sim/aarch64/cpustate.c - binutils-gdb - Git at Google

 /* cpustate.h -- Prototypes for AArch64 simulator functions.

    Copyright (C) 2015-2022 Free Software Foundation, Inc.

    Contributed by Red Hat.

    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/>.  */

 /* This must come before any other includes.  */
 #include "defs.h"

 #include <stdio.h>
 #include <math.h>

 #include "sim-main.h"
 #include "sim-signal.h"
 #include "cpustate.h"
 #include "simulator.h"
 #include "libiberty.h"

 /* Some operands are allowed to access the stack pointer (reg 31).
    For others a read from r31 always returns 0, and a write to r31 is ignored.  */
 #define reg_num(reg) (((reg) == R31 && !r31_is_sp) ? 32 : (reg))

 void
 aarch64_set_reg_u64 (sim_cpu *cpu, GReg reg, int r31_is_sp, uint64_t val)
 {
   if (reg == R31 && ! r31_is_sp)
     {
       TRACE_REGISTER (cpu, "GR[31] NOT CHANGED!");
       return;
     }

   if (val != cpu->gr[reg].u64)
     TRACE_REGISTER (cpu,
 		    "GR[%2d] changes from %16" PRIx64 " to %16" PRIx64,
 		    reg, cpu->gr[reg].u64, val);

   cpu->gr[reg].u64 = val;
 }

 void
 aarch64_set_reg_s64 (sim_cpu *cpu, GReg reg, int r31_is_sp, int64_t val)
 {
   if (reg == R31 && ! r31_is_sp)
     {
       TRACE_REGISTER (cpu, "GR[31] NOT CHANGED!");
       return;
     }

   if (val != cpu->gr[reg].s64)
     TRACE_REGISTER (cpu,
 		    "GR[%2d] changes from %16" PRIx64 " to %16" PRIx64,
 		    reg, cpu->gr[reg].s64, val);

   cpu->gr[reg].s64 = val;
 }

 uint64_t
 aarch64_get_reg_u64 (sim_cpu *cpu, GReg reg, int r31_is_sp)
 {
   return cpu->gr[reg_num(reg)].u64;
 }

 int64_t
 aarch64_get_reg_s64 (sim_cpu *cpu, GReg reg, int r31_is_sp)
 {
   return cpu->gr[reg_num(reg)].s64;
 }

 uint32_t
 aarch64_get_reg_u32 (sim_cpu *cpu, GReg reg, int r31_is_sp)
 {
   return cpu->gr[reg_num(reg)].u32;
 }

 int32_t
 aarch64_get_reg_s32 (sim_cpu *cpu, GReg reg, int r31_is_sp)
 {
   return cpu->gr[reg_num(reg)].s32;
 }

 void
 aarch64_set_reg_s32 (sim_cpu *cpu, GReg reg, int r31_is_sp, int32_t val)
 {
   if (reg == R31 && ! r31_is_sp)
     {
       TRACE_REGISTER (cpu, "GR[31] NOT CHANGED!");
       return;
     }

   if (val != cpu->gr[reg].s32)
     TRACE_REGISTER (cpu, "GR[%2d] changes from %8x to %8x",
 		    reg, cpu->gr[reg].s32, val);

   /* The ARM ARM states that (C1.2.4):
         When the data size is 32 bits, the lower 32 bits of the
 	register are used and the upper 32 bits are ignored on
 	a read and cleared to zero on a write.
      We simulate this by first clearing the whole 64-bits and
      then writing to the 32-bit value in the GRegister union.  */
   cpu->gr[reg].s64 = 0;
   cpu->gr[reg].s32 = val;
 }

 void
 aarch64_set_reg_u32 (sim_cpu *cpu, GReg reg, int r31_is_sp, uint32_t val)
 {
   if (reg == R31 && ! r31_is_sp)
     {
       TRACE_REGISTER (cpu, "GR[31] NOT CHANGED!");
       return;
     }

   if (val != cpu->gr[reg].u32)
     TRACE_REGISTER (cpu, "GR[%2d] changes from %8x to %8x",
 		    reg, cpu->gr[reg].u32, val);

   cpu->gr[reg].u64 = 0;
   cpu->gr[reg].u32 = val;
 }

 uint32_t
 aarch64_get_reg_u16 (sim_cpu *cpu, GReg reg, int r31_is_sp)
 {
   return cpu->gr[reg_num(reg)].u16;
 }

 int32_t
 aarch64_get_reg_s16 (sim_cpu *cpu, GReg reg, int r31_is_sp)
 {
   return cpu->gr[reg_num(reg)].s16;
 }

 uint32_t
 aarch64_get_reg_u8 (sim_cpu *cpu, GReg reg, int r31_is_sp)
 {
   return cpu->gr[reg_num(reg)].u8;
 }

 int32_t
 aarch64_get_reg_s8 (sim_cpu *cpu, GReg reg, int r31_is_sp)
 {
   return cpu->gr[reg_num(reg)].s8;
 }

