[tbm] correctly check tbm features

Author: gnzlbg

src/x86/runtime.rs

@@ -254,8 +254,17 @@ fn detect_features() -> usize {
         }
     }
 
-    if test_bit(proc_info_ecx, 21) && is_amd() {
-        value = set_bit(value, __Feature::tbm as u32);
+    if is_amd() {
+        let extended_proc_info_ecx: u32;
+        /// 3. EAX=80000001h: Queries "Extended Processor Info and Feature Bits"
+        asm!("cpuid"
+             : "={ecx}"(extended_proc_info_ecx)
+             : "{eax}"(0x8000_0001_u32), "{ecx}"(0 as u32)
+             : :);
+
+        if test_bit(extended_proc_info_ecx, 21) {
+            value = set_bit(value, __Feature::tbm as u32);
+        }
     }
 
     value

tests/cpu-detection.rs

@@ -24,6 +24,7 @@ fn works() {
     assert_eq!(cfg_feature_enabled!("bmi"), information.bmi1());
     assert_eq!(cfg_feature_enabled!("bmi2"), information.bmi2());
     assert_eq!(cfg_feature_enabled!("popcnt"), information.popcnt());
-
-    // TODO: tbm, abm, lzcnt
+    assert_eq!(cfg_feature_enabled!("tbm"), information.tbm());
+    assert_eq!(cfg_feature_enabled!("lzcnt"), information.lzcnt());
+    // TODO: abm
 }