Remove mt port

This patch removes the MT port.  The removal was annoucned
https://sourceware.org/ml/gdb-announce/2017/msg00006.html
I'll remove MT from the top-level configure later.

gdb:

2018-01-22  Yao Qi  <yao.qi@linaro.org>

	* Makefile.in (ALL_TARGET_OBS): Remove mt-tdep.o.
	* configure.tgt: Remove target mt.
	* mt-tdep.c: Remove.
	* regcache.c (cooked_read_test): Remove the check for mt.

5 files changed, 10 insertions, 1239 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 61c6599..ea53da6 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,12 @@
 2018-01-22  Yao Qi  <yao.qi@linaro.org>
 
+	* Makefile.in (ALL_TARGET_OBS): Remove mt-tdep.o.
+	* configure.tgt: Remove target mt.
+	* mt-tdep.c: Remove.
+	* regcache.c (cooked_read_test): Remove the check for mt.
+
+2018-01-22  Yao Qi  <yao.qi@linaro.org>
+
 	* jit.c (jit_frame_prev_register): Call regcache::cooked_read
 	instead of gdbarch_pseudo_register_read_value.
 
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 0a4a06b..364ea7a 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -733,7 +733,6 @@ ALL_TARGET_OBS = \
 	mn10300-tdep.o \
 	moxie-tdep.o \
 	msp430-tdep.o \
-	mt-tdep.o \
 	nbsd-tdep.o \
 	nds32-tdep.o \
 	nios2-linux-tdep.o \
diff --git a/gdb/configure.tgt b/gdb/configure.tgt
index fb8014a..dbd9114 100644
--- a/gdb/configure.tgt
+++ b/gdb/configure.tgt
@@ -29,6 +29,7 @@ case $targ in
  hppa*-*-hpux* | \
  ia64-*-hpux* | \
  *-*-vxworks* | \
+ mt-*-* | \
  null)
     echo "*** Configuration $targ is obsolete." >&2
     echo "*** Support has been REMOVED." >&2
@@ -442,11 +443,6 @@ msp430*-*-elf)
 	gdb_sim=../sim/msp430/libsim.a
 	;;
 
-mt-*-*)
-	# Target: Morpho Technologies ms1 processor
-	gdb_target_obs="mt-tdep.o"
-	;;
-
 nds32*-*-elf)
 	# Target: AndesTech NDS32 core
 	gdb_target_obs="nds32-tdep.o"
diff --git a/gdb/mt-tdep.c b/gdb/mt-tdep.c
deleted file mode 100644
index a4ad0c6..0000000
--- a/gdb/mt-tdep.c
+++ /dev/null
@@ -1,1218 +0,0 @@
-/* Target-dependent code for Morpho mt processor, for GDB.
-
-   Copyright (C) 2005-2018 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/>.  */
-
-/* Contributed by Michael Snyder, msnyder@redhat.com.  */
-
-#include "defs.h"
-#include "frame.h"
-#include "frame-unwind.h"
-#include "frame-base.h"
-#include "symtab.h"
-#include "dis-asm.h"
-#include "arch-utils.h"
-#include "gdbtypes.h"
-#include "regcache.h"
-#include "reggroups.h"
-#include "gdbcore.h"
-#include "trad-frame.h"
-#include "inferior.h"
-#include "dwarf2-frame.h"
-#include "infcall.h"
-#include "language.h"
-#include "valprint.h"
-#include "common/byte-vector.h"
-
-enum mt_arch_constants
-{
-  MT_MAX_STRUCT_SIZE = 16
-};
-
-enum mt_gdb_regnums
-{
-  MT_R0_REGNUM,			/* 32 bit regs.  */
-  MT_R1_REGNUM,
-  MT_1ST_ARGREG = MT_R1_REGNUM,
-  MT_R2_REGNUM,
-  MT_R3_REGNUM,
-  MT_R4_REGNUM,
-  MT_LAST_ARGREG = MT_R4_REGNUM,
-  MT_R5_REGNUM,
-  MT_R6_REGNUM,
-  MT_R7_REGNUM,
-  MT_R8_REGNUM,
-  MT_R9_REGNUM,
-  MT_R10_REGNUM,
-  MT_R11_REGNUM,
-  MT_R12_REGNUM,
-  MT_FP_REGNUM = MT_R12_REGNUM,
-  MT_R13_REGNUM,
-  MT_SP_REGNUM = MT_R13_REGNUM,
-  MT_R14_REGNUM,
-  MT_RA_REGNUM = MT_R14_REGNUM,
-  MT_R15_REGNUM,
-  MT_IRA_REGNUM = MT_R15_REGNUM,
-  MT_PC_REGNUM,
-
-  /* Interrupt Enable pseudo-register, exported by SID.  */
-  MT_INT_ENABLE_REGNUM,
-  /* End of CPU regs.  */
-
-  MT_NUM_CPU_REGS,
-
-  /* Co-processor registers.  */
-  MT_COPRO_REGNUM = MT_NUM_CPU_REGS,	/* 16 bit regs.  */
-  MT_CPR0_REGNUM,
-  MT_CPR1_REGNUM,
-  MT_CPR2_REGNUM,
-  MT_CPR3_REGNUM,
-  MT_CPR4_REGNUM,
-  MT_CPR5_REGNUM,
-  MT_CPR6_REGNUM,
-  MT_CPR7_REGNUM,
-  MT_CPR8_REGNUM,
-  MT_CPR9_REGNUM,
-  MT_CPR10_REGNUM,
-  MT_CPR11_REGNUM,
-  MT_CPR12_REGNUM,
-  MT_CPR13_REGNUM,
-  MT_CPR14_REGNUM,
-  MT_CPR15_REGNUM,
-  MT_BYPA_REGNUM,		/* 32 bit regs.  */
-  MT_BYPB_REGNUM,
-  MT_BYPC_REGNUM,
-  MT_FLAG_REGNUM,
-  MT_CONTEXT_REGNUM,		/* 38 bits (treat as array of
-				   six bytes).  */
-  MT_MAC_REGNUM,			/* 32 bits.  */
-  MT_Z1_REGNUM,			/* 16 bits.  */
-  MT_Z2_REGNUM,			/* 16 bits.  */
-  MT_ICHANNEL_REGNUM,		/* 32 bits.  */
-  MT_ISCRAMB_REGNUM,		/* 32 bits.  */
-  MT_QSCRAMB_REGNUM,		/* 32 bits.  */
-  MT_OUT_REGNUM,			/* 16 bits.  */
-  MT_EXMAC_REGNUM,		/* 32 bits (8 used).  */
-  MT_QCHANNEL_REGNUM,		/* 32 bits.  */
-  MT_ZI2_REGNUM,                /* 16 bits.  */
-  MT_ZQ2_REGNUM,                /* 16 bits.  */
-  MT_CHANNEL2_REGNUM,           /* 32 bits.  */