 uint64_t
 aarch64_get_PC (sim_cpu *cpu)
 {
   return cpu->pc;
 }

 uint64_t
 aarch64_get_next_PC (sim_cpu *cpu)
 {
   return cpu->nextpc;
 }

 void
 aarch64_set_next_PC (sim_cpu *cpu, uint64_t next)
 {
   if (next != cpu->nextpc + 4)
     TRACE_REGISTER (cpu,
 		    "NextPC changes from %16" PRIx64 " to %16" PRIx64,
 		    cpu->nextpc, next);

   cpu->nextpc = next;
 }

 void
 aarch64_set_next_PC_by_offset (sim_cpu *cpu, int64_t offset)
 {
   if (cpu->pc + offset != cpu->nextpc + 4)
     TRACE_REGISTER (cpu,
 		    "NextPC changes from %16" PRIx64 " to %16" PRIx64,
 		    cpu->nextpc, cpu->pc + offset);

   cpu->nextpc = cpu->pc + offset;
 }

 /* Install nextpc as current pc.  */
 void
 aarch64_update_PC (sim_cpu *cpu)
 {
   cpu->pc = cpu->nextpc;
   /* Rezero the register we hand out when asked for ZR just in case it
      was used as the destination for a write by the previous
      instruction.  */
   cpu->gr[32].u64 = 0UL;
 }

 /* This instruction can be used to save the next PC to LR
    just before installing a branch PC.  */
 void
 aarch64_save_LR (sim_cpu *cpu)
 {
   if (cpu->gr[LR].u64 != cpu->nextpc)
     TRACE_REGISTER (cpu,
 		    "LR    changes from %16" PRIx64 " to %16" PRIx64,
 		    cpu->gr[LR].u64, cpu->nextpc);

   cpu->gr[LR].u64 = cpu->nextpc;
 }

 static const char *
 decode_cpsr (FlagMask flags)
 {
   switch (flags & CPSR_ALL_FLAGS)
     {
     default:
     case 0:  return "----";
     case 1:  return "---V";
     case 2:  return "--C-";
     case 3:  return "--CV";
     case 4:  return "-Z--";
     case 5:  return "-Z-V";
     case 6:  return "-ZC-";
     case 7:  return "-ZCV";
     case 8:  return "N---";
     case 9:  return "N--V";
     case 10: return "N-C-";
     case 11: return "N-CV";
     case 12: return "NZ--";
     case 13: return "NZ-V";
     case 14: return "NZC-";
     case 15: return "NZCV";
     }
 }

 /* Retrieve the CPSR register as an int.  */
 uint32_t
 aarch64_get_CPSR (sim_cpu *cpu)
 {
   return cpu->CPSR;
 }

 /* Set the CPSR register as an int.  */
 void
 aarch64_set_CPSR (sim_cpu *cpu, uint32_t new_flags)
 {
   if (TRACE_REGISTER_P (cpu))
     {
       if (cpu->CPSR != new_flags)
 	TRACE_REGISTER (cpu,
 			"CPSR changes from %s to %s",
 			decode_cpsr (cpu->CPSR), decode_cpsr (new_flags));
       else
 	TRACE_REGISTER (cpu,
 			"CPSR stays at %s", decode_cpsr (cpu->CPSR));
     }

   cpu->CPSR = new_flags & CPSR_ALL_FLAGS;
 }

 /* Read a specific subset of the CPSR as a bit pattern.  */
 uint32_t
 aarch64_get_CPSR_bits (sim_cpu *cpu, FlagMask mask)
 {
   return cpu->CPSR & mask;
 }

 /* Assign a specific subset of the CPSR as a bit pattern.  */
 void
 aarch64_set_CPSR_bits (sim_cpu *cpu, uint32_t mask, uint32_t value)
 {
   uint32_t old_flags = cpu->CPSR;

   mask &= CPSR_ALL_FLAGS;
   cpu->CPSR &= ~ mask;
   cpu->CPSR |= (value & mask);

   if (old_flags != cpu->CPSR)
     TRACE_REGISTER (cpu,
 		    "CPSR changes from %s to %s",
 		    decode_cpsr (old_flags), decode_cpsr (cpu->CPSR));
 }

 /* Test the value of a single CPSR returned as non-zero or zero.  */
 uint32_t
 aarch64_test_CPSR_bit (sim_cpu *cpu, FlagMask bit)
 {
   return cpu->CPSR & bit;
 }

 /* Set a single flag in the CPSR.  */
 void
 aarch64_set_CPSR_bit (sim_cpu *cpu, FlagMask bit)
 {
   uint32_t old_flags = cpu->CPSR;

   cpu->CPSR |= (bit & CPSR_ALL_FLAGS);

   if (old_flags != cpu->CPSR)
     TRACE_REGISTER (cpu,
 		    "CPSR changes from %s to %s",
 		    decode_cpsr (old_flags), decode_cpsr (cpu->CPSR));
 }

