re PR target/67071 (GCC misses an optimization to load vector constants)

re PR target/67071 (GCC misses an optimization to load vector constants)

[gcc]
2015-08-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/67071
	* config/rs6000/predicates.md (easy_vector_constant_vsldoi): New
	predicate to allow construction of vector constants using the
	VSLDOI vector shift instruction.

	* config/rs6000/rs6000-protos.h (vspltis_shifted): Add
	declaration.

	* config/rs6000/rs6000.c (vspltis_shifted): New function to return
	the number of bytes to be shifted left and filled in with either
	all zero or all one bits.
	(gen_easy_altivec_constant): Call vsplitis_shifted if no other
	methods exist.
	(output_vec_const_move): On power8, generate XXLORC to generate
	a vector constant with all 1's. Do a split if we need to use a
	VSLDOI instruction.

	* config/rs6000/rs6000.h (EASY_VECTOR_MSB): Use mode mask to
	properly test for the MSB.

	* config/rs6000/altivec.md (VSLDOI splitter): Add splitter for
	vector constants that can be created with VSLDOI.

[gcc/testsuite]
2015-08-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/67071
	* gcc.target/powerpc/pr67071-1.c: New file to test PR 67071 new
	vector constants.
	* gcc.target/powerpc/pr67071-2.c: Likewise.
	* gcc.target/powerpc/pr67071-3.c: Likewise.

From-SVN: r226836