Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 89 insertions, 0 deletions

diff --git a/third_party/rust/memchr/src/memmem/x86/sse.rs b/third_party/rust/memchr/src/memmem/x86/sse.rs
new file mode 100644
index 0000000000..22e7d9933a
--- /dev/null
+++ b/third_party/rust/memchr/src/memmem/x86/sse.rs
@@ -0,0 +1,89 @@
+use core::arch::x86_64::__m128i;
+
+use crate::memmem::{genericsimd, NeedleInfo};
+
+/// An SSE accelerated vectorized substring search routine that only works on
+/// small needles.
+#[derive(Clone, Copy, Debug)]
+pub(crate) struct Forward(genericsimd::Forward);
+
+impl Forward {
+    /// Create a new "generic simd" forward searcher. If one could not be
+    /// created from the given inputs, then None is returned.
+    pub(crate) fn new(ninfo: &NeedleInfo, needle: &[u8]) -> Option<Forward> {
+        if !cfg!(memchr_runtime_sse2) {
+            return None;
+        }
+        genericsimd::Forward::new(ninfo, needle).map(Forward)
+    }
+
+    /// Returns the minimum length of haystack that is needed for this searcher
+    /// to work. Passing a haystack with a length smaller than this will cause
+    /// `find` to panic.
+    #[inline(always)]
+    pub(crate) fn min_haystack_len(&self) -> usize {
+        self.0.min_haystack_len::<__m128i>()
+    }
+
+    #[inline(always)]
+    pub(crate) fn find(
+        &self,
+        haystack: &[u8],
+        needle: &[u8],
+    ) -> Option<usize> {
+        // SAFETY: sse2 is enabled on all x86_64 targets, so this is always
+        // safe to call.
+        unsafe { self.find_impl(haystack, needle) }
+    }
+
+    /// The implementation of find marked with the appropriate target feature.
+    ///
+    /// # Safety
+    ///
+    /// This is safe to call in all cases since sse2 is guaranteed to be part
+    /// of x86_64. It is marked as unsafe because of the target feature
+    /// attribute.
+    #[target_feature(enable = "sse2")]
+    unsafe fn find_impl(
+        &self,
+        haystack: &[u8],
+        needle: &[u8],
+    ) -> Option<usize> {
+        genericsimd::fwd_find::<__m128i>(&self.0, haystack, needle)
+    }
+}
+
+#[cfg(all(test, feature = "std", not(miri)))]
+mod tests {
+    use crate::memmem::{prefilter::PrefilterState, NeedleInfo};
+
+    fn find(
+        _: &mut PrefilterState,
+        ninfo: &NeedleInfo,
+        haystack: &[u8],
+        needle: &[u8],
+    ) -> Option<usize> {
+        super::Forward::new(ninfo, needle).unwrap().find(haystack, needle)
+    }
+
+    #[test]
+    fn prefilter_permutations() {
+        use crate::memmem::prefilter::tests::PrefilterTest;
+
+        // SAFETY: sse2 is enabled on all x86_64 targets, so this is always
+        // safe to call.
+        unsafe {
+            PrefilterTest::run_all_tests_filter(find, |t| {
+                // This substring searcher only works on certain configs, so
+                // filter our tests such that Forward::new will be guaranteed
+                // to succeed. (And also remove tests with a haystack that is
+                // too small.)
+                let fwd = match super::Forward::new(&t.ninfo, &t.needle) {
+                    None => return false,
+                    Some(fwd) => fwd,
+                };
+                t.haystack.len() >= fwd.min_haystack_len()
+            })
+        }
+    }
+}