-  MT_ISCRAMB2_REGNUM,           /* 32 bits.  */
-  MT_QSCRAMB2_REGNUM,           /* 32 bits.  */
-  MT_QCHANNEL2_REGNUM,          /* 32 bits.  */
-
-  /* Number of real registers.  */
-  MT_NUM_REGS,
-
-  /* Pseudo-registers.  */
-  MT_COPRO_PSEUDOREG_REGNUM = MT_NUM_REGS,
-  MT_MAC_PSEUDOREG_REGNUM,
-  MT_COPRO_PSEUDOREG_ARRAY,
-
-  MT_COPRO_PSEUDOREG_DIM_1 = 2,
-  MT_COPRO_PSEUDOREG_DIM_2 = 8,
-  /* The number of pseudo-registers for each coprocessor.  These
-     include the real coprocessor registers, the pseudo-registe for
-     the coprocessor number, and the pseudo-register for the MAC.  */
-  MT_COPRO_PSEUDOREG_REGS = MT_NUM_REGS - MT_NUM_CPU_REGS + 2,
-  /* The register number of the MAC, relative to a given coprocessor.  */
-  MT_COPRO_PSEUDOREG_MAC_REGNUM = MT_COPRO_PSEUDOREG_REGS - 1,
-
-  /* Two pseudo-regs ('coprocessor' and 'mac').  */
-  MT_NUM_PSEUDO_REGS = 2 + (MT_COPRO_PSEUDOREG_REGS
-			    * MT_COPRO_PSEUDOREG_DIM_1
-			    * MT_COPRO_PSEUDOREG_DIM_2)
-};
-
-/* The tdep structure.  */
-struct gdbarch_tdep
-{
-  /* ISA-specific types.  */
-  struct type *copro_type;
-};
-
-
-/* Return name of register number specified by REGNUM.  */
-
-static const char *
-mt_register_name (struct gdbarch *gdbarch, int regnum)
-{
-  static const char *const register_names[] = {
-    /* CPU regs.  */
-    "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
-    "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
-    "pc", "IE",
-    /* Co-processor regs.  */
-    "",				/* copro register.  */
-    "cr0", "cr1", "cr2", "cr3", "cr4", "cr5", "cr6", "cr7",
-    "cr8", "cr9", "cr10", "cr11", "cr12", "cr13", "cr14", "cr15",
-    "bypa", "bypb", "bypc", "flag", "context", "" /* mac.  */ , "z1", "z2",
-    "Ichannel", "Iscramb", "Qscramb", "out", "" /* ex-mac.  */ , "Qchannel",
-    "zi2", "zq2", "Ichannel2", "Iscramb2", "Qscramb2", "Qchannel2",
-    /* Pseudo-registers.  */
-    "coprocessor", "MAC"
-  };
-  static const char *array_names[MT_COPRO_PSEUDOREG_REGS
-				 * MT_COPRO_PSEUDOREG_DIM_1
-				 * MT_COPRO_PSEUDOREG_DIM_2];
-
-  if (regnum < 0)
-    return "";
-  if (regnum < ARRAY_SIZE (register_names))
-    return register_names[regnum];
-  if (array_names[regnum - MT_COPRO_PSEUDOREG_ARRAY])
-    return array_names[regnum - MT_COPRO_PSEUDOREG_ARRAY];
-  
-  {
-    char *name;
-    const char *stub;
-    unsigned dim_1;
-    unsigned dim_2;
-    unsigned index;
-    
-    regnum -= MT_COPRO_PSEUDOREG_ARRAY;
-    index = regnum % MT_COPRO_PSEUDOREG_REGS;
-    dim_2 = (regnum / MT_COPRO_PSEUDOREG_REGS) % MT_COPRO_PSEUDOREG_DIM_2;
-    dim_1 = ((regnum / MT_COPRO_PSEUDOREG_REGS / MT_COPRO_PSEUDOREG_DIM_2)
-	     %  MT_COPRO_PSEUDOREG_DIM_1);
-    
-    if (index == MT_COPRO_PSEUDOREG_MAC_REGNUM)
-      stub = register_names[MT_MAC_PSEUDOREG_REGNUM];
-    else if (index >= MT_NUM_REGS - MT_CPR0_REGNUM)
-      stub = "";
-    else
-      stub = register_names[index + MT_CPR0_REGNUM];
-    if (!*stub)
-      {
-	array_names[regnum] = stub;
-	return stub;
-      }
-    name = (char *) xmalloc (30);
-    sprintf (name, "copro_%d_%d_%s", dim_1, dim_2, stub);
-    array_names[regnum] = name;
-    return name;
-  }
-}
-
-/* Return the type of a coprocessor register.  */
-
-static struct type *
-mt_copro_register_type (struct gdbarch *arch, int regnum)
-{
-  switch (regnum)
-    {
-    case MT_INT_ENABLE_REGNUM:
-    case MT_ICHANNEL_REGNUM:
-    case MT_QCHANNEL_REGNUM:
-    case MT_ISCRAMB_REGNUM:
-    case MT_QSCRAMB_REGNUM:
-      return builtin_type (arch)->builtin_int32;
-    case MT_BYPA_REGNUM:
-    case MT_BYPB_REGNUM:
-    case MT_BYPC_REGNUM:
-    case MT_Z1_REGNUM:
-    case MT_Z2_REGNUM:
-    case MT_OUT_REGNUM:
-    case MT_ZI2_REGNUM:
-    case MT_ZQ2_REGNUM:
-      return builtin_type (arch)->builtin_int16;
-    case MT_EXMAC_REGNUM:
-    case MT_MAC_REGNUM:
-      return builtin_type (arch)->builtin_uint32;
-    case MT_CONTEXT_REGNUM:
-      return builtin_type (arch)->builtin_long_long;
-    case MT_FLAG_REGNUM:
-      return builtin_type (arch)->builtin_unsigned_char;
-    default:
-      if (regnum >= MT_CPR0_REGNUM && regnum <= MT_CPR15_REGNUM)
-	return builtin_type (arch)->builtin_int16;
-      else if (regnum == MT_CPR0_REGNUM + MT_COPRO_PSEUDOREG_MAC_REGNUM)
-	{
-	  if (gdbarch_bfd_arch_info (arch)->mach == bfd_mach_mrisc2
-	      || gdbarch_bfd_arch_info (arch)->mach == bfd_mach_ms2)
