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

[Will Newton <will.newton@linaro.org>]

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?

> +
> +      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