diff options
| -rw-r--r-- | CMakeLists.txt | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt index 0cb08fc7..b21090f7 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -1007,6 +1007,56 @@ calculation if supported by the system" ON) endif() endif() +# ARM64 C Language Extensions define CRC32 functions in arm_acle.h. +# These are supported by at least GCC and Clang which both need +# __attribute__((__target__("+crc"))), unless the needed compiler flags +# are used to support the CRC instruction. +option(ALLOW_ARM64_CRC32 "Allow ARM64 CRC32 instruction if supported by \ +the system" ON) + +if(ALLOW_ARM64_CRC32) + check_c_source_compiles(" + #include <stdint.h> + + #ifndef _MSC_VER + #include <arm_acle.h> + #endif + + #if (defined(__GNUC__) || defined(__clang__)) && !defined(__EDG__) + __attribute__((__target__(\"+crc\"))) + #endif + uint32_t my_crc(uint32_t a, uint64_t b) + { + return __crc32d(a, b); + } + int main(void) { return 0; } + " + HAVE_ARM64_CRC32) + + if(HAVE_ARM64_CRC32) + target_compile_definitions(liblzma PRIVATE HAVE_ARM64_CRC32) + + # Check for ARM64 CRC32 instruction runtime detection. + # getauxval() is supported on Linux. + check_symbol_exists(getauxval sys/auxv.h HAVE_GETAUXVAL) + tuklib_add_definition_if(liblzma HAVE_GETAUXVAL) + + # elf_aux_info() is supported on FreeBSD. + check_symbol_exists(elf_aux_info sys/auxv.h HAVE_ELF_AUX_INFO) + tuklib_add_definition_if(liblzma HAVE_ELF_AUX_INFO) + + # sysctlbyname("hw.optional.armv8_crc32", ...) is supported on Darwin + # (macOS, iOS, etc.). Note that sysctlbyname() is supported on FreeBSD, + # NetBSD, and possibly others too but the string is specific to + # Apple OSes. The C code is responsible for checking + # defined(__APPLE__) before using + # sysctlbyname("hw.optional.armv8_crc32", ...). + check_symbol_exists(sysctlbyname sys/sysctl.h HAVE_SYSCTLBYNAME) + tuklib_add_definition_if(liblzma HAVE_SYSCTLBYNAME) + endif() +endif() + + # Support -fvisiblity=hidden when building shared liblzma. # These lines do nothing on Windows (even under Cygwin). # HAVE_VISIBILITY should always be defined to 0 or 1. |