Initial checkin of GCC 4.9.0 from trunk (r208799).

Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba

1 files changed, 855 insertions, 0 deletions

diff --git a/gcc-4.9/libgcc/unwind-arm-common.inc b/gcc-4.9/libgcc/unwind-arm-common.inc
new file mode 100644
index 000000000..eedcf2429
--- /dev/null
+++ b/gcc-4.9/libgcc/unwind-arm-common.inc
@@ -0,0 +1,855 @@
+/* Common unwinding code for ARM EABI and C6X.
+   Copyright (C) 2004-2014 Free Software Foundation, Inc.
+   Contributed by Paul Brook
+
+   This file 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, or (at your option) any
+   later version.
+
+   This file 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.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "unwind.h"
+
+/* Used for SystemTap unwinder probe.  */
+#ifdef HAVE_SYS_SDT_H
+#include <sys/sdt.h>
+#endif
+
+/* We add a prototype for abort here to avoid creating a dependency on
+   target headers.  */
+extern void abort (void);
+
+/* Definitions for C++ runtime support routines.  We make these weak
+   declarations to avoid pulling in libsupc++ unnecessarily.  */
+typedef unsigned char bool;
+
+typedef struct _ZSt9type_info type_info; /* This names C++ type_info type */
+enum __cxa_type_match_result
+  {
+    ctm_failed = 0,
+    ctm_succeeded = 1,
+    ctm_succeeded_with_ptr_to_base = 2
+  };
+
+void __attribute__((weak)) __cxa_call_unexpected(_Unwind_Control_Block *ucbp);
+bool __attribute__((weak)) __cxa_begin_cleanup(_Unwind_Control_Block *ucbp);
+enum __cxa_type_match_result __attribute__((weak)) __cxa_type_match
+  (_Unwind_Control_Block *ucbp, const type_info *rttip,
+   bool is_reference, void **matched_object);
+
+_Unwind_Ptr __attribute__((weak))
+__gnu_Unwind_Find_exidx (_Unwind_Ptr, int *);
+
+#define EXIDX_CANTUNWIND 1
+#define uint32_highbit (((_uw) 1) << 31)
+
+#define UCB_FORCED_STOP_FN(ucbp) ((ucbp)->unwinder_cache.reserved1)
+#define UCB_PR_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved2)
+#define UCB_SAVED_CALLSITE_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved3)
+#define UCB_FORCED_STOP_ARG(ucbp) ((ucbp)->unwinder_cache.reserved4)
+
+/* Unwind descriptors.  */
+
+typedef struct
+{
+  _uw16 length;
+  _uw16 offset;
+} EHT16;
+
+typedef struct
+{
+  _uw length;
+  _uw offset;
+} EHT32;
+
+/* An exception index table entry.  */
+
+typedef struct __EIT_entry
+{
+  _uw fnoffset;
+  _uw content;
+} __EIT_entry;
+
+/* Assembly helper functions.  */
+
+/* Restore core register state.  Never returns.  */
+void __attribute__((noreturn)) restore_core_regs (struct core_regs *);
+
+
+/* Restore coprocessor state after phase1 unwinding.  */
+static void restore_non_core_regs (phase1_vrs * vrs);
+
+/* A better way to do this would probably be to compare the absolute address
+   with a segment relative relocation of the same symbol.  */
+
+extern int __text_start;
+extern int __data_start;
+
+/* The exception index table location.  */
+extern __EIT_entry __exidx_start;
+extern __EIT_entry __exidx_end;
+
+/* Core unwinding functions.  */
+
+/* Calculate the address encoded by a 31-bit self-relative offset at address
+   P.  */
+static inline _uw selfrel_offset31 (const _uw *p);
+
+static _uw __gnu_unwind_get_pr_addr (int idx);
+
+static void _Unwind_DebugHook (void *, void *)
+  __attribute__ ((__noinline__, __used__, __noclone__));
+
+/* This function is called during unwinding.  It is intended as a hook
+   for a debugger to intercept exceptions.  CFA is the CFA of the
+   target frame.  HANDLER is the PC to which control will be
+   transferred.  */
+
+static void
+_Unwind_DebugHook (void *cfa __attribute__ ((__unused__)),
+		   void *handler __attribute__ ((__unused__)))
+{
+  /* We only want to use stap probes starting with v3.  Earlier
+     versions added too much startup cost.  */
+#if defined (HAVE_SYS_SDT_H) && defined (STAP_PROBE2) && _SDT_NOTE_TYPE >= 3
+  STAP_PROBE2 (libgcc, unwind, cfa, handler);
+#else
+  asm ("");
+#endif
+}
+
+/* This is a wrapper to be called when we need to restore core registers.
