1 files changed, 54 insertions, 0 deletions

diff --git a/src/platform.rs b/src/platform.rs
index dafa934..c0eb21d 100644
--- a/src/platform.rs
+++ b/src/platform.rs
@@ -41,6 +41,8 @@ cfg_if::cfg_if! {
 pub enum Platform {
     Portable,
     #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+    SSE2,
+    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
     SSE41,
     #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
     AVX2,
@@ -68,6 +70,9 @@ impl Platform {
             if sse41_detected() {
                 return Platform::SSE41;
             }
+            if sse2_detected() {
+                return Platform::SSE2;
+            }
         }
         // We don't use dynamic feature detection for NEON. If the "neon"
         // feature is on, NEON is assumed to be supported.
@@ -82,6 +87,8 @@ impl Platform {
         let degree = match self {
             Platform::Portable => 1,
             #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+            Platform::SSE2 => 4,
+            #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
             Platform::SSE41 => 4,
             #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
             Platform::AVX2 => 8,
@@ -107,6 +114,11 @@ impl Platform {
             Platform::Portable => portable::compress_in_place(cv, block, block_len, counter, flags),
             // Safe because detect() checked for platform support.
             #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+            Platform::SSE2 => unsafe {
+                crate::sse2::compress_in_place(cv, block, block_len, counter, flags)
+            },
+            // Safe because detect() checked for platform support.
+            #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
             Platform::SSE41 | Platform::AVX2 => unsafe {
                 crate::sse41::compress_in_place(cv, block, block_len, counter, flags)
             },
@@ -134,6 +146,11 @@ impl Platform {
             Platform::Portable => portable::compress_xof(cv, block, block_len, counter, flags),
             // Safe because detect() checked for platform support.
             #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+            Platform::SSE2 => unsafe {
+                crate::sse2::compress_xof(cv, block, block_len, counter, flags)
+            },
+            // Safe because detect() checked for platform support.
+            #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
             Platform::SSE41 | Platform::AVX2 => unsafe {
                 crate::sse41::compress_xof(cv, block, block_len, counter, flags)
             },
@@ -183,6 +200,20 @@ impl Platform {
             ),
             // Safe because detect() checked for platform support.
             #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+            Platform::SSE2 => unsafe {
+                crate::sse2::hash_many(
+                    inputs,
+                    key,
+                    counter,
+                    increment_counter,
+                    flags,
+                    flags_start,
+                    flags_end,
+                    out,
+                )
+            },
+            // Safe because detect() checked for platform support.
+            #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
             Platform::SSE41 => unsafe {
                 crate::sse41::hash_many(
                     inputs,
@@ -248,6 +279,15 @@ impl Platform {
     }
 
     #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+    pub fn sse2() -> Option<Self> {
+        if sse2_detected() {
+            Some(Self::SSE2)
+        } else {
+            None
+        }
+    }
+
+    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
     pub fn sse41() -> Option<Self> {
         if sse41_detected() {
             Some(Self::SSE41)
@@ -351,6 +391,20 @@ pub fn sse41_detected() -> bool {
     false
 }
 
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+#[inline(always)]
+pub fn sse2_detected() -> bool {
+    // A testing-only short-circuit.
+    if cfg!(feature = "no_sse2") {
+        return false;
+    }
+    // Static check, e.g. for building with target-cpu=native.
+    #[cfg(target_feature = "sse2")]
+    {
+        return true;
+    }
+}
+
 #[inline(always)]
 pub fn words_from_le_bytes_32(bytes: &[u8; 32]) -> [u32; 8] {
     let mut out = [0; 8];