-	    return builtin_type (arch)->builtin_uint64;
-	  else
-	    return builtin_type (arch)->builtin_uint32;
-	}
-      else
-	return builtin_type (arch)->builtin_uint32;
-    }
-}
-
-/* Given ARCH and a register number specified by REGNUM, return the
-   type of that register.  */
-
-static struct type *
-mt_register_type (struct gdbarch *arch, int regnum)
-{
-  struct gdbarch_tdep *tdep = gdbarch_tdep (arch);
-
-  if (regnum >= 0 && regnum < MT_NUM_REGS + MT_NUM_PSEUDO_REGS)
-    {
-      switch (regnum)
-	{
-	case MT_PC_REGNUM:
-	case MT_RA_REGNUM:
-	case MT_IRA_REGNUM:
-	  return builtin_type (arch)->builtin_func_ptr;
-	case MT_SP_REGNUM:
-	case MT_FP_REGNUM:
-	  return builtin_type (arch)->builtin_data_ptr;
-	case MT_COPRO_REGNUM:
-	case MT_COPRO_PSEUDOREG_REGNUM:
-	  if (tdep->copro_type == NULL)
-	    {
-	      struct type *elt = builtin_type (arch)->builtin_int16;
-	      tdep->copro_type = lookup_array_range_type (elt, 0, 1);
-	    }
-	  return tdep->copro_type;
-	case MT_MAC_PSEUDOREG_REGNUM:
-	  return mt_copro_register_type (arch,
-					 MT_CPR0_REGNUM
-					 + MT_COPRO_PSEUDOREG_MAC_REGNUM);
-	default:
-	  if (regnum >= MT_R0_REGNUM && regnum <= MT_R15_REGNUM)
-	    return builtin_type (arch)->builtin_int32;
-	  else if (regnum < MT_COPRO_PSEUDOREG_ARRAY)
-	    return mt_copro_register_type (arch, regnum);
-	  else
-	    {
-	      regnum -= MT_COPRO_PSEUDOREG_ARRAY;
-	      regnum %= MT_COPRO_PSEUDOREG_REGS;
-	      regnum += MT_CPR0_REGNUM;
-	      return mt_copro_register_type (arch, regnum);
-	    }
-	}
-    }
-  internal_error (__FILE__, __LINE__,
-		  _("mt_register_type: illegal register number %d"), regnum);
-}
-
-/* Return true if register REGNUM is a member of the register group
-   specified by GROUP.  */
-
-static int
-mt_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
-			 struct reggroup *group)
-{
-  /* Groups of registers that can be displayed via "info reg".  */
-  if (group == all_reggroup)
-    return (regnum >= 0
-	    && regnum < MT_NUM_REGS + MT_NUM_PSEUDO_REGS
-	    && mt_register_name (gdbarch, regnum)[0] != '\0');
-
-  if (group == general_reggroup)
-    return (regnum >= MT_R0_REGNUM && regnum <= MT_R15_REGNUM);
-
-  if (group == float_reggroup)
-    return 0;			/* No float regs.  */
-
-  if (group == vector_reggroup)
-    return 0;			/* No vector regs.  */
-
-  /* For any that are not handled above.  */
-  return default_register_reggroup_p (gdbarch, regnum, group);
-}
-
-/* Return the return value convention used for a given type TYPE.
-   Optionally, fetch or set the return value via READBUF or
-   WRITEBUF respectively using REGCACHE for the register
-   values.  */
-
-static enum return_value_convention
-mt_return_value (struct gdbarch *gdbarch, struct value *function,
-		 struct type *type, struct regcache *regcache,
-		 gdb_byte *readbuf, const gdb_byte *writebuf)
-{
-  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-
-  if (TYPE_LENGTH (type) > 4)
-    {
-      /* Return values > 4 bytes are returned in memory, 
-         pointed to by R11.  */
-      if (readbuf)
-	{
-	  ULONGEST addr;
-
-	  regcache_cooked_read_unsigned (regcache, MT_R11_REGNUM, &addr);
-	  read_memory (addr, readbuf, TYPE_LENGTH (type));
-	}
-
-      if (writebuf)
-	{
-	  ULONGEST addr;
-
-	  regcache_cooked_read_unsigned (regcache, MT_R11_REGNUM, &addr);
-	  write_memory (addr, writebuf, TYPE_LENGTH (type));
-	}
-
-      return RETURN_VALUE_ABI_RETURNS_ADDRESS;
-    }
-  else
-    {
-      if (readbuf)
-	{
-	  ULONGEST temp;
-
-	  /* Return values of <= 4 bytes are returned in R11.  */
-	  regcache_cooked_read_unsigned (regcache, MT_R11_REGNUM, &temp);
-	  store_unsigned_integer (readbuf, TYPE_LENGTH (type),
-				  byte_order, temp);
-	}
-
-      if (writebuf)
-	{
-	  if (TYPE_LENGTH (type) < 4)
-	    {
-	      gdb_byte buf[4];
-	      /* Add leading zeros to the value.  */
-	      memset (buf, 0, sizeof (buf));
-	      memcpy (buf + sizeof (buf) - TYPE_LENGTH (type),
-		      writebuf, TYPE_LENGTH (type));
-	      regcache_cooked_write (regcache, MT_R11_REGNUM, buf);
-	    }
-	  else			/* (TYPE_LENGTH (type) == 4 */
-	    regcache_cooked_write (regcache, MT_R11_REGNUM, writebuf);
-	}
-
-      return RETURN_VALUE_REGISTER_CONVENTION;
-    }
-}
-
-/* If the input address, PC, is in a function prologue, return the
-   address of the end of the prologue, otherwise return the input
-   address.
