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Re: [PATCH] gcc/genrecog.c: Check matching constraint in MATCH_OPERAND.


On 02/26/2015 04:04 PM, Chen Gang S wrote:
> If check fails, genrecog needs to stop and report error, so can let the
> issue be found in time. The implementation is referenced from "gcc/doc/
> md.log":
> 
>   [...]
> 
>   whitespace
>        Whitespace characters are ignored and can be inserted at any
>        position except the first.  This enables each alternative for
>        different operands to be visually aligned in the machine
>        description even if they have different number of constraints and
>        modifiers.
> 
>   [...]
> 
>   '0', '1', '2', ... '9'
>        [...]
>        If a digit is used together with letters within the same
>        alternative, the digit should come last.
> 

Oh, I guess, I misunderstood the contents above. e.g. "Up3" which
defined in aarch64 is not "matching constraint", I should skip it.

>        This number is allowed to be more than a single digit.  If multiple
>        digits are encountered consecutively, they are interpreted as a
>        single decimal integer. [...]
> 
>        [...]
> 
>        [...]                               Moreover, the digit must be a
>        smaller number than the number of the operand that uses it in the
>        constraint.
> 
>   [...]
> 
>   The overall constraint for an operand is made from the letters for this
>   operand from the first alternative, a comma, the letters for this
>   operand from the second alternative, a comma, and so on until the last
>   alternative.
> 
>   [...]
> 
> The patch passes test:
> 
>  - genrecog can report the related issue when cross compiling xtensa.
>    And after the related xtensa issue is fixed, genrecog will not report
>    error, either.
> 
>  - For x86_64-unknown-linux-gnu building all-gcc, it is OK, too.
> 
> 
> 2015-02-26  Chen Gang  <gang.chen.5i5j@gmail.com>
> 
> 	* genrecog.c (validate_pattern): Check matching constraint in
> 	MATCH_OPERAND and use 'opnu' for all 'XINT (pattern, 0)'.
> ---
>  gcc/genrecog.c | 39 +++++++++++++++++++++++++++++++++++----
>  1 file changed, 35 insertions(+), 4 deletions(-)
> 
> diff --git a/gcc/genrecog.c b/gcc/genrecog.c
> index 81a0e79..4b508e8 100644
> --- a/gcc/genrecog.c
> +++ b/gcc/genrecog.c
> @@ -503,7 +503,9 @@ validate_pattern (rtx pattern, rtx insn, rtx set, int set_code)
>  
>  	if (code == MATCH_OPERAND)
>  	  {
> -	    const char constraints0 = XSTR (pattern, 2)[0];
> +	    int opnu = XINT (pattern, 0);
> +	    const char *constraints = XSTR (pattern, 2);
> +	    const char constraints0 = constraints[0];
>  
>  	    if (!constraints_supported_in_insn_p (insn))
>  	      {
> @@ -525,17 +527,46 @@ validate_pattern (rtx pattern, rtx insn, rtx set, int set_code)
>  		    /* If we've only got an output reload for this operand,
>  		       we'd better have a matching input operand.  */
>  		    else if (constraints0 == '='
> -			     && find_matching_operand (insn, XINT (pattern, 0)))
> +			     && find_matching_operand (insn, opnu))
>  		      ;
>  		    else
>  		      error_with_line (pattern_lineno,
>  				       "operand %d missing in-out reload",
> -				       XINT (pattern, 0));
> +				       opnu);
>  		  }
>  		else if (constraints0 != '=' && constraints0 != '+')
>  		  error_with_line (pattern_lineno,
>  				   "operand %d missing output reload",
> -				   XINT (pattern, 0));
> +				   opnu);
> +	      }
> +
> +	    /* For matching constraint in MATCH_OPERAND, the digit must be a
> +	       smaller number than the number of the operand that uses it in the
> +	       constraint.  */
> +	    while (1)
> +	      {
> +		int val;
> +
> +		while (constraints[0]
> +		       && (constraints[0] < '0' || constraints[0] > '9'))
> +		  constraints++;
> +		if (!constraints[0])
> +		  break;
> +
> +		sscanf (constraints, "%d", &val);
> +		while ((constraints[0] >= '0' && constraints[0] <= '9'))
> +		  constraints++;
> +
> +		while (constraints[0] == ' ')
> +		  constraints++;
> +		if (constraints[0] && constraints[0] != ',')
> +		  continue;
> +
> +		if (val >= opnu)
> +		  error_with_line (pattern_lineno,
> +				   "constraint digit %d is not smaller than"
> +				   " operand %d",
> +				   val, opnu);
>  	      }
>  	  }
>  
> 


-- 
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