Re: Fix disable-checking bootstrap problem on ppc-darwin

[Richard Henderson <rth at redhat dot com>]

On Tue, Aug 24, 2004 at 05:45:57PM -0400, Andrew MacLeod wrote:
> Is it strictly necessary for the VUSE operands to be sorted in order for
> this comparison to be true? Someone who knows more about what causes
> various VUSEs to be created might answer that better.

I've sort of lost track of this thread.  Is the argument for sorting
the VUSEs that we have hashes that are applied to them, and thus we
need to have the hashes come out the same?

If true, another solution is to ensure that for any commutative 
operation that we're hashing, that we use a commutative hash.  So
instead of always

	for each operand (op) {
	  hash <<= n;
	  hash ^= munge(op);
	}

do

	if (commutative (operation)) {
	  hash <<= n;
	  hash ^= munge(operation);
	  for each operand (op) {
	    hash += munge(op);
	  }
	} else {
	  ...
	}


r~