-
-   Note:  PC is likely to be the function start, since this function
-   is mainly used for advancing a breakpoint to the first line, or
-   stepping to the first line when we have stepped into a function
-   call.  */
-
-static CORE_ADDR
-mt_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
-{
-  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-  CORE_ADDR func_addr = 0, func_end = 0;
-  const char *func_name;
-  unsigned long instr;
-
-  if (find_pc_partial_function (pc, &func_name, &func_addr, &func_end))
-    {
-      struct symtab_and_line sal;
-      struct symbol *sym;
-
-      /* Found a function.  */
-      sym = lookup_symbol (func_name, NULL, VAR_DOMAIN, NULL).symbol;
-      if (sym && SYMBOL_LANGUAGE (sym) != language_asm)
-	{
-	  /* Don't use this trick for assembly source files.  */
-	  sal = find_pc_line (func_addr, 0);
-
-	  if (sal.end && sal.end < func_end)
-	    {
-	      /* Found a line number, use it as end of prologue.  */
-	      return sal.end;
-	    }
-	}
-    }
-
-  /* No function symbol, or no line symbol.  Use prologue scanning method.  */
-  for (;; pc += 4)
-    {
-      instr = read_memory_unsigned_integer (pc, 4, byte_order);
-      if (instr == 0x12000000)	/* nop */
-	continue;
-      if (instr == 0x12ddc000)	/* copy sp into fp */
-	continue;
-      instr >>= 16;
-      if (instr == 0x05dd)	/* subi sp, sp, imm */
-	continue;
-      if (instr >= 0x43c0 && instr <= 0x43df)	/* push */
-	continue;
-      /* Not an obvious prologue instruction.  */
-      break;
-    }
-
-  return pc;
-}
-
-/* Implement the breakpoint_kind_from_pc gdbarch method.  */
-
-static int
-mt_breakpoint_kind_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr)
-{
-  return 4;
-}
-
-/* Implement the sw_breakpoint_from_kind gdbarch method.  */
-
-static const gdb_byte *
-mt_sw_breakpoint_from_kind (struct gdbarch *gdbarch, int kind, int *size)
-{
-  /* The breakpoint instruction must be the same size as the smallest
-     instruction in the instruction set.
-
-     The BP for ms1 is defined as 0x68000000 (BREAK).
-     The BP for ms2 is defined as 0x69000000 (illegal).  */
-  static gdb_byte ms1_breakpoint[] = { 0x68, 0, 0, 0 };
-  static gdb_byte ms2_breakpoint[] = { 0x69, 0, 0, 0 };
-
-  *size = kind;
-
-  if (gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_ms2)
-    return ms2_breakpoint;
-
-  return ms1_breakpoint;
-}
-
-/* Select the correct coprocessor register bank.  Return the pseudo
-   regnum we really want to read.  */
-
-static int
-mt_select_coprocessor (struct gdbarch *gdbarch,
-			struct regcache *regcache, int regno)
-{
-  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-  unsigned index, base;
-  gdb_byte copro[4];
-
-  /* Get the copro pseudo regnum.  */
-  regcache_raw_read (regcache, MT_COPRO_REGNUM, copro);
-  base = ((extract_signed_integer (&copro[0], 2, byte_order)
-	   * MT_COPRO_PSEUDOREG_DIM_2)
-	  + extract_signed_integer (&copro[2], 2, byte_order));
-
-  regno -= MT_COPRO_PSEUDOREG_ARRAY;
-  index = regno % MT_COPRO_PSEUDOREG_REGS;
-  regno /= MT_COPRO_PSEUDOREG_REGS;
-  if (base != regno)
-    {
-      /* Select the correct coprocessor register bank.  Invalidate the
-	 coprocessor register cache.  */
-      unsigned ix;
-
-      store_signed_integer (&copro[0], 2, byte_order,
-			    regno / MT_COPRO_PSEUDOREG_DIM_2);
-      store_signed_integer (&copro[2], 2, byte_order,
-			    regno % MT_COPRO_PSEUDOREG_DIM_2);
-      regcache_raw_write (regcache, MT_COPRO_REGNUM, copro);
-      
-      /* We must flush the cache, as it is now invalid.  */
-      for (ix = MT_NUM_CPU_REGS; ix != MT_NUM_REGS; ix++)
-	regcache_invalidate (regcache, ix);
-    }
-  
-  return index;
-}
-
-/* Fetch the pseudo registers:
-
-   There are two regular pseudo-registers:
-   1) The 'coprocessor' pseudo-register (which mirrors the 
-   "real" coprocessor register sent by the target), and
-   2) The 'MAC' pseudo-register (which represents the union
-   of the original 32 bit target MAC register and the new
-   8-bit extended-MAC register).
-
-   Additionally there is an array of coprocessor registers which track
-   the coprocessor registers for each coprocessor.  */
-
-static enum register_status
-mt_pseudo_register_read (struct gdbarch *gdbarch,
-			 struct regcache *regcache, int regno, gdb_byte *buf)
-{
-  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-
-  switch (regno)
-    {
-    case MT_COPRO_REGNUM:
-    case MT_COPRO_PSEUDOREG_REGNUM:
-      return regcache_raw_read (regcache, MT_COPRO_REGNUM, buf);
-    case MT_MAC_REGNUM:
-    case MT_MAC_PSEUDOREG_REGNUM:
-      if (gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_mrisc2
-	  || gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_ms2)
-	{
-	  enum register_status status;
-	  ULONGEST oldmac = 0, ext_mac = 0;
-	  ULONGEST newmac;
-
-	  status = regcache_cooked_read_unsigned (regcache, MT_MAC_REGNUM, &oldmac);
-	  if (status != REG_VALID)
-	    return status;
-
-	  regcache_cooked_read_unsigned (regcache, MT_EXMAC_REGNUM, &ext_mac);
-	  if (status != REG_VALID)
-	    return status;
-
-	  newmac =
-	    (oldmac & 0xffffffff) | ((long long) (ext_mac & 0xff) << 32);
-	  store_signed_integer (buf, 8, byte_order, newmac);
-
-	  return REG_VALID;
-	}
-      else
-	return regcache_raw_read (regcache, MT_MAC_REGNUM, buf);
-      break;
-    default:
-      {
-	unsigned index = mt_select_coprocessor (gdbarch, regcache, regno);
-	
-	if (index == MT_COPRO_PSEUDOREG_MAC_REGNUM)
-	  return mt_pseudo_register_read (gdbarch, regcache,
-					  MT_MAC_PSEUDOREG_REGNUM, buf);
-	else if (index < MT_NUM_REGS - MT_CPR0_REGNUM)
-	  return regcache_raw_read (regcache, index + MT_CPR0_REGNUM, buf);
-	else
-	  /* ??? */
-	  return REG_VALID;
-      }
-      break;
-    }
-}
-
-/* Write the pseudo registers:
-
-   Mt pseudo-registers are stored directly to the target.  The
-   'coprocessor' register is special, because when it is modified, all
