Address C4244 warnings in MSVC build

deflate.c

@@ -1553,10 +1553,10 @@ local block_state deflate_stored(s, flush)
         _tr_stored_block(s, (char *)0, 0L, last);
 
         /* Replace the lengths in the dummy stored block with len. */
-        s->pending_buf[s->pending - 4] = len;
-        s->pending_buf[s->pending - 3] = len >> 8;
-        s->pending_buf[s->pending - 2] = ~len;
-        s->pending_buf[s->pending - 1] = ~len >> 8;
+        s->pending_buf[s->pending - 4] = (Bytef)len;
+        s->pending_buf[s->pending - 3] = (Bytef)(len >> 8);
+        s->pending_buf[s->pending - 2] = (Bytef)~len;
+        s->pending_buf[s->pending - 1] = (Bytef)(~len >> 8);
 
         /* Write the stored block header bytes. */
         flush_pending(s->strm);

deflate_quick.c

@@ -136,7 +136,7 @@ local inline void quick_send_bits(deflate_state *z_const s, z_const int value,
 
     b = w >> 3;
     s->pending += b;
-    s->bi_buf =  out >> (b << 3);
+    s->bi_buf = (ush)(out >> (b << 3));
     s->bi_valid = w - (b << 3);
 }
 
@@ -224,7 +224,7 @@ block_state deflate_quick(deflate_state *s, int flush)
         }
 
         if (s->lookahead >= MIN_MATCH) {
-            hash_head = quick_insert_string(s, s->strstart);
+            hash_head = quick_insert_string(s, (Pos)s->strstart);
             dist = s->strstart - hash_head;
 
             if ((dist-1) < (s->w_size - 1)) {

slide_sse.c

@@ -18,7 +18,7 @@ void slide_hash_sse(deflate_state *s)
     unsigned n;
     Posf *p;
     uInt wsize = s->w_size;
-    z_const __m128i xmm_wsize = _mm_set1_epi16(s->w_size);
+    z_const __m128i xmm_wsize = _mm_set1_epi16((short)s->w_size);
 
     n = s->hash_size;
     p = &s->head[n] - 8;

trees.c

@@ -717,7 +717,7 @@ local void scan_tree(s, tree, max_code)
         if (++count < max_count && curlen == nextlen) {
             continue;
         } else if (count < min_count) {
-            s->bl_tree[curlen].Freq += count;
+            s->bl_tree[curlen].Freq += (ush)count;
         } else if (curlen != 0) {
             if (curlen != prevlen) s->bl_tree[curlen].Freq++;
             s->bl_tree[REP_3_6].Freq++;