1 # host-cpu-c-abi.m4 serial 3
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, the C compiler may be generating 64-bit (= aarch64) code
93 # or 32-bit (= arm) code.
95 [#if defined(__aarch64__) || defined(__ARM_64BIT_STATE) || defined(__ARM_PCS_AAPCS64)
98 [gl_cv_host_cpu_c_abi=arm64],
99 [# Don't distinguish little-endian and big-endian arm, since they
100 # don't require different machine code for simple operations and
101 # since the user can distinguish them through the preprocessot
102 # defines __ARMEL__ vs. __ARMEB__.
103 # But distinguish arm which passes floating-point arguments and
104 # return values in integer registers (r0, r1, ...) - this is
105 # gcc -mfloat-abi=soft or gcc -mfloat-abi=softfp - from arm which
106 # passes them in float registers (s0, s1, ...) and double registers
107 # (d0, d1, ...) - rhis is gcc -mfloat-abi=hard. GCC 4.6 or newer
108 # sets the preprocessor defines __ARM_PCS (for the first case) and
109 # __ARM_PCS_VFP (for the second case), but older GCC does not.
110 echo 'double ddd; void func (double dd) { ddd = dd; }' > conftest.c
111 # Look for a reference to the register d0 in the .s file.
112 AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS $gl_c_asm_opt conftest.c) >/dev/null 2>&1
113 if LC_ALL=C grep -E 'd0,' conftest.$gl_asmext >/dev/null; then
114 gl_cv_host_cpu_c_abi=armhf
116 gl_cv_host_cpu_c_abi=arm
122 hppa1.0 | hppa1.1 | hppa2.0* | hppa64 )
123 # On hppa, the C compiler may be generating 32-bit code or 64-bit
124 # code. In the latter case, it defines _LP64 and __LP64__.
126 [#if defined(__LP64__)
129 [gl_cv_host_cpu_c_abi=hppa64],
130 [gl_cv_host_cpu_c_abi=hppa])
134 # We should also check for (_MIPS_SZPTR == 64), but gcc keeps this
137 [#if defined _MIPS_SZLONG && (_MIPS_SZLONG == 64)
140 [gl_cv_host_cpu_c_abi=mips64],
141 [# Strictly speaking, the MIPS ABI (-32 or -n32) is independent
142 # from the CPU identification (-mips[12] or -mips[34]). But -n32
143 # is commonly used together with -mips3, and it's easier to test
144 # the CPU identification.
149 [gl_cv_host_cpu_c_abi=mipsn32],
150 [gl_cv_host_cpu_c_abi=mips])])
154 # Different ABIs are in use on AIX vs. Mac OS X vs. Linux,*BSD.
155 # No need to distinguish them here; the caller may distinguish
156 # them based on the OS.
157 # On powerpc64 systems, the C compiler may still be generating
158 # 32-bit code. And on powerpc-ibm-aix systems, the C compiler may
159 # be generating 64-bit code.
161 [#if defined __powerpc64__ || defined _ARCH_PPC64
164 [# On powerpc64, there are two ABIs on Linux: The AIX compatible
165 # one and the ELFv2 one. The latter defines _CALL_ELF=2.
167 [#if defined _CALL_ELF && _CALL_ELF == 2
170 [gl_cv_host_cpu_c_abi=powerpc64-elfv2],
171 [gl_cv_host_cpu_c_abi=powerpc64])
173 [gl_cv_host_cpu_c_abi=powerpc])
177 gl_cv_host_cpu_c_abi=powerpc
181 # On s390x, the C compiler may be generating 64-bit (= s390x) code
182 # or 31-bit (= s390) code.
184 [#if defined(__LP64__) || defined(__s390x__)
187 [gl_cv_host_cpu_c_abi=s390x],
188 [gl_cv_host_cpu_c_abi=s390])
192 # UltraSPARCs running Linux have `uname -m` = "sparc64", but the
193 # C compiler still generates 32-bit code.
195 [#if defined __sparcv9 || defined __arch64__
198 [gl_cv_host_cpu_c_abi=sparc64],
199 [gl_cv_host_cpu_c_abi=sparc])
203 gl_cv_host_cpu_c_abi="$host_cpu"
208 dnl In most cases, $HOST_CPU and $HOST_CPU_C_ABI are the same.
209 HOST_CPU=`echo "$gl_cv_host_cpu_c_abi" | sed -e 's/-.*//'`
210 HOST_CPU_C_ABI="$gl_cv_host_cpu_c_abi"
212 AC_SUBST([HOST_CPU_C_ABI])
215 # AC_DEFINE_UNQUOTED([__${HOST_CPU}__])
216 # AC_DEFINE_UNQUOTED([__${HOST_CPU_C_ABI}__])
217 # earlier, but KAI C++ 3.2d doesn't like this.
218 sed -e 's/-/_/g' >> confdefs.h <<EOF
219 #ifndef __${HOST_CPU}__
220 #define __${HOST_CPU}__ 1
222 #ifndef __${HOST_CPU_C_ABI}__
223 #define __${HOST_CPU_C_ABI}__ 1
226 AH_TOP([/* CPU and C ABI indicator */
230 #ifndef __x86_64_x32__
231 #undef __x86_64_x32__
272 #ifndef __powerpc64__
275 #ifndef __powerpc64_elfv2__
276 #undef __powerpc64_elfv2__