Support AArch32 Neon dotprod intrinsics.

Note that the feature detection requires a recent Linux kernel (v6.2).

2 files changed, 11 insertions, 1 deletions

diff --git a/library/stdarch/crates/std_detect/src/detect/arch/arm.rs b/library/stdarch/crates/std_detect/src/detect/arch/arm.rs
index a7dea27fb3f..fd332e0b2ca 100644
--- a/library/stdarch/crates/std_detect/src/detect/arch/arm.rs
+++ b/library/stdarch/crates/std_detect/src/detect/arch/arm.rs
@@ -22,5 +22,7 @@ features! {
     @FEATURE: #[unstable(feature = "stdsimd", issue = "27731")] sha2: "sha2";
     /// FEAT_SHA1 & FEAT_SHA256 (SHA1 & SHA2-256 instructions)
     @FEATURE: #[unstable(feature = "stdsimd", issue = "27731")] i8mm: "i8mm";
-    /// FEAT_I8MM
+    /// FEAT_I8MM (integer matrix multiplication, plus ASIMD support)
+    @FEATURE: #[unstable(feature = "stdsimd", issue = "27731")] dotprod: "dotprod";
+    /// FEAT_DotProd (Vector Dot-Product - ASIMDDP)
 }
diff --git a/library/stdarch/crates/std_detect/src/detect/os/linux/arm.rs b/library/stdarch/crates/std_detect/src/detect/os/linux/arm.rs
index 7601cf0a841..4dc9590e18b 100644
--- a/library/stdarch/crates/std_detect/src/detect/os/linux/arm.rs
+++ b/library/stdarch/crates/std_detect/src/detect/os/linux/arm.rs
@@ -17,6 +17,8 @@ pub(crate) fn detect_features() -> cache::Initializer {
     //
     // [hwcap]: https://github.com/torvalds/linux/blob/master/arch/arm/include/uapi/asm/hwcap.h
     if let Ok(auxv) = auxvec::auxv() {
+        enable_feature(&mut value, Feature::i8mm, bit::test(auxv.hwcap, 27));
+        enable_feature(&mut value, Feature::dotprod, bit::test(auxv.hwcap, 24));
         enable_feature(&mut value, Feature::neon, bit::test(auxv.hwcap, 12));
         enable_feature(&mut value, Feature::pmull, bit::test(auxv.hwcap2, 1));
         enable_feature(&mut value, Feature::crc, bit::test(auxv.hwcap2, 4));
@@ -37,6 +39,12 @@ pub(crate) fn detect_features() -> cache::Initializer {
             Feature::neon,
             c.field("Features").has("neon") && !has_broken_neon(&c),
         );
+        enable_feature(&mut value, Feature::i8mm, c.field("Features").has("i8mm"));
+        enable_feature(
+            &mut value,
+            Feature::dotprod,
+            c.field("Features").has("asimddp"),
+        );
         enable_feature(&mut value, Feature::pmull, c.field("Features").has("pmull"));
         enable_feature(&mut value, Feature::crc, c.field("Features").has("crc32"));
         enable_feature(&mut value, Feature::aes, c.field("Features").has("aes"));