+   It will call `_Unwind_DebugHook' before restoring the registers, thus
+   making it possible to intercept and debug exceptions.
+
+   When calling `_Unwind_DebugHook', the first argument (the CFA) is zero
+   because we are not interested in it.  However, it must be there (even
+   being zero) because GDB expects to find it when using the probe.  */
+
+#define uw_restore_core_regs(TARGET, CORE)				      \
+  do									      \
+    {									      \
+      void *handler = __builtin_frob_return_addr ((void *) VRS_PC (TARGET));  \
+      _Unwind_DebugHook (0, handler);					      \
+      restore_core_regs (CORE);						      \
+    }									      \
+  while (0)
+
+/* Perform a binary search for RETURN_ADDRESS in TABLE.  The table contains
+   NREC entries.  */
+
+static const __EIT_entry *
+search_EIT_table (const __EIT_entry * table, int nrec, _uw return_address)
+{
+  _uw next_fn;
+  _uw this_fn;
+  int n, left, right;
+
+  if (nrec == 0)
+    return (__EIT_entry *) 0;
+
+  left = 0;
+  right = nrec - 1;
+
+  while (1)
+    {
+      n = (left + right) / 2;
+      this_fn = selfrel_offset31 (&table[n].fnoffset);
+      if (n != nrec - 1)
+	next_fn = selfrel_offset31 (&table[n + 1].fnoffset) - 1;
+      else
+	next_fn = (_uw)0 - 1;
+
+      if (return_address < this_fn)
+	{
+	  if (n == left)
+	    return (__EIT_entry *) 0;
+	  right = n - 1;
+	}
+      else if (return_address <= next_fn)
+	return &table[n];
+      else
+	left = n + 1;
+    }
+}
+
+/* Find the exception index table eintry for the given address.
+   Fill in the relevant fields of the UCB.
+   Returns _URC_FAILURE if an error occurred, _URC_OK on success.  */
+
+static _Unwind_Reason_Code
+get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)
+{
+  const __EIT_entry * eitp;
+  int nrec;
+  
+  /* The return address is the address of the instruction following the
+     call instruction (plus one in thumb mode).  If this was the last
+     instruction in the function the address will lie in the following
+     function.  Subtract 2 from the address so that it points within the call
+     instruction itself.  */
+  return_address -= 2;
+
+  if (__gnu_Unwind_Find_exidx)
+    {
+      eitp = (const __EIT_entry *) __gnu_Unwind_Find_exidx (return_address,
+							    &nrec);
+      if (!eitp)
+	{
+	  UCB_PR_ADDR (ucbp) = 0;
+	  return _URC_FAILURE;
+	}
+    }
+  else
+    {
+      eitp = &__exidx_start;
+      nrec = &__exidx_end - &__exidx_start;
+    }
+
+  eitp = search_EIT_table (eitp, nrec, return_address);
+
+  if (!eitp)
+    {
+      UCB_PR_ADDR (ucbp) = 0;
+      return _URC_FAILURE;
+    }
+  ucbp->pr_cache.fnstart = selfrel_offset31 (&eitp->fnoffset);
+
+  /* Can this frame be unwound at all?  */
+  if (eitp->content == EXIDX_CANTUNWIND)
+    {
+      UCB_PR_ADDR (ucbp) = 0;
+      return _URC_END_OF_STACK;
+    }
+
+  /* Obtain the address of the "real" __EHT_Header word.  */
+
+  if (eitp->content & uint32_highbit)
+    {
+      /* It is immediate data.  */
+      ucbp->pr_cache.ehtp = (_Unwind_EHT_Header *)&eitp->content;
+      ucbp->pr_cache.additional = 1;
+    }
+  else
+    {
+      /* The low 31 bits of the content field are a self-relative
+	 offset to an _Unwind_EHT_Entry structure.  */
+      ucbp->pr_cache.ehtp =
+	(_Unwind_EHT_Header *) selfrel_offset31 (&eitp->content);
+      ucbp->pr_cache.additional = 0;
