diff --git a/src/nfa/accel.c b/src/nfa/accel.c
index 8c9b6e72..34bd24a9 100644
--- a/src/nfa/accel.c
+++ b/src/nfa/accel.c
@@ -91,6 +91,28 @@ const u8 *run_accel(const union AccelAux *accel, const u8 *c, const u8 *c_end) {
 
         rv = vermicelli16Exec(accel->verm16.mask, c, c_end);
         break;
+
+    case ACCEL_DVERM16:
+        DEBUG_PRINTF("accel dverm16 %p %p\n", c, c_end);
+        if (c_end - c < 18) {
+            return c;
+        }
+
+        /* need to stop one early to get an accurate end state */
+        rv = vermicelliDouble16Exec(accel->dverm16.mask, accel->dverm16.firsts,
+                                    c, c_end - 1);
+        break;
+
+    case ACCEL_DVERM16_MASKED:
+        DEBUG_PRINTF("accel dverm16 masked %p %p\n", c, c_end);
+        if (c_end - c < 18) {
+            return c;
+        }
+
+        /* need to stop one early to get an accurate end state */
+        rv = vermicelliDoubleMasked16Exec(accel->mdverm16.mask, accel->mdverm16.c1,
+                                          accel->mdverm16.m1, c, c_end - 1);
+        break;
 #endif // HAVE_SVE2
 
     case ACCEL_DVERM_MASKED:
diff --git a/src/nfa/accel.h b/src/nfa/accel.h
index 0676239a..3fccdd7b 100644
--- a/src/nfa/accel.h
+++ b/src/nfa/accel.h
@@ -63,7 +63,9 @@ enum AccelType {
     ACCEL_TRUFFLE,
     ACCEL_RED_TAPE,
     ACCEL_DVERM_MASKED,
-    ACCEL_VERM16
+    ACCEL_VERM16,
+    ACCEL_DVERM16,
+    ACCEL_DVERM16_MASKED,
 };
 
 /** \brief Structure for accel framework. */
@@ -104,6 +106,19 @@ union AccelAux {
         u8 offset;
         m128 mask;
     } verm16;
+    struct {
+        u8 accel_type;
+        u8 offset;
+        u64a firsts;
+        m128 mask;
+    } dverm16;
+    struct {
+        u8 accel_type;
+        u8 offset;
+        u8 c1; // used for partial match
+        u8 m1; // used for partial match
+        m128 mask;
+    } mdverm16;
     struct {
         u8 accel_type;
         u8 offset;
diff --git a/src/nfa/accel_dfa_build_strat.cpp b/src/nfa/accel_dfa_build_strat.cpp
index cfca9397..6793a65c 100644
--- a/src/nfa/accel_dfa_build_strat.cpp
+++ b/src/nfa/accel_dfa_build_strat.cpp
@@ -442,45 +442,75 @@ accel_dfa_build_strat::buildAccel(UNUSED dstate_id_t this_idx,
         return;
     }
 
-    if (double_byte_ok(info) && info.double_cr.none() &&
-        (info.double_byte.size() == 2 || info.double_byte.size() == 4)) {
-        bool ok = true;
+    if (double_byte_ok(info) && info.double_cr.none()) {
+        if ((info.double_byte.size() == 2 || info.double_byte.size() == 4)) {
+            bool ok = true;
 
-        assert(!info.double_byte.empty());
-        u8 firstC = info.double_byte.begin()->first & CASE_CLEAR;
-        u8 secondC = info.double_byte.begin()->second & CASE_CLEAR;
+            assert(!info.double_byte.empty());
+            u8 firstC = info.double_byte.begin()->first & CASE_CLEAR;
+            u8 secondC = info.double_byte.begin()->second & CASE_CLEAR;
 