 /* Clear a single flag in the CPSR.  */
 void
 aarch64_clear_CPSR_bit (sim_cpu *cpu, FlagMask bit)
 {
   uint32_t old_flags = cpu->CPSR;

   cpu->CPSR &= ~(bit & CPSR_ALL_FLAGS);

   if (old_flags != cpu->CPSR)
     TRACE_REGISTER (cpu,
 		    "CPSR changes from %s to %s",
 		    decode_cpsr (old_flags), decode_cpsr (cpu->CPSR));
 }

 float
 aarch64_get_FP_half (sim_cpu *cpu, VReg reg)
 {
   union
   {
     uint16_t h[2];
     float    f;
   } u;

   u.h[0] = 0;
   u.h[1] = cpu->fr[reg].h[0];
   return u.f;
 }


 float
 aarch64_get_FP_float (sim_cpu *cpu, VReg reg)
 {
   return cpu->fr[reg].s;
 }

 double
 aarch64_get_FP_double (sim_cpu *cpu, VReg reg)
 {
   return cpu->fr[reg].d;
 }

 void
 aarch64_get_FP_long_double (sim_cpu *cpu, VReg reg, FRegister *a)
 {
   a->v[0] = cpu->fr[reg].v[0];
   a->v[1] = cpu->fr[reg].v[1];
 }

 void
 aarch64_set_FP_half (sim_cpu *cpu, VReg reg, float val)
 {
   union
   {
     uint16_t h[2];
     float    f;
   } u;

   u.f = val;
   cpu->fr[reg].h[0] = u.h[1];
   cpu->fr[reg].h[1] = 0;
 }


 void
 aarch64_set_FP_float (sim_cpu *cpu, VReg reg, float val)
 {
   if (val != cpu->fr[reg].s
       /* Handle +/- zero.  */
       || signbit (val) != signbit (cpu->fr[reg].s))
     {
       FRegister v;

       v.s = val;
       TRACE_REGISTER (cpu,
 		      "FR[%d].s changes from %f to %f [hex: %0" PRIx64 "]",
 		      reg, cpu->fr[reg].s, val, v.v[0]);
     }

   cpu->fr[reg].s = val;
 }

 void
 aarch64_set_FP_double (sim_cpu *cpu, VReg reg, double val)
 {
   if (val != cpu->fr[reg].d
       /* Handle +/- zero.  */
       || signbit (val) != signbit (cpu->fr[reg].d))
     {
       FRegister v;

       v.d = val;
       TRACE_REGISTER (cpu,
 		      "FR[%d].d changes from %f to %f [hex: %0" PRIx64 "]",
 		      reg, cpu->fr[reg].d, val, v.v[0]);
     }
   cpu->fr[reg].d = val;
 }

 void
 aarch64_set_FP_long_double (sim_cpu *cpu, VReg reg, FRegister a)
 {
   if (cpu->fr[reg].v[0] != a.v[0]
       || cpu->fr[reg].v[1] != a.v[1])
     TRACE_REGISTER (cpu,
 		    "FR[%d].q changes from [%0" PRIx64 " %0" PRIx64 "] to [%0"
 		    PRIx64 " %0" PRIx64 "] ",
 		    reg,
 		    cpu->fr[reg].v[0], cpu->fr[reg].v[1],
 		    a.v[0], a.v[1]);

   cpu->fr[reg].v[0] = a.v[0];
   cpu->fr[reg].v[1] = a.v[1];
 }

 #define GET_VEC_ELEMENT(REG, ELEMENT, FIELD)	   \
   do						   \
     {						   \
       if (ELEMENT >= ARRAY_SIZE (cpu->fr[0].FIELD)) \
 	{								\
 	  TRACE_REGISTER (cpu, \
 			  "Internal SIM error: invalid element number: %d ",\
 			  ELEMENT);					\
 	  sim_engine_halt (CPU_STATE (cpu), cpu, NULL, aarch64_get_PC (cpu), \
 			   sim_stopped, SIM_SIGBUS);			\
 	}								\
       return cpu->fr[REG].FIELD [ELEMENT];				\
     }									\
   while (0)

 uint64_t
 aarch64_get_vec_u64 (sim_cpu *cpu, VReg reg, unsigned element)
 {
   GET_VEC_ELEMENT (reg, element, v);
 }

 uint32_t
 aarch64_get_vec_u32 (sim_cpu *cpu, VReg reg, unsigned element)
 {
   GET_VEC_ELEMENT (reg, element, w);
 }

 uint16_t
 aarch64_get_vec_u16 (sim_cpu *cpu, VReg reg, unsigned element)
 {
   GET_VEC_ELEMENT (reg, element, h);
 }

 uint8_t
 aarch64_get_vec_u8 (sim_cpu *cpu, VReg reg, unsigned element)
 {
   GET_VEC_ELEMENT (reg, element, b);
 }

 int64_t
 aarch64_get_vec_s64 (sim_cpu *cpu, VReg reg, unsigned element)
 {
   GET_VEC_ELEMENT (reg, element, V);
 }

 int32_t
 aarch64_get_vec_s32 (sim_cpu *cpu, VReg reg, unsigned element)
 {
   GET_VEC_ELEMENT (reg, element, W);
 }

 int16_t
 aarch64_get_vec_s16 (sim_cpu *cpu, VReg reg, unsigned element)
 {
   GET_VEC_ELEMENT (reg, element, H);
 }

 int8_t
 aarch64_get_vec_s8 (sim_cpu *cpu, VReg reg, unsigned element)
 {
   GET_VEC_ELEMENT (reg, element, B);
 }

 float
 aarch64_get_vec_float (sim_cpu *cpu, VReg reg, unsigned element)
 {
   GET_VEC_ELEMENT (reg, element, S);
 }

 double
 aarch64_get_vec_double (sim_cpu *cpu, VReg reg, unsigned element)
 {
   GET_VEC_ELEMENT (reg, element, D);
 }


