diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c
index 5e63b5e..305c75b 100644
--- a/gdb/amd64-tdep.c
+++ b/gdb/amd64-tdep.c
@@ -252,9 +252,7 @@ amd64_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int  
reg)
    if (reg >= 0 && reg < amd64_dwarf_regmap_len)
      regnum = amd64_dwarf_regmap[reg];

-  if (regnum == -1)
-    warning (_("Unmapped DWARF Register #%d encountered."), reg);
-  else if (ymm0_regnum >= 0
+  if (ymm0_regnum >= 0
  	   && i386_xmm_regnum_p (gdbarch, regnum))
      regnum += ymm0_regnum - I387_XMM0_REGNUM (tdep);

diff --git a/gdb/avr-tdep.c b/gdb/avr-tdep.c
index dff0be9..44081fa 100644
--- a/gdb/avr-tdep.c
+++ b/gdb/avr-tdep.c
@@ -1364,9 +1364,6 @@ avr_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int  
reg)
      return reg;
    if (reg == 32)
      return AVR_SP_REGNUM;
-
-  warning (_("Unmapped DWARF Register #%d encountered."), reg);
-
    return -1;
  }

diff --git a/gdb/bfin-tdep.c b/gdb/bfin-tdep.c
index 4532e1b..0f34e64 100644
--- a/gdb/bfin-tdep.c
+++ b/gdb/bfin-tdep.c
@@ -566,8 +566,8 @@ bfin_push_dummy_call (struct gdbarch *gdbarch,
  static int
  bfin_reg_to_regnum (struct gdbarch *gdbarch, int reg)
  {
-  if (reg > ARRAY_SIZE (map_gcc_gdb))
-    return 0;
+  if (reg < 0 || reg >= ARRAY_SIZE (map_gcc_gdb))
+    return -1;

    return map_gcc_gdb[reg];
  }
diff --git a/gdb/compile/compile-loc2c.c b/gdb/compile/compile-loc2c.c
index b201d13..3b4df9b 100644
--- a/gdb/compile/compile-loc2c.c
+++ b/gdb/compile/compile-loc2c.c
@@ -817,15 +817,15 @@ do_compile_dwarf_expr_to_c (int indent, struct  
ui_file *stream,
  	case DW_OP_reg31:
  	  dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
  	  pushf_register_address (indent, stream, registers_used, arch,
-				  dwarf2_reg_to_regnum_or_error (arch,
-							      op - DW_OP_reg0));
+				  dwarf_reg_to_regnum_or_error
+				    (arch, op - DW_OP_reg0));
  	  break;

  	case DW_OP_regx:
  	  op_ptr = safe_read_uleb128 (op_ptr, op_end, &reg);
  	  dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
  	  pushf_register_address (indent, stream, registers_used, arch,
-				  dwarf2_reg_to_regnum_or_error (arch, reg));
+				  dwarf_reg_to_regnum_or_error (arch, reg));
  	  break;

  	case DW_OP_breg0:
@@ -862,8 +862,8 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file  
*stream,
  	case DW_OP_breg31:
  	  op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
  	  pushf_register (indent, stream, registers_used, arch,
-			  dwarf2_reg_to_regnum_or_error (arch,
-							 op - DW_OP_breg0),
+			  dwarf_reg_to_regnum_or_error (arch,
+							op - DW_OP_breg0),
  			  offset);
  	  break;
  	case DW_OP_bregx:
@@ -871,7 +871,7 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file  
*stream,
  	    op_ptr = safe_read_uleb128 (op_ptr, op_end, &reg);
  	    op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
  	    pushf_register (indent, stream, registers_used, arch,
-			    dwarf2_reg_to_regnum_or_error (arch, reg), offset);
+			    dwarf_reg_to_regnum_or_error (arch, reg), offset);
  	  }
  	  break;
  	case DW_OP_fbreg:
diff --git a/gdb/cris-tdep.c b/gdb/cris-tdep.c
index 2273887..232f75c 100644
--- a/gdb/cris-tdep.c
+++ b/gdb/cris-tdep.c
@@ -1791,9 +1791,6 @@ cris_dwarf2_reg_to_regnum (struct gdbarch *gdbarch,  
int reg)
    if (reg >= 0 && reg < ARRAY_SIZE (cris_dwarf_regmap))
      regnum = cris_dwarf_regmap[reg];

