Add runtime feature detection for F16C

Author: gnzlbg

crates/core_arch/src/x86/f16c.rs

@@ -1,5 +1,6 @@
-//! F16C intrinsics:
-//! https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=fp16&expand=1769
+//! [F16C intrinsics].
+//!
+//! [F16C intrinsics]: https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=fp16&expand=1769
 
 use crate::{
     core_arch::{simd::*, x86::*},

crates/core_arch/tests/cpu-detection.rs

@@ -31,6 +31,7 @@ fn x86_all() {
         "avx512_vpopcntdq {:?}",
         is_x86_feature_detected!("avx512vpopcntdq")
     );
+    println!("f16c: {:?}", is_x86_feature_detected!("f16c"));
     println!("fma: {:?}", is_x86_feature_detected!("fma"));
     println!("abm: {:?}", is_x86_feature_detected!("abm"));
     println!("bmi: {:?}", is_x86_feature_detected!("bmi1"));

crates/std_detect/src/detect/arch/x86.rs

@@ -62,6 +62,7 @@
 /// * `"avx512ifma"`
 /// * `"avx512vbmi"`
 /// * `"avx512vpopcntdq"`
+/// * `"f16c"`
 /// * `"fma"`
 /// * `"bmi1"`
 /// * `"bmi2"`
@@ -179,6 +180,10 @@ macro_rules! is_x86_feature_detected {
         cfg!(target_feature = "avx512vpopcntdq") || $crate::detect::check_for(
             $crate::detect::Feature::avx512_vpopcntdq)
     };
+    ("f16c") => {
+        cfg!(target_feature = "avx512f") || $crate::detect::check_for(
+            $crate::detect::Feature::f16c)
+    };
     ("fma") => {
         cfg!(target_feature = "fma") || $crate::detect::check_for(
             $crate::detect::Feature::fma)
@@ -309,6 +314,8 @@ pub enum Feature {
     /// AVX-512 VPOPCNTDQ (Vector Population Count Doubleword and
     /// Quadword)
     avx512_vpopcntdq,
+    /// F16C (Conversions between IEEE-754 `binary16` and `binary32` formats)
+    f16c,
     /// FMA (Fused Multiply Add)
     fma,
     /// BMI1 (Bit Manipulation Instructions 1)

crates/std_detect/src/detect/os/x86.rs

@@ -113,13 +113,14 @@ fn detect_features() -> cache::Initializer {
         };
 
         enable(proc_info_ecx, 0, Feature::sse3);
+        enable(proc_info_ecx, 1, Feature::pclmulqdq);
         enable(proc_info_ecx, 9, Feature::ssse3);
         enable(proc_info_ecx, 13, Feature::cmpxchg16b);
         enable(proc_info_ecx, 19, Feature::sse4_1);
         enable(proc_info_ecx, 20, Feature::sse4_2);
         enable(proc_info_ecx, 23, Feature::popcnt);
         enable(proc_info_ecx, 25, Feature::aes);
-        enable(proc_info_ecx, 1, Feature::pclmulqdq);
+        enable(proc_info_ecx, 29, Feature::f16c);
         enable(proc_info_ecx, 30, Feature::rdrand);
         enable(extended_features_ebx, 18, Feature::rdseed);
         enable(extended_features_ebx, 19, Feature::adx);

crates/std_detect/tests/cpu-detection.rs

@@ -87,6 +87,7 @@ fn x86_all() {
         "avx512_vpopcntdq {:?}",
         is_x86_feature_detected!("avx512vpopcntdq")
     );
+    println!("f16c: {:?}", is_x86_feature_detected!("f16c"));
     println!("fma: {:?}", is_x86_feature_detected!("fma"));
     println!("bmi1: {:?}", is_x86_feature_detected!("bmi1"));
     println!("bmi2: {:?}", is_x86_feature_detected!("bmi2"));