rs6000.c (rs6000_expand_vector_init): Set initialization of all 0's to the 0 constant, instead of directly generating XOR.

[gcc]
2016-08-23  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* config/rs6000/rs6000.c (rs6000_expand_vector_init): Set
	initialization of all 0's to the 0 constant, instead of directly
	generating XOR.  Add support for V4SImode vector initialization on
	64-bit systems with direct move, and rework the ISA 3.0 V4SImode
	initialization.  Change variables used in V4SFmode vector
	intialization.  For V4SFmode vector splat on ISA 3.0, make sure
	any memory addresses are in index form.  Add support for using
	VSPLTH/VSPLTB to initialize vector short and vector char vectors
	with all of the same element.
	(regno_or_subregno): New helper function to return a register
	number for either REG or SUBREG.
	(rs6000_adjust_vec_address): Do not generate ADDI <reg>,R0,<num>.
	Use regno_or_subregno where possible.
	(rs6000_split_v4si_init_di_reg): New helper function to build up a
	DImode value from two SImode values in order to generate V4SImode
	vector initialization on 64-bit systems with direct move.
	(rs6000_split_v4si_init): Split up the insns for a V4SImode vector
	initialization.
	(rtx_is_swappable_p): V4SImode vector initialization insn is not
	swappable.
	* config/rs6000/rs6000-protos.h (rs6000_split_v4si_init): Add
	declaration.
	* config/rs6000/vsx.md (VSX_SPLAT_I): New mode iterators and
	attributes to initialize V8HImode and V16QImode vectors with the
	same element.
	(VSX_SPLAT_COUNT): Likewise.
	(VSX_SPLAT_SUFFIX): Likewise.
	(UNSPEC_VSX_VEC_INIT): New unspec.
	(vsx_concat_v2sf): Eliminate using 'preferred' register classes.
	Allow SFmode values to come from Altivec registers.
	(vsx_init_v4si): New insn/split for V4SImode vector initialization
	on 64-bit systems with direct move.
	(vsx_splat_<mode>, VSX_W iterator): Rework V4SImode and V4SFmode
	vector initializations, to allow V4SImode vector initializations
	on 64-bit systems with direct move.
	(vsx_splat_v4si): Likewise.
	(vsx_splat_v4si_di): Likewise.
	(vsx_splat_v4sf): Likewise.
	(vsx_splat_v4sf_internal): Likewise.
	(vsx_xxspltw_<mode>, VSX_W iterator): Eliminate using 'preferred'
	register classes.
	(vsx_xxspltw_<mode>_direct, VSX_W iterator): Likewise.
	(vsx_vsplt<VSX_SPLAT_SUFFIX>_di): New insns to support
	initializing V8HImode and V16QImode vectors with the same
	element.
	* config/rs6000/rs6000.h (TARGET_DIRECT_MOVE_64BIT): Disallow
	optimization if -maltivec=be.

[gcc/testsuite]
2016-08-23  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* gcc.target/powerpc/vec-init-1.c: Add tests where the vector is
	being created from pointers to memory locations.
	* gcc.target/powerpc/vec-init-2.c: Likewise.

From-SVN: r239712