tm.texi (CLZ_DEFINED_VALUE_AT_ZERO, [...]): Document change in interpretation of...

tm.texi (CLZ_DEFINED_VALUE_AT_ZERO, [...]): Document change in interpretation of value from boolean to tri-state integer.

2007-08-09  Sandra Loosemore  <sandra@codesourcery.com>
	    Nigel Stephens  <nigel@mips.com>

	gcc/
	* doc/tm.texi (CLZ_DEFINED_VALUE_AT_ZERO, CTZ_DEFINED_VALUE_AT_ZERO):
	Document change in interpretation of value from boolean to
	tri-state integer.
	* optabs.c (expand_ffs, expand_ctz): New functions to compute
	ffs and ctz using clz.
	(expand_unop):  Call them.
	* config/rs6000/rs6000.h (CLZ_DEFINED_VALUE_AT_ZERO): Fix its
	result value.
	(CTZ_DEFINED_VALUE_AT_ZERO): Likewise.
	* config/mips/mips.h (CLZ_DEFINED_VALUE_AT_ZERO): Likewise, to
	enable the new ffs expansion on this target.

Co-Authored-By: Nigel Stephens <nigel@mips.com>
From-SVN: r127318