[07/10,ARC,FIX] Consider command line ffixed- option.

From: claziss <claziss@synopsys.com>

Track which regs are set fixed/call saved/call used from commnad line.
Do not try to override their properties if user says otherwise.

gcc/
2017-06-08  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (overrideregs): New variable.
	(arc_override_options): Track fixed/call saved/call options.
	(arc_conditional_register_usage): Check against overrideregs
	variable whenever we change register properties.
---
 gcc/config/arc/arc.c | 60 +++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 48 insertions(+), 12 deletions(-)

* Claudiu Zissulescu <Claudiu.Zissulescu@synopsys.com> [2017-11-27 12:09:56 +0100]:

> From: claziss <claziss@synopsys.com>
> 
> Track which regs are set fixed/call saved/call used from commnad line.
> Do not try to override their properties if user says otherwise.
> 
> gcc/
> 2017-06-08  Claudiu Zissulescu  <claziss@synopsys.com>
> 
> 	* config/arc/arc.c (overrideregs): New variable.
> 	(arc_override_options): Track fixed/call saved/call options.
> 	(arc_conditional_register_usage): Check against overrideregs
> 	variable whenever we change register properties.

Looks good.

Thanks,
Andrew


> ---
>  gcc/config/arc/arc.c | 60 +++++++++++++++++++++++++++++++++++++++++-----------
>  1 file changed, 48 insertions(+), 12 deletions(-)
> 
> diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
> index 42ea921..0eeeb42 100644
> --- a/gcc/config/arc/arc.c
> +++ b/gcc/config/arc/arc.c
> @@ -79,6 +79,9 @@ typedef struct GTY (()) _arc_jli_section
>  
>  static arc_jli_section *arc_jli_sections = NULL;
>  
> +/* Track which regs are set fixed/call saved/call used from commnad line.  */
> +HARD_REG_SET overrideregs;
> +
>  /* Maximum size of a loop.  */
>  #define ARC_MAX_LOOP_LENGTH 4095
>  
> @@ -1144,6 +1147,30 @@ arc_override_options (void)
>  	  }
>        }
>  
> +  CLEAR_HARD_REG_SET (overrideregs);
> +  if (common_deferred_options)
> +    {
> +      vec<cl_deferred_option> v =
> +	*((vec<cl_deferred_option> *) common_deferred_options);
> +      int reg, nregs, j;
> +
> +      FOR_EACH_VEC_ELT (v, i, opt)
> +	{
> +	  switch (opt->opt_index)
> +	    {
> +	    case OPT_ffixed_:
> +	    case OPT_fcall_used_:
> +	    case OPT_fcall_saved_:
> +	      if ((reg = decode_reg_name_and_count (opt->arg, &nregs)) >= 0)
> +		for (j = reg;  j < reg + nregs; j++)
> +		  SET_HARD_REG_BIT (overrideregs, j);
> +	      break;
> +	    default:
> +	      break;
> +	    }
> +	}
> +    }
> +
>    /* Set cpu flags accordingly to architecture/selected cpu.  The cpu
>       specific flags are set in arc-common.c.  The architecture forces
>       the default hardware configurations in, regardless what command
> @@ -1673,14 +1700,20 @@ arc_conditional_register_usage (void)
>        /* For ARCv2 the core register set is changed.  */
>        strcpy (rname29, "ilink");
>        strcpy (rname30, "r30");
> -      call_used_regs[30] = 1;
> -      fixed_regs[30] = 0;
> -
> -      arc_regno_reg_class[30] = WRITABLE_CORE_REGS;
> -      SET_HARD_REG_BIT (reg_class_contents[WRITABLE_CORE_REGS], 30);
> -      SET_HARD_REG_BIT (reg_class_contents[CHEAP_CORE_REGS], 30);
> -      SET_HARD_REG_BIT (reg_class_contents[GENERAL_REGS], 30);
> -      SET_HARD_REG_BIT (reg_class_contents[MPY_WRITABLE_CORE_REGS], 30);
> +
> +      if (!TEST_HARD_REG_BIT (overrideregs, 30))
> +	{
> +	  /* No user interference.  Set the r30 to be used by the
> +	     compiler.  */
> +	  call_used_regs[30] = 1;
> +	  fixed_regs[30] = 0;
> +
> +	  arc_regno_reg_class[30] = WRITABLE_CORE_REGS;
> +	  SET_HARD_REG_BIT (reg_class_contents[WRITABLE_CORE_REGS], 30);
> +	  SET_HARD_REG_BIT (reg_class_contents[CHEAP_CORE_REGS], 30);
> +	  SET_HARD_REG_BIT (reg_class_contents[GENERAL_REGS], 30);
> +	  SET_HARD_REG_BIT (reg_class_contents[MPY_WRITABLE_CORE_REGS], 30);
> +	}
>     }
>  
>    if (TARGET_MUL64_SET)
> @@ -1935,11 +1968,14 @@ arc_conditional_register_usage (void)
>      SET_HARD_REG_BIT (reg_class_contents[MPY_WRITABLE_CORE_REGS], ACCL_REGNO);
>      SET_HARD_REG_BIT (reg_class_contents[MPY_WRITABLE_CORE_REGS], ACCH_REGNO);
>  
> -     /* Allow the compiler to freely use them.  */
> -    fixed_regs[ACCL_REGNO] = 0;
> -    fixed_regs[ACCH_REGNO] = 0;
> +    /* Allow the compiler to freely use them.  */
> +    if (!TEST_HARD_REG_BIT (overrideregs, ACCL_REGNO))
> +      fixed_regs[ACCL_REGNO] = 0;
> +    if (!TEST_HARD_REG_BIT (overrideregs, ACCH_REGNO))
> +      fixed_regs[ACCH_REGNO] = 0;
>  
> -    arc_hard_regno_modes[ACC_REG_FIRST] = D_MODES;
> +    if (!fixed_regs[ACCH_REGNO] && !fixed_regs[ACCL_REGNO])
> +      arc_hard_regno_modes[ACC_REG_FIRST] = D_MODES;
>    }
>  }
>  
> -- 
> 1.9.1
>