1 files changed, 93 insertions, 0 deletions
diff --git a/third_party/rust/regex-automata/src/util/memchr.rs b/third_party/rust/regex-automata/src/util/memchr.rs
new file mode 100644
index 0000000000..a2cbb07321
--- /dev/null
+++ b/third_party/rust/regex-automata/src/util/memchr.rs
@@ -0,0 +1,93 @@
+/*!
+This module defines simple wrapper routines for the memchr functions from the
+`memchr` crate. Basically, when the `memchr` crate is available, we use it,
+otherwise we use a naive implementation which is still pretty fast.
+*/
+
+pub(crate) use self::inner::*;
+
+#[cfg(feature = "perf-literal-substring")]
+pub(super) mod inner {
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memchr(n1: u8, haystack: &[u8]) -> Option<usize> {
+        memchr::memchr(n1, haystack)
+    }
+
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memchr2(n1: u8, n2: u8, haystack: &[u8]) -> Option<usize> {
+        memchr::memchr2(n1, n2, haystack)
+    }
+
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memchr3(
+        n1: u8,
+        n2: u8,
+        n3: u8,
+        haystack: &[u8],
+    ) -> Option<usize> {
+        memchr::memchr3(n1, n2, n3, haystack)
+    }
+
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memrchr(n1: u8, haystack: &[u8]) -> Option<usize> {
+        memchr::memrchr(n1, haystack)
+    }
+
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memrchr2(n1: u8, n2: u8, haystack: &[u8]) -> Option<usize> {
+        memchr::memrchr2(n1, n2, haystack)
+    }
+
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memrchr3(
+        n1: u8,
+        n2: u8,
+        n3: u8,
+        haystack: &[u8],
+    ) -> Option<usize> {
+        memchr::memrchr3(n1, n2, n3, haystack)
+    }
+}
+
+#[cfg(not(feature = "perf-literal-substring"))]
+pub(super) mod inner {
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memchr(n1: u8, haystack: &[u8]) -> Option<usize> {
+        haystack.iter().position(|&b| b == n1)
+    }
+
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memchr2(n1: u8, n2: u8, haystack: &[u8]) -> Option<usize> {
+        haystack.iter().position(|&b| b == n1 || b == n2)
+    }
+
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memchr3(
+        n1: u8,
+        n2: u8,
+        n3: u8,
+        haystack: &[u8],
+    ) -> Option<usize> {
+        haystack.iter().position(|&b| b == n1 || b == n2 || b == n3)
+    }
+
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memrchr(n1: u8, haystack: &[u8]) -> Option<usize> {
+        haystack.iter().rposition(|&b| b == n1)
+    }
+
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memrchr2(n1: u8, n2: u8, haystack: &[u8]) -> Option<usize> {
+        haystack.iter().rposition(|&b| b == n1 || b == n2)
+    }
+
+    #[cfg_attr(feature = "perf-inline", inline(always))]
+    pub(crate) fn memrchr3(
+        n1: u8,
+        n2: u8,
+        n3: u8,
+        haystack: &[u8],
+    ) -> Option<usize> {
+        haystack.iter().rposition(|&b| b == n1 || b == n2 || b == n3)
+    }
+}