 #define SET_VEC_ELEMENT(REG, ELEMENT, VAL, FIELD, PRINTER)		\
   do									\
     {									\
       if (ELEMENT >= ARRAY_SIZE (cpu->fr[0].FIELD))			\
 	{								\
 	  TRACE_REGISTER (cpu,						\
 			  "Internal SIM error: invalid element number: %d ",\
 			  ELEMENT);					\
 	  sim_engine_halt (CPU_STATE (cpu), cpu, NULL, aarch64_get_PC (cpu), \
 			   sim_stopped, SIM_SIGBUS);			\
 	}								\
       if (VAL != cpu->fr[REG].FIELD [ELEMENT])				\
 	TRACE_REGISTER (cpu,						\
 			"VR[%2d]." #FIELD " [%d] changes from " PRINTER \
 			" to " PRINTER , REG,				\
 			ELEMENT, cpu->fr[REG].FIELD [ELEMENT], VAL);	\
 									\
       cpu->fr[REG].FIELD [ELEMENT] = VAL;				\
     }									\
   while (0)

 void
 aarch64_set_vec_u64 (sim_cpu *cpu, VReg reg, unsigned element, uint64_t val)
 {
   SET_VEC_ELEMENT (reg, element, val, v, "%16" PRIx64);
 }

 void
 aarch64_set_vec_u32 (sim_cpu *cpu, VReg reg, unsigned element, uint32_t val)
 {
   SET_VEC_ELEMENT (reg, element, val, w, "%8x");
 }

 void
 aarch64_set_vec_u16 (sim_cpu *cpu, VReg reg, unsigned element, uint16_t val)
 {
   SET_VEC_ELEMENT (reg, element, val, h, "%4x");
 }

 void
 aarch64_set_vec_u8 (sim_cpu *cpu, VReg reg, unsigned element, uint8_t val)
 {
   SET_VEC_ELEMENT (reg, element, val, b, "%x");
 }

 void
 aarch64_set_vec_s64 (sim_cpu *cpu, VReg reg, unsigned element, int64_t val)
 {
   SET_VEC_ELEMENT (reg, element, val, V, "%16" PRIx64);
 }

 void
 aarch64_set_vec_s32 (sim_cpu *cpu, VReg reg, unsigned element, int32_t val)
 {
   SET_VEC_ELEMENT (reg, element, val, W, "%8x");
 }

 void
 aarch64_set_vec_s16 (sim_cpu *cpu, VReg reg, unsigned element, int16_t val)
 {
   SET_VEC_ELEMENT (reg, element, val, H, "%4x");
 }

 void
 aarch64_set_vec_s8 (sim_cpu *cpu, VReg reg, unsigned element, int8_t val)
 {
   SET_VEC_ELEMENT (reg, element, val, B, "%x");
 }

 void
 aarch64_set_vec_float (sim_cpu *cpu, VReg reg, unsigned element, float val)
 {
   SET_VEC_ELEMENT (reg, element, val, S, "%f");
 }

 void
 aarch64_set_vec_double (sim_cpu *cpu, VReg reg, unsigned element, double val)
 {
   SET_VEC_ELEMENT (reg, element, val, D, "%f");
 }

 void
 aarch64_set_FPSR (sim_cpu *cpu, uint32_t value)
 {
   if (cpu->FPSR != value)
     TRACE_REGISTER (cpu,
 		    "FPSR changes from %x to %x", cpu->FPSR, value);

   cpu->FPSR = value & FPSR_ALL_FPSRS;
 }

 uint32_t
 aarch64_get_FPSR (sim_cpu *cpu)
 {
   return cpu->FPSR;
 }

 void
 aarch64_set_FPSR_bits (sim_cpu *cpu, uint32_t mask, uint32_t value)
 {
   uint32_t old_FPSR = cpu->FPSR;

   mask &= FPSR_ALL_FPSRS;
   cpu->FPSR &= ~mask;
   cpu->FPSR |= (value & mask);

   if (cpu->FPSR != old_FPSR)
     TRACE_REGISTER (cpu,
 		    "FPSR changes from %x to %x", old_FPSR, cpu->FPSR);
 }

 uint32_t
 aarch64_get_FPSR_bits (sim_cpu *cpu, uint32_t mask)
 {
   mask &= FPSR_ALL_FPSRS;
   return cpu->FPSR & mask;
 }

 int
 aarch64_test_FPSR_bit (sim_cpu *cpu, FPSRMask flag)
 {
   return cpu->FPSR & flag;
 }

 uint64_t
 aarch64_get_thread_id (sim_cpu *cpu)
 {
   return cpu->tpidr;
 }

 uint32_t
 aarch64_get_FPCR (sim_cpu *cpu)
 {
   return cpu->FPCR;
 }

 void
 aarch64_set_FPCR (sim_cpu *cpu, uint32_t val)
 {
   if (cpu->FPCR != val)
     TRACE_REGISTER (cpu,
 		    "FPCR changes from %x to %x", cpu->FPCR, val);
   cpu->FPCR = val;
 }
	/* cpustate.h -- Prototypes for AArch64 simulator functions.

