Move `std_detect` from `library/stdarch` to `library`

1 files changed, 35 insertions, 0 deletions

diff --git a/library/std_detect/src/detect/os/linux/powerpc.rs b/library/std_detect/src/detect/os/linux/powerpc.rs
new file mode 100644
index 00000000000..6a4f7e715d9
--- /dev/null
+++ b/library/std_detect/src/detect/os/linux/powerpc.rs
@@ -0,0 +1,35 @@
+//! Run-time feature detection for PowerPC on Linux.
+
+use super::auxvec;
+use crate::detect::{Feature, cache};
+
+/// Try to read the features from the auxiliary vector.
+pub(crate) fn detect_features() -> cache::Initializer {
+    let mut value = cache::Initializer::default();
+    let enable_feature = |value: &mut cache::Initializer, f, enable| {
+        if enable {
+            value.set(f as u32);
+        }
+    };
+
+    // The values are part of the platform-specific [asm/cputable.h][cputable]
+    //
+    // [cputable]: https://github.com/torvalds/linux/blob/master/arch/powerpc/include/uapi/asm/cputable.h
+    if let Ok(auxv) = auxvec::auxv() {
+        // note: the PowerPC values are the mask to do the test (instead of the
+        // index of the bit to test like in ARM and Aarch64)
+        enable_feature(&mut value, Feature::altivec, auxv.hwcap & 0x10000000 != 0);
+        enable_feature(&mut value, Feature::vsx, auxv.hwcap & 0x00000080 != 0);
+        let power8_features = auxv.hwcap2 & 0x80000000 != 0;
+        enable_feature(&mut value, Feature::power8, power8_features);
+        enable_feature(&mut value, Feature::power8_altivec, power8_features);
+        enable_feature(&mut value, Feature::power8_crypto, power8_features);
+        enable_feature(&mut value, Feature::power8_vector, power8_features);
+        let power9_features = auxv.hwcap2 & 0x00800000 != 0;
+        enable_feature(&mut value, Feature::power9, power9_features);
+        enable_feature(&mut value, Feature::power9_altivec, power9_features);
+        enable_feature(&mut value, Feature::power9_vector, power9_features);
+        return value;
+    }
+    value
+}