ggml-cpu: add arm64 CPU feature check for OpenBSD, FreeBSD

Author: brad0

ggml/src/ggml-cpu/CMakeLists.txt

@@ -312,6 +312,12 @@ function(ggml_add_cpu_backend_variant_impl tag_name)
         message(STATUS "Unknown architecture")
     endif()
 
+    include(CheckSymbolExists)
+    check_symbol_exists(elf_aux_info sys/auxv.h HAVE_ELF_AUX_INFO)
+    if (HAVE_ELF_AUX_INFO)
+        add_compile_definitions(HAVE_ELF_AUX_INFO)
+    endif()
+
     if (GGML_CPU_AARCH64)
         target_compile_definitions(${GGML_CPU_NAME} PRIVATE GGML_USE_CPU_AARCH64)
     endif()

ggml/src/ggml-cpu/ggml-cpu.c

@@ -2371,7 +2371,7 @@ bool ggml_is_numa(void) {
 
 #if defined(__ARM_ARCH)
 
-#if defined(__linux__) && defined(__aarch64__)
+#if (defined(__linux__) || defined(HAVE_ELF_AUX_INFO)) && defined(__aarch64__)
 #include <sys/auxv.h>
 #elif defined(__APPLE__)
 #include <sys/sysctl.h>
@@ -2382,9 +2382,16 @@ bool ggml_is_numa(void) {
 #endif
 
 static void ggml_init_arm_arch_features(void) {
-#if defined(__linux__) && defined(__aarch64__)
+#if (defined(__linux__) || defined(HAVE_ELF_AUX_INFO)) && defined(__aarch64__)
+#if defined(HAVE_ELF_AUX_INFO)
+    uint32_t hwcap = 0;
+    uint32_t hwcap2 = 0;
+    elf_aux_info(AT_HWCAP, &hwcap, sizeof(hwcap));
+    elf_aux_info(AT_HWCAP2, &hwcap2, sizeof(hwcap2));
+#else
     uint32_t hwcap = getauxval(AT_HWCAP);
     uint32_t hwcap2 = getauxval(AT_HWCAP2);
+#endif
 
     ggml_arm_arch_features.has_neon = !!(hwcap & HWCAP_ASIMD);
     ggml_arm_arch_features.has_dotprod = !!(hwcap & HWCAP_ASIMDDP);