-        for (const pair<u8, u8> &p : info.double_byte) {
-            if ((p.first & CASE_CLEAR) != firstC ||
-                (p.second & CASE_CLEAR) != secondC) {
-                ok = false;
-                break;
+            for (const pair<u8, u8> &p : info.double_byte) {
+                if ((p.first & CASE_CLEAR) != firstC ||
+                    (p.second & CASE_CLEAR) != secondC) {
+                    ok = false;
+                    break;
+                }
+            }
+
+            if (ok) {
+                accel->accel_type = ACCEL_DVERM_NOCASE;
+                accel->dverm.c1 = firstC;
+                accel->dverm.c2 = secondC;
+                accel->dverm.offset = verify_u8(info.double_offset);
+                DEBUG_PRINTF("state %hu is nc double vermicelli\n", this_idx);
+                return;
+            }
+
+            u8 m1;
+            u8 m2;
+            if (buildDvermMask(info.double_byte, &m1, &m2)) {
+                u8 c1 = info.double_byte.begin()->first & m1;
+                u8 c2 = info.double_byte.begin()->second & m2;
+#ifdef HAVE_SVE2
+                if (vermicelliDoubleMasked16Build(c1, c2, m1, m2, (u8 *)&accel->mdverm16.mask)) {
+                    accel->accel_type = ACCEL_DVERM16_MASKED;
+                    accel->mdverm16.offset = verify_u8(info.double_offset);
+                    accel->mdverm16.c1 = c1;
+                    accel->mdverm16.m1 = m1;
+                    DEBUG_PRINTF("building maskeddouble16-vermicelli for 0x%02hhx%02hhx\n",
+                                c1, c2);
+                    return;
+                } else if (info.double_byte.size() <= 8 &&
+                        vermicelliDouble16Build(info.double_byte, (u8 *)&accel->dverm16.mask,
+                                                (u8 *)&accel->dverm16.firsts)) {
+                    accel->accel_type = ACCEL_DVERM16;
+                    accel->dverm16.offset = verify_u8(info.double_offset);
+                    DEBUG_PRINTF("building double16-vermicelli\n");
+                    return;
+                }
+#endif // HAVE_SVE2
+                accel->accel_type = ACCEL_DVERM_MASKED;
+                accel->dverm.offset = verify_u8(info.double_offset);
+                accel->dverm.c1 = c1;
+                accel->dverm.c2 = c2;
+                accel->dverm.m1 = m1;
+                accel->dverm.m2 = m2;
+                DEBUG_PRINTF(
+                    "building maskeddouble-vermicelli for 0x%02hhx%02hhx\n", c1, c2);
+                return;
             }
         }
-
-        if (ok) {
-            accel->accel_type = ACCEL_DVERM_NOCASE;
-            accel->dverm.c1 = firstC;
-            accel->dverm.c2 = secondC;
-            accel->dverm.offset = verify_u8(info.double_offset);
-            DEBUG_PRINTF("state %hu is nc double vermicelli\n", this_idx);
-            return;
-        }
-
-        u8 m1;
-        u8 m2;
-        if (buildDvermMask(info.double_byte, &m1, &m2)) {
-            accel->accel_type = ACCEL_DVERM_MASKED;
-            accel->dverm.offset = verify_u8(info.double_offset);
-            accel->dverm.c1 = info.double_byte.begin()->first & m1;
-            accel->dverm.c2 = info.double_byte.begin()->second & m2;
-            accel->dverm.m1 = m1;
-            accel->dverm.m2 = m2;
-            DEBUG_PRINTF(
-                "building maskeddouble-vermicelli for 0x%02hhx%02hhx\n",
-                accel->dverm.c1, accel->dverm.c2);
+#ifdef HAVE_SVE2
+        if (info.double_byte.size() <= 8 &&
+            vermicelliDouble16Build(info.double_byte, (u8 *)&accel->dverm16.mask,
+                                    (u8 *)&accel->dverm16.firsts)) {
+            accel->accel_type = ACCEL_DVERM16;
+            accel->dverm16.offset = verify_u8(info.double_offset);
+            DEBUG_PRINTF("building double16-vermicelli\n");
             return;
         }
+#endif // HAVE_SVE2
     }
 
     if (double_byte_ok(info) &&
diff --git a/src/nfa/accelcompile.cpp b/src/nfa/accelcompile.cpp
index f68ed1b9..e0be910d 100644
--- a/src/nfa/accelcompile.cpp
+++ b/src/nfa/accelcompile.cpp
@@ -207,16 +207,45 @@ void buildAccelDouble(const AccelInfo &info, AccelAux *aux) {
         u8 m2;
 
         if (buildDvermMask(info.double_stop2, &m1, &m2)) {
+            u8 c1 = info.double_stop2.begin()->first & m1;
+            u8 c2 = info.double_stop2.begin()->second & m2;
+#ifdef HAVE_SVE2
+            if (vermicelliDoubleMasked16Build(c1, c2, m1, m2, (u8 *)&aux->mdverm16.mask)) {
+                aux->accel_type = ACCEL_DVERM16_MASKED;
+                aux->mdverm16.offset = offset;
+                aux->mdverm16.c1 = c1;
+                aux->mdverm16.m1 = m1;
+                DEBUG_PRINTF("building maskeddouble16-vermicelli for 0x%02hhx%02hhx\n",
+                             c1, c2);
+                return;
+            } else if (outs2 <= 8 &&
+                       vermicelliDouble16Build(info.double_stop2, (u8 *)&aux->dverm16.mask,
+                                               (u8 *)&aux->dverm16.firsts)) {
+                aux->accel_type = ACCEL_DVERM16;
+                aux->dverm16.offset = offset;
+                DEBUG_PRINTF("building double16-vermicelli\n");
+                return;
+            }
+#endif // HAVE_SVE2
             aux->accel_type = ACCEL_DVERM_MASKED;
             aux->dverm.offset = offset;
-            aux->dverm.c1 = info.double_stop2.begin()->first & m1;
-            aux->dverm.c2 = info.double_stop2.begin()->second & m2;
+            aux->dverm.c1 = c1;
+            aux->dverm.c2 = c2;
             aux->dverm.m1 = m1;
             aux->dverm.m2 = m2;
-            DEBUG_PRINTF("building maskeddouble-vermicelli for 0x%02hhx%02hhx\n",
-                         aux->dverm.c1, aux->dverm.c2);
+            DEBUG_PRINTF("building maskeddouble-vermicelli for 0x%02hhx%02hhx\n", c1, c2);
             return;
         }
+#ifdef HAVE_SVE2
+        if (outs2 <= 8 &&
+            vermicelliDouble16Build(info.double_stop2, (u8 *)&aux->dverm16.mask,
+                                    (u8 *)&aux->dverm16.firsts)) {
+            aux->accel_type = ACCEL_DVERM16;
+            aux->dverm16.offset = offset;
+            DEBUG_PRINTF("building double16-vermicelli\n");
+            return;
+        }
+#endif // HAVE_SVE2
     }
 
     if (outs1 < outs2 && outs1 <= 2) { // Heuristic from UE-438.
diff --git a/src/nfa/vermicelli_sve.h b/src/nfa/vermicelli_sve.h
index 88ed688c..42476a69 100644
--- a/src/nfa/vermicelli_sve.h
+++ b/src/nfa/vermicelli_sve.h
@@ -267,9 +267,7 @@ const u8 *rvermSearch(svuint8_t chars, const u8 *buf, const u8 *buf_end,
 }
 