-  if (regnum == -1)
-    warning (_("Unmapped DWARF Register #%d encountered."), reg);
-
    return regnum;
  }

diff --git a/gdb/dwarf2-frame.c b/gdb/dwarf2-frame.c
index 8fb2ac7..b42fc8a 100644
--- a/gdb/dwarf2-frame.c
+++ b/gdb/dwarf2-frame.c
@@ -292,7 +292,7 @@ read_addr_from_reg (void *baton, int reg)
  {
    struct frame_info *this_frame = (struct frame_info *) baton;
    struct gdbarch *gdbarch = get_frame_arch (this_frame);
-  int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
+  int regnum = dwarf_reg_to_regnum_or_error (gdbarch, reg);

    return address_from_register (regnum, this_frame);
  }
@@ -304,7 +304,7 @@ get_reg_value (void *baton, struct type *type, int reg)
  {
    struct frame_info *this_frame = (struct frame_info *) baton;
    struct gdbarch *gdbarch = get_frame_arch (this_frame);
-  int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
+  int regnum = dwarf_reg_to_regnum_or_error (gdbarch, reg);

    return value_from_register (type, regnum, this_frame);
  }
@@ -336,13 +336,15 @@ dwarf2_restore_rule (struct gdbarch *gdbarch,  
ULONGEST reg_num,
      fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNSPECIFIED;

    if (fs->regs.reg[reg].how == DWARF2_FRAME_REG_UNSPECIFIED)
-    complaint (&symfile_complaints, _("\
+    {
+      int regnum = dwarf_reg_to_regnum (gdbarch, reg);
+
+      complaint (&symfile_complaints, _("\
  incomplete CFI data; DW_CFA_restore unspecified\n\
  register %s (#%d) at %s"),
-		       gdbarch_register_name
-		       (gdbarch, gdbarch_dwarf2_reg_to_regnum (gdbarch, reg)),
-		       gdbarch_dwarf2_reg_to_regnum (gdbarch, reg),
-		       paddress (gdbarch, fs->pc));
+		 gdbarch_register_name (gdbarch, regnum), regnum,
+		 paddress (gdbarch, fs->pc));
+    }
  }

  /* Virtual method table for execute_stack_op below.  */
@@ -936,11 +938,7 @@ dwarf2_fetch_cfa_info (struct gdbarch *gdbarch,  
CORE_ADDR pc,
      {
      case CFA_REG_OFFSET:
        {
-	int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, fs.regs.cfa_reg);
-
-	if (regnum == -1)
-	  error (_("Unable to access DWARF register number %d"),
-		 (int) fs.regs.cfa_reg); /* FIXME */
+	int regnum = dwarf_reg_to_regnum_or_error (gdbarch, fs.regs.cfa_reg);

  	*regnum_out = regnum;
  	if (fs.armcc_cfa_offsets_reversed)
@@ -1087,7 +1085,7 @@ dwarf2_frame_cache (struct frame_info *this_frame,  
void **this_cache)
  				   entry_pc, fs);

        if (fs->regs.cfa_how == CFA_REG_OFFSET
-	  && (gdbarch_dwarf2_reg_to_regnum (gdbarch, fs->regs.cfa_reg)
+	  && (dwarf_reg_to_regnum (gdbarch, fs->regs.cfa_reg)
  	      == gdbarch_sp_regnum (gdbarch)))
  	{
  	  cache->entry_cfa_sp_offset = fs->regs.cfa_offset;
@@ -1150,19 +1148,18 @@ dwarf2_frame_cache (struct frame_info *this_frame,  
void **this_cache)
    /* Go through the DWARF2 CFI generated table and save its register
       location information in the cache.  Note that we don't skip the
       return address column; it's perfectly all right for it to
-     correspond to a real register.  If it doesn't correspond to a
-     real register, or if we shouldn't treat it as such,
-     gdbarch_dwarf2_reg_to_regnum should be defined to return a number  
outside
-     the range [0, gdbarch_num_regs).  */
+     correspond to a real register.  */
    {
      int column;		/* CFI speak for "register number".  */

      for (column = 0; column < fs->regs.num_regs; column++)
        {
  	/* Use the GDB register number as the destination index.  */
-	int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, column);
+	int regnum = dwarf_reg_to_regnum (gdbarch, column);

-	/* If there's no corresponding GDB register, ignore it.  */
+	/* If there's no corresponding GDB register, ignore it.
+	   Some targets return num_regs (+ num_pseudo_regs) for bad registers.
+	   Handle them until they are fixed.  */
  	if (regnum < 0 || regnum >= num_regs)
  	  continue;

