re PR target/71805 (incorrect code for test pr45752.c with -mcpu=power9)

re PR target/71805 (incorrect code for test pr45752.c with -mcpu=power9)

[gcc]
2016-07-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/71805
	* config/rs6000/altivec.md (altivec_vperm_<mode>_internal):
	The xxperm and xxpermr instructions require that the 2nd input
	operand overlap with the output operand, and not the 1st.
	(altivec_vperm_v8hiv16qi): Likewise.
	(altivec_vperm_<mode>_uns_internal): Likewise.
	(altivec_vpermr_<mode>_internal): Likewise.
	(vperm_v8hiv4si): Likewise.
	(vperm_v16qiv8hi): Likewise.

[gcc/testsuite]
2016-07-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/71805
	* gcc.target/powerpc/pr71805.c: New test.

From-SVN: r238256