From ed3fd0da1d049ab531bcd358630da02ece504464 Mon Sep 17 00:00:00 2001
From: Nazar Mokrynskyi <nazar@mokrynskyi.com>
Date: Wed, 9 Apr 2025 08:54:58 +0300
Subject: Check x86 features even in `no_std`

---
 Cargo.toml      |  3 +++
 src/platform.rs | 68 ++++++++++-----------------------------------------------
 2 files changed, 15 insertions(+), 56 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 25ab345..bdd719f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -120,6 +120,9 @@ rayon-core = { version = "1.12.1", optional = true }
 serde = { version = "1.0", default-features = false, features = ["derive"], optional = true }
 zeroize = { version = "1", default-features = false, optional = true }
 
+[target.'cfg(any(target_arch = "x86", target_arch = "x86_64"))'.dependencies]
+cpufeatures = "0.2.17"
+
 [dev-dependencies]
 hmac = "0.12.0"
 hex = "0.4.2"
diff --git a/src/platform.rs b/src/platform.rs
index 51b3b7b..3a05420 100644
--- a/src/platform.rs
+++ b/src/platform.rs
@@ -408,7 +408,6 @@ impl Platform {
 #[cfg(blake3_avx512_ffi)]
 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
 #[inline(always)]
-#[allow(unreachable_code)]
 pub fn avx512_detected() -> bool {
     if cfg!(miri) {
         return false;
@@ -418,24 +417,13 @@ pub fn avx512_detected() -> bool {
     if cfg!(feature = "no_avx512") {
         return false;
     }
-    // Static check, e.g. for building with target-cpu=native.
-    #[cfg(all(target_feature = "avx512f", target_feature = "avx512vl"))]
-    {
-        return true;
-    }
-    // Dynamic check, if std is enabled.
-    #[cfg(feature = "std")]
-    {
-        if is_x86_feature_detected!("avx512f") && is_x86_feature_detected!("avx512vl") {
-            return true;
-        }
-    }
-    false
+
+    cpufeatures::new!(has_avx512, "avx512f", "avx512vl");
+    has_avx512::get()
 }
 
 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
 #[inline(always)]
-#[allow(unreachable_code)]
 pub fn avx2_detected() -> bool {
     if cfg!(miri) {
         return false;
@@ -445,24 +433,13 @@ pub fn avx2_detected() -> bool {
     if cfg!(feature = "no_avx2") {
         return false;
     }
-    // Static check, e.g. for building with target-cpu=native.
-    #[cfg(target_feature = "avx2")]
-    {
-        return true;
-    }
-    // Dynamic check, if std is enabled.
-    #[cfg(feature = "std")]
-    {
-        if is_x86_feature_detected!("avx2") {
-            return true;
-        }
-    }
-    false
+
+    cpufeatures::new!(has_avx2, "avx2");
+    has_avx2::get()
 }
 
 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
 #[inline(always)]
-#[allow(unreachable_code)]
 pub fn sse41_detected() -> bool {
     if cfg!(miri) {
         return false;
@@ -472,24 +449,13 @@ pub fn sse41_detected() -> bool {
     if cfg!(feature = "no_sse41") {
         return false;
     }
-    // Static check, e.g. for building with target-cpu=native.
-    #[cfg(target_feature = "sse4.1")]
-    {
-        return true;
-    }
-    // Dynamic check, if std is enabled.
-    #[cfg(feature = "std")]
-    {
-        if is_x86_feature_detected!("sse4.1") {
-            return true;
-        }
-    }
-    false
+
+    cpufeatures::new!(has_sse41, "sse4.1");
+    has_sse41::get()
 }
 
 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
 #[inline(always)]
-#[allow(unreachable_code)]
 pub fn sse2_detected() -> bool {
     if cfg!(miri) {
         return false;
@@ -499,19 +465,9 @@ pub fn sse2_detected() -> bool {
     if cfg!(feature = "no_sse2") {
         return false;
     }
-    // Static check, e.g. for building with target-cpu=native.
-    #[cfg(target_feature = "sse2")]
-    {
-        return true;
-    }
-    // Dynamic check, if std is enabled.
-    #[cfg(feature = "std")]
-    {
-        if is_x86_feature_detected!("sse2") {
-            return true;
-        }
-    }
-    false
+
+    cpufeatures::new!(has_sse2, "sse2");
+    has_sse2::get()
 }
 
 #[inline(always)]
-- 
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