@@ -1324,8 +1321,8 @@ dwarf2_frame_prev_register (struct frame_info  
*this_frame, void **this_cache,
        return frame_unwind_got_memory (this_frame, regnum, addr);

      case DWARF2_FRAME_REG_SAVED_REG:
-      realnum
-	= gdbarch_dwarf2_reg_to_regnum (gdbarch, cache->reg[regnum].loc.reg);
+      realnum = dwarf_reg_to_regnum_or_error
+	(gdbarch, cache->reg[regnum].loc.reg);
        return frame_unwind_got_register (this_frame, regnum, realnum);

      case DWARF2_FRAME_REG_SAVED_EXP:
@@ -1368,7 +1365,7 @@ dwarf2_frame_prev_register (struct frame_info  
*this_frame, void **this_cache,

      case DWARF2_FRAME_REG_RA_OFFSET:
        addr = cache->reg[regnum].loc.offset;
-      regnum = gdbarch_dwarf2_reg_to_regnum
+      regnum = dwarf_reg_to_regnum_or_error
  	(gdbarch, cache->retaddr_reg.loc.reg);
        addr += get_frame_register_unsigned (this_frame, regnum);
        return frame_unwind_got_address (this_frame, regnum, addr);
diff --git a/gdb/dwarf2expr.c b/gdb/dwarf2expr.c
index 862a753..1b9cbd6 100644
--- a/gdb/dwarf2expr.c
+++ b/gdb/dwarf2expr.c
@@ -26,6 +26,7 @@
  #include "gdbcore.h"
  #include "dwarf2.h"
  #include "dwarf2expr.h"
+#include "dwarf2loc.h"

  /* Local prototypes.  */

@@ -613,7 +614,7 @@ dwarf_block_to_sp_offset (struct gdbarch *gdbarch,  
const gdb_byte *buf,
  	return 0;
      }

-  if (gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_reg)
+  if (dwarf_reg_to_regnum (gdbarch, dwarf_reg)
        != gdbarch_sp_regnum (gdbarch))
      return 0;

diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c
index d8e432e..8c514bf 100644
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -32,7 +32,7 @@
  #include "objfiles.h"
  #include "block.h"
  #include "gdbcmd.h"
-
+#include "complaints.h"
  #include "dwarf2.h"
  #include "dwarf2expr.h"
  #include "dwarf2loc.h"
@@ -312,7 +312,7 @@ dwarf_expr_read_addr_from_reg (void *baton, int  
dwarf_regnum)
  {
    struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
    struct gdbarch *gdbarch = get_frame_arch (debaton->frame);
-  int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum);
+  int regnum = dwarf_reg_to_regnum_or_error (gdbarch, dwarf_regnum);

    return address_from_register (regnum, debaton->frame);
  }
@@ -324,7 +324,7 @@ dwarf_expr_get_reg_value (void *baton, struct type  
*type, int dwarf_regnum)
  {
    struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
    struct gdbarch *gdbarch = get_frame_arch (debaton->frame);
-  int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum);
+  int regnum = dwarf_reg_to_regnum_or_error (gdbarch, dwarf_regnum);

    return value_from_register (type, regnum, debaton->frame);
  }
@@ -1682,40 +1682,31 @@ read_pieced_value (struct value *v)
  	case DWARF_VALUE_REGISTER:
  	  {
  	    struct gdbarch *arch = get_frame_arch (frame);
-	    int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.regno);
+	    int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, p->v.regno);
+	    int optim, unavail;
+	    int reg_offset = source_offset;

-	    if (gdb_regnum != -1)
+	    if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
+		&& this_size < register_size (arch, gdb_regnum))
  	      {
-		int optim, unavail;
-		int reg_offset = source_offset;
-
-		if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
-		    && this_size < register_size (arch, gdb_regnum))
-		  {
-		    /* Big-endian, and we want less than full size.  */
-		    reg_offset = register_size (arch, gdb_regnum) - this_size;
-		    /* We want the lower-order THIS_SIZE_BITS of the bytes
-		       we extract from the register.  */
-		    source_offset_bits += 8 * this_size - this_size_bits;
-		 }
-
-		if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset,
-					       this_size, buffer,
-					       &optim, &unavail))
-		  {
-		    /* Just so garbage doesn't ever shine through.  */
-		    memset (buffer, 0, this_size);
-
-		    if (optim)
-		      mark_value_bits_optimized_out (v, offset, this_size_bits);
-		    if (unavail)
-		      mark_value_bits_unavailable (v, offset, this_size_bits);
-		  }
+		/* Big-endian, and we want less than full size.  */
+		reg_offset = register_size (arch, gdb_regnum) - this_size;
+		/* We want the lower-order THIS_SIZE_BITS of the bytes
+		   we extract from the register.  */
+		source_offset_bits += 8 * this_size - this_size_bits;
  	      }
-	    else
+
+	    if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset,
+					   this_size, buffer,
+					   &optim, &unavail))
  	      {
-		error (_("Unable to access DWARF register number %s"),
-		       paddress (arch, p->v.regno));
+		/* Just so garbage doesn't ever shine through.  */
+		memset (buffer, 0, this_size);
+
+		if (optim)
+		  mark_value_bits_optimized_out (v, offset, this_size_bits);
+		if (unavail)
+		  mark_value_bits_unavailable (v, offset, this_size_bits);
  	      }
  	  }
  	  break;
@@ -1874,52 +1865,43 @@ write_pieced_value (struct value *to, struct value  
*from)
  	case DWARF_VALUE_REGISTER:
  	  {
  	    struct gdbarch *arch = get_frame_arch (frame);
-	    int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.regno);
+	    int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, p->v.regno);
+	    int reg_offset = dest_offset;