	Copyright (C) 2015-2022 Free Software Foundation, Inc.

	Contributed by Red Hat.

	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/>. */

	/* This must come before any other includes. */
	#include "defs.h"

	#include <stdio.h>
	#include <math.h>

	#include "sim-main.h"
	#include "sim-signal.h"
	#include "cpustate.h"
	#include "simulator.h"
	#include "libiberty.h"

	/* Some operands are allowed to access the stack pointer (reg 31).
	For others a read from r31 always returns 0, and a write to r31 is ignored. */
	#define reg_num(reg) (((reg) == R31 && !r31_is_sp) ? 32 : (reg))

	void
	aarch64_set_reg_u64 (sim_cpu *cpu, GReg reg, int r31_is_sp, uint64_t val)
	{
	if (reg == R31 && ! r31_is_sp)
	{
	TRACE_REGISTER (cpu, "GR[31] NOT CHANGED!");
	return;
	}

	if (val != cpu->gr[reg].u64)
	TRACE_REGISTER (cpu,
	"GR[%2d] changes from %16" PRIx64 " to %16" PRIx64,
	reg, cpu->gr[reg].u64, val);

	cpu->gr[reg].u64 = val;
	}

	void
	aarch64_set_reg_s64 (sim_cpu *cpu, GReg reg, int r31_is_sp, int64_t val)
	{
	if (reg == R31 && ! r31_is_sp)
	{
	TRACE_REGISTER (cpu, "GR[31] NOT CHANGED!");
	return;
	}

	if (val != cpu->gr[reg].s64)
	TRACE_REGISTER (cpu,
	"GR[%2d] changes from %16" PRIx64 " to %16" PRIx64,
	reg, cpu->gr[reg].s64, val);

	cpu->gr[reg].s64 = val;
	}

	uint64_t
	aarch64_get_reg_u64 (sim_cpu *cpu, GReg reg, int r31_is_sp)
	{
	return cpu->gr[reg_num(reg)].u64;
	}

	int64_t
	aarch64_get_reg_s64 (sim_cpu *cpu, GReg reg, int r31_is_sp)
	{
	return cpu->gr[reg_num(reg)].s64;
	}

	uint32_t
	aarch64_get_reg_u32 (sim_cpu *cpu, GReg reg, int r31_is_sp)
	{
	return cpu->gr[reg_num(reg)].u32;
	}

	int32_t
	aarch64_get_reg_s32 (sim_cpu *cpu, GReg reg, int r31_is_sp)
	{
	return cpu->gr[reg_num(reg)].s32;
	}

	void
	aarch64_set_reg_s32 (sim_cpu *cpu, GReg reg, int r31_is_sp, int32_t val)
	{
	if (reg == R31 && ! r31_is_sp)
	{
	TRACE_REGISTER (cpu, "GR[31] NOT CHANGED!");
	return;
	}

	if (val != cpu->gr[reg].s32)
	TRACE_REGISTER (cpu, "GR[%2d] changes from %8x to %8x",
	reg, cpu->gr[reg].s32, val);

	/* The ARM ARM states that (C1.2.4):
	When the data size is 32 bits, the lower 32 bits of the
	register are used and the upper 32 bits are ignored on
	a read and cleared to zero on a write.
	We simulate this by first clearing the whole 64-bits and
	then writing to the 32-bit value in the GRegister union. */
	cpu->gr[reg].s64 = 0;
	cpu->gr[reg].s32 = val;
	}

	void
	aarch64_set_reg_u32 (sim_cpu *cpu, GReg reg, int r31_is_sp, uint32_t val)
	{
	if (reg == R31 && ! r31_is_sp)
	{
	TRACE_REGISTER (cpu, "GR[31] NOT CHANGED!");
	return;
	}

	if (val != cpu->gr[reg].u32)
	TRACE_REGISTER (cpu, "GR[%2d] changes from %8x to %8x",
	reg, cpu->gr[reg].u32, val);

	cpu->gr[reg].u64 = 0;
	cpu->gr[reg].u32 = val;
	}

	uint32_t
	aarch64_get_reg_u16 (sim_cpu *cpu, GReg reg, int r31_is_sp)
	{
	return cpu->gr[reg_num(reg)].u16;
	}

	int32_t
	aarch64_get_reg_s16 (sim_cpu *cpu, GReg reg, int r31_is_sp)
	{
	return cpu->gr[reg_num(reg)].s16;
	}

	uint32_t
	aarch64_get_reg_u8 (sim_cpu *cpu, GReg reg, int r31_is_sp)
	{
	return cpu->gr[reg_num(reg)].u8;
	}

	int32_t
	aarch64_get_reg_s8 (sim_cpu *cpu, GReg reg, int r31_is_sp)
	{
	return cpu->gr[reg_num(reg)].s8;
	}

