1 files changed, 160 insertions, 0 deletions
diff --git a/src/tools/rustfmt/tests/target/cfg_if/detect/os/linux/aarch64.rs b/src/tools/rustfmt/tests/target/cfg_if/detect/os/linux/aarch64.rs
new file mode 100644
index 000000000..8d874f228
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/cfg_if/detect/os/linux/aarch64.rs
@@ -0,0 +1,160 @@
+//! Run-time feature detection for Aarch64 on Linux.
+
+use super::{auxvec, cpuinfo};
+use crate::detect::{bit, cache, Feature};
+
+/// Performs run-time feature detection.
+#[inline]
+pub fn check_for(x: Feature) -> bool {
+    cache::test(x as u32, detect_features)
+}
+
+/// Try to read the features from the auxiliary vector, and if that fails, try
+/// to read them from /proc/cpuinfo.
+fn detect_features() -> cache::Initializer {
+    if let Ok(auxv) = auxvec::auxv() {
+        let hwcap: AtHwcap = auxv.into();
+        return hwcap.cache();
+    }
+    if let Ok(c) = cpuinfo::CpuInfo::new() {
+        let hwcap: AtHwcap = c.into();
+        return hwcap.cache();
+    }
+    cache::Initializer::default()
+}
+
+/// These values are part of the platform-specific [asm/hwcap.h][hwcap] .
+///
+/// [hwcap]: https://github.com/torvalds/linux/blob/master/arch/arm64/include/uapi/asm/hwcap.h
+struct AtHwcap {
+    fp: bool,    // 0
+    asimd: bool, // 1
+    // evtstrm: bool, // 2
+    aes: bool,     // 3
+    pmull: bool,   // 4
+    sha1: bool,    // 5
+    sha2: bool,    // 6
+    crc32: bool,   // 7
+    atomics: bool, // 8
+    fphp: bool,    // 9
+    asimdhp: bool, // 10
+    // cpuid: bool, // 11
+    asimdrdm: bool, // 12
+    // jscvt: bool, // 13
+    // fcma: bool, // 14
+    lrcpc: bool, // 15
+    // dcpop: bool, // 16
+    // sha3: bool, // 17
+    // sm3: bool, // 18
+    // sm4: bool, // 19
+    asimddp: bool, // 20
+    // sha512: bool, // 21
+    sve: bool, // 22
+}
+
+impl From<auxvec::AuxVec> for AtHwcap {
+    /// Reads AtHwcap from the auxiliary vector.
+    fn from(auxv: auxvec::AuxVec) -> Self {
+        AtHwcap {
+            fp: bit::test(auxv.hwcap, 0),
+            asimd: bit::test(auxv.hwcap, 1),
+            // evtstrm: bit::test(auxv.hwcap, 2),
+            aes: bit::test(auxv.hwcap, 3),
+            pmull: bit::test(auxv.hwcap, 4),
+            sha1: bit::test(auxv.hwcap, 5),
+            sha2: bit::test(auxv.hwcap, 6),
+            crc32: bit::test(auxv.hwcap, 7),
+            atomics: bit::test(auxv.hwcap, 8),
+            fphp: bit::test(auxv.hwcap, 9),
+            asimdhp: bit::test(auxv.hwcap, 10),
+            // cpuid: bit::test(auxv.hwcap, 11),
+            asimdrdm: bit::test(auxv.hwcap, 12),
+            // jscvt: bit::test(auxv.hwcap, 13),
+            // fcma: bit::test(auxv.hwcap, 14),
+            lrcpc: bit::test(auxv.hwcap, 15),
+            // dcpop: bit::test(auxv.hwcap, 16),
+            // sha3: bit::test(auxv.hwcap, 17),
+            // sm3: bit::test(auxv.hwcap, 18),
+            // sm4: bit::test(auxv.hwcap, 19),
+            asimddp: bit::test(auxv.hwcap, 20),
+            // sha512: bit::test(auxv.hwcap, 21),
+            sve: bit::test(auxv.hwcap, 22),
+        }
+    }
+}
+
+impl From<cpuinfo::CpuInfo> for AtHwcap {
+    /// Reads AtHwcap from /proc/cpuinfo .
+    fn from(c: cpuinfo::CpuInfo) -> Self {
+        let f = &c.field("Features");
+        AtHwcap {
+            // 64-bit names. FIXME: In 32-bit compatibility mode /proc/cpuinfo will
+            // map some of the 64-bit names to some 32-bit feature names. This does not
+            // cover that yet.
+            fp: f.has("fp"),
+            asimd: f.has("asimd"),
+            // evtstrm: f.has("evtstrm"),
+            aes: f.has("aes"),
+            pmull: f.has("pmull"),
+            sha1: f.has("sha1"),
+            sha2: f.has("sha2"),
+            crc32: f.has("crc32"),
+            atomics: f.has("atomics"),
+            fphp: f.has("fphp"),
+            asimdhp: f.has("asimdhp"),
+            // cpuid: f.has("cpuid"),
+            asimdrdm: f.has("asimdrdm"),
+            // jscvt: f.has("jscvt"),
+            // fcma: f.has("fcma"),
+            lrcpc: f.has("lrcpc"),
+            // dcpop: f.has("dcpop"),
+            // sha3: f.has("sha3"),
+            // sm3: f.has("sm3"),
+            // sm4: f.has("sm4"),
+            asimddp: f.has("asimddp"),
+            // sha512: f.has("sha512"),
+            sve: f.has("sve"),
+        }
+    }
+}
+
+impl AtHwcap {
+    /// Initializes the cache from the feature -bits.
+    ///
+    /// The features are enabled approximately like in LLVM host feature detection:
+    /// https://github.com/llvm-mirror/llvm/blob/master/lib/Support/Host.cpp#L1273
+    fn cache(self) -> cache::Initializer {
+        let mut value = cache::Initializer::default();
+        {
+            let mut enable_feature = |f, enable| {
+                if enable {
+                    value.set(f as u32);
+                }
+            };
+
+            enable_feature(Feature::fp, self.fp);
+            // Half-float support requires float support
+            enable_feature(Feature::fp16, self.fp && self.fphp);
+            enable_feature(Feature::pmull, self.pmull);
+            enable_feature(Feature::crc, self.crc32);
+            enable_feature(Feature::lse, self.atomics);
+            enable_feature(Feature::rcpc, self.lrcpc);
+
+            // SIMD support requires float support - if half-floats are
+            // supported, it also requires half-float support:
+            let asimd = self.fp && self.asimd && (!self.fphp | self.asimdhp);
+            enable_feature(Feature::asimd, asimd);
+            // SIMD extensions require SIMD support:
+            enable_feature(Feature::rdm, self.asimdrdm && asimd);
+            enable_feature(Feature::dotprod, self.asimddp && asimd);
+            enable_feature(Feature::sve, self.sve && asimd);
+
+            // Crypto is specified as AES + PMULL + SHA1 + SHA2 per LLVM/hosts.cpp
+            enable_feature(
+                Feature::crypto,
+                self.aes && self.pmull && self.sha1 && self.sha2,
+            );
+        }
+        value
+    }
+}