&& bits (this_instr, 4, 7) == 9)	/* multiply */
 	      error ("Illegal update to pc in instruction");
 
+	    /* BX <reg>, BLX <reg> */
+	    if (bits (this_instr, 4, 28) == 0x12fff1
+		|| bits (this_instr, 4, 28) == 0x12fff3)
+	      {
+		rn = bits (this_instr, 0, 3);
+		result = (rn == 15) ? pc_val + 8 : read_register (rn);
+		nextpc = (CORE_ADDR) ADDR_BITS_REMOVE (result);
+
+		if (nextpc == pc)
+		  error ("Infinite loop detected");
+
+		return nextpc;
+	      }
+
 	    /* Multiply into PC */
 	    c = (status & FLAG_C) ? 1 : 0;
 	    rn = bits (this_instr, 16, 19);
@@ -1862,6 +1887,10 @@ arm_get_next_pc (CORE_ADDR pc)
 	  {
 	    nextpc = BranchDest (pc, this_instr);
 
+	    /* BLX */
+	    if (bits (this_instr, 28, 31) == INST_NV)
+	      nextpc |= bit (this_instr, 24) << 1;
+
 	    nextpc = ADDR_BITS_REMOVE (nextpc);
 	    if (nextpc == pc)
 	      error ("Infinite loop detected");
-- 
2.11.0