re PR bootstrap/12269 (Mainline failed to bootstrap on Linux/ia64)

re PR bootstrap/12269 (Mainline failed to bootstrap on Linux/ia64)

	PR bootstrap/12269
	* simplify-rtx.c (simplify_gen_relational): Allow the cmp_mode
	argument to be VOIDmode, taking the mode of the comparison from
	the operands.  Only call simplify_relational_operation if we
	know the mode of the comparison.  Honor FLOAT_STORE_FLAG_VALUE
	if comparison has a floating point result.  Ensure that the
	result is always of the specified mode.
	(simplify_replace_rtx): Simplify call to simplify_gen_relational.
	(simplify_unary_operation): Ensure the correct mode and cmp_mode
	are always passed to simplify_gen_relational.  Simplify NOT of
	comparison operator in any mode, not just BImode.
	(simplify_ternary_operation): Correct tests on the return value
	of simplify_relational_operation to use const_true_rtx, not
	const1_rtx.  Abort if it ever returns a non-constant result.

	* cfgloopanal.c (count_strange_loop_iterations): Use the function
	simplify_relational_operation, not simplify_gen_relational, if
	we're only interested in constant comparisons and will ignore
	non-constant results.

From-SVN: r71439