# host-cpu-c-abi.m4 serial 16 dnl Copyright (C) 2002-2024 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. dnl From Bruno Haible and Sam Steingold. dnl Sets the HOST_CPU variable to the canonical name of the CPU. dnl Sets the HOST_CPU_C_ABI variable to the canonical name of the CPU with its dnl C language ABI (application binary interface). dnl Also defines __${HOST_CPU}__ and __${HOST_CPU_C_ABI}__ as C macros in dnl config.h. dnl dnl This canonical name can be used to select a particular assembly language dnl source file that will interoperate with C code on the given host. dnl dnl For example: dnl * 'i386' and 'sparc' are different canonical names, because code for i386 dnl will not run on SPARC CPUs and vice versa. They have different dnl instruction sets. dnl * 'sparc' and 'sparc64' are different canonical names, because code for dnl 'sparc' and code for 'sparc64' cannot be linked together: 'sparc' code dnl contains 32-bit instructions, whereas 'sparc64' code contains 64-bit dnl instructions. A process on a SPARC CPU can be in 32-bit mode or in 64-bit dnl mode, but not both. dnl * 'mips' and 'mipsn32' are different canonical names, because they use dnl different argument passing and return conventions for C functions, and dnl although the instruction set of 'mips' is a large subset of the dnl instruction set of 'mipsn32'. dnl * 'mipsn32' and 'mips64' are different canonical names, because they use dnl different sizes for the C types like 'int' and 'void *', and although dnl the instruction sets of 'mipsn32' and 'mips64' are the same. dnl * The same canonical name is used for different endiannesses. You can dnl determine the endianness through preprocessor symbols: dnl - 'arm': test __ARMEL__. dnl - 'mips', 'mipsn32', 'mips64': test _MIPSEB vs. _MIPSEL. dnl - 'powerpc64': test _BIG_ENDIAN vs. _LITTLE_ENDIAN. dnl * The same name 'i386' is used for CPUs of type i386, i486, i586 dnl (Pentium), AMD K7, Pentium II, Pentium IV, etc., because dnl - Instructions that do not exist on all of these CPUs (cmpxchg, dnl MMX, SSE, SSE2, 3DNow! etc.) are not frequently used. If your dnl assembly language source files use such instructions, you will dnl need to make the distinction. dnl - Speed of execution of the common instruction set is reasonable across dnl the entire family of CPUs. If you have assembly language source files dnl that are optimized for particular CPU types (like GNU gmp has), you dnl will need to make the distinction. dnl See . AC_DEFUN([gl_HOST_CPU_C_ABI], [ AC_REQUIRE([AC_CANONICAL_HOST]) AC_REQUIRE([gl_C_ASM]) AC_CACHE_CHECK([host CPU and C ABI], [gl_cv_host_cpu_c_abi], [case "$host_cpu" in changequote(,)dnl i[34567]86 ) changequote([,])dnl gl_cv_host_cpu_c_abi=i386 ;; x86_64 ) # On x86_64 systems, the C compiler may be generating code in one of # these ABIs: # - 64-bit instruction set, 64-bit pointers, 64-bit 'long': x86_64. # - 64-bit instruction set, 64-bit pointers, 32-bit 'long': x86_64 # with native Windows (mingw, MSVC). # - 64-bit instruction set, 32-bit pointers, 32-bit 'long': x86_64-x32. # - 32-bit instruction set, 32-bit pointers, 32-bit 'long': i386. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if (defined __x86_64__ || defined __amd64__ \ || defined _M_X64 || defined _M_AMD64) int ok; #else error fail #endif ]])], [AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if defined __ILP32__ || defined _ILP32 int ok; #else error fail #endif ]])], [gl_cv_host_cpu_c_abi=x86_64-x32], [gl_cv_host_cpu_c_abi=x86_64])], [gl_cv_host_cpu_c_abi=i386]) ;; changequote(,)dnl alphaev[4-8] | alphaev56 | alphapca5[67] | alphaev6[78] ) changequote([,])dnl gl_cv_host_cpu_c_abi=alpha ;; arm* | aarch64 ) # Assume arm with EABI. # On arm64 systems, the C compiler may be generating code in one of # these ABIs: # - aarch64 instruction set, 64-bit pointers, 64-bit 'long': arm64. # - aarch64 instruction set, 32-bit pointers, 32-bit 'long': arm64-ilp32. # - 32-bit instruction set, 32-bit pointers, 32-bit 'long': arm or armhf. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#ifdef __aarch64__ int ok; #else error fail #endif ]])], [AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if defined __ILP32__ || defined _ILP32 int ok; #else error fail #endif ]])], [gl_cv_host_cpu_c_abi=arm64-ilp32], [gl_cv_host_cpu_c_abi=arm64])], [# Don't distinguish little-endian and big-endian arm, since they # don't require different machine code for simple operations and # since the user can distinguish them through the preprocessor # defines __ARMEL__ vs. __ARMEB__. # But distinguish arm which passes floating-point arguments and # return values in integer registers (r0, r1, ...) - this is # gcc -mfloat-abi=soft or gcc -mfloat-abi=softfp - from arm which # passes them in float registers (s0, s1, ...) and double registers # (d0, d1, ...) - this is gcc -mfloat-abi=hard. GCC 4.6 or newer # sets the preprocessor defines __ARM_PCS (for the first case) and # __ARM_PCS_VFP (for the second case), but older GCC does not. echo 'double ddd; void func (double dd) { ddd = dd; }' > conftest.c # Look for a reference to the register d0 in the .s file. AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS $gl_c_asm_opt conftest.c) >/dev/null 2>&1 if LC_ALL=C grep 'd0,' conftest.