 static really_inline
-const u8 *dvermSearch(char c1, char c2, bool nocase, const u8 *buf,
-                      const u8 *buf_end) {
-    svuint16_t chars = getCharMaskDouble(c1, c2, nocase);
+const u8 *dvermSearch(svuint8_t chars, const u8 *buf, const u8 *buf_end) {
     size_t len = buf_end - buf;
     if (len <= svcntb()) {
         return dvermSearchOnce(chars, buf, buf_end);
@@ -374,7 +372,8 @@ const u8 *vermicelliDoubleExec(char c1, char c2, bool nocase, const u8 *buf,
     assert(buf < buf_end);
     if (buf_end - buf > 1) {
         ++buf;
-        const u8 *ptr = dvermSearch(c1, c2, nocase, buf, buf_end);
+        svuint16_t chars = getCharMaskDouble(c1, c2, nocase);
+        const u8 *ptr = dvermSearch(chars, buf, buf_end);
         if (ptr) {
             return ptr;
         }
@@ -406,42 +405,92 @@ const u8 *rvermicelliDoubleExec(char c1, char c2, bool nocase, const u8 *buf,
 }
 
 static really_inline
-svuint8_t getDupSVEMaskFrom128(m128 _mask) {
-    return svld1rq_u8(svptrue_b8(), (const uint8_t *)&_mask);
+svuint8_t getDupSVEMaskFrom128(m128 mask) {
+    return svld1rq_u8(svptrue_b8(), (const uint8_t *)&mask);
 }
 
 static really_inline
-const u8 *vermicelli16Exec(const m128 _chars, const u8 *buf,
+const u8 *vermicelli16Exec(const m128 mask, const u8 *buf,
                            const u8 *buf_end) {
     DEBUG_PRINTF("verm16 scan over %td bytes\n", buf_end - buf);
-    svuint8_t chars = getDupSVEMaskFrom128(_chars);
+    svuint8_t chars = getDupSVEMaskFrom128(mask);
     const u8 *ptr = vermSearch(chars, buf, buf_end, false);
     return ptr ? ptr : buf_end;
 }
 
 static really_inline
-const u8 *nvermicelli16Exec(const m128 _chars, const u8 *buf,
+const u8 *nvermicelli16Exec(const m128 mask, const u8 *buf,
                             const u8 *buf_end) {
     DEBUG_PRINTF("nverm16 scan over %td bytes\n", buf_end - buf);
-    svuint8_t chars = getDupSVEMaskFrom128(_chars);
+    svuint8_t chars = getDupSVEMaskFrom128(mask);
     const u8 *ptr = vermSearch(chars, buf, buf_end, true);
     return ptr ? ptr : buf_end;
 }
 
 static really_inline
-const u8 *rvermicelli16Exec(const m128 _chars, const u8 *buf,
+const u8 *rvermicelli16Exec(const m128 mask, const u8 *buf,
                             const u8 *buf_end) {
     DEBUG_PRINTF("rverm16 scan over %td bytes\n", buf_end - buf);
-    svuint8_t chars = getDupSVEMaskFrom128(_chars);
+    svuint8_t chars = getDupSVEMaskFrom128(mask);
     const u8 *ptr = rvermSearch(chars, buf, buf_end, false);
     return ptr ? ptr : buf - 1;
 }
 
 static really_inline
-const u8 *rnvermicelli16Exec(const m128 _chars, const u8 *buf,
+const u8 *rnvermicelli16Exec(const m128 mask, const u8 *buf,
                              const u8 *buf_end) {
     DEBUG_PRINTF("rnverm16 scan over %td bytes\n", buf_end - buf);
-    svuint8_t chars = getDupSVEMaskFrom128(_chars);
+    svuint8_t chars = getDupSVEMaskFrom128(mask);
     const u8 *ptr = rvermSearch(chars, buf, buf_end, true);
     return ptr ? ptr : buf - 1;
-}
\ No newline at end of file
+}
+
+static really_inline
+bool vermicelliDouble16CheckPartial(const u64a first_chars, const u8 *buf_end) {
+    svuint8_t firsts = svreinterpret_u8(svdup_u64(first_chars));
+    svbool_t matches = svcmpeq(svptrue_b8(), firsts, svdup_u8(buf_end[-1]));
+    return svptest_any(svptrue_b8(), matches);
+}
+
+static really_inline
+const u8 *vermicelliDouble16Exec(const m128 mask, const u64a firsts,
+                                 const u8 *buf, const u8 *buf_end) {
+    assert(buf < buf_end);
+    DEBUG_PRINTF("double verm16 scan over %td bytes\n", buf_end - buf);
+    if (buf_end - buf > 1) {
+        ++buf;
+        svuint16_t chars = svreinterpret_u16(getDupSVEMaskFrom128(mask));
+        const u8 *ptr = dvermSearch(chars, buf, buf_end);
+        if (ptr) {
+            return ptr;
+        }
+    }
+    /* check for partial match at end */
+    if (vermicelliDouble16CheckPartial(firsts, buf_end)) {
+        DEBUG_PRINTF("partial!!!\n");
+        return buf_end - 1;
+    }
+    return buf_end;
+}
+
+static really_inline
+const u8 *vermicelliDoubleMasked16Exec(const m128 mask, char c1, char m1,
+                                       const u8 *buf, const u8 *buf_end) {
+    assert(buf < buf_end);
+    DEBUG_PRINTF("double verm16 masked scan over %td bytes\n", buf_end - buf);
+    if (buf_end - buf > 1) {
+        ++buf;
+        svuint16_t chars = svreinterpret_u16(getDupSVEMaskFrom128(mask));
+        const u8 *ptr = dvermSearch(chars, buf, buf_end);
+        if (ptr) {
+            return ptr;
+        }
+    }
+    /* check for partial match at end */
+    if ((buf_end[-1] & m1) == (u8)c1) {
+        DEBUG_PRINTF("partial!!!\n");
+        return buf_end - 1;
+    }
+
+    return buf_end;
+}
diff --git a/src/nfa/vermicellicompile.cpp b/src/nfa/vermicellicompile.cpp
index 5b6ca036..d72ecece 100644
--- a/src/nfa/vermicellicompile.cpp
+++ b/src/nfa/vermicellicompile.cpp
@@ -50,4 +50,207 @@ bool vermicelli16Build(const CharReach &chars, u8 *rv) {
     return true;
 }
 