-   the other coprocessor regs must be flushed from the reg cache.  */
-
-static void
-mt_pseudo_register_write (struct gdbarch *gdbarch,
-			   struct regcache *regcache,
-			   int regno, const gdb_byte *buf)
-{
-  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-  int i;
-
-  switch (regno)
-    {
-    case MT_COPRO_REGNUM:
-    case MT_COPRO_PSEUDOREG_REGNUM:
-      regcache_raw_write (regcache, MT_COPRO_REGNUM, buf);
-      for (i = MT_NUM_CPU_REGS; i < MT_NUM_REGS; i++)
-	regcache_invalidate (regcache, i);
-      break;
-    case MT_MAC_REGNUM:
-    case MT_MAC_PSEUDOREG_REGNUM:
-      if (gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_mrisc2
-	  || gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_ms2)
-	{
-	  /* The 8-byte MAC pseudo-register must be broken down into two
-	     32-byte registers.  */
-	  unsigned int oldmac, ext_mac;
-	  ULONGEST newmac;
-
-	  newmac = extract_unsigned_integer (buf, 8, byte_order);
-	  oldmac = newmac & 0xffffffff;
-	  ext_mac = (newmac >> 32) & 0xff;
-	  regcache_cooked_write_unsigned (regcache, MT_MAC_REGNUM, oldmac);
-	  regcache_cooked_write_unsigned (regcache, MT_EXMAC_REGNUM, ext_mac);
-	}
-      else
-	regcache_raw_write (regcache, MT_MAC_REGNUM, buf);
-      break;
-    default:
-      {
-	unsigned index = mt_select_coprocessor (gdbarch, regcache, regno);
-	
-	if (index == MT_COPRO_PSEUDOREG_MAC_REGNUM)
-	  mt_pseudo_register_write (gdbarch, regcache,
-				    MT_MAC_PSEUDOREG_REGNUM, buf);
-	else if (index < MT_NUM_REGS - MT_CPR0_REGNUM)
-	  regcache_raw_write (regcache, index + MT_CPR0_REGNUM, buf);
-      }
-      break;
-    }
-}
-
-static CORE_ADDR
-mt_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
-{
-  /* Register size is 4 bytes.  */
-  return align_down (sp, 4);
-}
-
-/* Implements the "info registers" command.   When ``all'' is non-zero,
-   the coprocessor registers will be printed in addition to the rest
-   of the registers.  */
-
-static void
-mt_registers_info (struct gdbarch *gdbarch,
-		   struct ui_file *file,
-		   struct frame_info *frame, int regnum, int all)
-{
-  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-
-  if (regnum == -1)
-    {
-      int lim;
-
-      lim = all ? MT_NUM_REGS : MT_NUM_CPU_REGS;
-
-      for (regnum = 0; regnum < lim; regnum++)
-	{
-	  /* Don't display the Qchannel register since it will be displayed
-	     along with Ichannel.  (See below.)  */
-	  if (regnum == MT_QCHANNEL_REGNUM)
-	    continue;
-
-	  mt_registers_info (gdbarch, file, frame, regnum, all);
-
-	  /* Display the Qchannel register immediately after Ichannel.  */
-	  if (regnum == MT_ICHANNEL_REGNUM)
-	    mt_registers_info (gdbarch, file, frame, MT_QCHANNEL_REGNUM, all);
-	}
-    }
-  else
-    {
-      if (regnum == MT_EXMAC_REGNUM)
-	return;
-      else if (regnum == MT_CONTEXT_REGNUM)
-	{
-	  /* Special output handling for 38-bit context register.  */
-	  unsigned char *buff;
-	  unsigned int i, regsize;
-
-	  regsize = register_size (gdbarch, regnum);
-
-	  buff = (unsigned char *) alloca (regsize);
-
-	  deprecated_frame_register_read (frame, regnum, buff);
-
-	  fputs_filtered (gdbarch_register_name
-			  (gdbarch, regnum), file);
-	  print_spaces_filtered (15 - strlen (gdbarch_register_name
-					        (gdbarch, regnum)),
-				 file);
-	  fputs_filtered ("0x", file);
-
-	  for (i = 0; i < regsize; i++)
-	    fprintf_filtered (file, "%02x", (unsigned int)
-			      extract_unsigned_integer (buff + i, 1, byte_order));
-	  fputs_filtered ("\t", file);
-	  print_longest (file, 'd', 0,
-			 extract_unsigned_integer (buff, regsize, byte_order));
-	  fputs_filtered ("\n", file);
-	}
-      else if (regnum == MT_COPRO_REGNUM
-               || regnum == MT_COPRO_PSEUDOREG_REGNUM)
-	{
-	  /* Special output handling for the 'coprocessor' register.  */
-	  struct value_print_options opts;
-	  struct value *val;
-
-	  val = get_frame_register_value (frame, MT_COPRO_REGNUM);
-	  /* And print.  */
-	  regnum = MT_COPRO_PSEUDOREG_REGNUM;
-	  fputs_filtered (gdbarch_register_name (gdbarch, regnum),
-			  file);
-	  print_spaces_filtered (15 - strlen (gdbarch_register_name
-					        (gdbarch, regnum)),
-				 file);
-	  get_no_prettyformat_print_options (&opts);
-	  opts.deref_ref = 1;
-	  val_print (register_type (gdbarch, regnum),
-		     0, 0, file, 0, val,
-		     &opts, current_language);
-	  fputs_filtered ("\n", file);
-	}
-      else if (regnum == MT_MAC_REGNUM || regnum == MT_MAC_PSEUDOREG_REGNUM)
-	{
-	  ULONGEST oldmac, ext_mac, newmac;
-	  gdb_byte buf[3 * sizeof (LONGEST)];
-
-	  /* Get the two "real" mac registers.  */
-	  deprecated_frame_register_read (frame, MT_MAC_REGNUM, buf);
-	  oldmac = extract_unsigned_integer
-	    (buf, register_size (gdbarch, MT_MAC_REGNUM), byte_order);
-	  if (gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_mrisc2
-	      || gdbarch_bfd_arch_info (gdbarch)->mach == bfd_mach_ms2)
-	    {
-	      deprecated_frame_register_read (frame, MT_EXMAC_REGNUM, buf);
-	      ext_mac = extract_unsigned_integer
-		(buf, register_size (gdbarch, MT_EXMAC_REGNUM), byte_order);
-	    }
-	  else
-	    ext_mac = 0;
-
-	  /* Add them together.  */
-	  newmac = (oldmac & 0xffffffff) + ((ext_mac & 0xff) << 32);
-
-	  /* And print.  */
-	  regnum = MT_MAC_PSEUDOREG_REGNUM;
-	  fputs_filtered (gdbarch_register_name (gdbarch, regnum),
-			  file);
-	  print_spaces_filtered (15 - strlen (gdbarch_register_name
-					      (gdbarch, regnum)),
-				 file);
-	  fputs_filtered ("0x", file);
-	  print_longest (file, 'x', 0, newmac);
-	  fputs_filtered ("\t", file);
-	  print_longest (file, 'u', 0, newmac);
-	  fputs_filtered ("\n", file);
-	}
-      else
-	default_print_registers_info (gdbarch, file, frame, regnum, all);
-    }
-}
-
-/* Set up the callee's arguments for an inferior function call.  The
-   arguments are pushed on the stack or are placed in registers as
-   appropriate.  It also sets up the return address (which points to
-   the call dummy breakpoint).
