re PR target/81593 (Optimize PowerPC vector set from vector extract)

[gcc]
2017-08-07  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/81593
	* config/rs6000/vsx.md (vsx_concat_<mode>, VSX_D): Cleanup
	constraints since the -mupper-regs-* switches have been
	eliminated.
	(vsx_concat_<mode>_1): New combiner insns to recognize inserting
	into a vector from a double word element that was extracted from
	another vector, and eliminate extra XXPERMDI instructions.
	(vsx_concat_<mode>_2): Likewise.
	(vsx_concat_<mode>_3): Likewise.
	(vsx_set_<mode>, VSX_D): Rewrite vector set in terms of vector
	concat to allow optimizing inserts from previous extracts.

[gcc/testsuite]
2017-08-07  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/81593
	* gcc.target/powerpc/vec-setup.h: New tests to test various
	combinations of setting up vectors of 2 double word elements.
	* gcc.target/powerpc/vec-setup-long.c: Likewise.
	* gcc.target/powerpc/vec-setup-double.c: Likewise.
	* gcc.target/powerpc/vec-setup-be-long.c: Likewise.
	* gcc.target/powerpc/vec-setup-be-double.c: Likewise.
	* gcc.target/powerpc/vsx-extract-6.c: New tests for optimzing
	vector inserts from vector extracts.
	* gcc.target/powerpc/vsx-extract-7.c: Likewise.

From-SVN: r250936