+bool vermicelliDouble16Build(const flat_set<std::pair<u8, u8>> &twochar,
+                             u8 *chars, u8 *firsts) {
+    constexpr size_t count_limit = 8;
+    if (twochar.size() > count_limit) return false;
+    size_t count = 0;
+    for (const auto &p : twochar) {
+        firsts[count] = p.first;
+        chars[2 * count] = p.first;
+        chars[(2 * count) + 1] = p.second;
+        ++count;
+    }
+    for(; count < count_limit; ++count) {
+        firsts[count] = chars[0];
+        chars[2 * count] = chars[0];
+        chars[(2 * count) + 1] = chars[1];
+    }
+    return true;
+}
+
+static really_inline
+void fillMask(u8 matches[], size_t len, u8 *rv) {
+    for (size_t i = 0; i < 16; ++i) {
+        rv[i] = matches[i % len];
+    }
+}
+
+static really_inline
+void getTwoCases(u8 cases[2], u8 bit, char c) {
+    const u8 set = 1UL << bit;
+    cases[0] = c & (~set);
+    cases[1] = c | set;
+}
+
+static really_inline
+void getFourCases(u8 cases[4], u8 bit, char case1, char case2) {
+    const u8 set = 1UL << bit;
+    cases[0] = case1 & (~set);
+    cases[1] = case1 | set;
+    cases[2] = case2 & (~set);
+    cases[3] = case2 | set;
+}
+
+static really_inline
+void getEightCases(u8 cases[8], u8 bit, char case1, char case2,
+                                        char case3, char case4) {
+    const u8 set = 1UL << bit;
+    cases[0] = case1 & (~set);
+    cases[1] = case1 | set;
+    cases[2] = case2 & (~set);
+    cases[3] = case2 | set;
+    cases[4] = case3 & (~set);
+    cases[5] = case3 | set;
+    cases[6] = case4 & (~set);
+    cases[7] = case4 | set;
+}
+
+static really_inline
+bool getDoubleMatchesForBits(u8 c1, u8 c2, u8 holes[3], u8 c1_holes,
+                             u8 c2_holes, u8 *rv) {
+    u8 cases[8];
+    switch (c1_holes) {
+        case 0:
+            switch (c2_holes) {
+                case 0: {
+                    u8 matches[2] = { c1, c2 };
+                    fillMask(matches, 2, rv);
+                    return true;
+                }
+                case 1: {
+                    getTwoCases(cases, holes[0], c2);
+                    u8 matches[4] = { c1, cases[0], c1, cases[1] };
+                    fillMask(matches, 4, rv);
+                    return true;
+                }
+                case 2: {
+                    getTwoCases(cases, holes[0], c2);
+                    getFourCases(&cases[2], holes[1], cases[0], cases[1]);
+                    u8 matches[8] = { c1, cases[2], c1, cases[3],
+                                      c1, cases[4], c1, cases[5] };
+                    fillMask(matches, 8, rv);
+                    return true;
+                }
+                case 3: {
+                    getTwoCases(cases, holes[0], c2);
+                    getFourCases(&cases[4], holes[1], cases[0], cases[1]);
+                    getEightCases(cases, holes[2], cases[4], cases[5],
+                                                  cases[6], cases[7]);
+                    u8 matches[16] = { c1, cases[0], c1, cases[1],
+                                       c1, cases[2], c1, cases[3],
+                                       c1, cases[4], c1, cases[5],
+                                       c1, cases[6], c1, cases[7] };
+                    memcpy(rv, matches, sizeof(matches));
+                    return true;
+                }
+                default:
+                    assert(c2_holes < 4);
+                    break;
+            }
+            break;
+        case 1:
+            getTwoCases(cases, holes[0], c1);
+            switch (c2_holes) {
+                case 0: {
+                    u8 matches[4] = { cases[0] , c2, cases[1], c2 };
+                    fillMask(matches, 4, rv);
+                    return true;
+                }
+                case 1: {
+                    getTwoCases(&cases[2], holes[1], c2);
+                    u8 matches[8] = { cases[0], cases[2],
+                                      cases[0], cases[3],
+                                      cases[1], cases[2],
+                                      cases[1], cases[3] };
+                    fillMask(matches, 8, rv);
+                    return true;
+                }
+                case 2: {
+                    getTwoCases(&cases[2], holes[1], c2);
+                    getFourCases(&cases[4], holes[2], cases[2], cases[3]);
+                    u8 matches[16] = { cases[0], cases[4], cases[0], cases[5],
+                                       cases[0], cases[6], cases[0], cases[7],
+                                       cases[1], cases[4], cases[1], cases[5],
+                                       cases[1], cases[6], cases[1], cases[7] };
+                    memcpy(rv, matches, sizeof(matches));
+                    return true;
+                }
+                default:
+                    assert(c2_holes < 3);
+                    break;
+            }
+            break;
+        case 2:
+            getTwoCases(cases, holes[0], c1);
+            getFourCases(&cases[2], holes[1], cases[0], cases[1]);
+            switch (c2_holes) {
+                case 0: {
+                    u8 matches[8] = { cases[2], c2, cases[3], c2,
+                                      cases[4], c2, cases[5], c2 };
+                    fillMask(matches, 8, rv);
+                    return true;
+                }
+                case 1: {
+                    getTwoCases(&cases[6], holes[2], c2);
+                    u8 matches[16] = { cases[2], cases[6], cases[3], cases[6],
+                                       cases[4], cases[6], cases[5], cases[6],
+                                       cases[2], cases[7], cases[3], cases[7],
+                                       cases[4], cases[7], cases[5], cases[7] };
+                    memcpy(rv, matches, sizeof(matches));
+                    return true;
+                }
+                default:
+                    assert(c2_holes < 2);
+                    break;
+            }
+            break;
+        case 3: {
+            assert(!c2_holes);
+            getTwoCases(cases, holes[0], c1);
+            getFourCases(&cases[4], holes[1], cases[0], cases[1]);
+            getEightCases(cases, holes[2], cases[4], cases[5],
+                                        cases[6], cases[7]);
+            u8 matches[16] = { cases[0], c2, cases[1], c2,
+                                cases[2], c2, cases[3], c2,
+                                cases[4], c2, cases[5], c2,
+                                cases[6], c2, cases[7], c2 };
+            memcpy(rv, matches, sizeof(matches));
+            return true;
+        }
+    }
+    return false;
+}
+
+static really_inline
+bool getDoubleMatchesForMask(char c1, char c2, char m1, char m2,
+                             u8 c1_holes, u8 c2_holes, u8 *rv) {
+    u8 holes[3] = { 0 };
+    int count = 0;
+    if (c1_holes) {
+        for (int i = 0; i < 8; ++i) {
+            if (!(m1 & (1UL << i))) {
+                holes[count++] = i;
+            }
+        }
+    }
+    if (c2_holes) {
+        for (int i = 0; i < 8; ++i) {
+            if (!(m2 & (1UL << i))) {
+                holes[count++] = i;
+            }
+        }
+    }
+    return getDoubleMatchesForBits(c1, c2, holes, c1_holes, c2_holes, rv);
+}
+
+bool vermicelliDoubleMasked16Build(char c1, char c2, char m1, char m2, u8 *rv) {
+    u8 c1_holes = 8 - __builtin_popcount(m1);
+    u8 c2_holes = 8 - __builtin_popcount(m2);
+    if (c1_holes + c2_holes > 3) {
+        return false;
+    }
+    return getDoubleMatchesForMask(c1, c2, m1, m2, c1_holes, c2_holes, rv);
+}
+
 } // namespace ue2
diff --git a/src/nfa/vermicellicompile.h b/src/nfa/vermicellicompile.h
index 5c70100a..0075273c 100644
--- a/src/nfa/vermicellicompile.h
+++ b/src/nfa/vermicellicompile.h
@@ -43,6 +43,11 @@ namespace ue2 {
 
