__get_cpuid_count is also unavailable on older versions of GCC
diff --git a/lib/fusion.c b/lib/fusion.c
index c121bee..43bc336 100644
--- a/lib/fusion.c
+++ b/lib/fusion.c
@@ -850,21 +850,19 @@
sizeof(struct aesgcm_context),
aes128gcm_setup};
-#include <cpuid.h>
-
int ptls_fusion_is_supported_by_cpu(void)
{
unsigned leaf1_ecx, leaf7_ebx;
{ /* GCC-specific code to obtain CPU features */
- unsigned unused1, unused2, unused3;
- if (!__get_cpuid(1, &unused1, &unused2, &leaf1_ecx, &unused3))
+ unsigned leaf_cnt;
+ __asm__("cpuid" : "=a"(leaf_cnt) : "a"(0) : "ebx", "ecx", "edx");
+ if (leaf_cnt < 7)
return 0;
- if (!__get_cpuid_count(7, 0, &unused1, &leaf7_ebx, &unused2, &unused3))
- return 0;
+ __asm__("cpuid" : "=c"(leaf1_ecx) : "a"(1) : "ebx", "edx");
+ __asm__("cpuid" : "=b"(leaf7_ebx) : "a"(7), "c"(0) : "edx");
}
-
/* AVX2 */
if ((leaf7_ebx & (1 << 5)) == 0)
return 0;