-	    if (gdb_regnum != -1)
+	    if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
+		&& this_size <= register_size (arch, gdb_regnum))
  	      {
-		int reg_offset = dest_offset;
+		/* Big-endian, and we want less than full size.  */
+		reg_offset = register_size (arch, gdb_regnum) - this_size;
+	      }

-		if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
-		    && this_size <= register_size (arch, gdb_regnum))
-		  {
-		    /* Big-endian, and we want less than full size.  */
-		    reg_offset = register_size (arch, gdb_regnum) - this_size;
-		  }
+	    if (need_bitwise)
+	      {
+		int optim, unavail;

-		if (need_bitwise)
+		if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset,
+					       this_size, buffer,
+					       &optim, &unavail))
  		  {
-		    int optim, unavail;
-
-		    if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset,
-						   this_size, buffer,
-						   &optim, &unavail))
-		      {
-			if (optim)
-			  throw_error (OPTIMIZED_OUT_ERROR,
-				       _("Can't do read-modify-write to "
-					 "update bitfield; containing word "
-					 "has been optimized out"));
-			if (unavail)
-			  throw_error (NOT_AVAILABLE_ERROR,
-				       _("Can't do read-modify-write to update "
-					 "bitfield; containing word "
-					 "is unavailable"));
-		      }
-		    copy_bitwise (buffer, dest_offset_bits,
-				  contents, source_offset_bits,
-				  this_size_bits,
-				  bits_big_endian);
+		    if (optim)
+		      throw_error (OPTIMIZED_OUT_ERROR,
+				   _("Can't do read-modify-write to "
+				     "update bitfield; containing word "
+				     "has been optimized out"));
+		    if (unavail)
+		      throw_error (NOT_AVAILABLE_ERROR,
+				   _("Can't do read-modify-write to update "
+				     "bitfield; containing word "
+				     "is unavailable"));
  		  }
-
-		put_frame_register_bytes (frame, gdb_regnum, reg_offset,
-					  this_size, source_buffer);
-	      }
-	    else
-	      {
-		error (_("Unable to write to DWARF register number %s"),
-		       paddress (arch, p->v.regno));
+		copy_bitwise (buffer, dest_offset_bits,
+			      contents, source_offset_bits,
+			      this_size_bits,
+			      bits_big_endian);
  	      }
+
+	    put_frame_register_bytes (frame, gdb_regnum, reg_offset,
+				      this_size, source_buffer);
  	  }
  	  break;
  	case DWARF_VALUE_MEMORY:
@@ -2260,30 +2242,27 @@ dwarf2_evaluate_loc_desc_full (struct type *type,  
struct frame_info *frame,
  	    struct gdbarch *arch = get_frame_arch (frame);
  	    int dwarf_regnum
  	      = longest_to_int (value_as_long (dwarf_expr_fetch (ctx, 0)));
-	    int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_regnum);
+	    int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, dwarf_regnum);

  	    if (byte_offset != 0)
  	      error (_("cannot use offset on synthetic pointer to register"));
  	    do_cleanups (value_chain);
-	   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))
-	     {
-	       struct value *tmp;
-
-	       /* 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, $sp, etc.), return a
-		  generic optimized out value instead, so that we show
-		  <optimized out> instead of <not saved>.  */
-	       do_cleanups (value_chain);
-	       tmp = allocate_value (type);
-	       value_contents_copy (tmp, 0, retval, 0, TYPE_LENGTH (type));
-	       retval = tmp;
-	     }
+	    retval = value_from_register (type, gdb_regnum, frame);
+	    if (value_optimized_out (retval))
+	      {
+		struct value *tmp;
+
+		/* This means the register has undefined value / was
+		   not saved.  As we're computing the location of some
+		   variable etc. in the program, not a value for
+		   inspecting a register ($pc, $sp, etc.), return a
+		   generic optimized out value instead, so that we show
+		   <optimized out> instead of <not saved>.  */
+		do_cleanups (value_chain);
+		tmp = allocate_value (type);
+		value_contents_copy (tmp, 0, retval, 0, TYPE_LENGTH (type));
+		retval = tmp;
+	      }
  	  }
  	  break;