-
-   Returns the updated (and aligned) stack pointer.  */
-
-static CORE_ADDR
-mt_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
-		     struct regcache *regcache, CORE_ADDR bp_addr,
-		     int nargs, struct value **args, CORE_ADDR sp,
-		     int struct_return, CORE_ADDR struct_addr)
-{
-#define wordsize 4
-  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
-  gdb_byte buf[MT_MAX_STRUCT_SIZE];
-  int argreg = MT_1ST_ARGREG;
-  int split_param_len = 0;
-  int stack_dest = sp;
-  int slacklen;
-  int typelen;
-  int i, j;
-
-  /* First handle however many args we can fit into MT_1ST_ARGREG thru
-     MT_LAST_ARGREG.  */
-  for (i = 0; i < nargs && argreg <= MT_LAST_ARGREG; i++)
-    {
-      const gdb_byte *val;
-      typelen = TYPE_LENGTH (value_type (args[i]));
-      switch (typelen)
-	{
-	case 1:
-	case 2:
-	case 3:
-	case 4:
-	  regcache_cooked_write_unsigned (regcache, argreg++,
-					  extract_unsigned_integer
-					  (value_contents (args[i]),
-					   wordsize, byte_order));
-	  break;
-	case 8:
-	case 12:
-	case 16:
-	  val = value_contents (args[i]);
-	  while (typelen > 0)
-	    {
-	      if (argreg <= MT_LAST_ARGREG)
-		{
-		  /* This word of the argument is passed in a register.  */
-		  regcache_cooked_write_unsigned (regcache, argreg++,
-						  extract_unsigned_integer
-						  (val, wordsize, byte_order));
-		  typelen -= wordsize;
-		  val += wordsize;
-		}
-	      else
-		{
-		  /* Remainder of this arg must be passed on the stack
-		     (deferred to do later).  */
-		  split_param_len = typelen;
-		  memcpy (buf, val, typelen);
-		  break;	/* No more args can be handled in regs.  */
-		}
-	    }
-	  break;
-	default:
-	  /* By reverse engineering of gcc output, args bigger than
-	     16 bytes go on the stack, and their address is passed
-	     in the argreg.  */
-	  stack_dest -= typelen;
-	  write_memory (stack_dest, value_contents (args[i]), typelen);
-	  regcache_cooked_write_unsigned (regcache, argreg++, stack_dest);
-	  break;
-	}
-    }
-
-  /* Next, the rest of the arguments go onto the stack, in reverse order.  */
-  for (j = nargs - 1; j >= i; j--)
-    {
-      const gdb_byte *contents = value_contents (args[j]);
-      
-      /* Right-justify the value in an aligned-length buffer.  */
-      typelen = TYPE_LENGTH (value_type (args[j]));
-      slacklen = (wordsize - (typelen % wordsize)) % wordsize;
-      gdb::byte_vector val (typelen + slacklen);
-      memcpy (val.data (), contents, typelen);
-      memset (val.data () + typelen, 0, slacklen);
-      /* Now write this data to the stack.  */
-      stack_dest -= typelen + slacklen;
-      write_memory (stack_dest, val.data (), typelen + slacklen);
-    }
-
-  /* Finally, if a param needs to be split between registers and stack, 
-     write the second half to the stack now.  */
-  if (split_param_len != 0)
-    {
-      stack_dest -= split_param_len;
-      write_memory (stack_dest, buf, split_param_len);
-    }
-
-  /* Set up return address (provided to us as bp_addr).  */
-  regcache_cooked_write_unsigned (regcache, MT_RA_REGNUM, bp_addr);
-
-  /* Store struct return address, if given.  */
-  if (struct_return && struct_addr != 0)
-    regcache_cooked_write_unsigned (regcache, MT_R11_REGNUM, struct_addr);
-
-  /* Set aside 16 bytes for the callee to save regs 1-4.  */
-  stack_dest -= 16;
-
-  /* Update the stack pointer.  */
-  regcache_cooked_write_unsigned (regcache, MT_SP_REGNUM, stack_dest);
-
-  /* And that should do it.  Return the new stack pointer.  */
-  return stack_dest;
-}
-
-
-/* The 'unwind_cache' data structure.  */
-
-struct mt_unwind_cache
-{
-  /* The previous frame's inner most stack address.
-     Used as this frame ID's stack_addr.  */
-  CORE_ADDR prev_sp;
-  CORE_ADDR frame_base;
-  int framesize;
-  int frameless_p;
-
-  /* Table indicating the location of each and every register.  */
-  struct trad_frame_saved_reg *saved_regs;
-};
-
-/* Initialize an unwind_cache.  Build up the saved_regs table etc. for
-   the frame.  */
-
-static struct mt_unwind_cache *
-mt_frame_unwind_cache (struct frame_info *this_frame,
-			void **this_prologue_cache)
-{
-  struct gdbarch *gdbarch;
-  struct mt_unwind_cache *info;
-  CORE_ADDR next_addr, start_addr, end_addr, prologue_end_addr;
-  unsigned long instr, upper_half, delayed_store = 0;
-  int regnum, offset;
-  ULONGEST sp, fp;
-
-  if ((*this_prologue_cache))
-    return (struct mt_unwind_cache *) (*this_prologue_cache);
-
-  gdbarch = get_frame_arch (this_frame);
-  info = FRAME_OBSTACK_ZALLOC (struct mt_unwind_cache);
-  (*this_prologue_cache) = info;
-
-  info->prev_sp = 0;
-  info->framesize = 0;
-  info->frame_base = 0;
-  info->frameless_p = 1;
-  info->saved_regs = trad_frame_alloc_saved_regs (this_frame);
-
-  /* Grab the frame-relative values of SP and FP, needed below.
