take mask overhang into account for hwlm accel, float min dist

src/hwlm/hwlm_build.cpp

@@ -64,6 +64,28 @@ namespace ue2 {
 static const unsigned int MAX_ACCEL_OFFSET = 16;
 static const unsigned int MAX_SHUFTI_WIDTH = 240;
 
+static
+size_t mask_overhang(const hwlmLiteral &lit) {
+    size_t msk_true_size = lit.msk.size();
+    assert(msk_true_size <= HWLM_MASKLEN);
+    assert(HWLM_MASKLEN <= MAX_ACCEL_OFFSET);
+    for (u8 c : lit.msk) {
+        if (!c) {
+            msk_true_size--;
+        } else {
+            break;
+        }
+    }
+
+    if (lit.s.length() >= msk_true_size) {
+        return 0;
+    }
+
+    /* only short literals should be able to have a mask which overhangs */
+    assert(lit.s.length() < MAX_ACCEL_OFFSET);
+    return msk_true_size - lit.s.length();
+}
+
 static
 bool findDVerm(const vector<const hwlmLiteral *> &lits, AccelAux *aux) {
     const hwlmLiteral &first = *lits.front();
@@ -169,7 +191,8 @@ bool findDVerm(const vector<const hwlmLiteral *> &lits, AccelAux *aux) {
                 }
 
                 if (found) {
-                    curr.max_offset = MAX(curr.max_offset, j);
+                    assert(j + mask_overhang(lit) <= MAX_ACCEL_OFFSET);
+                    ENSURE_AT_LEAST(&curr.max_offset, j + mask_overhang(lit));
                     break;
                 }
             }
@@ -290,8 +313,8 @@ bool findSVerm(const vector<const hwlmLiteral *> &lits, AccelAux *aux) {
                 }
 
                 if (found) {
-                    curr.max_offset = MAX(curr.max_offset, j);
-                    break;
+                    assert(j + mask_overhang(lit) <= MAX_ACCEL_OFFSET);
+                    ENSURE_AT_LEAST(&curr.max_offset, j + mask_overhang(lit));
                 }
             }
         }
@@ -392,13 +415,25 @@ void findForwardAccelScheme(const vector<hwlmLiteral> &lits,
             continue;
         }
 
-        for (u32 i = 0; i < MAX_ACCEL_OFFSET; i++) {
+        u32 overhang = mask_overhang(lit);
+        for (u32 i = 0; i < overhang; i++) {
+            /* this offset overhangs the start of the real literal; look at the
+             * msk/cmp */
+            for (u32 j = 0; j < N_CHARS; j++) {
+                if ((j & lit.msk[i]) == lit.cmp[i]) {
+                    reach[i].set(j);
+                }
+            }
+        }
+        for (u32 i = overhang; i < MAX_ACCEL_OFFSET; i++) {
             CharReach &reach_i = reach[i];
+            u32 i_effective = i - overhang;
 
-            if (litGuardedByCharReach(reach_i, lit, i)) {
+            if (litGuardedByCharReach(reach_i, lit, i_effective)) {
                 continue;
             }
-            unsigned char c = i < lit.s.length() ? lit.s[i] : lit.s.back();
+            unsigned char c = i_effective < lit.s.length() ? lit.s[i_effective]
+                                                           : lit.s.back();
             if (lit.nocase) {
                 reach_i.set(mytoupper(c));
                 reach_i.set(mytolower(c));

src/rose/rose_build_bytecode.cpp

@@ -5031,6 +5031,9 @@ void fillMatcherDistances(const RoseBuildImpl &build, RoseEngine *engine) {
             u32 max_d = g[v].max_offset;
             u32 min_d = g[v].min_offset;
 
+            DEBUG_PRINTF("checking %u: elen %zu min/max %u/%u\n", lit_id,
+                         key.elength_including_mask(), min_d, max_d);
+
             if (build.literal_info[lit_id].undelayed_id != lit_id) {
                 /* this is a delayed match; need to update delay properties */
                 /* TODO: can delayed literals ever be in another table ? */
@@ -5050,9 +5053,9 @@ void fillMatcherDistances(const RoseBuildImpl &build, RoseEngine *engine) {
             switch (key.table) {
             case ROSE_FLOATING:
                 ENSURE_AT_LEAST(&engine->floatingDistance, max_d);
-                if (min_d >= key.elength()) {
+                if (min_d >= key.elength_including_mask()) {
                     LIMIT_TO_AT_MOST(&engine->floatingMinDistance,
-                                     min_d - (u32)key.elength());
+                                     min_d - (u32)key.elength_including_mask());
                 } else {
                     /* overlapped literals from rose + anchored table can
                      * cause us to underflow due to sloppiness in

src/rose/rose_build_impl.h

@@ -277,6 +277,17 @@ struct rose_literal_id {
     u32 distinctiveness;
 
     size_t elength(void) const { return s.length() + delay; }
+    size_t elength_including_mask(void) const {
+        size_t mask_len = msk.size();
+        for (u8 c : msk) {
+            if (!c) {
+                mask_len--;
+            } else {
+                break;
+            }
+        }
+        return MAX(mask_len, s.length()) + delay;
+    }
 };
 
 static inline