@@ -2774,14 +2753,54 @@ unimplemented (unsigned int op)
  	   op);
  }

-/* See dwarf2loc.h.  */
+/* See dwarf2loc.h.
+
+   This is basically a wrapper on gdbarch_dwarf2_reg_to_regnum so that we
+   can issue a complaint, which is better than having every target's
+   implementation of dwarf2_reg_to_regnum do it.  */

  int
-dwarf2_reg_to_regnum_or_error (struct gdbarch *arch, int dwarf_reg)
+dwarf_reg_to_regnum (struct gdbarch *arch, int dwarf_reg)
  {
    int reg = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_reg);
+
    if (reg == -1)
-    error (_("Unable to access DWARF register number %d"), dwarf_reg);
+    {
+      complaint (&symfile_complaints,
+		 _("bad DWARF register number %d"), dwarf_reg);
+    }
+  return reg;
+}
+
+/* Subroutine of dwarf_reg_to_regnum_or_error to simplify it.
+   Throw an error because DWARF_REG is bad.  */
+
+static void
+throw_bad_regnum_error (ULONGEST dwarf_reg)
+{
+  /* Still want to print -1 as "-1".
+     We *could* have int and ULONGEST versions of  
dwarf2_reg_to_regnum_or_error
+     but that's overkill for now.  */
+  if ((int) dwarf_reg == dwarf_reg)
+    error (_("Unable to access DWARF register number %d"), (int)  
dwarf_reg);
+  error (_("Unable to access DWARF register number %s"),
+	 pulongest (dwarf_reg));
+}
+
+/* See dwarf2loc.h.  */
+
+int
+dwarf_reg_to_regnum_or_error (struct gdbarch *arch, ULONGEST dwarf_reg)
+{
+  int reg;
+
+  if (dwarf_reg > INT_MAX)
+    throw_bad_regnum_error (dwarf_reg);
+  /* Yes, we will end up issuing a complaint and an error if DWARF_REG is
+     bad, but that's ok.  */
+  reg = dwarf_reg_to_regnum (arch, (int) dwarf_reg);
+  if (reg == -1)
+    throw_bad_regnum_error (dwarf_reg);
    return reg;
  }

@@ -3028,14 +3047,14 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr,  
struct axs_value *loc,
  	case DW_OP_reg30:
  	case DW_OP_reg31:
  	  dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
-	  loc->u.reg = dwarf2_reg_to_regnum_or_error (arch, op - DW_OP_reg0);
+	  loc->u.reg = dwarf_reg_to_regnum_or_error (arch, op - DW_OP_reg0);
  	  loc->kind = axs_lvalue_register;
  	  break;

  	case DW_OP_regx:
  	  op_ptr = safe_read_uleb128 (op_ptr, op_end, &reg);
  	  dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
-	  loc->u.reg = dwarf2_reg_to_regnum_or_error (arch, reg);
+	  loc->u.reg = dwarf_reg_to_regnum_or_error (arch, reg);
  	  loc->kind = axs_lvalue_register;
  	  break;

@@ -3098,7 +3117,7 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr,  
struct axs_value *loc,
  	case DW_OP_breg30:
  	case DW_OP_breg31:
  	  op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
-	  i = dwarf2_reg_to_regnum_or_error (arch, op - DW_OP_breg0);
+	  i = dwarf_reg_to_regnum_or_error (arch, op - DW_OP_breg0);
  	  ax_reg (expr, i);
  	  if (offset != 0)
  	    {
@@ -3110,7 +3129,7 @@ dwarf2_compile_expr_to_ax (struct agent_expr *expr,  
struct axs_value *loc,
  	  {
  	    op_ptr = safe_read_uleb128 (op_ptr, op_end, &reg);
  	    op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
-	    i = dwarf2_reg_to_regnum_or_error (arch, reg);
+	    i = dwarf_reg_to_regnum_or_error (arch, reg);
  	    ax_reg (expr, i);
  	    if (offset != 0)
  	      {
@@ -3572,7 +3591,17 @@ locexpr_regname (struct gdbarch *gdbarch, int  
dwarf_regnum)
  {
    int regnum;

