Re: [PATCH v3 4/6] Implement support for recording extension register ld/st insn

[Omair Javaid <omair dot javaid at linaro dot org>]

On 13 August 2014 19:10, Will Newton <will.newton@linaro.org> wrote:
> On 13 August 2014 14:12, Omair Javaid <omair.javaid@linaro.org> wrote:
>> gdb:
>>
>> 2014-08-13  Omair Javaid  <omair.javaid@linaro.org>
>>
>>         * arm-tdep.c (arm_record_asimd_vfp_coproc): Updated.
>>         (arm_record_exreg_ld_st_insn): Added record handler for ex-register
>>         load/store instructions.
>>
>> ---
>>  gdb/arm-tdep.c | 167 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 165 insertions(+), 2 deletions(-)
>>
>> diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
>> index d003619..315b5b0 100644
>> --- a/gdb/arm-tdep.c
>> +++ b/gdb/arm-tdep.c
>> @@ -11990,6 +11990,169 @@ arm_record_unsupported_insn (insn_decode_record *arm_insn_r)
>>    return -1;
>>  }
>>
>> +/* Record handler for extension register load/store instructions.  */
>> +
>> +static int
>> +arm_record_exreg_ld_st_insn (insn_decode_record *arm_insn_r)
>> +{
>> +  uint32_t opcode, single_reg;
>> +  uint8_t op_vldm_vstm;
>> +  uint32_t record_buf[8], record_buf_mem[128];
>> +  ULONGEST u_regval = 0;
>> +
>> +  struct regcache *reg_cache = arm_insn_r->regcache;
>> +  const int num_regs = gdbarch_num_regs (arm_insn_r->gdbarch);
>> +
>> +  opcode = bits (arm_insn_r->arm_insn, 20, 24);
>> +  single_reg = bit (arm_insn_r->arm_insn, 8);
>> +  op_vldm_vstm = opcode & 0x1b;
>> +
>> +  /* Handle VMOV instructions.  */
>> +  if ((opcode & 0x1e) == 0x04)
>> +    {
>> +      if (bit (arm_insn_r->arm_insn, 4))
>> +        {
>> +          record_buf[0] = bits (arm_insn_r->arm_insn, 12, 15);
>> +          record_buf[1] = bits (arm_insn_r->arm_insn, 16, 19);
>> +          arm_insn_r->reg_rec_count = 2;
>> +        }
>> +      else
>> +        {
>> +          uint8_t reg_m = (bits (arm_insn_r->arm_insn, 0, 3) << 1)
>> +                          | bit (arm_insn_r->arm_insn, 5);
>> +
>> +          if (!single_reg)
>> +            {
>> +              record_buf[0] = num_regs + reg_m;
>> +              record_buf[1] = num_regs + reg_m + 1;
>> +              arm_insn_r->reg_rec_count = 2;
>> +            }
>> +          else
>> +            {
>> +              record_buf[0] = reg_m + ARM_D0_REGNUM;
>> +              arm_insn_r->reg_rec_count = 1;
>> +            }
>> +        }
>> +    }
>> +  /* Handle VSTM and VPUSH instructions.  */
>> +  else if (op_vldm_vstm == 0x08 || op_vldm_vstm == 0x0a
>> +          || op_vldm_vstm == 0x12)
>> +    {
>> +      uint32_t start_address, reg_rn, imm_off32, imm_off8, memory_count;
>> +      uint32_t memory_index = 0;
>> +
>> +      reg_rn = bits (arm_insn_r->arm_insn, 16, 19);
>> +      regcache_raw_read_unsigned (reg_cache, reg_rn, &u_regval);
>> +      imm_off8 = bits (arm_insn_r->arm_insn, 0, 7);
>> +      imm_off32 = imm_off8 << 24;
>> +      memory_count = imm_off8;
>> +
>> +      if (bit (arm_insn_r->arm_insn, 23))
>> +        start_address = u_regval;
>> +      else
>> +        start_address = u_regval - imm_off32;
>> +
>> +      if (bit (arm_insn_r->arm_insn, 21))
>> +        {
>> +          record_buf[0] = reg_rn;
>> +          arm_insn_r->reg_rec_count = 1;
>> +        }
>> +
>> +      while (memory_count)
>> +        {
>> +          if (!single_reg)
>> +            {
>> +              record_buf_mem[memory_index] = start_address;
>> +              record_buf_mem[memory_index + 1] = 4;
>> +              start_address = start_address + 4;
>> +              memory_index = memory_index + 2;
>> +            }
>> +          else
>> +            {
>> +              record_buf_mem[memory_index] = start_address;
>> +              record_buf_mem[memory_index + 1] = 4;
>> +              record_buf_mem[memory_index + 2] = start_address + 4;
>> +              record_buf_mem[memory_index + 3] = 4;
>> +              start_address = start_address + 8;
>> +              memory_index = memory_index + 4;
>> +            }
>> +          memory_count--;
>> +        }
>> +    }
>> +  /* Handle VLDM instructions.  */
>> +  else if (op_vldm_vstm == 0x09 || op_vldm_vstm == 0x0b
>> +          || op_vldm_vstm == 0x13)
>> +    {
>> +      uint32_t reg_count, reg_vd;
>> +      uint32_t reg_index = 0;
>> +
>> +      reg_vd = bits (arm_insn_r->arm_insn, 12, 15);
>> +      reg_count = bits (arm_insn_r->arm_insn, 0, 7);
>> +
>> +      if (single_reg)
>> +        reg_vd = reg_vd | (bit (arm_insn_r->arm_insn, 0) << 4);
>> +      else
>> +        reg_vd = (reg_vd << 1) | bit (arm_insn_r->arm_insn, 0);
>> +
>> +      if (bit (arm_insn_r->arm_insn, 21))
>> +        record_buf[reg_index++] = bits (arm_insn_r->arm_insn, 16, 19);
>> +
>> +      while (reg_count)
>> +        {
>> +          if (single_reg)
>> +              record_buf[reg_index++] = num_regs + reg_vd + reg_count - 1;
>> +          else
>> +              record_buf[reg_index++] = ARM_D0_REGNUM + reg_vd + reg_count - 1;
>> +
>> +          reg_count--;
>> +        }
>> +    }
>> +  /* VSTR Vector store register.  */
>> +  else if ((opcode & 0x13) == 0x10)
>> +    {
>> +      uint32_t start_address, reg_rn, imm_off32, imm_off8, memory_count;
>> +      uint32_t memory_index = 0;
>> +
>> +      reg_rn = bits (arm_insn_r->arm_insn, 16, 19);
>> +      regcache_raw_read_unsigned (reg_cache, reg_rn, &u_regval);
>> +      imm_off8 = bits (arm_insn_r->arm_insn, 0, 7);
>> +      imm_off32 = imm_off8 << 24;
>> +      memory_count = imm_off8;
>> +
>> +      if (bit (arm_insn_r->arm_insn, 23))
>> +        start_address = u_regval + imm_off32;
>> +      else
>> +        start_address = u_regval - imm_off32;
>> +
>> +      if (single_reg)
>> +        {
>> +          record_buf_mem[memory_index] = start_address;
>> +          record_buf_mem[memory_index + 1] = 4;
>> +        }
>> +      else
>> +        {
>> +          record_buf_mem[memory_index] = start_address;
>> +          record_buf_mem[memory_index + 1] = 4;
>> +          record_buf_mem[memory_index + 2] = start_address + 4;
>> +          record_buf_mem[memory_index + 3] = 4;
>> +        }
>> +    }
>> +  /* VLDR Vector load register.  */
>> +  else if ((opcode & 0x13) == 0x11)
>> +    {
>> +      uint8_t single_reg = 0;
>> +      uint8_t special_case;
>
> Is there some missing code here? Should there be a TODO comment?