	uint64_t
	aarch64_get_PC (sim_cpu *cpu)
	{
	return cpu->pc;
	}

	uint64_t
	aarch64_get_next_PC (sim_cpu *cpu)
	{
	return cpu->nextpc;
	}

	void
	aarch64_set_next_PC (sim_cpu *cpu, uint64_t next)
	{
	if (next != cpu->nextpc + 4)
	TRACE_REGISTER (cpu,
	"NextPC changes from %16" PRIx64 " to %16" PRIx64,
	cpu->nextpc, next);

	cpu->nextpc = next;
	}

	void
	aarch64_set_next_PC_by_offset (sim_cpu *cpu, int64_t offset)
	{
	if (cpu->pc + offset != cpu->nextpc + 4)
	TRACE_REGISTER (cpu,
	"NextPC changes from %16" PRIx64 " to %16" PRIx64,
	cpu->nextpc, cpu->pc + offset);

	cpu->nextpc = cpu->pc + offset;
	}

	/* Install nextpc as current pc. */
	void
	aarch64_update_PC (sim_cpu *cpu)
	{
	cpu->pc = cpu->nextpc;
	/* Rezero the register we hand out when asked for ZR just in case it
	was used as the destination for a write by the previous
	instruction. */
	cpu->gr[32].u64 = 0UL;
	}

	/* This instruction can be used to save the next PC to LR
	just before installing a branch PC. */
	void
	aarch64_save_LR (sim_cpu *cpu)
	{
	if (cpu->gr[LR].u64 != cpu->nextpc)
	TRACE_REGISTER (cpu,
	"LR changes from %16" PRIx64 " to %16" PRIx64,
	cpu->gr[LR].u64, cpu->nextpc);

	cpu->gr[LR].u64 = cpu->nextpc;
	}

	static const char *
	decode_cpsr (FlagMask flags)
	{
	switch (flags & CPSR_ALL_FLAGS)
	{
	default:
	case 0: return "----";
	case 1: return "---V";
	case 2: return "--C-";
	case 3: return "--CV";
	case 4: return "-Z--";
	case 5: return "-Z-V";
	case 6: return "-ZC-";
	case 7: return "-ZCV";
	case 8: return "N---";
	case 9: return "N--V";
	case 10: return "N-C-";
	case 11: return "N-CV";
	case 12: return "NZ--";
	case 13: return "NZ-V";
	case 14: return "NZC-";
	case 15: return "NZCV";
	}
	}

	/* Retrieve the CPSR register as an int. */
	uint32_t
	aarch64_get_CPSR (sim_cpu *cpu)
	{
	return cpu->CPSR;
	}

	/* Set the CPSR register as an int. */
	void
	aarch64_set_CPSR (sim_cpu *cpu, uint32_t new_flags)
	{
	if (TRACE_REGISTER_P (cpu))
	{
	if (cpu->CPSR != new_flags)
	TRACE_REGISTER (cpu,
	"CPSR changes from %s to %s",
	decode_cpsr (cpu->CPSR), decode_cpsr (new_flags));
	else
	TRACE_REGISTER (cpu,
	"CPSR stays at %s", decode_cpsr (cpu->CPSR));
	}

	cpu->CPSR = new_flags & CPSR_ALL_FLAGS;
	}

	/* Read a specific subset of the CPSR as a bit pattern. */
	uint32_t
	aarch64_get_CPSR_bits (sim_cpu *cpu, FlagMask mask)
	{
	return cpu->CPSR & mask;
	}

	/* Assign a specific subset of the CPSR as a bit pattern. */
	void
	aarch64_set_CPSR_bits (sim_cpu *cpu, uint32_t mask, uint32_t value)
	{
	uint32_t old_flags = cpu->CPSR;

	mask &= CPSR_ALL_FLAGS;
	cpu->CPSR &= ~ mask;
	cpu->CPSR \|= (value & mask);

	if (old_flags != cpu->CPSR)
	TRACE_REGISTER (cpu,
	"CPSR changes from %s to %s",
	decode_cpsr (old_flags), decode_cpsr (cpu->CPSR));
	}

	/* Test the value of a single CPSR returned as non-zero or zero. */
	uint32_t
	aarch64_test_CPSR_bit (sim_cpu *cpu, FlagMask bit)
	{
	return cpu->CPSR & bit;
	}

	/* Set a single flag in the CPSR. */
	void
	aarch64_set_CPSR_bit (sim_cpu *cpu, FlagMask bit)
	{
	uint32_t old_flags = cpu->CPSR;

	cpu->CPSR \|= (bit & CPSR_ALL_FLAGS);

	if (old_flags != cpu->CPSR)
	TRACE_REGISTER (cpu,
	"CPSR changes from %s to %s",
	decode_cpsr (old_flags), decode_cpsr (cpu->CPSR));
	}