-  regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum);
+  /* This doesn't use dwarf_reg_to_regnum_or_error on purpose.
+     We'd rather print *something* here than throw an error.  */
+  regnum = dwarf_reg_to_regnum (gdbarch, dwarf_regnum);
+  /* gdbarch_register_name may just return "", return something more
+     descriptive for bad register numbers.  */
+  if (regnum == -1)
+    {
+      /* The text is output as "$bad_register_number".
+	 That is why we use the underscores.  */
+      return _("bad_register_number");
+    }
    return gdbarch_register_name (gdbarch, regnum);
  }

diff --git a/gdb/dwarf2loc.h b/gdb/dwarf2loc.h
index f3630ac..c3375e4 100644
--- a/gdb/dwarf2loc.h
+++ b/gdb/dwarf2loc.h
@@ -286,9 +286,18 @@ extern struct call_site_chain *call_site_find_chain  
(struct gdbarch *gdbarch,
  /* A helper function to convert a DWARF register to an arch register.
     ARCH is the architecture.
     DWARF_REG is the register.
-   This will throw an exception if the DWARF register cannot be
-   translated to an architecture register.  */
+   If DWARF_REG is bad then a complaint is issued and -1 is returned.
+   Note: Some targets get this wrong.  */

-extern int dwarf2_reg_to_regnum_or_error (struct gdbarch *arch, int  
dwarf_reg);
+extern int dwarf_reg_to_regnum (struct gdbarch *arch, int dwarf_reg);
+
+/* A wrapper on dwarf_reg_to_regnum to throw an exception if the
+   DWARF register cannot be translated to an architecture register.
+   This takes a ULONGEST instead of an int because some callers actually  
have
+   a ULONGEST.  Negative values passed as ints will still be flagged as
+   invalid.  */
+
+extern int dwarf_reg_to_regnum_or_error (struct gdbarch *arch,
+					 ULONGEST dwarf_reg);

  #endif /* dwarf2loc.h */
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index c1e2c1a..d74a157 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -335,7 +335,8 @@ typedef int (gdbarch_sdb_reg_to_regnum_ftype) (struct  
gdbarch *gdbarch, int sdb_
  extern int gdbarch_sdb_reg_to_regnum (struct gdbarch *gdbarch, int  
sdb_regnr);
  extern void set_gdbarch_sdb_reg_to_regnum (struct gdbarch *gdbarch,  
gdbarch_sdb_reg_to_regnum_ftype *sdb_reg_to_regnum);

-/* Provide a default mapping from a DWARF2 register number to a gdb  
REGNUM. */
+/* Provide a default mapping from a DWARF2 register number to a gdb REGNUM.
+   Return -1 for bad REGNUM.  Note: Several targets get this wrong. */

  typedef int (gdbarch_dwarf2_reg_to_regnum_ftype) (struct gdbarch *gdbarch,  
int dwarf2_regnr);
  extern int gdbarch_dwarf2_reg_to_regnum (struct gdbarch *gdbarch, int  
dwarf2_regnr);
@@ -924,7 +925,7 @@ extern void set_gdbarch_max_insn_length (struct gdbarch  
*gdbarch, ULONGEST max_i
     If your architecture doesn't need to adjust instructions before
     single-stepping them, consider using simple_displaced_step_copy_insn
     here.
-
+
     If the instruction cannot execute out of line, return NULL.  The
     core falls back to stepping past the instruction in-line instead in
     that case. */
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 994a87b..ddd4edd 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -461,6 +461,7 @@ m:int:ecoff_reg_to_regnum:int  
ecoff_regnr:ecoff_regnr::no_op_reg_to_regnum::0
  # Convert from an sdb register number to an internal gdb register number.
  m:int:sdb_reg_to_regnum:int sdb_regnr:sdb_regnr::no_op_reg_to_regnum::0
  # Provide a default mapping from a DWARF2 register number to a gdb REGNUM.
+# Return -1 for bad REGNUM.  Note: Several targets get this wrong.
  m:int:dwarf2_reg_to_regnum:int  
dwarf2_regnr:dwarf2_regnr::no_op_reg_to_regnum::0
  m:const char *:register_name:int regnr:regnr::0

diff --git a/gdb/hppa-linux-tdep.c b/gdb/hppa-linux-tdep.c
index 6dc2e84..db6abc6 100644
--- a/gdb/hppa-linux-tdep.c
+++ b/gdb/hppa-linux-tdep.c
@@ -39,14 +39,13 @@ static int
  hppa_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
  {
    /* The general registers and the sar are the same in both sets.  */
-  if (reg <= 32)
+  if (reg >= 0 && reg <= 32)
      return reg;

    /* fr4-fr31 (left and right halves) are mapped from 72.  */
    if (reg >= 72 && reg <= 72 + 28 * 2)
      return HPPA_FP4_REGNUM + (reg - 72);

