cross-checks: rust-checks: Replace simd dependency with core::simd and core::arch calls

Author: ahomescu

cross-checks/rust-checks/runtime/Cargo.toml

@@ -13,10 +13,9 @@ publish = false
 [features]
 xcheck-with-dlsym = []
 xcheck-with-weak = []
-djb2-ssse3 = ["simd"]
+djb2-ssse3 = []
 libc-hash = ["libc"]
 fixed-length-array-hash = []
 
 [dependencies]
-simd = { version = "0.2", optional = true }
 libc = { version = "0.2", optional = true, default-features = false }

cross-checks/rust-checks/runtime/src/hash/djb2.rs

@@ -27,8 +27,7 @@ impl Hasher for Djb2Hasher {
     #[cfg(feature = "djb2-ssse3")]
     #[inline]
     fn write(&mut self, bytes: &[u8]) {
-        use simd::u32x4;
-        use simd::x86::ssse3::Ssse3U32x4;
+        use core::simd::u32x4;
 
         let mut u32_chunks = bytes.chunks(4);
         let last_chunk = if bytes.len() % 4 != 0 {
@@ -37,14 +36,15 @@ impl Hasher for Djb2Hasher {
             None
         };
         self.0 = u32_chunks.fold(self.0, |h, cb| {
-            let cvec = u32x4::new(cb[0] as u32, cb[1] as u32, cb[2] as u32, cb[3] as u32);
+            let cvec = u32x4::from_array([cb[0] as u32, cb[1] as u32, cb[2] as u32, cb[3] as u32]);
             // The djb2 factors: powers of 33 from 33^3 to 33^0
-            const DJB2_FACTORS: u32x4 = u32x4::new(35937, 1089, 33, 1);
+            const DJB2_FACTORS: u32x4 = u32x4::from_array([35937, 1089, 33, 1]);
             let cmul = cvec * DJB2_FACTORS;
-            let ch1 = Ssse3U32x4::hadd(cmul, cmul);
-            let ch2 = Ssse3U32x4::hadd(ch1, ch1);
+            let ch1 = unsafe { core::arch::x86_64::_mm_hadd_epi32(cmul.into(), cmul.into()) };
+            let ch2 = unsafe { core::arch::x86_64::_mm_hadd_epi32(ch1, ch1) };
+            let cval = unsafe { core::arch::x86_64::_mm_extract_epi32(ch2, 0) };
             // h = h * 33^4 + ch2[0]
-            h.wrapping_mul(1185921u32).wrapping_add(ch2.extract(0))
+            h.wrapping_mul(1185921u32).wrapping_add(cval as u32)
         });
         // Add in the last 1-3 bytes manually
         if let Some(last_bytes) = last_chunk {

cross-checks/rust-checks/runtime/src/lib.rs

@@ -4,11 +4,9 @@
 #![cfg_attr(feature = "xcheck-with-dlsym", feature(libc))]
 #![cfg_attr(feature = "xcheck-with-weak", feature(linkage))]
 #![cfg_attr(feature = "libc-hash", feature(libc))]
+#![cfg_attr(feature = "djb2-ssse3", feature(portable_simd))]
 #![no_std]
 
-#[cfg(feature = "djb2-ssse3")]
-extern crate simd;
-
 #[cfg(feature = "libc-hash")]
 extern crate libc;