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From: Eli Zaretskii <eliz@gnu.org>
Newsgroups: gmane.emacs.devel
Subject: Compiler warning in count_trailing_zero_bits
Date: Fri, 15 Nov 2013 11:02:19 +0200
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The line in data.c marked below:

  else
    {
      int count;
      for (count = 0;
	   count < BITS_PER_BITS_WORD - BITS_PER_ULL;
	   count += BITS_PER_ULL)
	{
	  if (val & ULLONG_MAX)
	    return count + count_trailing_zeros_ll (val);
	  val = shift_right_ull (val);
	}

      if (BITS_PER_BITS_WORD % BITS_PER_ULL != 0
	  && BITS_WORD_MAX == (bits_word) -1)
 >>>>>	val |= (bits_word) 1 << (BITS_PER_BITS_WORD % BITS_PER_ULL);
      return count + count_trailing_zeros_ll (val);
    }

causes a compiler warning in a 32-bit unoptimized build:

  data.c: In function `count_trailing_zero_bits':
  data.c:3114: warning: left shift count >= width of type

This is result of commit in revision 115095.

I hope it will be possible to prevent this nuisance.