1 # host-cpu-c-abi.m4 serial 4
2 dnl Copyright (C) 2002-2017 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 dnl From Bruno Haible and Sam Steingold.
9 dnl Sets the HOST_CPU variable to the canonical name of the CPU.
10 dnl Sets the HOST_CPU_C_ABI variable to the canonical name of the CPU with its
11 dnl C language ABI (application binary interface).
12 dnl Also defines __${HOST_CPU}__ and __${HOST_CPU_C_ABI}__ as C macros in
15 dnl This canonical name can be used to select a particular assembly language
16 dnl source file that will interoperate with C code on the given host.
19 dnl * 'i386' and 'sparc' are different canonical names, because code for i386
20 dnl will not run on SPARC CPUs and vice versa. They have different
22 dnl * 'sparc' and 'sparc64' are different canonical names, because code for
23 dnl 'sparc' and code for 'sparc64' cannot be linked together: 'sparc' code
24 dnl contains 32-bit instructions, whereas 'sparc64' code contains 64-bit
25 dnl instructions. A process on a SPARC CPU can be in 32-bit mode or in 64-bit
26 dnl mode, but not both.
27 dnl * 'mips' and 'mipsn32' are different canonical names, because they use
28 dnl different argument passing and return conventions for C functions, and
29 dnl although the instruction set of 'mips' is a large subset of the
30 dnl instruction set of 'mipsn32'.
31 dnl * 'mipsn32' and 'mips64' are different canonical names, because they use
32 dnl different sizes for the C types like 'int' and 'void *', and although
33 dnl the instruction sets of 'mipsn32' and 'mips64' are the same.
34 dnl * The same canonical name is used for different endiannesses. You can
35 dnl determine the endianness through preprocessor symbols:
36 dnl - 'arm': test __ARMEL__.
37 dnl - 'mips', 'mipsn32', 'mips64': test _MIPSEB vs. _MIPSEL.
38 dnl - 'powerpc64': test _BIG_ENDIAN vs. _LITTLE_ENDIAN.
39 dnl * The same name 'i386' is used for CPUs of type i386, i486, i586
40 dnl (Pentium), AMD K7, Pentium II, Pentium IV, etc., because
41 dnl - Instructions that do not exist on all of these CPUs (cmpxchg,
42 dnl MMX, SSE, SSE2, 3DNow! etc.) are not frequently used. If your
43 dnl assembly language source files use such instructions, you will
44 dnl need to make the distinction.
45 dnl - Speed of execution of the common instruction set is reasonable across
46 dnl the entire family of CPUs. If you have assembly language source files
47 dnl that are optimized for particular CPU types (like GNU gmp has), you
48 dnl will need to make the distinction.
49 dnl See <http://en.wikipedia.org/wiki/X86_instruction_listings>.
50 AC_DEFUN([gl_HOST_CPU_C_ABI],
52 AC_REQUIRE([AC_CANONICAL_HOST])
53 AC_REQUIRE([gl_C_ASM])
54 AC_CACHE_CHECK([host CPU and C ABI], [gl_cv_host_cpu_c_abi],
60 gl_cv_host_cpu_c_abi=i386
64 # On x86_64 systems, the C compiler may be generating code in one of
66 # - 64-bit instruction set, 64-bit pointers, 64-bit 'long': x86_64.
67 # - 64-bit instruction set, 64-bit pointers, 32-bit 'long': x86_64
68 # with native Windows (mingw, MSVC).
69 # - 64-bit instruction set, 32-bit pointers, 32-bit 'long': x86_64-x32.
70 # - 32-bit instruction set, 32-bit pointers, 32-bit 'long': i386.
72 [#if defined __x86_64__ || defined __amd64__ || defined _M_X64 || defined _M_AMD64
76 [#if defined __ILP32__ || defined _ILP32
79 [gl_cv_host_cpu_c_abi=x86_64-x32],
80 [gl_cv_host_cpu_c_abi=x86_64])],
81 [gl_cv_host_cpu_c_abi=i386])
85 alphaev[4-8] | alphaev56 | alphapca5[67] | alphaev6[78] )
87 gl_cv_host_cpu_c_abi=alpha
91 # Assume arm with EABI.
92 # On arm64 systems, the C compiler may be generating code in one of
94 # - aarch64 instruction set, 64-bit pointers, 64-bit 'long': arm64.
95 # - aarch64 instruction set, 32-bit pointers, 32-bit 'long': arm64-ilp32.
96 # - 32-bit instruction set, 32-bit pointers, 32-bit 'long': arm or armhf.
98 [#if defined(__aarch64__) || defined(__ARM_64BIT_STATE) || defined(__ARM_PCS_AAPCS64)
102 [#if defined __ILP32__ || defined _ILP32
105 [gl_cv_host_cpu_c_abi=arm64-ilp32],
106 [gl_cv_host_cpu_c_abi=arm64])],
107 [# Don't distinguish little-endian and big-endian arm, since they
108 # don't require different machine code for simple operations and
109 # since the user can distinguish them through the preprocessot
110 # defines __ARMEL__ vs. __ARMEB__.