 bool vermicelli16Build(const CharReach &chars, u8 *rv);
 
+bool vermicelliDouble16Build(const flat_set<std::pair<u8, u8>> &twochar,
+                             u8 *chars, u8 *firsts);
+
+bool vermicelliDoubleMasked16Build(char c1, char c2, char m1, char m2, u8 *rv);
+
 } // namespace ue2
 
 #endif // VERM_COMPILE_H
diff --git a/unit/internal/rvermicelli.cpp b/unit/internal/rvermicelli.cpp
index 2806c5d8..d89067d0 100644
--- a/unit/internal/rvermicelli.cpp
+++ b/unit/internal/rvermicelli.cpp
@@ -311,11 +311,6 @@ TEST(RDoubleVermicelli, Exec5) {
 #include "nfa/vermicellicompile.h"
 using namespace ue2;
 
-union Matches {
-    u8 val8[16];
-    m128 val128;
-};
-
 TEST(RVermicelli16, ExecNoMatch1) {
     char t1[] = "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb";
 
@@ -323,8 +318,8 @@ TEST(RVermicelli16, ExecNoMatch1) {
     chars.set('a');
     chars.set('B');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
@@ -332,7 +327,7 @@ TEST(RVermicelli16, ExecNoMatch1) {
             const u8 *begin = (const u8 *)t1 + i;
             const u8 *end = (const u8 *)t1 + strlen(t1) - j;
 
-            const u8 *rv = rvermicelli16Exec(matches.val128, begin, end);
+            const u8 *rv = rvermicelli16Exec(matches, begin, end);
             ASSERT_EQ(begin - 1, rv);
         }
     }
@@ -345,12 +340,12 @@ TEST(RVermicelli16, Exec1) {
     CharReach chars;
     chars.set('a');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = rvermicelli16Exec(matches.val128, buf, buf + strlen(t1) - i);
+        const u8 *rv = rvermicelli16Exec(matches, buf, buf + strlen(t1) - i);
         ASSERT_EQ(buf + 48, rv);
     }
 }
@@ -362,12 +357,12 @@ TEST(RVermicelli16,  Exec2) {
     CharReach chars;
     chars.set('a');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = rvermicelli16Exec(matches.val128, buf + i, buf + strlen(t1));
+        const u8 *rv = rvermicelli16Exec(matches, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 48, rv);
     }
 }
@@ -378,20 +373,20 @@ TEST(RVermicelli16,  Exec3) {
 
