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	.It mips64hf Ta Dv __mips__, Dv __MIPSEB__, Dv __mips_n64			.It mips64hf Ta Dv __mips__, Dv __MIPSEB__, Dv __mips_n64
	.It powerpc Ta Dv __powerpc__			.It powerpc Ta Dv __powerpc__
	.It powerpcspe Ta Dv __powerpc__, Dv __SPE__			.It powerpcspe Ta Dv __powerpc__, Dv __SPE__
	.It powerpc64 Ta Dv __powerpc__, Dv __powerpc64__			.It powerpc64 Ta Dv __powerpc__, Dv __powerpc64__
	.It riscv64 Ta Dv __riscv, Dv __riscv_xlen == 64			.It riscv64 Ta Dv __riscv, Dv __riscv_xlen == 64
	.It riscv64sf Ta Dv __riscv, Dv __riscv_xlen == 64			.It riscv64sf Ta Dv __riscv, Dv __riscv_xlen == 64
	.It sparc64 Ta Dv __sparc64__			.It sparc64 Ta Dv __sparc64__
	.El			.El
				.Ss Important Xr make 1 variables
				Most of the externally settable variables are defined in the
				.Xr build 7
				man page.
				These variables are not otherwise documented and are used extensively
				in the build system.
				.Bl -column -offset indent "Sy Variable" "Sy Meaning and usage"
				.It Dv MACHINE Represent the hardware platform.
				This is the same as the native platform's
				.Xr uname 1
				.Fl m
				output.
				It defines both the userland / kernel interface, as well as the
				bootloader / kernel interface.
				It should only be used in these contexts.
				Each CPU architecture may have multiple hardware platforms it supports
				where
				.Dv MACHINE
				differs among them.
				It is used to collect together all the files from
				.Xr config 8
				to build the kernel.
				It is often the same as
				.Dv MACHINE_ARCH
				just as one CPU architecture can be implemented by many different
				hardware platforms, one hardware platform may support multiple CPU
				architecture family members, though with different binaries.
				For example,
				.Dv MACHINE
				of i386 supported the IBM-AT hardware platform while the
				.Dv MACHINE
				of pc98 supported the Japanese company NEC's PC-9801 and PC-9821
				hardware platforms.
				Both of these hardware platforms supported only the
				.Dv MACHINE_ARCH
				of i386 where they shared a common ABI, except for certain kernel /
				userland interfaces relating to underlying hardware platform
				differences in bus architecture, device enumeration and boot interface.
				.It Dv MACHINE_ARCH Represents the CPU processor architecture.
				This is the same as the native platforms
				.Xr uname 1
				.Fl p
				output.
				It defines the CPU instruction family supported.
				It may also encode a variation in the byte ordering of multi-byte
				integers (endian).
				It may also encode a variation in the size of the integer or pointer.
				It may also encode a ISA revision.
				It may also encode hard versus soft floating point ABI and usage.
				It may also encode a variant ABI when there other factors don't
				uniquely define the ABI (eg, MIPS' n32 ABI).
				It, along with
				.Dv MACHINE, define the ABI used by the system.
				For example, the MIPS CPU processor family supports 9 different
				combinations encoding pointer size, endian and hard vs soft float (for
				8 combinations) as well as N32 (which only ever had one variation of
				all these).
				Generally, the plain CPU name specifies the most common (or at least
				first) variant of the CPU.
				This is why mips and mips64 imply 'big endian' while 'arm' and 'armv7'
				imply little endian.
				If we ever were to support the so-called x32 ABI (using 32-bit
				pointers on the amd64 architecture), it would most likely be encoded
				as amd64-x32.
				It is unfortunate that amd64 speifies the 64-bit evolution of the x86
				platform (it matches the 'first rule') as everybody else uses x86_64.
				There is no standard name for the processor: each OS selects its own
				conventions.
				.It Dv CPUTYPE Sets the flavor of
				.Dv MACHINE_ARCH
				to build.
				It is used to optimize the build for a specific CPU / core that the
				binaries run on.
				Generally, this doesn't change the ABI, though it can be a fine line
				between optimization for specific cases.
				.It Dv TARGET Used to set Dv MACHINE in the top level Makefile for cross building.
				Unused outside of that scope.
				It is not passed down to the rest of the build.
				Makefiles outside of the top level shouldn't use it at all (though
				some have their own private copy for hysterical raisons).
				.It Dv TARGET_ARCH Used to set Dv MACHINE_ARCH by Fx's top level Makefile for cross building.
				Like
				.Dv TARGET , it is unused outside of that scope.
				.El
	.Sh SEE ALSO			.Sh SEE ALSO
	.Xr src.conf 5 ,			.Xr src.conf 5 ,
	.Xr build 7			.Xr build 7
	.Sh HISTORY			.Sh HISTORY
	An			An
	.Nm			.Nm
	manual page appeared in			manual page appeared in
	.Fx 12 .			.Fx 12 .