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

[Chen Gang S]

On 02/26/2015 08:13 PM, Chen Gang S wrote:
> 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.
> 

If I really misunderstood, for me, the related patch should be:

diff --git a/gcc/genrecog.c b/gcc/genrecog.c
index 81a0e79..9367d74 100644
--- a/gcc/genrecog.c
+++ b/gcc/genrecog.c
@@ -503,7 +503,8 @@ validate_pattern (rtx pattern, rtx insn, rtx set, int set_code)
 
 	if (code == MATCH_OPERAND)
 	  {
-	    const char constraints0 = XSTR (pattern, 2)[0];
+	    const char *constraints = XSTR (pattern, 2);
+	    const char constraints0 = constraints[0];
 
 	    if (!constraints_supported_in_insn_p (insn))
 	      {
@@ -537,6 +538,33 @@ validate_pattern (rtx pattern, rtx insn, rtx set, int set_code)
 				   "operand %d missing output reload",
 				   XINT (pattern, 0));
 	      }
+
+	    /* 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)
+	      {
+		while (constraints[0]
+		       && (constraints[0] == ' ' || constraints[0] == ','))
+		  constraints++;
+		if (!constraints[0])
+		  break;
+
+		if (constraints[0] >= '0' && constraints[0] <= '9')
+		  {
+		    int val;
+
+		    sscanf (constraints, "%d", &val);
+		    if (val >= XINT (pattern, 0))
+		      error_with_line (pattern_lineno,
+				       "constraint digit %d is not smaller than"
+				       " operand %d",
+				       val, XINT (pattern, 0));
+		  }
+
+		while (constraints[0] && constraints[0] != ',')
+		  constraints++;
+	      }
 	  }
 
 	/* Allowing non-lvalues in destinations -- particularly CONST_INT --


If necessary (I guess, it is), I shall send patch v2 for it.

Thanks.

>>        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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