re PR target/81193 (PowerPC GCC __builtin_cpu_is and __builtin_cpu_supports should warn about old libraries)

[gcc]
2017-07-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/81193
	* config/rs6000/rs6000-c.c (rs6000_cpu_cpp_builtins): If GLIBC
	provides the hardware capability bits, define the macro
	__BUILTIN_CPU_SUPPORTS__.
	* config/rs6000/rs6000.c (cpu_expand_builtin): Generate a warning
	if GLIBC does not provide the hardware capability bits.  Add a
	gcc_unreachable call if the built-in cpu function is neither
	__builtin_cpu_is nor __builtin_cpu_supports.
	(rs6000_get_function_versions_dispatcher): Change the warning
	that an old GLIBC is used which does not export the capability
	bits to be an error.
	* doc/extend.texi (target_clones attribute): Document the
	restriction that GLIBC 2.23 or newer is needed on the PowerPC.
	(PowerPC built-in functions): Document that GLIBC 2.23 or newer is
	needed by __builtin_cpu_is and __builtin_cpu_supports.  Document
	the macros defined by GCC if the newer GLIBC is available.

[gcc/testsuite]
2017-07-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/81193
	* gcc.target/powerpc/bmi-andn-1.c: Add guard against using
	__builtin_cpu_supports with old GLIBC's.
	* gcc.target/powerpc/bmi-andn-2.c: Likewise.
	* gcc.target/powerpc/bmi-bextr-1.c: Likewise.
	* gcc.target/powerpc/bmi-bextr-2.c: Likewise.
	* gcc.target/powerpc/bmi-bextr-4.c: Likewise.
	* gcc.target/powerpc/bmi-bextr-5.c: Likewise.
	* gcc.target/powerpc/bmi-blsi-1.c: Likewise.
	* gcc.target/powerpc/bmi-blsi-2.c: Likewise.
	* gcc.target/powerpc/bmi-blsmsk-1.c: Likewise.
	* gcc.target/powerpc/bmi-blsmsk-2.c: Likewise.
	* gcc.target/powerpc/bmi-blsr-1.c: Likewise.
	* gcc.target/powerpc/bmi-blsr-2.c: Likewise.
	* gcc.target/powerpc/bmi-tzcnt-1.c: Likewise.
	* gcc.target/powerpc/bmi-tzcnt-2.c: Likewise.
	* gcc.target/powerpc/bmi2-bzhi32-1.c: Likewise.
	* gcc.target/powerpc/bmi2-bzhi64-1.c: Likewise.
	* gcc.target/powerpc/bmi2-mulx32-1.c: Likewise.
	* gcc.target/powerpc/bmi2-mulx32-2.c: Likewise.
	* gcc.target/powerpc/bmi2-mulx64-1.c: Likewise.
	* gcc.target/powerpc/bmi2-mulx64-2.c: Likewise.
	* gcc.target/powerpc/bmi2-pdep32-1.c: Likewise.
	* gcc.target/powerpc/bmi2-pdep64-1.c: Likewise.
	* gcc.target/powerpc/bmi2-pext32-1.c: Likewise.
	* gcc.target/powerpc/bmi2-pext64-1.c: Likewise.
	* gcc.target/powerpc/cpu-builtin-1.c: Likewise.

[libgcc]
2017-07-12  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/81193
	* configure.ac (PowerPC float128 hardware support): Test whether
	we can use __builtin_cpu_supports before enabling the ifunc
	handler.
	* configure: Regenerate.

From-SVN: r250165