$gl_asmext >/dev/null; then gl_cv_host_cpu_c_abi=armhf else gl_cv_host_cpu_c_abi=arm fi rm -f conftest* ]) ;; hppa1.0 | hppa1.1 | hppa2.0* | hppa64 ) # On hppa, the C compiler may be generating 32-bit code or 64-bit # code. In the latter case, it defines _LP64 and __LP64__. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#ifdef __LP64__ int ok; #else error fail #endif ]])], [gl_cv_host_cpu_c_abi=hppa64], [gl_cv_host_cpu_c_abi=hppa]) ;; ia64* ) # On ia64 on HP-UX, the C compiler may be generating 64-bit code or # 32-bit code. In the latter case, it defines _ILP32. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#ifdef _ILP32 int ok; #else error fail #endif ]])], [gl_cv_host_cpu_c_abi=ia64-ilp32], [gl_cv_host_cpu_c_abi=ia64]) ;; mips* ) # We should also check for (_MIPS_SZPTR == 64), but gcc keeps this # at 32. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if defined _MIPS_SZLONG && (_MIPS_SZLONG == 64) int ok; #else error fail #endif ]])], [gl_cv_host_cpu_c_abi=mips64], [# In the n32 ABI, _ABIN32 is defined, _ABIO32 is not defined (but # may later get defined by ), and _MIPS_SIM == _ABIN32. # In the 32 ABI, _ABIO32 is defined, _ABIN32 is not defined (but # may later get defined by ), and _MIPS_SIM == _ABIO32. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if (_MIPS_SIM == _ABIN32) int ok; #else error fail #endif ]])], [gl_cv_host_cpu_c_abi=mipsn32], [gl_cv_host_cpu_c_abi=mips])]) ;; powerpc* ) # Different ABIs are in use on AIX vs. Mac OS X vs. Linux,*BSD. # No need to distinguish them here; the caller may distinguish # them based on the OS. # On powerpc64 systems, the C compiler may still be generating # 32-bit code. And on powerpc-ibm-aix systems, the C compiler may # be generating 64-bit code. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if defined __powerpc64__ || defined __LP64__ int ok; #else error fail #endif ]])], [# On powerpc64, there are two ABIs on Linux: The AIX compatible # one and the ELFv2 one. The latter defines _CALL_ELF=2. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if defined _CALL_ELF && _CALL_ELF == 2 int ok; #else error fail #endif ]])], [gl_cv_host_cpu_c_abi=powerpc64-elfv2], [gl_cv_host_cpu_c_abi=powerpc64]) ], [gl_cv_host_cpu_c_abi=powerpc]) ;; rs6000 ) gl_cv_host_cpu_c_abi=powerpc ;; riscv32 | riscv64 ) # There are 2 architectures (with variants): rv32* and rv64*. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if __riscv_xlen == 64 int ok; #else error fail #endif ]])], [cpu=riscv64], [cpu=riscv32]) # There are 6 ABIs: ilp32, ilp32f, ilp32d, lp64, lp64f, lp64d. # Size of 'long' and 'void *': AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if defined __LP64__ int ok; #else error fail #endif ]])], [main_abi=lp64], [main_abi=ilp32]) # Float ABIs: # __riscv_float_abi_double: # 'float' and 'double' are passed in floating-point registers. # __riscv_float_abi_single: # 'float' are passed in floating-point registers. # __riscv_float_abi_soft: # No values are passed in floating-point registers. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if defined __riscv_float_abi_double int ok; #else error fail #endif ]])], [float_abi=d], [AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if defined __riscv_float_abi_single int ok; #else error fail #endif ]])], [float_abi=f], [float_abi='']) ]) gl_cv_host_cpu_c_abi="${cpu}-${main_abi}${float_abi}" ;; s390* ) # On s390x, the C compiler may be generating 64-bit (= s390x) code # or 31-bit (= s390) code. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if defined __LP64__ || defined __s390x__ int ok; #else error fail #endif ]])], [gl_cv_host_cpu_c_abi=s390x], [gl_cv_host_cpu_c_abi=s390]) ;; sparc | sparc64 ) # UltraSPARCs running Linux have `uname -m` = "sparc64", but the # C compiler still generates 32-bit code. AC_COMPILE_IFELSE( [AC_LANG_SOURCE( [[#if defined __sparcv9 || defined __arch64__ int ok; #else error fail #endif ]])], [gl_cv_host_cpu_c_abi=sparc64], [gl_cv_host_cpu_c_abi=sparc]) ;; *) gl_cv_host_cpu_c_abi="$host_cpu" ;; esac ]) dnl In most cases, $HOST_CPU and $HOST_CPU_C_ABI are the same. HOST_CPU=`echo "$gl_cv_host_cpu_c_abi" | sed -e 's/-.*//'` HOST_CPU_C_ABI="$gl_cv_host_cpu_c_abi" AC_SUBST([HOST_CPU]) AC_SUBST([HOST_CPU_C_ABI]) # This was # AC_DEFINE_UNQUOTED([__${HOST_CPU}__]) # AC_DEFINE_UNQUOTED([__${HOST_CPU_C_ABI}__]) # earlier, but KAI C++ 3.2d doesn't like this. sed -e 's/-/_/g' >> confdefs.h <