+    }
+
+  /* Discover the personality routine address.  */
+  if (*ucbp->pr_cache.ehtp & (1u << 31))
+    {
+      /* One of the predefined standard routines.  */
+      _uw idx = (*(_uw *) ucbp->pr_cache.ehtp >> 24) & 0xf;
+      UCB_PR_ADDR (ucbp) = __gnu_unwind_get_pr_addr (idx);
+      if (UCB_PR_ADDR (ucbp) == 0)
+	{
+	  /* Failed */
+	  return _URC_FAILURE;
+	}
+    } 
+  else
+    {
+      /* Execute region offset to PR */
+      UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp);
+    }
+  return _URC_OK;
+}
+
+
+/* Perform phase2 unwinding.  VRS is the initial virtual register state.  */
+
+static void __attribute__((noreturn))
+unwind_phase2 (_Unwind_Control_Block * ucbp, phase2_vrs * vrs)
+{
+  _Unwind_Reason_Code pr_result;
+
+  do
+    {
+      /* Find the entry for this routine.  */
+      if (get_eit_entry (ucbp, VRS_PC(vrs)) != _URC_OK)
+	abort ();
+
+      UCB_SAVED_CALLSITE_ADDR (ucbp) = VRS_PC(vrs);
+
+      /* Call the pr to decide what to do.  */
+      pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
+	(_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);
+    }
+  while (pr_result == _URC_CONTINUE_UNWIND);
+  
+  if (pr_result != _URC_INSTALL_CONTEXT)
+    abort();
+
+  uw_restore_core_regs (vrs, &vrs->core);
+}
+
+/* Perform phase2 forced unwinding.  */
+
+static _Unwind_Reason_Code
+unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs,
+		      int resuming)
+{
+  _Unwind_Stop_Fn stop_fn = (_Unwind_Stop_Fn) UCB_FORCED_STOP_FN (ucbp);
+  void *stop_arg = (void *)UCB_FORCED_STOP_ARG (ucbp);
+  _Unwind_Reason_Code pr_result = 0;
+  /* We use phase1_vrs here even though we do not demand save, for the
+     prev_sp field.  */
+  phase1_vrs saved_vrs, next_vrs;
+
+  /* Save the core registers.  */
+  saved_vrs.core = entry_vrs->core;
+  /* We don't need to demand-save the non-core registers, because we
+     unwind in a single pass.  */
+  saved_vrs.demand_save_flags = 0;
+
+  /* Unwind until we reach a propagation barrier.  */
+  do
+    {
+      _Unwind_State action;
+      _Unwind_Reason_Code entry_code;
+      _Unwind_Reason_Code stop_code;
+
+      /* Find the entry for this routine.  */
+      entry_code = get_eit_entry (ucbp, VRS_PC (&saved_vrs));
+
+      if (resuming)
+	{
+	  action = _US_UNWIND_FRAME_RESUME | _US_FORCE_UNWIND;
+	  resuming = 0;
+	}
+      else
+	action = _US_UNWIND_FRAME_STARTING | _US_FORCE_UNWIND;
+
+      if (entry_code == _URC_OK)
+	{
+	  UCB_SAVED_CALLSITE_ADDR (ucbp) = VRS_PC (&saved_vrs);
+
+	  next_vrs = saved_vrs;
+
+	  /* Call the pr to decide what to do.  */
+	  pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
+	    (action, ucbp, (void *) &next_vrs);
+
+	  saved_vrs.prev_sp = VRS_SP (&next_vrs);
+	}
+      else
+	{
+	  /* Treat any failure as the end of unwinding, to cope more
+	     gracefully with missing EH information.  Mixed EH and
+	     non-EH within one object will usually result in failure,
+	     because the .ARM.exidx tables do not indicate the end
+	     of the code to which they apply; but mixed EH and non-EH
+	     shared objects should return an unwind failure at the
+	     entry of a non-EH shared object.  */
+	  action |= _US_END_OF_STACK;
+
+	  saved_vrs.prev_sp = VRS_SP (&saved_vrs);
+	}
+
+      stop_code = stop_fn (1, action, ucbp->exception_class, ucbp,
+			   (void *)&saved_vrs, stop_arg);
