diff --git a/src/bitboard.h b/src/bitboard.h
index db1e69633..eb86e1a65 100644
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -34,6 +34,8 @@
 #ifdef __aarch64__
     #include <arm_acle.h>
     #define USE_HYPERBOLA_QUINT
+#elif defined(__loongarch__) && __loongarch_grlen == 64
+    #define USE_HYPERBOLA_QUINT
 #endif
 
 namespace Stockfish {
@@ -80,6 +82,17 @@ extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
 extern Bitboard RayPassBB[SQUARE_NB][SQUARE_NB];
 
 #ifdef USE_HYPERBOLA_QUINT
+
+inline Bitboard reverse_bb(Bitboard bb) {
+    #ifdef __aarch64__
+    return __rbitll(bb);
+    #else  // loongarch
+    Bitboard out;
+    asm("bitrev.d %0, %1" : "=r"(out) : "r"(bb));
+    return out;
+    #endif
+}
+
 // Hyperbola quintessence implementation for ARM, thanks to the availability of an
 // efficient bit reversal instruction.
 // See https://www.chessprogramming.org/Hyperbola_Quintessence
@@ -92,8 +105,8 @@ struct Magic {
     Bitboard hyperbola(Bitboard occupied, Bitboard mask) const {
         Bitboard o   = occupied & mask;
         Bitboard fwd = o - r;
-        Bitboard rev = __rbitll(o) - rr;
-        return (fwd ^ __rbitll(rev)) & mask;
+        Bitboard rev = reverse_bb(o) - rr;
+        return (fwd ^ reverse_bb(rev)) & mask;
     }
 
     Bitboard attacks_bb(Bitboard occupied) const {
diff --git a/src/nnue/nnue_accumulator.cpp b/src/nnue/nnue_accumulator.cpp
index a1480fd89..0c13e0ee6 100644
--- a/src/nnue/nnue_accumulator.cpp
+++ b/src/nnue/nnue_accumulator.cpp
@@ -527,8 +527,8 @@ Bitboard get_changed_pieces(const std::array<Piece, SQUARE_NB>& oldPieces,
         const __m256i new_v = __lasx_xvld(reinterpret_cast<const void*>(&newPieces[i]), 0);
         const __m256i diff  = __lasx_xvxor_v(old_v, new_v);
         const __m256i mask  = __lasx_xvmsknz_b(diff);
-        const auto    lo    = static_cast<std::uint16_t>(__lasx_xvpickve2gr_d(mask, 0));
-        const auto    hi    = static_cast<std::uint16_t>(__lasx_xvpickve2gr_d(mask, 2));
+        const auto    lo    = __lasx_xvpickve2gr_d(mask, 0);
+        const auto    hi    = __lasx_xvpickve2gr_d(mask, 2);
 
         changed |= (static_cast<Bitboard>(lo) | (static_cast<Bitboard>(hi) << 16)) << i;
     }
@@ -546,8 +546,7 @@ Bitboard get_changed_pieces(const std::array<Piece, SQUARE_NB>& oldPieces,
         const __m128i diff  = __lsx_vxor_v(old_v, new_v);
         const __m128i mask  = __lsx_vmsknz_b(diff);
 
-        changed |= static_cast<Bitboard>(static_cast<std::uint16_t>(__lsx_vpickve2gr_d(mask, 0)))
-                << i;
+        changed |= static_cast<Bitboard>(__lsx_vpickve2gr_d(mask, 0)) << i;
     }
 
     return changed;
diff --git a/src/nnue/simd.h b/src/nnue/simd.h
index d1592e88b..c9c585b50 100644
--- a/src/nnue/simd.h
+++ b/src/nnue/simd.h
@@ -312,8 +312,7 @@ inline __m256i lasx_cvtepi8_epi16(__m128i a) {
 inline int lasx_vec_nnz(__m256i a) {
     const __m256i cmp = __lasx_xvslt_w(__lasx_xvldi(0), a);
     const __m256i msk = __lasx_xvmskltz_w(cmp);
-    return ((int) __lasx_xvpickve2gr_w(msk, 0) & 0xF)
-         | (((int) __lasx_xvpickve2gr_w(msk, 4) & 0xF) << 4);
+    return ((int) __lasx_xvpickve2gr_w(msk, 0)) | (((int) __lasx_xvpickve2gr_w(msk, 4)) << 4);
 }
 
 #elif USE_LSX
@@ -360,7 +359,7 @@ inline __m128i lsx_packus_32(__m128i a, __m128i b) {
 inline int lsx_vec_nnz(__m128i a) {
     const __m128i cmp = __lsx_vslt_w(__lsx_vldi(0), a);
     const __m128i msk = __lsx_vmskltz_w(cmp);
-    return ((int) __lsx_vpickve2gr_w(msk, 0) & 0xF);
+    return ((int) __lsx_vpickve2gr_w(msk, 0));
 }
     #define vec_nnz(a) lsx_vec_nnz(a)