i386.c (processor_target_table): Add skylake_cost for skylake-avx512.

i386.c (processor_target_table): Add skylake_cost for skylake-avx512.

	* config/i386/i386.c (processor_target_table): Add skylake_cost for
	skylake-avx512.
	* config/i386/x86-tune-costs.h (skylake_memcpy, skylake_memset,
	skylake_cost): New.

	* config/i386/driver-i386.c (host_detect_local_cpu):
	Detect skylake-avx512.

	* config.gcc: Add -march=cannonlake.
	* config/i386/driver-i386.c (host_detect_local_cpu): Detect cannonlake.
	* config/i386/i386-c.c (ix86_target_macros_internal): Handle cannonlake.
	* config/i386/i386.c (processor_costs): Add m_CANNONLAKE.
	(PTA_CANNONLAKE): New.
	(processor_target_table): Add cannonlake.
	(ix86_option_override_internal): Ditto.
	(fold_builtin_cpu): Ditto.
	(get_builtin_code_for_version): Handle cannonlake.
	(M_INTEL_COREI7_CANNONLAKE): New.
	* config/i386/i386.h (TARGET_CANNONLAKE, PROCESSOR_CANNONLAKE): New.
	* doc/invoke.texi: Add -march=cannonlake.

gcc/testsuite/

	* gcc.target/i386/funcspec-56.inc: Handle new march.
	* g++.dg/ext/mv16.C: Ditto.

libgcc/

	* config/i386/cpuinfo.c (get_intel_cpu): Handle cannonlake.
	* config/i386/cpuinfo.h (processor_subtypes): Add
	INTEL_COREI7_CANNONLAKE.

From-SVN: r255155