+      if (stop_code != _URC_NO_REASON)
+	return _URC_FAILURE;
+
+      if (entry_code != _URC_OK)
+	return entry_code;
+
+      saved_vrs = next_vrs;
+    }
+  while (pr_result == _URC_CONTINUE_UNWIND);
+
+  if (pr_result != _URC_INSTALL_CONTEXT)
+    {
+      /* Some sort of failure has occurred in the pr and probably the
+	 pr returned _URC_FAILURE.  */
+      return _URC_FAILURE;
+    }
+
+  uw_restore_core_regs (&saved_vrs, &saved_vrs.core);
+}
+
+/* This is a very limited implementation of _Unwind_GetCFA.  It returns
+   the stack pointer as it is about to be unwound, and is only valid
+   while calling the stop function during forced unwinding.  If the
+   current personality routine result is going to run a cleanup, this
+   will not be the CFA; but when the frame is really unwound, it will
+   be.  */
+
+_Unwind_Word
+_Unwind_GetCFA (_Unwind_Context *context)
+{
+  return ((phase1_vrs *) context)->prev_sp;
+}
+
+/* Perform phase1 unwinding.  UCBP is the exception being thrown, and
+   entry_VRS is the register state on entry to _Unwind_RaiseException.  */
+
+_Unwind_Reason_Code
+__gnu_Unwind_RaiseException (_Unwind_Control_Block *, phase2_vrs *);
+
+_Unwind_Reason_Code
+__gnu_Unwind_RaiseException (_Unwind_Control_Block * ucbp,
+			     phase2_vrs * entry_vrs)
+{
+  phase1_vrs saved_vrs;
+  _Unwind_Reason_Code pr_result;
+
+  /* Set the pc to the call site.  */
+  VRS_PC (entry_vrs) = VRS_RETURN(entry_vrs);
+
+  /* Save the core registers.  */
+  saved_vrs.core = entry_vrs->core;
+  /* Set demand-save flags.  */
+  saved_vrs.demand_save_flags = ~(_uw) 0;
+  
+  /* Unwind until we reach a propagation barrier.  */
+  do
+    {
+      /* Find the entry for this routine.  */
+      if (get_eit_entry (ucbp, VRS_PC (&saved_vrs)) != _URC_OK)
+	return _URC_FAILURE;
+
+      /* Call the pr to decide what to do.  */
+      pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
+	(_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);
+    }
+  while (pr_result == _URC_CONTINUE_UNWIND);
+
+  /* We've unwound as far as we want to go, so restore the original
+     register state.  */
+  restore_non_core_regs (&saved_vrs);
+  if (pr_result != _URC_HANDLER_FOUND)
+    {
+      /* Some sort of failure has occurred in the pr and probably the
+	 pr returned _URC_FAILURE.  */
+      return _URC_FAILURE;
+    }
+  
+  unwind_phase2 (ucbp, entry_vrs);
+}
+
+/* Resume unwinding after a cleanup has been run.  UCBP is the exception
+   being thrown and ENTRY_VRS is the register state on entry to
+   _Unwind_Resume.  */
+_Unwind_Reason_Code
+__gnu_Unwind_ForcedUnwind (_Unwind_Control_Block *,
+			   _Unwind_Stop_Fn, void *, phase2_vrs *);
+
+_Unwind_Reason_Code
+__gnu_Unwind_ForcedUnwind (_Unwind_Control_Block *ucbp,
+			   _Unwind_Stop_Fn stop_fn, void *stop_arg,
+			   phase2_vrs *entry_vrs)
+{
+  UCB_FORCED_STOP_FN (ucbp) = (_uw) stop_fn;
+  UCB_FORCED_STOP_ARG (ucbp) = (_uw) stop_arg;
+
+  /* Set the pc to the call site.  */
+  VRS_PC (entry_vrs) = VRS_RETURN(entry_vrs);
+
+  return unwind_phase2_forced (ucbp, entry_vrs, 0);
+}
+
+_Unwind_Reason_Code
+__gnu_Unwind_Resume (_Unwind_Control_Block *, phase2_vrs *);
+
+_Unwind_Reason_Code
+__gnu_Unwind_Resume (_Unwind_Control_Block * ucbp, phase2_vrs * entry_vrs)
+{
+  _Unwind_Reason_Code pr_result;
+
+  /* Recover the saved address.  */