Seems like a bit of code missing here will update it in the final patch.
>
>> +
>> +      record_buf[0] = 0;
>> +      record_buf[1] = 0;
>> +      arm_insn_r->reg_rec_count = 2;
>> +    }
>> +
>> +  REG_ALLOC (arm_insn_r->arm_regs, arm_insn_r->reg_rec_count, record_buf);
>> +  MEM_ALLOC (arm_insn_r->arm_mems, arm_insn_r->mem_rec_count, record_buf_mem);
>> +  return 0;
>> +}
>> +
>>  /* Record handler for arm/thumb mode VFP data processing instructions.  */
>>
>>  static int
>> @@ -12218,11 +12381,11 @@ arm_record_asimd_vfp_coproc (insn_decode_record *arm_insn_r)
>>      {
>>        /* Handle extension register ld/st instructions.  */
>>        if (!(op1 & 0x20))
>> -        return arm_record_unsupported_insn (arm_insn_r);
>> +        return arm_record_exreg_ld_st_insn (arm_insn_r);
>>
>>        /* 64-bit transfers between arm core and extension registers.  */
>>        if ((op1 & 0x3e) == 0x04)
>> -        return arm_record_unsupported_insn (arm_insn_r);
>> +        return arm_record_exreg_ld_st_insn (arm_insn_r);
>>      }
>>    else
>>      {
>> --
>> 1.9.1
>>
>
>
>
> --
> Will Newton
> Toolchain Working Group, Linaro

Ping! Kindly provide your feedback any further comments will help me
approve this patch series.