diff --git a/rtengine/dcraw.cc b/rtengine/dcraw.cc
index 05f1a32a2..227efe6b9 100644
--- a/rtengine/dcraw.cc
+++ b/rtengine/dcraw.cc
@@ -9937,6 +9937,7 @@ static void decodeFPDeltaRow(Bytef * src, Bytef * dst, size_t tileWidth, size_t
 
 }
 
+#ifndef __F16C__
 // From DNG SDK dng_utils.h
 static inline uint32_t DNG_HalfToFloat(uint16_t halfValue) {
   int32_t sign     = (halfValue >> 15) & 0x00000001;
@@ -9970,6 +9971,7 @@ static inline uint32_t DNG_HalfToFloat(uint16_t halfValue) {
   // Assemble sign, exponent and mantissa.
   return (uint32_t) ((sign << 31) | (exponent << 23) | mantissa);
 }
+#endif
 
 static inline uint32_t DNG_FP24ToFloat(const uint8_t * input) {
   int32_t sign     = (input [0] >> 7) & 0x01;
@@ -10006,11 +10008,32 @@ static inline uint32_t DNG_FP24ToFloat(const uint8_t * input) {
 
 static void expandFloats(Bytef * dst, int tileWidth, int bytesps) {
   if (bytesps == 2) {
-    uint16_t * dst16 = (uint16_t *) dst;
-    uint32_t * dst32 = (uint32_t *) dst;
+    uint16_t* const dst16 = reinterpret_cast<uint16_t*>(dst);
+#ifndef __F16C__
+    uint32_t* const dst32 = reinterpret_cast<uint32_t*>(dst);
     for (int index = tileWidth - 1; index >= 0; --index) {
-      dst32[index] = DNG_HalfToFloat(dst16[index]);
+        dst32[index] = DNG_HalfToFloat(dst16[index]);
     }
+#else
+    float* const dst32 = reinterpret_cast<float*>(dst);
+    int index = tileWidth - 8;
+    for (; index >= 0; index -= 8) {
+        __m128i halfFloatv = _mm_loadu_si128((__m128i*)&dst16[index]);
+        STVFU(dst32[index], _mm_cvtph_ps(halfFloatv));
+        STVFU(dst32[index + 4], _mm_cvtph_ps(_mm_shuffle_epi32(halfFloatv, _MM_SHUFFLE(0,0,3,2))));
+    }
+    index += 4;
+    if(index >= 0) {
+        __m128i halfFloatv = _mm_loadu_si128((__m128i*)&dst16[index]);
+        STVFU(dst32[index], _mm_cvtph_ps(halfFloatv));
+        index--;
+    } else {
+        index += 3;
+    }
+    for (; index >= 0; --index) {
+        dst32[index] = _cvtsh_ss(dst16[index]);
+    }
+#endif
   } else if (bytesps == 3) {
     uint8_t  * dst8  = ((uint8_t *) dst) + (tileWidth - 1) * 3;
     uint32_t * dst32 = (uint32_t *) dst;