-     The frame_saved_register function will find them on the
-     stack or in the registers as appropriate.  */
-  sp = get_frame_register_unsigned (this_frame, MT_SP_REGNUM);
-  fp = get_frame_register_unsigned (this_frame, MT_FP_REGNUM);
-
-  start_addr = get_frame_func (this_frame);
-
-  /* Return early if GDB couldn't find the function.  */
-  if (start_addr == 0)
-    return info;
-
-  end_addr = get_frame_pc (this_frame);
-  prologue_end_addr = skip_prologue_using_sal (gdbarch, start_addr);
-  if (end_addr == 0)
-  for (next_addr = start_addr; next_addr < end_addr; next_addr += 4)
-    {
-      instr = get_frame_memory_unsigned (this_frame, next_addr, 4);
-      if (delayed_store)	/* Previous instr was a push.  */
-	{
-	  upper_half = delayed_store >> 16;
-	  regnum = upper_half & 0xf;
-	  offset = delayed_store & 0xffff;
-	  switch (upper_half & 0xfff0)
-	    {
-	    case 0x43c0:	/* push using frame pointer.  */
-	      info->saved_regs[regnum].addr = offset;
-	      break;
-	    case 0x43d0:	/* push using stack pointer.  */
-	      info->saved_regs[regnum].addr = offset;
-	      break;
-	    default:		/* lint */
-	      break;
-	    }
-	  delayed_store = 0;
-	}
-
-      switch (instr)
-	{
-	case 0x12000000:	/* NO-OP */
-	  continue;
-	case 0x12ddc000:	/* copy sp into fp */
-	  info->frameless_p = 0;	/* Record that the frame
-					   pointer is in use.  */
-	  continue;
-	default:
-	  upper_half = instr >> 16;
-	  if (upper_half == 0x05dd ||	/* subi  sp, sp, imm */
-	      upper_half == 0x07dd)	/* subui sp, sp, imm */
-	    {
-	      /* Record the frame size.  */
-	      info->framesize = instr & 0xffff;
-	      continue;
-	    }
-	  if ((upper_half & 0xfff0) == 0x43c0 ||	/* frame push */
-	      (upper_half & 0xfff0) == 0x43d0)	/* stack push */
-	    {
-	      /* Save this instruction, but don't record the 
-	         pushed register as 'saved' until we see the
-	         next instruction.  That's because of deferred stores
-	         on this target -- GDB won't be able to read the register
-	         from the stack until one instruction later.  */
-	      delayed_store = instr;
-	      continue;
-	    }
-	  /* Not a prologue instruction.  Is this the end of the prologue?
-	     This is the most difficult decision; when to stop scanning. 
-
-	     If we have no line symbol, then the best thing we can do
-	     is to stop scanning when we encounter an instruction that
-	     is not likely to be a part of the prologue. 
-
-	     But if we do have a line symbol, then we should 
-	     keep scanning until we reach it (or we reach end_addr).  */
-
-	  if (prologue_end_addr && (prologue_end_addr > (next_addr + 4)))
-	    continue;	/* Keep scanning, recording saved_regs etc.  */
-	  else
-	    break;	/* Quit scanning: breakpoint can be set here.  */
-	}
-    }
-
-  /* Special handling for the "saved" address of the SP:
-     The SP is of course never saved on the stack at all, so
-     by convention what we put here is simply the previous 
-     _value_ of the SP (as opposed to an address where the
-     previous value would have been pushed).  This will also
-     give us the frame base address.  */
-
-  if (info->frameless_p)
-    {
-      info->frame_base = sp + info->framesize;
-      info->prev_sp = sp + info->framesize;
-    }
-  else
-    {
-      info->frame_base = fp + info->framesize;
-      info->prev_sp = fp + info->framesize;
-    }
-  /* Save prev_sp in saved_regs as a value, not as an address.  */
-  trad_frame_set_value (info->saved_regs, MT_SP_REGNUM, info->prev_sp);
-
-  /* Now convert frame offsets to actual addresses (not offsets).  */
-  for (regnum = 0; regnum < MT_NUM_REGS; regnum++)
-    if (trad_frame_addr_p (info->saved_regs, regnum))
-      info->saved_regs[regnum].addr += info->frame_base - info->framesize;
-
-  /* The call instruction moves the caller's PC in the callee's RA reg.
-     Since this is an unwind, do the reverse.  Copy the location of RA
-     into PC (the address / regnum) so that a request for PC will be
-     converted into a request for the RA.  */
-  info->saved_regs[MT_PC_REGNUM] = info->saved_regs[MT_RA_REGNUM];
-
-  return info;
-}
-
-static CORE_ADDR
-mt_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
-{
-  ULONGEST pc;
-
-  pc = frame_unwind_register_unsigned (next_frame, MT_PC_REGNUM);
-  return pc;
-}
-
-static CORE_ADDR
-mt_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame)
-{
-  ULONGEST sp;
-
-  sp = frame_unwind_register_unsigned (next_frame, MT_SP_REGNUM);
-  return sp;
-}
-
-/* Assuming THIS_FRAME is a dummy, return the frame ID of that dummy
-   frame.  The frame ID's base needs to match the TOS value saved by
-   save_dummy_frame_tos(), and the PC match the dummy frame's breakpoint.  */
-
-static struct frame_id
-mt_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
-{
-  CORE_ADDR sp = get_frame_register_unsigned (this_frame, MT_SP_REGNUM);
-  return frame_id_build (sp, get_frame_pc (this_frame));
-}
-
-/* Given a GDB frame, determine the address of the calling function's
-   frame.  This will be used to create a new GDB frame struct.  */
-
-static void
-mt_frame_this_id (struct frame_info *this_frame,
-		   void **this_prologue_cache, struct frame_id *this_id)
-{
-  struct mt_unwind_cache *info =
-    mt_frame_unwind_cache (this_frame, this_prologue_cache);
-
-  if (!(info == NULL || info->prev_sp == 0))
-    (*this_id) = frame_id_build (info->prev_sp, get_frame_func (this_frame));
-
-  return;
-}
-
-static struct value *
-mt_frame_prev_register (struct frame_info *this_frame,
-			 void **this_prologue_cache, int regnum)
-{
-  struct mt_unwind_cache *info =
-    mt_frame_unwind_cache (this_frame, this_prologue_cache);
-
-  return trad_frame_get_prev_register (this_frame, info->saved_regs, regnum);
-}
-
-static CORE_ADDR
-mt_frame_base_address (struct frame_info *this_frame,
-			void **this_prologue_cache)
-{
-  struct mt_unwind_cache *info =
-    mt_frame_unwind_cache (this_frame, this_prologue_cache);
-
-  return info->frame_base;
-}
-
-/* This is a shared interface:  the 'frame_unwind' object is what's
-   returned by the 'sniffer' function, and in turn specifies how to
-   get a frame's ID and prev_regs.
