1 files changed, 39 insertions, 12 deletions

diff --git a/include/coverage-64.h b/include/coverage-64.h
index 54fe9d33..ab29506c 100644
--- a/include/coverage-64.h
+++ b/include/coverage-64.h
@@ -72,6 +72,23 @@ inline void classify_counts(afl_forkserver_t *fsrv) {
 
 }
 
+inline void classify_counts_off(afl_forkserver_t *fsrv, u32 off) {
+
+  u64 *mem = (u64 *)(fsrv->trace_bits + off);
+  u32  i = ((fsrv->map_size - off) >> 3);
+
+  while (i--) {
+
+    /* Optimize for sparse bitmaps. */
+
+    if (unlikely(*mem)) { *mem = classify_word(*mem); }
+
+    mem++;
+
+  }
+
+}
+
 /* Updates the virgin bits, then reflects whether a new count or a new tuple is
  * seen in ret. */
 inline void discover_word(u8 *ret, u64 *current, u64 *virgin) {
@@ -110,17 +127,20 @@ inline void discover_word(u8 *ret, u64 *current, u64 *virgin) {
   #define PACK_SIZE 64
 inline u32 skim(const u64 *virgin, const u64 *current, const u64 *current_end) {
 
+  u64 *save = (u64*) current;
+
   for (; current != current_end; virgin += 8, current += 8) {
 
     __m512i  value = *(__m512i *)current;
     __mmask8 mask = _mm512_testn_epi64_mask(value, value);
 
     /* All bytes are zero. */
-    if (mask == 0xff) continue;
+    if (likely(mask == 0xff)) continue;
 
       /* Look for nonzero bytes and check for new bits. */
-  #define UNROLL(x) \
-    if (!(mask & (1 << x)) && classify_word(current[x]) & virgin[x]) return 1
+  #define UNROLL(x)                                                            \
+    if (unlikely(!(mask & (1 << x)) && classify_word(current[x]) & virgin[x])) \
+    return (u32)(&current[x + 1] - save)
     UNROLL(0);
     UNROLL(1);
     UNROLL(2);
@@ -143,6 +163,7 @@ inline u32 skim(const u64 *virgin, const u64 *current, const u64 *current_end) {
   #define PACK_SIZE 32
 inline u32 skim(const u64 *virgin, const u64 *current, const u64 *current_end) {
 
+  u64 *save = (u64*) current;
   __m256i zeroes = _mm256_setzero_si256();
 
   for (; current < current_end; virgin += 4, current += 4) {
@@ -152,13 +173,17 @@ inline u32 skim(const u64 *virgin, const u64 *current, const u64 *current_end) {
     u32     mask = _mm256_movemask_epi8(cmp);
 
     /* All bytes are zero. */
-    if (mask == (u32)-1) continue;
+    if (likely(mask == (u32)-1)) continue;
 
     /* Look for nonzero bytes and check for new bits. */
-    if (!(mask & 0xff) && classify_word(current[0]) & virgin[0]) return 1;
-    if (!(mask & 0xff00) && classify_word(current[1]) & virgin[1]) return 1;
-    if (!(mask & 0xff0000) && classify_word(current[2]) & virgin[2]) return 1;
-    if (!(mask & 0xff000000) && classify_word(current[3]) & virgin[3]) return 1;
+    if (unlikely(!(mask & 0xff) && classify_word(current[0]) & virgin[0]))
+      return (u32)(&current[1] - save);
+    if (unlikely(!(mask & 0xff00) && classify_word(current[1]) & virgin[1]))
+      return (u32)(&current[2] - save);
+    if (unlikely(!(mask & 0xff0000) && classify_word(current[2]) & virgin[2]))
+      return (u32)(&current[3] - save);
+    if (unlikely(!(mask & 0xff000000) && classify_word(current[3]) & virgin[3]))
+      return (u32)(&current[4] - save);
 
   }
 
@@ -172,12 +197,14 @@ inline u32 skim(const u64 *virgin, const u64 *current, const u64 *current_end) {
   #define PACK_SIZE 32
 inline u32 skim(const u64 *virgin, const u64 *current, const u64 *current_end) {
 
+  u64 *save = (u64*) current;
+
   for (; current < current_end; virgin += 4, current += 4) {
 
-    if (current[0] && classify_word(current[0]) & virgin[0]) return 1;
-    if (current[1] && classify_word(current[1]) & virgin[1]) return 1;
-    if (current[2] && classify_word(current[2]) & virgin[2]) return 1;
-    if (current[3] && classify_word(current[3]) & virgin[3]) return 1;
+    if (unlikely(current[0] && classify_word(current[0]) & virgin[0])) return (u32)(&current[1] - save);
+    if (unlikely(current[1] && classify_word(current[1]) & virgin[1])) return (u32)(&current[2] - save);
+    if (unlikely(current[2] && classify_word(current[2]) & virgin[2])) return (u32)(&current[3] - save);
+    if (unlikely(current[3] && classify_word(current[3]) & virgin[3])) return (u32)(&current[4] - save);
 
   }