     CharReach chars;
     chars.set('a');
-    Matches matches_a;
-    bool ret = vermicelli16Build(chars, matches_a.val8);
+    m128 matches_a;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches_a);
     ASSERT_TRUE(ret);
 
     chars.set('A');
-    Matches matches_A;
-    ret = vermicelli16Build(chars, matches_A.val8);
+    m128 matches_A;
+    ret = vermicelli16Build(chars, (u8 *)&matches_A);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = rvermicelli16Exec(matches_a.val128, buf, buf + strlen(t1) - i);
+        const u8 *rv = rvermicelli16Exec(matches_a, buf, buf + strlen(t1) - i);
         ASSERT_EQ(buf + 47, rv);
 
-        rv = rvermicelli16Exec(matches_A.val128, buf, buf + strlen(t1) - i);
+        rv = rvermicelli16Exec(matches_A, buf, buf + strlen(t1) - i);
         ASSERT_EQ(buf + 48, rv);
     }
 }
@@ -402,21 +397,21 @@ TEST(RVermicelli16, Exec4) {
 
     CharReach chars;
     chars.set('a');
-    Matches matches_a;
-    bool ret = vermicelli16Build(chars, matches_a.val8);
+    m128 matches_a;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches_a);
     ASSERT_TRUE(ret);
 
     chars.set('A');
-    Matches matches_A;
-    ret = vermicelli16Build(chars, matches_A.val8);
+    m128 matches_A;
+    ret = vermicelli16Build(chars, (u8 *)&matches_A);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 31; i++) {
         t1[16 + i] = 'a';
-        const u8 *rv = rvermicelli16Exec(matches_a.val128, buf, buf + strlen(t1));
+        const u8 *rv = rvermicelli16Exec(matches_a, buf, buf + strlen(t1));
         ASSERT_EQ(buf + 16 + i, rv);
 
-        rv = rvermicelli16Exec(matches_A.val128, buf, buf + strlen(t1));
+        rv = rvermicelli16Exec(matches_A, buf, buf + strlen(t1));
         ASSERT_EQ(buf + 16 + i, rv);
     }
 }
@@ -426,18 +421,18 @@ TEST(RVermicelli16, Exec5) {
     const u8 *buf = (const u8 *)t1;
 
     CharReach chars;
-    Matches matches[16];
+    m128 matches[16];
     bool ret;
 
     for (int i = 0; i < 16; ++i) {
         chars.set('a' + i);
-        ret = vermicelli16Build(chars, matches[i].val8);
+        ret = vermicelli16Build(chars, (u8 *)&matches[i]);
         ASSERT_TRUE(ret);
     }
 
     for (int j = 0; j < 16; ++j) {
         for (size_t i = 0; i < 16; i++) {
-            const u8 *rv = rvermicelli16Exec(matches[j].val128, buf, buf + strlen(t1) - i);
+            const u8 *rv = rvermicelli16Exec(matches[j], buf, buf + strlen(t1) - i);
             ASSERT_EQ(buf + j + 17, rv);
         }
     }
@@ -451,13 +446,13 @@ TEST(RNVermicelli16, ExecNoMatch1) {
     chars.set('b');
     chars.set('B');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
         for (size_t j = 0; j < 16; j++) {
-            const u8 *rv = rnvermicelli16Exec(matches.val128, buf + i, buf + strlen(t1) - j);
+            const u8 *rv = rnvermicelli16Exec(matches, buf + i, buf + strlen(t1) - j);
             ASSERT_EQ(buf + i - 1, rv);
         }
     }
@@ -470,12 +465,12 @@ TEST(RNVermicelli16, Exec1) {
     CharReach chars;
     chars.set('b');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = rnvermicelli16Exec(matches.val128, buf + i, buf + strlen(t1) - i);
+        const u8 *rv = rnvermicelli16Exec(matches, buf + i, buf + strlen(t1) - i);
         ASSERT_EQ(buf + 48, rv);
     }
 }
@@ -487,12 +482,12 @@ TEST(RNVermicelli16,  Exec2) {
     CharReach chars;
     chars.set('b');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = rnvermicelli16Exec(matches.val128, buf, buf + strlen(t1) - i);
+        const u8 *rv = rnvermicelli16Exec(matches, buf, buf + strlen(t1) - i);
         ASSERT_EQ(buf + 48, rv);
     }
 }
@@ -503,20 +498,20 @@ TEST(RNVermicelli16,  Exec3) {
 
     CharReach chars;
     chars.set('b');
-    Matches matches_b;
-    bool ret = vermicelli16Build(chars, matches_b.val8);
+    m128 matches_b;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches_b);
     ASSERT_TRUE(ret);
 
     chars.set('A');
-    Matches matches_A;
-    ret = vermicelli16Build(chars, matches_A.val8);
+    m128 matches_A;
+    ret = vermicelli16Build(chars, (u8 *)&matches_A);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = rnvermicelli16Exec(matches_b.val128, buf + i, buf + strlen(t1));
+        const u8 *rv = rnvermicelli16Exec(matches_b, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 48, rv);
 
