make portable_simd optional

1 files changed, 35 insertions, 8 deletions

diff --git a/src/aesround.rs b/src/aesround.rs
index 169c125..6f63243 100644
--- a/src/aesround.rs
+++ b/src/aesround.rs
@@ -80,15 +80,42 @@ pub mod x86_64 {
         null: __m128i,
     }
 
+    #[cfg(feature = "simd")]
+    fn to_simd(block: Block) -> __m128i {
+        block.simd().into()
+    }
+
+    #[cfg(not(feature = "simd"))]
+    fn to_simd(block: Block) -> __m128i {
+        let bytes = block.bytes();
+        // SAFETY: loadu can load from unaligned memory
+        unsafe { _mm_loadu_si128(bytes.as_ptr() as *const _) }
+    }
+
+    #[cfg(feature = "simd")]
+    fn from_simd(simd: __m128i) -> Block {
+        Block::from_simd(simd.into())
+    }
+
+    #[cfg(not(feature = "simd"))]
+    fn from_simd(simd: __m128i) -> Block {
+        let mut bytes = [0; 16];
+        // SAFETY: storeu can store to unaligned memory
+        unsafe {
+            _mm_storeu_si128(bytes.as_mut_ptr() as *mut _, simd);
+        }
+        Block::from(bytes)
+    }
+
     impl AesRound for AesNi {
         fn new(key_i: Block, key_j: Block, key_l: Block) -> Self {
             Self {
                 support: cpuid_aes::init(),
                 fallback: AesSoft::new(key_i, key_j, key_l),
-                key_i: key_i.simd().into(),
-                key_j: key_j.simd().into(),
-                key_l: key_l.simd().into(),
-                null: Block::null().simd().into(),
+                key_i: to_simd(key_i),
+                key_j: to_simd(key_j),
+                key_l: to_simd(key_l),
+                null: to_simd(Block::null()),
             }
         }
 
@@ -99,12 +126,12 @@ pub mod x86_64 {
 
             // SAFETY: Nothing should go wrong when calling AESENC
             unsafe {
-                let mut block = value.simd().into();
+                let mut block = to_simd(value);
                 block = _mm_aesenc_si128(block, self.key_j);
                 block = _mm_aesenc_si128(block, self.key_i);
                 block = _mm_aesenc_si128(block, self.key_l);
                 block = _mm_aesenc_si128(block, self.null);
-                Block::from_simd(block.into())
+                from_simd(block)
             }
         }
 
@@ -115,7 +142,7 @@ pub mod x86_64 {
 
             // SAFETY: Nothing should go wrong when calling AESENC
             unsafe {
-                let mut block = value.simd().into();
+                let mut block = to_simd(value);
                 block = _mm_aesenc_si128(block, self.key_i);
                 block = _mm_aesenc_si128(block, self.key_j);
                 block = _mm_aesenc_si128(block, self.key_l);
@@ -126,7 +153,7 @@ pub mod x86_64 {
                 block = _mm_aesenc_si128(block, self.key_j);
                 block = _mm_aesenc_si128(block, self.key_l);
                 block = _mm_aesenc_si128(block, self.key_i);
-                Block::from_simd(block.into())
+                from_simd(block)
             }
         }
     }