	/* Clear a single flag in the CPSR. */
	void
	aarch64_clear_CPSR_bit (sim_cpu *cpu, FlagMask bit)
	{
	uint32_t old_flags = cpu->CPSR;

	cpu->CPSR &= ~(bit & CPSR_ALL_FLAGS);

	if (old_flags != cpu->CPSR)
	TRACE_REGISTER (cpu,
	"CPSR changes from %s to %s",
	decode_cpsr (old_flags), decode_cpsr (cpu->CPSR));
	}

	float
	aarch64_get_FP_half (sim_cpu *cpu, VReg reg)
	{
	union
	{
	uint16_t h[2];
	float f;
	} u;

	u.h[0] = 0;
	u.h[1] = cpu->fr[reg].h[0];
	return u.f;
	}


	float
	aarch64_get_FP_float (sim_cpu *cpu, VReg reg)
	{
	return cpu->fr[reg].s;
	}

	double
	aarch64_get_FP_double (sim_cpu *cpu, VReg reg)
	{
	return cpu->fr[reg].d;
	}

	void
	aarch64_get_FP_long_double (sim_cpu cpu, VReg reg, FRegister a)
	{
	a->v[0] = cpu->fr[reg].v[0];
	a->v[1] = cpu->fr[reg].v[1];
	}

	void
	aarch64_set_FP_half (sim_cpu *cpu, VReg reg, float val)
	{
	union
	{
	uint16_t h[2];
	float f;
	} u;

	u.f = val;
	cpu->fr[reg].h[0] = u.h[1];
	cpu->fr[reg].h[1] = 0;
	}


	void
	aarch64_set_FP_float (sim_cpu *cpu, VReg reg, float val)
	{
	if (val != cpu->fr[reg].s
	/* Handle +/- zero. */
	\|\| signbit (val) != signbit (cpu->fr[reg].s))
	{
	FRegister v;

	v.s = val;
	TRACE_REGISTER (cpu,
	"FR[%d].s changes from %f to %f [hex: %0" PRIx64 "]",
	reg, cpu->fr[reg].s, val, v.v[0]);
	}

	cpu->fr[reg].s = val;
	}

	void
	aarch64_set_FP_double (sim_cpu *cpu, VReg reg, double val)
	{
	if (val != cpu->fr[reg].d
	/* Handle +/- zero. */
	\|\| signbit (val) != signbit (cpu->fr[reg].d))
	{
	FRegister v;

	v.d = val;
	TRACE_REGISTER (cpu,
	"FR[%d].d changes from %f to %f [hex: %0" PRIx64 "]",
	reg, cpu->fr[reg].d, val, v.v[0]);
	}
	cpu->fr[reg].d = val;
	}

	void
	aarch64_set_FP_long_double (sim_cpu *cpu, VReg reg, FRegister a)
	{
	if (cpu->fr[reg].v[0] != a.v[0]
	\|\| cpu->fr[reg].v[1] != a.v[1])
	TRACE_REGISTER (cpu,
	"FR[%d].q changes from [%0" PRIx64 " %0" PRIx64 "] to [%0"
	PRIx64 " %0" PRIx64 "] ",
	reg,
	cpu->fr[reg].v[0], cpu->fr[reg].v[1],
	a.v[0], a.v[1]);

	cpu->fr[reg].v[0] = a.v[0];
	cpu->fr[reg].v[1] = a.v[1];
	}

	#define GET_VEC_ELEMENT(REG, ELEMENT, FIELD) \
	do \
	{ \
	if (ELEMENT >= ARRAY_SIZE (cpu->fr[0].FIELD)) \
	{ \
	TRACE_REGISTER (cpu, \
	"Internal SIM error: invalid element number: %d ",\
	ELEMENT); \
	sim_engine_halt (CPU_STATE (cpu), cpu, NULL, aarch64_get_PC (cpu), \
	sim_stopped, SIM_SIGBUS); \
	} \
	return cpu->fr[REG].FIELD [ELEMENT]; \
	} \
	while (0)

	uint64_t
	aarch64_get_vec_u64 (sim_cpu *cpu, VReg reg, unsigned element)
	{
	GET_VEC_ELEMENT (reg, element, v);
	}

	uint32_t
	aarch64_get_vec_u32 (sim_cpu *cpu, VReg reg, unsigned element)
	{
	GET_VEC_ELEMENT (reg, element, w);
	}

	uint16_t
	aarch64_get_vec_u16 (sim_cpu *cpu, VReg reg, unsigned element)
	{
	GET_VEC_ELEMENT (reg, element, h);
	}

	uint8_t
	aarch64_get_vec_u8 (sim_cpu *cpu, VReg reg, unsigned element)
	{
	GET_VEC_ELEMENT (reg, element, b);
	}

	int64_t
	aarch64_get_vec_s64 (sim_cpu *cpu, VReg reg, unsigned element)
	{
	GET_VEC_ELEMENT (reg, element, V);
	}

	int32_t
	aarch64_get_vec_s32 (sim_cpu *cpu, VReg reg, unsigned element)
	{
	GET_VEC_ELEMENT (reg, element, W);
	}

	int16_t
	aarch64_get_vec_s16 (sim_cpu *cpu, VReg reg, unsigned element)
	{
	GET_VEC_ELEMENT (reg, element, H);
	}

	int8_t
	aarch64_get_vec_s8 (sim_cpu *cpu, VReg reg, unsigned element)
	{
	GET_VEC_ELEMENT (reg, element, B);
	}

	float
	aarch64_get_vec_float (sim_cpu *cpu, VReg reg, unsigned element)
	{
	GET_VEC_ELEMENT (reg, element, S);
	}

	double
	aarch64_get_vec_double (sim_cpu *cpu, VReg reg, unsigned element)
	{
	GET_VEC_ELEMENT (reg, element, D);
	}


