cpufeatures: check AVX availability when detecting AVX2 and FMA (#792)

RustCrypto · Aug 18, 2022 · b637d94 · b637d94
1 parent 8e74aa5
commit b637d94
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Showing 4 changed files with 25 additions and 6 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/cpufeatures/CHANGELOG.md b/cpufeatures/CHANGELOG.md
@@ -5,6 +5,16 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 0.2.3 (2022-08-18)
+### Changed
+- Update `libc` version to v0.2.95 ([#789])
+- Disable all target features under MIRI ([#779])
+- Check AVX availability when detecting AVX2 and FMA ([#792])
+
+[#779]: https://github.com/RustCrypto/utils/pull/779
+[#789]: https://github.com/RustCrypto/utils/pull/789
+[#792]: https://github.com/RustCrypto/utils/pull/792
+
 ## 0.2.2 (2022-03-18)
 ### Added
 - Support for Android on `aarch64` ([#752])

diff --git a/cpufeatures/Cargo.toml b/cpufeatures/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "cpufeatures"
-version = "0.2.2"
+version = "0.2.3"
 description = """
 Lightweight runtime CPU feature detection for x86/x86_64 and aarch64 with
 no_std support and support for mobile targets including Android and iOS

diff --git a/cpufeatures/src/x86.rs b/cpufeatures/src/x86.rs
@@ -46,25 +46,34 @@ macro_rules! __detect_target_features {
 }
 
 macro_rules! __expand_check_macro {
-    ($(($name:tt, $i:expr, $reg:ident, $offset:expr)),* $(,)?) => {
+    ($(($name:tt $(, $i:expr, $reg:ident, $offset:expr)*)),* $(,)?) => {
         #[macro_export]
         #[doc(hidden)]
         macro_rules! check {
             $(
-                ($cr:expr, $name) => { ($cr[$i].$reg & (1 << $offset) != 0) };
+                ($cr:expr, $name) => {
+                    true
+                    $(
+                        & ($cr[$i].$reg & (1 << $offset) != 0)
+                    )*
+                };
             )*
         }
     };
 }
 
+// Note that according to the [Intel manual][0] AVX2 and FMA require
+// that we check availability of AVX before using them.
+//
+// [0]: https://www.intel.com/content/dam/develop/external/us/en/documents/36945
 __expand_check_macro! {
     ("mmx", 0, edx, 23),
     ("sse", 0, edx, 25),
     ("sse2", 0, edx, 26),
     ("sse3", 0, ecx, 0),
     ("pclmulqdq", 0, ecx, 1),
     ("ssse3", 0, ecx, 9),
-    ("fma", 0, ecx, 12),
+    ("fma", 0, ecx, 28, 0, ecx, 12),
     ("sse4.1", 0, ecx, 19),
     ("sse4.2", 0, ecx, 20),
     ("popcnt", 0, ecx, 23),
@@ -73,7 +82,7 @@ __expand_check_macro! {
     ("rdrand", 0, ecx, 30),
     ("sgx", 1, ebx, 2),
     ("bmi1", 1, ebx, 3),
-    ("avx2", 1, ebx, 5),
+    ("avx2", 0, ecx, 28, 1, ebx, 5),
     ("bmi2", 1, ebx, 8),
     ("rdseed", 1, ebx, 18),
     ("adx", 1, ebx, 19),