-        rv = rnvermicelli16Exec(matches_A.val128, buf + i, buf + strlen(t1));
+        rv = rnvermicelli16Exec(matches_A, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 47, rv);
     }
 }
@@ -527,21 +522,21 @@ TEST(RNVermicelli16, Exec4) {
 
     CharReach chars;
     chars.set('b');
-    Matches matches_b;
-    bool ret = vermicelli16Build(chars, matches_b.val8);
+    m128 matches_b;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches_b);
     ASSERT_TRUE(ret);
 
     chars.set('A');
-    Matches matches_A;
-    ret = vermicelli16Build(chars, matches_A.val8);
+    m128 matches_A;
+    ret = vermicelli16Build(chars, (u8 *)&matches_A);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 31; i++) {
         t1[16 + i] = 'a';
-        const u8 *rv = rnvermicelli16Exec(matches_b.val128, buf, buf + strlen(t1));
+        const u8 *rv = rnvermicelli16Exec(matches_b, buf, buf + strlen(t1));
         ASSERT_EQ(buf + 16 + i, rv);
 
-        rv = rnvermicelli16Exec(matches_A.val128, buf, buf + strlen(t1));
+        rv = rnvermicelli16Exec(matches_A, buf, buf + strlen(t1));
         ASSERT_EQ(buf + 16 + i, rv);
     }
 }
@@ -551,18 +546,18 @@ TEST(RNVermicelli16, Exec5) {
     const u8 *buf = (const u8 *)t1;
 
     CharReach chars;
-    Matches matches[16];
+    m128 matches[16];
     bool ret;
 
     for (int i = 0; i < 16; ++i) {
         chars.set('q' - i);
-        ret = vermicelli16Build(chars, matches[i].val8);
+        ret = vermicelli16Build(chars, (u8 *)&matches[i]);
         ASSERT_TRUE(ret);
     }
 
     for (int j = 0; j < 16; ++j) {
         for (size_t i = 0; i < 16; i++) {
-            const u8 *rv = rnvermicelli16Exec(matches[j].val128, buf, buf + strlen(t1) - i);
+            const u8 *rv = rnvermicelli16Exec(matches[j], buf, buf + strlen(t1) - i);
             ASSERT_EQ(buf - j + 32, rv);
         }
     }
diff --git a/unit/internal/vermicelli.cpp b/unit/internal/vermicelli.cpp
index bc007e1a..dc458cb9 100644
--- a/unit/internal/vermicelli.cpp
+++ b/unit/internal/vermicelli.cpp
@@ -528,11 +528,6 @@ TEST(DoubleVermicelliMasked, Exec4) {
 #include "nfa/vermicellicompile.h"
 using namespace ue2;
 
-union Matches {
-    u8 val8[16];
-    m128 val128;
-};
-
 TEST(Vermicelli16, ExecNoMatch1) {
     char t1[] = "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb";
     const u8 *buf = (const u8 *)t1;
@@ -541,13 +536,13 @@ TEST(Vermicelli16, ExecNoMatch1) {
     chars.set('a');
     chars.set('B');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
         for (size_t j = 0; j < 16; j++) {
-            const u8 *rv = vermicelli16Exec(matches.val128, buf + i, buf + strlen(t1) - j);
+            const u8 *rv = vermicelli16Exec(matches, buf + i, buf + strlen(t1) - j);
             ASSERT_EQ(buf + strlen(t1) - j, rv);
         }
     }
@@ -560,12 +555,12 @@ TEST(Vermicelli16, Exec1) {
     CharReach chars;
     chars.set('a');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = vermicelli16Exec(matches.val128, buf + i, buf + strlen(t1));
+        const u8 *rv = vermicelli16Exec(matches, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 17, rv);
     }
 }
@@ -577,12 +572,12 @@ TEST(Vermicelli16,  Exec2) {
     CharReach chars;
     chars.set('a');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = vermicelli16Exec(matches.val128, buf + i, buf + strlen(t1));
+        const u8 *rv = vermicelli16Exec(matches, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 17, rv);
     }
 }
@@ -593,20 +588,20 @@ TEST(Vermicelli16,  Exec3) {
 
     CharReach chars;
     chars.set('a');
-    Matches matches_a;
-    bool ret = vermicelli16Build(chars, matches_a.val8);
+    m128 matches_a;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches_a);
     ASSERT_TRUE(ret);
 
     chars.set('A');
-    Matches matches_A;
-    ret = vermicelli16Build(chars, matches_A.val8);
+    m128 matches_A;
+    ret = vermicelli16Build(chars, (u8 *)&matches_A);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = vermicelli16Exec(matches_a.val128, buf + i, buf + strlen(t1));
+        const u8 *rv = vermicelli16Exec(matches_a, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 18, rv);
 
-        rv = vermicelli16Exec(matches_A.val128, buf + i, buf + strlen(t1));
+        rv = vermicelli16Exec(matches_A, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 17, rv);
     }
 }
@@ -617,21 +612,21 @@ TEST(Vermicelli16, Exec4) {
 
     CharReach chars;
     chars.set('a');
-    Matches matches_a;
-    bool ret = vermicelli16Build(chars, matches_a.val8);
+    m128 matches_a;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches_a);
     ASSERT_TRUE(ret);
 
     chars.set('A');
-    Matches matches_A;
-    ret = vermicelli16Build(chars, matches_A.val8);
+    m128 matches_A;
+    ret = vermicelli16Build(chars, (u8 *)&matches_A);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 31; i++) {
         t1[48 - i] = 'a';
-        const u8 *rv = vermicelli16Exec(matches_a.val128, buf, buf + strlen(t1));
+        const u8 *rv = vermicelli16Exec(matches_a, buf, buf + strlen(t1));
         ASSERT_EQ(buf + 48 - i, rv);
 
