diff --git a/faiss/Index2Layer.cpp b/faiss/Index2Layer.cpp
index b2a5168529..33d855f7f0 100644
--- a/faiss/Index2Layer.cpp
+++ b/faiss/Index2Layer.cpp
@@ -13,10 +13,6 @@
 #include <cstdint>
 #include <cstdio>
 
-#ifdef __SSE3__
-#include <immintrin.h>
-#endif
-
 #include <algorithm>
 
 #include <faiss/IndexIVFPQ.h>
@@ -177,34 +173,26 @@ struct DistanceXPQ4 : Distance2Level {
     }
 
     float operator()(idx_t i) override {
-#ifdef __SSE3__
         const uint8_t* code = storage.codes.data() + i * storage.code_size;
         idx_t key = 0;
         memcpy(&key, code, storage.code_size_1);
         code += storage.code_size_1;
 
-        // walking pointers
         const float* qa = q;
-        const __m128* l1_t = (const __m128*)(pq_l1_tab + d * key);
-        const __m128* pq_l2_t = (const __m128*)pq_l2_tab;
-        __m128 accu = _mm_setzero_ps();
+        const float* l1 = pq_l1_tab + d * key;
+        const float* l2 = pq_l2_tab;
+        float accu = 0;
 
         for (int m = 0; m < M; m++) {
-            __m128 qi = _mm_loadu_ps(qa);
-            __m128 recons = _mm_add_ps(l1_t[m], pq_l2_t[*code++]);
-            __m128 diff = _mm_sub_ps(qi, recons);
-            accu = _mm_add_ps(accu, _mm_mul_ps(diff, diff));
-            pq_l2_t += 256;
+            for (int j = 0; j < 4; j++) {
+                float diff = qa[j] - (l1[m * 4 + j] + l2[*code * 4 + j]);
+                accu += diff * diff;
+            }
+            code++;
+            l2 += 256 * 4;
             qa += 4;
         }
-
-        accu = _mm_hadd_ps(accu, accu);
-        accu = _mm_hadd_ps(accu, accu);
-        return _mm_cvtss_f32(accu);
-#else
-        (void)i;
-        FAISS_THROW_MSG("not implemented for non-x64 platforms");
-#endif
+        return accu;
     }
 };
 
@@ -229,42 +217,36 @@ struct Distance2xXPQ4 : Distance2Level {
         int64_t key01 = 0;
         memcpy(&key01, code, storage.code_size_1);
         code += storage.code_size_1;
-#ifdef __SSE3__
 
-        // walking pointers
         const float* qa = q;
-        const __m128* pq_l1_t = (const __m128*)pq_l1_tab;
-        const __m128* pq_l2_t = (const __m128*)pq_l2_tab;
-        __m128 accu = _mm_setzero_ps();
+        const float* l1 = pq_l1_tab;
+        const float* l2 = pq_l2_tab;
+        float accu = 0;
 
         for (int mi_m = 0; mi_m < 2; mi_m++) {
             int64_t l1_idx = key01 & (((int64_t)1 << mi_nbits) - 1);
-            const __m128* pq_l1 = pq_l1_t + M_2 * l1_idx;
+            const float* l1_sub = l1 + M_2 * l1_idx * 4;
 
             for (int m = 0; m < M_2; m++) {
-                __m128 qi = _mm_loadu_ps(qa);
-                __m128 recons = _mm_add_ps(pq_l1[m], pq_l2_t[*code++]);
-                __m128 diff = _mm_sub_ps(qi, recons);
-                accu = _mm_add_ps(accu, _mm_mul_ps(diff, diff));
-                pq_l2_t += 256;
+                for (int j = 0; j < 4; j++) {
+                    float diff =
+                            qa[j] - (l1_sub[m * 4 + j] + l2[*code * 4 + j]);
+                    accu += diff * diff;
+                }
+                code++;
+                l2 += 256 * 4;
                 qa += 4;
             }
-            pq_l1_t += M_2 << mi_nbits;
+            l1 += (M_2 << mi_nbits) * 4;
             key01 >>= mi_nbits;
         }
-        accu = _mm_hadd_ps(accu, accu);
-        accu = _mm_hadd_ps(accu, accu);
-        return _mm_cvtss_f32(accu);
-#else
-        FAISS_THROW_MSG("not implemented for non-x64 platforms");
-#endif
+        return accu;
     }
 };
 
 } // namespace
 
 DistanceComputer* Index2Layer::get_distance_computer() const {
-#ifdef __SSE3__
     const MultiIndexQuantizer* mi =
             dynamic_cast<MultiIndexQuantizer*>(q1.quantizer);
 
@@ -277,7 +259,6 @@ DistanceComputer* Index2Layer::get_distance_computer() const {
     if (fl && pq.dsub == 4) {
         return new DistanceXPQ4(*this);
     }
-#endif
 
     return Index::get_distance_computer();
 }