-  warning (_("Unmapped DWARF DBX Register #%d encountered."), reg);
    return -1;
  }

diff --git a/gdb/hppa-tdep.c b/gdb/hppa-tdep.c
index 01a7c80..60c0312 100644
--- a/gdb/hppa-tdep.c
+++ b/gdb/hppa-tdep.c
@@ -694,14 +694,13 @@ static int
  hppa64_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
  {
    /* The general registers and the sar are the same in both sets.  */
-  if (reg <= 32)
+  if (reg >= 0 && reg <= 32)
      return reg;

    /* fr4-fr31 are mapped from 72 in steps of 2.  */
    if (reg >= 72 && reg < 72 + 28 * 2 && !(reg & 1))
      return HPPA64_FP4_REGNUM + (reg - 72) / 2;

-  warning (_("Unmapped DWARF DBX Register #%d encountered."), reg);
    return -1;
  }

diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 9d52d4a..396e17f 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -502,11 +502,11 @@ i386_dbx_reg_to_regnum (struct gdbarch *gdbarch, int  
reg)
    return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
  }

-/* Convert SVR4 register number REG to the appropriate register number
+/* Convert SVR4 DWARF register number REG to the appropriate register  
number
     used by GDB.  */

  static int
-i386_svr4_reg_to_regnum (struct gdbarch *gdbarch, int reg)
+i386_svr4_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
  {
    struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

@@ -544,8 +544,20 @@ i386_svr4_reg_to_regnum (struct gdbarch *gdbarch, int  
reg)
      case 45: return I386_GS_REGNUM;
      }

-  /* This will hopefully provoke a warning.  */
-  return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
+  return -1;
+}
+
+/* Wrapper on i386_svr4_dwarf_reg_to_regnum to return
+   num_regs + num_pseudo_regs for other debug formats.  */
+
+static int
+i386_svr4_reg_to_regnum (struct gdbarch *gdbarch, int reg)
+{
+  int regnum = i386_svr4_dwarf_reg_to_regnum (gdbarch, reg);
+
+  if (regnum == -1)
+    return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
+  return regnum;
  }

  
@@ -8349,7 +8361,7 @@ i386_gdbarch_init (struct gdbarch_info info, struct  
gdbarch_list *arches)
    set_gdbarch_sdb_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum);

    /* Use the SVR4 register numbering scheme for DWARF 2.  */
-  set_gdbarch_dwarf2_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum);
+  set_gdbarch_dwarf2_reg_to_regnum (gdbarch,  
i386_svr4_dwarf_reg_to_regnum);

    /* We don't set gdbarch_stab_reg_to_regnum, since ECOFF doesn't seem to
       be in use on any of the supported i386 targets.  */
diff --git a/gdb/microblaze-tdep.c b/gdb/microblaze-tdep.c
index 8cc1df2..b09cd03 100644
--- a/gdb/microblaze-tdep.c
+++ b/gdb/microblaze-tdep.c
@@ -638,8 +638,9 @@ static int dwarf2_to_reg_map[78] =
  static int
  microblaze_dwarf2_reg_to_regnum (struct gdbarch *gdbarch, int reg)
  {
-  gdb_assert ((size_t) reg < sizeof (dwarf2_to_reg_map));
-  return dwarf2_to_reg_map[reg];
+  if (reg >= 0 && reg < sizeof (dwarf2_to_reg_map))
+    return dwarf2_to_reg_map[reg];
+  return -1;
  }

  static void
diff --git a/gdb/msp430-tdep.c b/gdb/msp430-tdep.c
index 622ce55..62e6973 100644
--- a/gdb/msp430-tdep.c
+++ b/gdb/msp430-tdep.c
@@ -581,13 +581,9 @@ static const struct frame_unwind msp430_unwind = {
  static int
  msp430_dwarf2_reg_to_regnum (struct gdbarch *gdbarch, int reg)
  {
-  if (reg < MSP430_NUM_REGS)
+  if (reg >= 0 && reg < MSP430_NUM_REGS)
      return reg + MSP430_NUM_REGS;
-  else
-    {
-      warning (_("Unmapped DWARF Register #%d encountered."), reg);
-      return -1;
-    }
+  return -1;
  }

  /* Implement the "return_value" gdbarch method.  */
diff --git a/gdb/nios2-tdep.c b/gdb/nios2-tdep.c
index 11073ee..ca64d4f 100644
--- a/gdb/nios2-tdep.c
+++ b/gdb/nios2-tdep.c
@@ -138,17 +138,15 @@ static int nios2_dwarf2gdb_regno_map[] =
    NIOS2_MPUACC_REGNUM     /* 48 */
  };

+gdb_static_assert (ARRAY_SIZE (nios2_dwarf2gdb_regno_map) ==  
NIOS2_NUM_REGS);