+  VRS_PC (entry_vrs) = UCB_SAVED_CALLSITE_ADDR (ucbp);
+
+  if (UCB_FORCED_STOP_FN (ucbp))
+    {
+      unwind_phase2_forced (ucbp, entry_vrs, 1);
+
+      /* We can't return failure at this point.  */
+      abort ();
+    }
+
+  /* Call the cached PR.  */
+  pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
+	(_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);
+
+  switch (pr_result)
+    {
+    case _URC_INSTALL_CONTEXT:
+      /* Upload the registers to enter the landing pad.  */
+      uw_restore_core_regs (entry_vrs, &entry_vrs->core);
+
+    case _URC_CONTINUE_UNWIND:
+      /* Continue unwinding the next frame.  */
+      unwind_phase2 (ucbp, entry_vrs);
+
+    default:
+      abort ();
+    }
+}
+
+_Unwind_Reason_Code
+__gnu_Unwind_Resume_or_Rethrow (_Unwind_Control_Block *, phase2_vrs *);
+
+_Unwind_Reason_Code
+__gnu_Unwind_Resume_or_Rethrow (_Unwind_Control_Block * ucbp,
+				phase2_vrs * entry_vrs)
+{
+  if (!UCB_FORCED_STOP_FN (ucbp))
+    return __gnu_Unwind_RaiseException (ucbp, entry_vrs);
+
+  /* Set the pc to the call site.  */
+  VRS_PC (entry_vrs) = VRS_RETURN (entry_vrs);
+  /* Continue unwinding the next frame.  */
+  return unwind_phase2_forced (ucbp, entry_vrs, 0);
+}
+
+/* Clean up an exception object when unwinding is complete.  */
+void
+_Unwind_Complete (_Unwind_Control_Block * ucbp __attribute__((unused)))
+{
+}
+
+
+/* Free an exception.  */
+
+void
+_Unwind_DeleteException (_Unwind_Exception * exc)
+{
+  if (exc->exception_cleanup)
+    (*exc->exception_cleanup) (_URC_FOREIGN_EXCEPTION_CAUGHT, exc);
+}
+
+
+/* Perform stack backtrace through unwind data.  */
+_Unwind_Reason_Code
+__gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument,
+		       phase2_vrs * entry_vrs);
+_Unwind_Reason_Code
+__gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument,
+		       phase2_vrs * entry_vrs)
+{
+  phase1_vrs saved_vrs;
+  _Unwind_Reason_Code code;
+
+  _Unwind_Control_Block ucb;
+  _Unwind_Control_Block *ucbp = &ucb;
+
+  /* Set the pc to the call site.  */
+  VRS_PC (entry_vrs) = VRS_RETURN (entry_vrs);
+
+  /* Save the core registers.  */
+  saved_vrs.core = entry_vrs->core;
+  /* Set demand-save flags.  */
+  saved_vrs.demand_save_flags = ~(_uw) 0;
+  
+  do
+    {
+      /* Find the entry for this routine.  */
+      if (get_eit_entry (ucbp, VRS_PC (&saved_vrs)) != _URC_OK)
+	{
+	  code = _URC_FAILURE;
+	  break;
+	}
+
+      /* The dwarf unwinder assumes the context structure holds things
+	 like the function and LSDA pointers.  The ARM implementation
+	 caches these in the exception header (UCB).  To avoid
+	 rewriting everything we make the virtual IP register point at
+	 the UCB.  */
+      _Unwind_SetGR((_Unwind_Context *)&saved_vrs, UNWIND_POINTER_REG, (_Unwind_Ptr) ucbp);
+
+      /* Call trace function.  */
+      if ((*trace) ((_Unwind_Context *) &saved_vrs, trace_argument) 
+	  != _URC_NO_REASON)
+	{
+	  code = _URC_FAILURE;
+	  break;
+	}
+
+      /* Call the pr to decide what to do.  */
+      code = ((personality_routine) UCB_PR_ADDR (ucbp))
+	(_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND, 
+	 ucbp, (void *) &saved_vrs);
+    }
+  while (code != _URC_END_OF_STACK
+	 && code != _URC_FAILURE);
+
+  restore_non_core_regs (&saved_vrs);
+  return code;
+}
+
+
+/* Common implementation for ARM ABI defined personality routines.