-
-   This exports the 'prev_register' and 'this_id' methods.  */
-
-static const struct frame_unwind mt_frame_unwind = {
-  NORMAL_FRAME,
-  default_frame_unwind_stop_reason,
-  mt_frame_this_id,
-  mt_frame_prev_register,
-  NULL,
-  default_frame_sniffer
-};
-
-/* Another shared interface:  the 'frame_base' object specifies how to
-   unwind a frame and secure the base addresses for frame objects
-   (locals, args).  */
-
-static struct frame_base mt_frame_base = {
-  &mt_frame_unwind,
-  mt_frame_base_address,
-  mt_frame_base_address,
-  mt_frame_base_address
-};
-
-static struct gdbarch *
-mt_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
-{
-  struct gdbarch *gdbarch;
-  struct gdbarch_tdep *tdep;
-
-  /* Find a candidate among the list of pre-declared architectures.  */
-  arches = gdbarch_list_lookup_by_info (arches, &info);
-  if (arches != NULL)
-    return arches->gdbarch;
-
-  /* None found, create a new architecture from the information
-     provided.  */
-  tdep = XCNEW (struct gdbarch_tdep);
-  gdbarch = gdbarch_alloc (&info, tdep);
-
-  set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
-  set_gdbarch_double_format (gdbarch, floatformats_ieee_double);
-  set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
-
-  set_gdbarch_register_name (gdbarch, mt_register_name);
-  set_gdbarch_num_regs (gdbarch, MT_NUM_REGS);
-  set_gdbarch_num_pseudo_regs (gdbarch, MT_NUM_PSEUDO_REGS);
-  set_gdbarch_pc_regnum (gdbarch, MT_PC_REGNUM);
-  set_gdbarch_sp_regnum (gdbarch, MT_SP_REGNUM);
-  set_gdbarch_pseudo_register_read (gdbarch, mt_pseudo_register_read);
-  set_gdbarch_pseudo_register_write (gdbarch, mt_pseudo_register_write);
-  set_gdbarch_skip_prologue (gdbarch, mt_skip_prologue);
-  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
-  set_gdbarch_breakpoint_kind_from_pc (gdbarch, mt_breakpoint_kind_from_pc);
-  set_gdbarch_sw_breakpoint_from_kind (gdbarch, mt_sw_breakpoint_from_kind);
-  set_gdbarch_decr_pc_after_break (gdbarch, 0);
-  set_gdbarch_frame_args_skip (gdbarch, 0);
-  set_gdbarch_register_type (gdbarch, mt_register_type);
-  set_gdbarch_register_reggroup_p (gdbarch, mt_register_reggroup_p);
-
-  set_gdbarch_return_value (gdbarch, mt_return_value);
-  set_gdbarch_sp_regnum (gdbarch, MT_SP_REGNUM);
-
-  set_gdbarch_frame_align (gdbarch, mt_frame_align);
-
-  set_gdbarch_print_registers_info (gdbarch, mt_registers_info);
-
-  set_gdbarch_push_dummy_call (gdbarch, mt_push_dummy_call);
-
-  /* Target builtin data types.  */
-  set_gdbarch_short_bit (gdbarch, 16);
-  set_gdbarch_int_bit (gdbarch, 32);
-  set_gdbarch_long_bit (gdbarch, 32);
-  set_gdbarch_long_long_bit (gdbarch, 64);
-  set_gdbarch_float_bit (gdbarch, 32);
-  set_gdbarch_double_bit (gdbarch, 64);
-  set_gdbarch_long_double_bit (gdbarch, 64);
-  set_gdbarch_ptr_bit (gdbarch, 32);
-
-  /* Register the DWARF 2 sniffer first, and then the traditional prologue
-     based sniffer.  */
-  dwarf2_append_unwinders (gdbarch);
-  frame_unwind_append_unwinder (gdbarch, &mt_frame_unwind);
-  frame_base_set_default (gdbarch, &mt_frame_base);
-
-  /* Register the 'unwind_pc' method.  */
-  set_gdbarch_unwind_pc (gdbarch, mt_unwind_pc);
-  set_gdbarch_unwind_sp (gdbarch, mt_unwind_sp);
-
-  /* Methods for saving / extracting a dummy frame's ID.
-     The ID's stack address must match the SP value returned by
-     PUSH_DUMMY_CALL, and saved by generic_save_dummy_frame_tos.  */
-  set_gdbarch_dummy_id (gdbarch, mt_dummy_id);
-
-  return gdbarch;
-}
-
-void
-_initialize_mt_tdep (void)
-{
-  register_gdbarch_init (bfd_arch_mt, mt_gdbarch_init);
-}
diff --git a/gdb/regcache.c b/gdb/regcache.c
index fb6a904..b99ae36 100644
--- a/gdb/regcache.c
+++ b/gdb/regcache.c
@@ -1845,15 +1845,8 @@ cooked_read_test (struct gdbarch *gdbarch)
 
       SELF_CHECK (REG_VALID == readwrite.cooked_read (regnum, buf.data ()));
 
-      if (gdbarch_bfd_arch_info (gdbarch)->arch != bfd_arch_mt)
-	{
-	  /* MT pseudo registers are banked, and different banks are
-	     selected by a raw registers, so GDB needs to write to
-	     that raw register to get different banked pseudo registers.
-	     See mt_select_coprocessor.  */
-	  SELF_CHECK (mock_target.fetch_registers_called == 0);
-	  SELF_CHECK (mock_target.store_registers_called == 0);
-	}
+      SELF_CHECK (mock_target.fetch_registers_called == 0);
+      SELF_CHECK (mock_target.store_registers_called == 0);
 
       /* Some SPU pseudo registers are got via TARGET_OBJECT_SPU.  */
       if (gdbarch_bfd_arch_info (gdbarch)->arch != bfd_arch_spu)
@@ -1872,12 +1865,6 @@ cooked_read_test (struct gdbarch *gdbarch)
        regnum < gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch);
        regnum++)
     {
-      if (gdbarch_bfd_arch_info (gdbarch)->arch == bfd_arch_mt)
-	{
-	  /* Trigger an internal error otherwise.  */
-	  continue;
-	}
-
       if (register_size (gdbarch, regnum) == 0)
 	continue;