Re: Miscellaneous testsuitsuite failures under hpux 10.20

[Jeffrey A Law <law at cygnus dot com>]

  In message <200006282308.QAA02706@localhost.cygnus.com>you write:
  > > about the portability of ffs which you have used in your patch.  The
  > 
  > That's one of the reasons the patch is not committed.  Probably it
  > should use something like exact_log2, or supply its own ffs
  > equivalent.
Right.  We've got routines to compute log2, and presumably that's all we
really want/need, right?


  > > HP man page says it is not portable.  Also, with your patch, alignments
  > > have to be a power of 2 and at the moment align and offset_align are
  > 
  > It's not clear to me what a non-power-of-two alignment would mean.  Is
  > it really sensible to specify that something is aligned to a 3-word
  > boundary?
Probably OK.  I can think of convoluted ways where non-power-of-two alignment
might be useful (bit/nibble addressable machines).  But I'm not aware of
any existing or planned port which would need that capability.

  > GCC already expects that many things are powers of two.
Yup.


  > > HOST_WIDE_INT is already long on some machines.  Would just eliminating
  > > the bit-fields for align and offset_align be a major killer space wise
  > > if both fields are actually needed?
  > 
  > Apparently, the majority (> 50%) of space gcc uses on C++ code is used
  > by trees.  So we don't want to make the trees any larger than necessary.
Yup.  Amazing, but true.  Also becoming more important for C too.

jeff