+   ID is the index of the personality routine, other arguments are as defined
+   by __aeabi_unwind_cpp_pr{0,1,2}.  */
+
+static _Unwind_Reason_Code
+__gnu_unwind_pr_common (_Unwind_State state,
+			_Unwind_Control_Block *ucbp,
+			_Unwind_Context *context,
+			int id)
+{
+  __gnu_unwind_state uws;
+  _uw *data;
+  _uw offset;
+  _uw len;
+  _uw rtti_count;
+  int phase2_call_unexpected_after_unwind = 0;
+  int in_range = 0;
+  int forced_unwind = state & _US_FORCE_UNWIND;
+
+  state &= _US_ACTION_MASK;
+
+  data = (_uw *) ucbp->pr_cache.ehtp;
+  uws.data = *(data++);
+  uws.next = data;
+  if (id == 0)
+    {
+      uws.data <<= 8;
+      uws.words_left = 0;
+      uws.bytes_left = 3;
+    }
+  else if (id < 3)
+    {
+      uws.words_left = (uws.data >> 16) & 0xff;
+      uws.data <<= 16;
+      uws.bytes_left = 2;
+      data += uws.words_left;
+    }
+
+  /* Restore the saved pointer.  */
+  if (state == _US_UNWIND_FRAME_RESUME)
+    data = (_uw *) ucbp->cleanup_cache.bitpattern[0];
+
+  if ((ucbp->pr_cache.additional & 1) == 0)
+    {
+      /* Process descriptors.  */
+      while (*data)
+	{
+	  _uw addr;
+	  _uw fnstart;
+
+	  if (id == 2)
+	    {
+	      len = ((EHT32 *) data)->length;
+	      offset = ((EHT32 *) data)->offset;
+	      data += 2;
+	    }
+	  else
+	    {
+	      len = ((EHT16 *) data)->length;
+	      offset = ((EHT16 *) data)->offset;
+	      data++;
+	    }
+
+	  fnstart = ucbp->pr_cache.fnstart + (offset & ~1);
+	  addr = _Unwind_GetGR (context, R_PC);
+	  in_range = (fnstart <= addr && addr < fnstart + (len & ~1));
+
+	  switch (((offset & 1) << 1) | (len & 1))
+	    {
+	    case 0:
+	      /* Cleanup.  */
+	      if (state != _US_VIRTUAL_UNWIND_FRAME
+		  && in_range)
+		{
+		  /* Cleanup in range, and we are running cleanups.  */
+		  _uw lp;
+
+		  /* Landing pad address is 31-bit pc-relative offset.  */
+		  lp = selfrel_offset31 (data);
+		  data++;
+		  /* Save the exception data pointer.  */
+		  ucbp->cleanup_cache.bitpattern[0] = (_uw) data;
+		  if (!__cxa_begin_cleanup (ucbp))
+		    return _URC_FAILURE;
+		  /* Setup the VRS to enter the landing pad.  */
+		  _Unwind_SetGR (context, R_PC, lp);
+		  return _URC_INSTALL_CONTEXT;
+		}
+	      /* Cleanup not in range, or we are in stage 1.  */
+	      data++;
+	      break;
+
+	    case 1:
+	      /* Catch handler.  */
+	      if (state == _US_VIRTUAL_UNWIND_FRAME)
+		{
+		  if (in_range)
+		    {
+		      /* Check for a barrier.  */
+		      _uw rtti;
+		      bool is_reference = (data[0] & uint32_highbit) != 0;
+		      void *matched;
+		      enum __cxa_type_match_result match_type;
+
+		      /* Check for no-throw areas.  */
+		      if (data[1] == (_uw) -2)
+			return _URC_FAILURE;
+
+		      /* The thrown object immediately follows the ECB.  */
+		      matched = (void *)(ucbp + 1);
+		      if (data[1] != (_uw) -1)
+			{
+			  /* Match a catch specification.  */
+			  rtti = _Unwind_decode_typeinfo_ptr (0,
+							      (_uw) &data[1]);
+			  match_type = __cxa_type_match (ucbp,
+							 (type_info *) rtti,
+							 is_reference,
+							 &matched);
+			}
+		      else
+			match_type = ctm_succeeded;
+
+		      if (match_type)
+			{
+			  ucbp->barrier_cache.sp =
+			    _Unwind_GetGR (context, R_SP);
+			  // ctm_succeeded_with_ptr_to_base really
+			  // means _c_t_m indirected the pointer
+			  // object.  We have to reconstruct the
+			  // additional pointer layer by using a temporary.
