sse3: _mm_movedup_pd

library/stdarch/src/x86/sse3.rs

@@ -1,4 +1,5 @@
 use x86::__m128i;
+use simd_llvm::simd_shuffle2;
 use v128::*;
 
 #[cfg(test)]
@@ -68,6 +69,15 @@ pub unsafe fn _mm_lddqu_si128(mem_addr: *const __m128i) -> __m128i {
     lddqu(mem_addr as *const _)
 }
 
+/// Duplicate the low double-precision (64-bit) floating-point element
+/// from `a`.
+#[inline(always)]
+#[target_feature = "+sse3"]
+#[cfg_attr(test, assert_instr(movddup))]
+pub unsafe fn _mm_movedup_pd(a: f64x2) -> f64x2 {
+    simd_shuffle2(a, a, [0, 0])
+}
+
 #[allow(improper_ctypes)]
 extern {
     #[link_name = "llvm.x86.sse3.addsub.ps"]
@@ -148,4 +158,11 @@ unsafe fn _mm_lddqu_si128() {
         let r = sse3::_mm_lddqu_si128(&a);
         assert_eq!(a, r);
     }
+
+    #[simd_test = "sse3"]
+    unsafe fn _mm_movedup_pd() {
+        let a = f64x2::new(-1.0, 5.0);
+        let r = sse3::_mm_movedup_pd(a);
+        assert_eq!(r, f64x2::new(-1.0, -1.0));
+    }
 }