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.Dd July 19, 2016
.Dt ARCH 7
.Os
.Sh NAME
.Nm arch
.Nd Architecture-specific details
.Sh DESCRIPTION
Differences between CPU architectures and platforms supported by
.Fx .
.Pp
.Ss Type sizes
On all supported architectures,
.Bl -column -offset -indent "long long" "Size"
.It Sy Type Ta Sy Size
.It short Ta 2
.It int Ta 4
.It long Ta sizeof(void*)
.It long long Ta 8
.It float Ta 4
.It double Ta 8
.El
.Bl -column -offset indent "Sy Architecture" "Sy sizeof(void *)" "Sy sizeof(long double)"
.It Sy Architecture Ta Sy sizeof(void *) Ta Sy sizeof(long double)
.It amd64       Ta 8 Ta 16
.It arm         Ta 4 Ta  8
.It armeb       Ta 4 Ta  8
.It armv6       Ta 4 Ta  8
.It arm64       Ta 8 Ta 16
.It i386        Ta 4 Ta 12
.It mips        Ta 4 Ta  8
.It mipsel      Ta 4 Ta  8
.It mipsn32     Ta 4 Ta  8
.It mips64      Ta 8 Ta  8
.It mips64el    Ta 8 Ta  8
.It powerpc     Ta 4 Ta  8
.It powerpc64   Ta 8 Ta  8
.It riscv       Ta 8 Ta
.It sparc64     Ta 8 Ta 16
.El
.Ss Endianness and Char Signedness
.Bl -column -offset indent "Sy Architecture" "Sy Endianness" "Sy char Signedness"
.It Sy Architecture Ta Sy Endianness Ta Sy char Signedness
.It amd64       Ta little Ta   signed
.It arm         Ta little Ta unsigned
.It armeb       Ta big    Ta unsigned
.It armv6       Ta little Ta unsigned
.It arm64       Ta little Ta unsigned
.It i386        Ta little Ta   signed
.It mips        Ta big    Ta   signed
.It mipsel      Ta little Ta   signed
.It mipsn32     Ta big    Ta   signed
.It mips64      Ta big    Ta   signed
.It mips64el    Ta little Ta   signed
.It powerpc     Ta big    Ta unsigned
.It powerpc64   Ta big    Ta unsigned
.It riscv       Ta little Ta   signed
.It sparc64     Ta big    Ta   signed
.El
.Ss Page Size
.Bl -column -offset indent "Sy Architecture" "Sy Page Sizes"
.It Sy Architecture Ta Sy Page Sizes
.It amd64       Ta 4K, 2M, 1G
.It arm         Ta 4K
.It armeb       Ta 4K
.It armv6       Ta 4K, 1M
.It arm64       Ta 4K, 2M, 1G
.It i386        Ta 4K, 2M (PAE), 4M
.It mips        Ta 4K
.It mipsel      Ta 4K
.It mipsn32     Ta 4K
.It mips64      Ta 4K
.It mips64el    Ta 4K
.It powerpc     Ta 4K
.It powerpc64   Ta 4K
.It riscv       Ta 4K
.It sparc64     Ta 8K
.El
.Ss Floating Point
.Bl -column -offset indent "Sy Architecture" "Sy float, double" "Sy long double"
.It Sy Architecture Ta Sy float, double Ta Sy long double
.It amd64       Ta hard Ta hard, 80 bit
.It arm         Ta soft Ta soft, double precision
.It armeb       Ta soft Ta soft, double precision
.It armv6       Ta hard Ta hard, double precision
.It arm64       Ta hard Ta soft, quad precision
.It i386        Ta hard Ta hard, 80 bit
.It mips        Ta soft Ta identical to double
.It mipsel      Ta soft Ta identical to double
.It mipsn32     Ta soft Ta  identical to double
.It mips64      Ta soft Ta identical to double
.It mips64el    Ta soft Ta identical to double
.It powerpc     Ta hard Ta hard, double precision
.It powerpc64   Ta hard Ta hard, double precision
.It riscv       Ta
.It sparc64     Ta hard Ta hard, quad precision
.El
.Ss Predefined Macros
The compiler provides a number of predefined macros.
Some of these provide architecture-specific details and are explained below.
Other macros, including those required by the language standard, are not
included here.
.Pp
The full set of predefined macros can be obtained with this command:
.Bd -literal -offset indent
cc -x c -Dm -E /dev/null
.Ed
.Pp
Common type size and endianness macros:
.Bl -column -offset indent "BYTE_ORDER" "Sy Meaning"
.It Sy Macro Ta Sy Meaning
.It Dv __LP64__ Ta 64-bit (8-byte) long and pointer, 32-bit (4-byte) int
.It Dv __ILP32__ Ta 32-bit (4-byte) int, long and pointer
.It Dv BYTE_ORDER Ta Either Dv BIG_ENDIAN or Dv LITTLE_ENDIAN .
.Dv PDP11_ENDIAN
is not used on
.Fx .
.El
.Pp
Architecture-specific macros:
.Bl -column -offset indent "Sy Architecture" "Sy Predefined macros"
.It Sy Architecture Ta Sy Predefined macros
.It amd64       Ta Dv __amd64__, Dv __x86_64__
.It arm         Ta Dv __arm__
.It armeb       Ta Dv __arm__
.It armv6       Ta Dv __arm__, Dv __ARM_ARCH >= 6
.It arm64       Ta Dv __aarch64__
.It i386        Ta Dv __i386__
.It mips        Ta Dv __mips__, Dv __MIPSEB__, Dv __mips_o32
.It mipsel      Ta Dv __mips__, Dv __mips_o32
.It mipsn32     Ta Dv __mips__, Dv __MIPSEB__, Dv __mips_n32
.It mips64      Ta Dv __mips__, Dv __MIPSEB__, Dv __mips_n64
.It mips64el    Ta Dv __mips__, Dv __mips_n64
.It powerpc     Ta Dv __powerpc__
.It powerpc64   Ta Dv __powerpc__, Dv __powerpc64__
.It riscv       Ta Dv __riscv__, Dv __riscv64
.It sparc64     Ta Dv __sparc64__
.El
.Sh SEE ALSO
.Xr src.conf 5 ,
.Xr build 7
.Sh HISTORY
An
.Nm
manual page appeared in
.Fx 12 .