core(intrinsics): v_load_low

modules/core/include/opencv2/core/hal/intrin_cpp.hpp

@@ -99,7 +99,7 @@ block and to save contents of the register to memory block.
 @ref v_setall_s8, @ref v_setall_u8, ...,
 @ref v_setzero_u8, @ref v_setzero_s8, ...
 - Memory operations:
-@ref v_load, @ref v_load_aligned, @ref v_load_halves,
+@ref v_load, @ref v_load_aligned, @ref v_load_low, @ref v_load_halves,
 @ref v_store, @ref v_store_aligned,
 @ref v_store_high, @ref v_store_low
 
@@ -1080,6 +1080,26 @@ inline v_reg<_Tp, V_SIMD128Traits<_Tp>::nlanes> v_load_aligned(const _Tp* ptr)
     return v_reg<_Tp, V_SIMD128Traits<_Tp>::nlanes>(ptr);
 }
 
+/** @brief Load 64-bits of data to lower part (high part is undefined).
+
+@param ptr memory block containing data for first half (0..n/2)
+
+@code{.cpp}
+int lo[2] = { 1, 2 };
+v_int32x4 r = v_load_low(lo);
+@endcode
+ */
+template<typename _Tp>
+inline v_reg<_Tp, V_SIMD128Traits<_Tp>::nlanes> v_load_low(const _Tp* ptr)
+{
+    v_reg<_Tp, V_SIMD128Traits<_Tp>::nlanes> c;
+    for( int i = 0; i < c.nlanes/2; i++ )
+    {
+        c.s[i] = ptr[i];
+    }
+    return c;
+}
+
 /** @brief Load register contents from two memory blocks
 
 @param loptr memory block containing data for first half (0..n/2)

modules/core/include/opencv2/core/hal/intrin_neon.hpp

@@ -763,6 +763,8 @@ inline _Tpvec v_load(const _Tp* ptr) \
 { return _Tpvec(vld1q_##suffix(ptr)); } \
 inline _Tpvec v_load_aligned(const _Tp* ptr) \
 { return _Tpvec(vld1q_##suffix(ptr)); } \
+inline _Tpvec v_load_low(const _Tp* ptr) \
+{ return _Tpvec(vcombine_##suffix(vld1_##suffix(ptr), vdup_n_##suffix((_Tp)0))); } \
 inline _Tpvec v_load_halves(const _Tp* ptr0, const _Tp* ptr1) \
 { return _Tpvec(vcombine_##suffix(vld1_##suffix(ptr0), vld1_##suffix(ptr1))); } \
 inline void v_store(_Tp* ptr, const _Tpvec& a) \

modules/core/include/opencv2/core/hal/intrin_sse.hpp

@@ -1016,6 +1016,8 @@ inline _Tpvec v_load(const _Tp* ptr) \
 { return _Tpvec(_mm_loadu_si128((const __m128i*)ptr)); } \
 inline _Tpvec v_load_aligned(const _Tp* ptr) \
 { return _Tpvec(_mm_load_si128((const __m128i*)ptr)); } \
+inline _Tpvec v_load_low(const _Tp* ptr) \
+{ return _Tpvec(_mm_loadl_epi64((const __m128i*)ptr)); } \
 inline _Tpvec v_load_halves(const _Tp* ptr0, const _Tp* ptr1) \
 { \
     return _Tpvec(_mm_unpacklo_epi64(_mm_loadl_epi64((const __m128i*)ptr0), \
@@ -1044,6 +1046,8 @@ inline _Tpvec v_load(const _Tp* ptr) \
 { return _Tpvec(_mm_loadu_##suffix(ptr)); } \
 inline _Tpvec v_load_aligned(const _Tp* ptr) \
 { return _Tpvec(_mm_load_##suffix(ptr)); } \
+inline _Tpvec v_load_low(const _Tp* ptr) \
+{ return _Tpvec(_mm_castsi128_##suffix(_mm_loadl_epi64((const __m128i*)ptr))); } \
 inline _Tpvec v_load_halves(const _Tp* ptr0, const _Tp* ptr1) \
 { \
     return _Tpvec(_mm_castsi128_##suffix( \

modules/core/include/opencv2/core/hal/intrin_vsx.hpp

@@ -281,6 +281,8 @@ inline _Tpvec v_load(const _Tp* ptr)                                        \
 { return _Tpvec(ld_func(0, ptr)); }                                         \
 inline _Tpvec v_load_aligned(const _Tp* ptr)                                \
 { return _Tpvec(ld_func(0, ptr)); }                                         \
+inline _Tpvec v_load_low(const _Tp* ptr)                                    \
+{ return _Tpvec(vec_ld_l8(ptr)); }                                          \
 inline _Tpvec v_load_halves(const _Tp* ptr0, const _Tp* ptr1)               \
 { return _Tpvec(vec_mergesqh(vec_ld_l8(ptr0), vec_ld_l8(ptr1))); }          \
 inline void v_store(_Tp* ptr, const _Tpvec& a)                              \

modules/core/include/opencv2/core/vsx_utils.hpp

@@ -556,17 +556,12 @@ VSX_IMPL_2VRG_F(vec_uint4, vec_udword2, "vpkudus %0,%2,%1", vec_packs)
  * vec_ld_l8(ptr) -> Load 64-bits of integer data to lower part
  * vec_ldz_l8(ptr) -> Load 64-bits of integer data to lower part and zero upper part
 **/
-#if defined(__clang__) && !defined(__IBMCPP__)
-#   define __VSX_LOAD_L8(Tvec, p) (Tvec)((vec_udword2)*((uint64*)(p)))
-#else
-#   define __VSX_LOAD_L8(Tvec, p) *((Tvec*)(p))
-#endif
-
 #define VSX_IMPL_LOAD_L8(Tvec, Tp)                                              \
 FORCE_INLINE(Tvec) vec_ld_l8(const Tp *p)                                       \
-{ return __VSX_LOAD_L8(Tvec, p); }                                              \
+{ return ((Tvec)vec_promote(*((uint64*)p), 0)); }                               \
 FORCE_INLINE(Tvec) vec_ldz_l8(const Tp *p)                                      \
 {                                                                               \
+    /* TODO: try (Tvec)(vec_udword2{*((uint64*)p), 0}) */                       \
     static const vec_bdword2 mask = {0xFFFFFFFFFFFFFFFF, 0x0000000000000000};   \
     return vec_and(vec_ld_l8(p), (Tvec)mask);                                   \
 }

modules/core/test/test_intrin_utils.hpp

@@ -198,6 +198,22 @@ template<typename R> struct TheTest
         EXPECT_EQ(data.a[0], r3.get0());
         EXPECT_EQ(data.u[0], r4.get0());
 
+        R r_low = v_load_low((LaneType*)data.u.d);
+        EXPECT_EQ(data.u[0], r_low.get0());
+        v_store(out.u.d, r_low);
+        for (int i = 0; i < R::nlanes/2; ++i)
+        {
+            EXPECT_EQ((LaneType)data.u[i], (LaneType)out.u[i]);
+        }
+
+        R r_low_align8byte = v_load_low((LaneType*)((char*)data.u.d + 8));
+        EXPECT_EQ(data.u[R::nlanes/2], r_low_align8byte.get0());
+        v_store(out.u.d, r_low_align8byte);
+        for (int i = 0; i < R::nlanes/2; ++i)
+        {
+            EXPECT_EQ((LaneType)data.u[i + R::nlanes/2], (LaneType)out.u[i]);
+        }
+
         // check some store methods
         out.u.clear();
         out.a.clear();