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From: Glen Nakamura <glen@imodulo.com>
To: nobody@gcc.gnu.org
Cc: gcc-prs@gcc.gnu.org,
Subject: Re: c/8224: Incorrect joining of signed and unsigned division
Date: Sat, 15 Mar 2003 21:56:00 -0000	[thread overview]
Message-ID: <20030315215600.23488.qmail@sources.redhat.com> (raw)

The following reply was made to PR c/8224; it has been noted by GNATS.

From: Glen Nakamura <glen@imodulo.com>
To: gcc-gnats@gcc.gnu.org, gcc-bugs@gcc.gnu.org,
	mikulas@artax.karlin.mff.cuni.cz
Cc:  
Subject: Re: c/8224: Incorrect joining of signed and unsigned division
Date: Sat, 15 Mar 2003 21:50:10 +0000

 I'm testing the following patch as a fix to PR c/8224:
 
 	* fold-const.c (extract_muldiv_1): Don't pass through type conversions
 	when signedness changes for division or modulus.
 
 diff -Nru3p gcc-3.3.orig/gcc/fold-const.c gcc-3.3/gcc/fold-const.c
 --- gcc-3.3.orig/gcc/fold-const.c	2003-02-16 08:25:20.000000000 +0000
 +++ gcc-3.3/gcc/fold-const.c	2003-02-16 08:25:20.000000000 +0000
 @@ -4117,7 +4117,12 @@ extract_muldiv_1 (t, c, code, wide_type)
  	      /* ... or its type is larger than ctype,
  		 then we cannot pass through this truncation.  */
  	      || (GET_MODE_SIZE (TYPE_MODE (ctype))
 -		  < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))))
 +		  < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
 +	      /* ... or signedness changes for division or modulus,
 +		 then we cannot pass through this conversion.  */
 +	      || (code != MULT_EXPR
 +		  && (TREE_UNSIGNED (ctype)
 +		      != TREE_UNSIGNED (TREE_TYPE (op0))))))
  	break;
  
        /* Pass the constant down and see if we can make a simplification.  If


             reply	other threads:[~2003-03-15 21:56 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-03-15 21:56 Glen Nakamura [this message]
  -- strict thread matches above, loose matches on Subject: below --
2003-03-23 23:06 mmitchel
2003-03-23 19:16 Glen Nakamura
2003-03-22  8:56 Glen Nakamura
2003-02-02 23:15 bangerth
2002-10-14  7:36 mikulas

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