111 # But distinguish arm which passes floating-point arguments and
112 # return values in integer registers (r0, r1, ...) - this is
113 # gcc -mfloat-abi=soft or gcc -mfloat-abi=softfp - from arm which
114 # passes them in float registers (s0, s1, ...) and double registers
115 # (d0, d1, ...) - rhis is gcc -mfloat-abi=hard. GCC 4.6 or newer
116 # sets the preprocessor defines __ARM_PCS (for the first case) and
117 # __ARM_PCS_VFP (for the second case), but older GCC does not.
118 echo 'double ddd; void func (double dd) { ddd = dd; }' > conftest.c
119 # Look for a reference to the register d0 in the .s file.
120 AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS $gl_c_asm_opt conftest.c) >/dev/null 2>&1
121 if LC_ALL=C grep -E 'd0,' conftest.$gl_asmext >/dev/null; then
122 gl_cv_host_cpu_c_abi=armhf
124 gl_cv_host_cpu_c_abi=arm
130 hppa1.0 | hppa1.1 | hppa2.0* | hppa64 )
131 # On hppa, the C compiler may be generating 32-bit code or 64-bit
132 # code. In the latter case, it defines _LP64 and __LP64__.
134 [#if defined(__LP64__)
137 [gl_cv_host_cpu_c_abi=hppa64],
138 [gl_cv_host_cpu_c_abi=hppa])
142 # We should also check for (_MIPS_SZPTR == 64), but gcc keeps this
145 [#if defined _MIPS_SZLONG && (_MIPS_SZLONG == 64)
148 [gl_cv_host_cpu_c_abi=mips64],
149 [# Strictly speaking, the MIPS ABI (-32 or -n32) is independent
150 # from the CPU identification (-mips[12] or -mips[34]). But -n32
151 # is commonly used together with -mips3, and it's easier to test
152 # the CPU identification.
157 [gl_cv_host_cpu_c_abi=mipsn32],
158 [gl_cv_host_cpu_c_abi=mips])])
162 # Different ABIs are in use on AIX vs. Mac OS X vs. Linux,*BSD.
163 # No need to distinguish them here; the caller may distinguish
164 # them based on the OS.
165 # On powerpc64 systems, the C compiler may still be generating
166 # 32-bit code. And on powerpc-ibm-aix systems, the C compiler may
167 # be generating 64-bit code.
169 [#if defined __powerpc64__ || defined _ARCH_PPC64
172 [# On powerpc64, there are two ABIs on Linux: The AIX compatible
173 # one and the ELFv2 one. The latter defines _CALL_ELF=2.
175 [#if defined _CALL_ELF && _CALL_ELF == 2
178 [gl_cv_host_cpu_c_abi=powerpc64-elfv2],
179 [gl_cv_host_cpu_c_abi=powerpc64])
181 [gl_cv_host_cpu_c_abi=powerpc])
185 gl_cv_host_cpu_c_abi=powerpc
189 # On s390x, the C compiler may be generating 64-bit (= s390x) code
190 # or 31-bit (= s390) code.
192 [#if defined(__LP64__) || defined(__s390x__)
195 [gl_cv_host_cpu_c_abi=s390x],
196 [gl_cv_host_cpu_c_abi=s390])
200 # UltraSPARCs running Linux have `uname -m` = "sparc64", but the
201 # C compiler still generates 32-bit code.
203 [#if defined __sparcv9 || defined __arch64__
206 [gl_cv_host_cpu_c_abi=sparc64],
207 [gl_cv_host_cpu_c_abi=sparc])
211 gl_cv_host_cpu_c_abi="$host_cpu"
216 dnl In most cases, $HOST_CPU and $HOST_CPU_C_ABI are the same.
217 HOST_CPU=`echo "$gl_cv_host_cpu_c_abi" | sed -e 's/-.*//'`
218 HOST_CPU_C_ABI="$gl_cv_host_cpu_c_abi"
220 AC_SUBST([HOST_CPU_C_ABI])
223 # AC_DEFINE_UNQUOTED([__${HOST_CPU}__])
224 # AC_DEFINE_UNQUOTED([__${HOST_CPU_C_ABI}__])
225 # earlier, but KAI C++ 3.2d doesn't like this.
226 sed -e 's/-/_/g' >> confdefs.h <<EOF
227 #ifndef __${HOST_CPU}__
228 #define __${HOST_CPU}__ 1
230 #ifndef __${HOST_CPU_C_ABI}__
231 #define __${HOST_CPU_C_ABI}__ 1
234 AH_TOP([/* CPU and C ABI indicator */
238 #ifndef __x86_64_x32__
239 #undef __x86_64_x32__
253 #ifndef __arm64_ilp32__
254 #undef __arm64_ilp32__
283 #ifndef __powerpc64__
286 #ifndef __powerpc64_elfv2__
287 #undef __powerpc64_elfv2__