Add cpuid.c.

bindings/go/server.c

@@ -21,3 +21,4 @@
 #include "consts.c"
 #include "vect.c"
 #include "exports.c"
+#include "cpuid.c"

src/cpuid.c

@@ -0,0 +1,82 @@
+/*
+ * Copyright Supranational LLC
+ * Licensed under the Apache License, Version 2.0, see LICENSE for details.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+int __blst_platform_cap = 0;
+
+#if defined(__x86_64__) || defined(__x86_64) || defined(_M_X64)
+
+# if defined(__GNUC__) || defined(__clang__) || defined(__SUNPRO_C)
+static void __cpuidex(int info[4], int func, int sub)
+{
+    int eax, ebx, ecx, edx;
+
+    __asm__("cpuid" : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx)
+                    : "a"(func), "c"(sub));
+
+    info[0] = eax;
+    info[1] = ebx;
+    info[2] = ecx;
+    info[3] = edx;
+}
+# else
+#  include <intrin.h>
+# endif
+
+# if defined(__GNUC__) || defined(__clang__)
+__attribute__((constructor))
+# endif
+int __blst_cpuid(void)
+{
+    int info[4], cap = 0;
+
+    __cpuidex(info, 0, 0);
+    if (info[0] > 6) {
+        __cpuidex(info, 7, 0);
+        cap |= (info[1]>>19) & 1; /* ADX */
+        cap |= (info[1]>>28) & 2; /* SHA */
+    }
+
+    __blst_platform_cap = cap;
+
+    return 0;
+}
+
+# if defined(_MSC_VER) && !defined(__clang__)
+#  pragma section(".CRT$XCU",read)
+__declspec(allocate(".CRT$XCU")) static int (*p)(void) = __blst_cpuid;
+# elif defined(__SUNPRO_C)
+#  pragma init(__blst_cpuid)
+# endif
+
+#elif defined(__aarch64__) || defined(__aarch64)
+
+# if defined(__linux__) && (defined(__GNUC__) || defined(__clang__))
+extern unsigned long getauxval(unsigned long type) __attribute__ ((weak));
+
+__attribute__((constructor))
+int __blst_cpuid(void)
+{
+    int cap = 0;
+
+    if (getauxval) {
+        unsigned long hwcap_ce = getauxval(16);
+        cap = (hwcap_ce>>6) & 1; /* SHA256 */
+    }
+
+    __blst_platform_cap = cap;
+
+    return 0;
+}
+# elif defined(__APPLE__) && (defined(__GNUC__) || defined(__clang__))
+__attribute__((constructor))
+int __blst_cpuid()
+{
+    __blst_platform_cap = 1; /* SHA256 */
+    return 0;
+}
+# endif
+
+#endif

src/server.c

@@ -25,3 +25,4 @@
 #ifdef BLST_FR_PENTAROOT
 # include "pentaroot.c"
 #endif
+#include "cpuid.c"