Comment lines that may produce compiler warnings

[wimlib] / src / decompress.c

diff --git a/src/decompress.c b/src/decompress.c
index 5c308b2d7bd2cdfba9425fc41c8cdf7abed11219..c5e739110783e5f3921c83e3e14a6f19af649a82 100644 (file)
--- a/src/decompress.c
+++ b/src/decompress.c
@@ -167,6 +167,10 @@ int make_huffman_decode_table(u16 decode_table[],  unsigned num_syms,
                const unsigned entries_per_long = sizeof(unsigned long) /
                                                  sizeof(decode_table[0]);
                if (num_entries >= entries_per_long) {
+                       /* Fill in the Huffman decode table entries one unsigned
+                        * long at a time.  On 32-bit systems this is 2 entries
+                        * per store, while on 64-bit systems this is 4 entries
+                        * per store. */
                        wimlib_assert2(decode_table_pos % entries_per_long == 0);
                        BUILD_BUG_ON(sizeof(unsigned long) != 4 &&
                                     sizeof(unsigned long) != 8);
@@ -176,14 +180,21 @@ int make_huffman_decode_table(u16 decode_table[],  unsigned num_syms,
                        unsigned long v = sym;
                        if (sizeof(unsigned long) >= 4)
                                v |= v << 16;
-                       if (sizeof(unsigned long) >= 8)
+                       if (sizeof(unsigned long) >= 8) {
+                               /* This may produce a compiler warning if an
+                                * unsigned long is 32 bits, but this won't be
+                                * executed unless an unsigned long is at least
+                                * 64 bits anyway. */
                                v |= v << 32;
+                       }
                        do {
                                *p++ = v;
                        } while (--n);
 
                        decode_table_pos += num_entries;
                } else {
+                       /* Fill in the Huffman decode table entries one 16-bit
+                        * integer at a time. */
                        do {
                                decode_table[decode_table_pos++] = sym;
                        } while (--num_entries);