+			  if (match_type == ctm_succeeded_with_ptr_to_base)
+			    {
+			      ucbp->barrier_cache.bitpattern[2]
+				= (_uw) matched;
+			      ucbp->barrier_cache.bitpattern[0]
+				= (_uw) &ucbp->barrier_cache.bitpattern[2];
+			    }
+			  else
+			    ucbp->barrier_cache.bitpattern[0] = (_uw) matched;
+			  ucbp->barrier_cache.bitpattern[1] = (_uw) data;
+			  return _URC_HANDLER_FOUND;
+			}
+		    }
+		  /* Handler out of range, or not matched.  */
+		}
+	      else if (ucbp->barrier_cache.sp == _Unwind_GetGR (context, R_SP)
+		       && ucbp->barrier_cache.bitpattern[1] == (_uw) data)
+		{
+		  /* Matched a previous propagation barrier.  */
+		  _uw lp;
+
+		  /* Setup for entry to the handler.  */
+		  lp = selfrel_offset31 (data);
+		  _Unwind_SetGR (context, R_PC, lp);
+		  _Unwind_SetGR (context, 0, (_uw) ucbp);
+		  return _URC_INSTALL_CONTEXT;
+		}
+	      /* Catch handler not matched.  Advance to the next descriptor.  */
+	      data += 2;
+	      break;
+
+	    case 2:
+	      rtti_count = data[0] & 0x7fffffff;
+	      /* Exception specification.  */
+	      if (state == _US_VIRTUAL_UNWIND_FRAME)
+		{
+		  if (in_range && (!forced_unwind || !rtti_count))
+		    {
+		      /* Match against the exception specification.  */
+		      _uw i;
+		      _uw rtti;
+		      void *matched;
+
+		      for (i = 0; i < rtti_count; i++)
+			{
+			  matched = (void *)(ucbp + 1);
+			  rtti = _Unwind_decode_typeinfo_ptr (0,
+			      (_uw) &data[i + 1]);
+			  if (__cxa_type_match (ucbp, (type_info *) rtti, 0,
+						&matched))
+			    break;
+			}
+
+		      if (i == rtti_count)
+			{
+			  /* Exception does not match the spec.  */
+			  ucbp->barrier_cache.sp =
+			    _Unwind_GetGR (context, R_SP);
+			  ucbp->barrier_cache.bitpattern[0] = (_uw) matched;
+			  ucbp->barrier_cache.bitpattern[1] = (_uw) data;
+			  return _URC_HANDLER_FOUND;
+			}
+		    }
+		  /* Handler out of range, or exception is permitted.  */
+		}
+	      else if (ucbp->barrier_cache.sp == _Unwind_GetGR (context, R_SP)
+		       && ucbp->barrier_cache.bitpattern[1] == (_uw) data)
+		{
+		  /* Matched a previous propagation barrier.  */
+		  _uw lp;
+		  /* Record the RTTI list for __cxa_call_unexpected.  */
+		  ucbp->barrier_cache.bitpattern[1] = rtti_count;
+		  ucbp->barrier_cache.bitpattern[2] = 0;
+		  ucbp->barrier_cache.bitpattern[3] = 4;
+		  ucbp->barrier_cache.bitpattern[4] = (_uw) &data[1];
+
+		  if (data[0] & uint32_highbit)
+		    {
+		      data += rtti_count + 1;
+		      /* Setup for entry to the handler.  */
+		      lp = selfrel_offset31 (data);
+		      data++;
+		      _Unwind_SetGR (context, R_PC, lp);
+		      _Unwind_SetGR (context, 0, (_uw) ucbp);
+		      return _URC_INSTALL_CONTEXT;
+		    }
+		  else
+		    phase2_call_unexpected_after_unwind = 1;
+		}
+	      if (data[0] & uint32_highbit)
+		data++;
+	      data += rtti_count + 1;
+	      break;
+
+	    default:
+	      /* Should never happen.  */
+	      return _URC_FAILURE;
+	    }
+	  /* Finished processing this descriptor.  */
+	}
+    }
+
+  if (id >= 3)
+    {
+      /* 24-bit ecoding */
+      if (__gnu_unwind_24bit (context, uws.data, id == 4) != _URC_OK)
+	return _URC_FAILURE;
+    }
+  else
+    {
+      if (__gnu_unwind_execute (context, &uws) != _URC_OK)
+	return _URC_FAILURE;
+    }
+    
+  if (phase2_call_unexpected_after_unwind)
+    {
+      /* Enter __cxa_unexpected as if called from the call site.  */
+      _Unwind_SetGR (context, R_LR, _Unwind_GetGR (context, R_PC));
+      _Unwind_SetGR (context, R_PC, (_uw) &__cxa_call_unexpected);
+      return _URC_INSTALL_CONTEXT;
+    }
+
+  return _URC_CONTINUE_UNWIND;
+}