  /* Implement the dwarf2_reg_to_regnum gdbarch method.  */

  static int
  nios2_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int dw_reg)
  {
-  if (dw_reg < 0 || dw_reg > NIOS2_NUM_REGS)
-    {
-      warning (_("Dwarf-2 uses unmapped register #%d"), dw_reg);
-      return dw_reg;
-    }
+  if (dw_reg < 0 || dw_reg >= NIOS2_NUM_REGS)
+    return -1;

    return nios2_dwarf2gdb_regno_map[dw_reg];
  }
diff --git a/gdb/rl78-tdep.c b/gdb/rl78-tdep.c
index a5861d8..5ccc55c 100644
--- a/gdb/rl78-tdep.c
+++ b/gdb/rl78-tdep.c
@@ -1215,9 +1215,7 @@ rl78_dwarf_reg_to_regnum (struct gdbarch *gdbarch,  
int reg)
    else if (reg == 37)
      return RL78_PC_REGNUM;
    else
-    internal_error (__FILE__, __LINE__,
-                    _("Undefined dwarf2 register mapping of reg %d"),
-		    reg);
+    return -1;
  }

  /* Implement the `register_sim_regno' gdbarch method.  */
diff --git a/gdb/rx-tdep.c b/gdb/rx-tdep.c
index 0bd91ff..7189168 100644
--- a/gdb/rx-tdep.c
+++ b/gdb/rx-tdep.c
@@ -1010,9 +1010,7 @@ rx_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int  
reg)
    else if (reg == 17)
      return RX_PC_REGNUM;
    else
-    internal_error (__FILE__, __LINE__,
-                    _("Undefined dwarf2 register mapping of reg %d"),
-		    reg);
+    return -1;
  }

  /* Allocate and initialize a gdbarch object.  */
diff --git a/gdb/testsuite/gdb.dwarf2/bad-regnum.c  
b/gdb/testsuite/gdb.dwarf2/bad-regnum.c
new file mode 100644
index 0000000..35230f2
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/bad-regnum.c
@@ -0,0 +1,22 @@
+/* Copyright 2015 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.   
*/
+
+int
+main ()
+{
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.dwarf2/bad-regnum.exp  
b/gdb/testsuite/gdb.dwarf2/bad-regnum.exp
new file mode 100644
index 0000000..749d721
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/bad-regnum.exp
@@ -0,0 +1,76 @@
+# Copyright 2015 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+    return 0
+}
+
+standard_testfile bad-regnum.c bad-regnum-dw.S
+
+# Make some DWARF for the test.
+set asm_file [standard_output_file $srcfile2]
+Dwarf::assemble $asm_file {
+    cu {} {
+	DW_TAG_compile_unit {
+	    {DW_AT_language @DW_LANG_C}
+	    {DW_AT_name     bad-regnum-dw.c}
+	    {DW_AT_comp_dir /tmp}
+	} {
+	    declare_labels integer_label
+
+	    integer_label: DW_TAG_base_type {
+		{DW_AT_byte_size 4 DW_FORM_sdata}
+		{DW_AT_encoding  @DW_ATE_signed}
+		{DW_AT_name      integer}
+	    }
+
+	    DW_TAG_variable {
+		{DW_AT_name foo1}
+		{DW_AT_type :$integer_label}
+		{DW_AT_location {
+		    DW_OP_regx 2147483647
+		} SPECIAL_expr}
+		{external 1 flag}
+	    }
+
+	    DW_TAG_variable {
+		{DW_AT_name foo2}
+		{DW_AT_type :$integer_label}
+		{DW_AT_location {
+		    DW_OP_regx -1
+		} SPECIAL_expr}
+		{external 1 flag}
+	    }
+	}
+    }
+}
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} \
+	  [list $srcfile $asm_file] {nodebug}] } {
+    return -1
+}
+
+if ![runto_main] {
+    return -1
+}
+
+gdb_test "info addr foo1" \
+    "Symbol \"foo1\" is a variable in \\\$bad_register_number."
+
+gdb_test "info addr foo2" \
+    "Symbol \"foo2\" is a variable in \\\$bad_register_number."
diff --git a/gdb/testsuite/lib/dwarf.exp b/gdb/testsuite/lib/dwarf.exp
index 515334e..df7a36d 100644
--- a/gdb/testsuite/lib/dwarf.exp
+++ b/gdb/testsuite/lib/dwarf.exp
@@ -836,6 +836,10 @@ namespace eval Dwarf {
  		    _op .${_cu_addr_size}byte [lindex $line 1]
  		}

+		DW_OP_regx {
+		    _op .uleb128 [lindex $line 1]
+		}
+
  		DW_OP_pick -
  		DW_OP_const1u -
  		DW_OP_const1s {