	#define SET_VEC_ELEMENT(REG, ELEMENT, VAL, FIELD, PRINTER) \
	do \
	{ \
	if (ELEMENT >= ARRAY_SIZE (cpu->fr[0].FIELD)) \
	{ \
	TRACE_REGISTER (cpu, \
	"Internal SIM error: invalid element number: %d ",\
	ELEMENT); \
	sim_engine_halt (CPU_STATE (cpu), cpu, NULL, aarch64_get_PC (cpu), \
	sim_stopped, SIM_SIGBUS); \
	} \
	if (VAL != cpu->fr[REG].FIELD [ELEMENT]) \
	TRACE_REGISTER (cpu, \
	"VR[%2d]." #FIELD " [%d] changes from " PRINTER \
	" to " PRINTER , REG, \
	ELEMENT, cpu->fr[REG].FIELD [ELEMENT], VAL); \
	\
	cpu->fr[REG].FIELD [ELEMENT] = VAL; \
	} \
	while (0)

	void
	aarch64_set_vec_u64 (sim_cpu *cpu, VReg reg, unsigned element, uint64_t val)
	{
	SET_VEC_ELEMENT (reg, element, val, v, "%16" PRIx64);
	}

	void
	aarch64_set_vec_u32 (sim_cpu *cpu, VReg reg, unsigned element, uint32_t val)
	{
	SET_VEC_ELEMENT (reg, element, val, w, "%8x");
	}

	void
	aarch64_set_vec_u16 (sim_cpu *cpu, VReg reg, unsigned element, uint16_t val)
	{
	SET_VEC_ELEMENT (reg, element, val, h, "%4x");
	}

	void
	aarch64_set_vec_u8 (sim_cpu *cpu, VReg reg, unsigned element, uint8_t val)
	{
	SET_VEC_ELEMENT (reg, element, val, b, "%x");
	}

	void
	aarch64_set_vec_s64 (sim_cpu *cpu, VReg reg, unsigned element, int64_t val)
	{
	SET_VEC_ELEMENT (reg, element, val, V, "%16" PRIx64);
	}

	void
	aarch64_set_vec_s32 (sim_cpu *cpu, VReg reg, unsigned element, int32_t val)
	{
	SET_VEC_ELEMENT (reg, element, val, W, "%8x");
	}

	void
	aarch64_set_vec_s16 (sim_cpu *cpu, VReg reg, unsigned element, int16_t val)
	{
	SET_VEC_ELEMENT (reg, element, val, H, "%4x");
	}

	void
	aarch64_set_vec_s8 (sim_cpu *cpu, VReg reg, unsigned element, int8_t val)
	{
	SET_VEC_ELEMENT (reg, element, val, B, "%x");
	}

	void
	aarch64_set_vec_float (sim_cpu *cpu, VReg reg, unsigned element, float val)
	{
	SET_VEC_ELEMENT (reg, element, val, S, "%f");
	}

	void
	aarch64_set_vec_double (sim_cpu *cpu, VReg reg, unsigned element, double val)
	{
	SET_VEC_ELEMENT (reg, element, val, D, "%f");
	}

	void
	aarch64_set_FPSR (sim_cpu *cpu, uint32_t value)
	{
	if (cpu->FPSR != value)
	TRACE_REGISTER (cpu,
	"FPSR changes from %x to %x", cpu->FPSR, value);

	cpu->FPSR = value & FPSR_ALL_FPSRS;
	}

	uint32_t
	aarch64_get_FPSR (sim_cpu *cpu)
	{
	return cpu->FPSR;
	}

	void
	aarch64_set_FPSR_bits (sim_cpu *cpu, uint32_t mask, uint32_t value)
	{
	uint32_t old_FPSR = cpu->FPSR;

	mask &= FPSR_ALL_FPSRS;
	cpu->FPSR &= ~mask;
	cpu->FPSR \|= (value & mask);

	if (cpu->FPSR != old_FPSR)
	TRACE_REGISTER (cpu,
	"FPSR changes from %x to %x", old_FPSR, cpu->FPSR);
	}

	uint32_t
	aarch64_get_FPSR_bits (sim_cpu *cpu, uint32_t mask)
	{
	mask &= FPSR_ALL_FPSRS;
	return cpu->FPSR & mask;
	}

	int
	aarch64_test_FPSR_bit (sim_cpu *cpu, FPSRMask flag)
	{
	return cpu->FPSR & flag;
	}

	uint64_t
	aarch64_get_thread_id (sim_cpu *cpu)
	{
	return cpu->tpidr;
	}

	uint32_t
	aarch64_get_FPCR (sim_cpu *cpu)
	{
	return cpu->FPCR;
	}

	void
	aarch64_set_FPCR (sim_cpu *cpu, uint32_t val)
	{
	if (cpu->FPCR != val)
	TRACE_REGISTER (cpu,
	"FPCR changes from %x to %x", cpu->FPCR, val);
	cpu->FPCR = val;
	}