-        rv = vermicelli16Exec(matches_A.val128, buf, buf + strlen(t1));
+        rv = vermicelli16Exec(matches_A, buf, buf + strlen(t1));
         ASSERT_EQ(buf + 48 - i, rv);
     }
 }
@@ -641,18 +636,18 @@ TEST(Vermicelli16, Exec5) {
     const u8 *buf = (const u8 *)t1;
 
     CharReach chars;
-    Matches matches[16];
+    m128 matches[16];
     bool ret;
 
     for (int i = 0; i < 16; ++i) {
         chars.set('p' - i);
-        ret = vermicelli16Build(chars, matches[i].val8);
+        ret = vermicelli16Build(chars, (u8 *)&matches[i]);
         ASSERT_TRUE(ret);
     }
 
     for (int j = 0; j < 16; ++j) {
         for (size_t i = 0; i < 16; i++) {
-            const u8 *rv = vermicelli16Exec(matches[j].val128, buf + i,buf + strlen(t1));
+            const u8 *rv = vermicelli16Exec(matches[j], buf + i,buf + strlen(t1));
             ASSERT_EQ(buf - j + 32, rv);
         }
     }
@@ -666,13 +661,13 @@ TEST(NVermicelli16, ExecNoMatch1) {
     chars.set('b');
     chars.set('B');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
         for (size_t j = 0; j < 16; j++) {
-            const u8 *rv = nvermicelli16Exec(matches.val128, buf + i, buf + strlen(t1) - j);
+            const u8 *rv = nvermicelli16Exec(matches, buf + i, buf + strlen(t1) - j);
             ASSERT_EQ((buf + strlen(t1) - j), rv);
         }
     }
@@ -685,12 +680,12 @@ TEST(NVermicelli16, Exec1) {
     CharReach chars;
     chars.set('b');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = nvermicelli16Exec(matches.val128, buf + i, buf + strlen(t1));
+        const u8 *rv = nvermicelli16Exec(matches, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 17, rv);
     }
 }
@@ -702,12 +697,12 @@ TEST(NVermicelli16,  Exec2) {
     CharReach chars;
     chars.set('b');
     chars.set('A');
-    Matches matches;
-    bool ret = vermicelli16Build(chars, matches.val8);
+    m128 matches;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = nvermicelli16Exec(matches.val128, buf + i, buf + strlen(t1));
+        const u8 *rv = nvermicelli16Exec(matches, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 17, rv);
     }
 }
@@ -718,20 +713,20 @@ TEST(NVermicelli16,  Exec3) {
 
     CharReach chars;
     chars.set('b');
-    Matches matches_b;
-    bool ret = vermicelli16Build(chars, matches_b.val8);
+    m128 matches_b;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches_b);
     ASSERT_TRUE(ret);
 
     chars.set('A');
-    Matches matches_A;
-    ret = vermicelli16Build(chars, matches_A.val8);
+    m128 matches_A;
+    ret = vermicelli16Build(chars, (u8 *)&matches_A);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 16; i++) {
-        const u8 *rv = nvermicelli16Exec(matches_b.val128, buf + i, buf + strlen(t1));
+        const u8 *rv = nvermicelli16Exec(matches_b, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 17, rv);
 
-        rv = nvermicelli16Exec(matches_A.val128, buf + i, buf + strlen(t1));
+        rv = nvermicelli16Exec(matches_A, buf + i, buf + strlen(t1));
         ASSERT_EQ(buf + 18, rv);
     }
 }
@@ -742,21 +737,21 @@ TEST(NVermicelli16, Exec4) {
 
     CharReach chars;
     chars.set('b');
-    Matches matches_b;
-    bool ret = vermicelli16Build(chars, matches_b.val8);
+    m128 matches_b;
+    bool ret = vermicelli16Build(chars, (u8 *)&matches_b);
     ASSERT_TRUE(ret);
 
     chars.set('A');
-    Matches matches_A;
-    ret = vermicelli16Build(chars, matches_A.val8);
+    m128 matches_A;
+    ret = vermicelli16Build(chars, (u8 *)&matches_A);
     ASSERT_TRUE(ret);
 
     for (size_t i = 0; i < 31; i++) {
         t1[48 - i] = 'a';
-        const u8 *rv = nvermicelli16Exec(matches_b.val128, buf, buf + strlen(t1));
+        const u8 *rv = nvermicelli16Exec(matches_b, buf, buf + strlen(t1));
         ASSERT_EQ(buf + 48 - i, rv);
 
-        rv = nvermicelli16Exec(matches_A.val128, buf, buf + strlen(t1));
+        rv = nvermicelli16Exec(matches_A, buf, buf + strlen(t1));
         ASSERT_EQ(buf + 48 - i, rv);
     }
 }
@@ -766,21 +761,393 @@ TEST(NVermicelli16, Exec5) {
     const u8 *buf = (const u8 *)t1;
 
     CharReach chars;
-    Matches matches[16];
+    m128 matches[16];
     bool ret;
 
     for (int i = 0; i < 16; ++i) {
         chars.set('a' + i);
-        ret = vermicelli16Build(chars, matches[i].val8);
+        ret = vermicelli16Build(chars, (u8 *)&matches[i]);
         ASSERT_TRUE(ret);
     }
 
     for (int j = 0; j < 16; ++j) {
         for (size_t i = 0; i < 16; i++) {
-            const u8 *rv = nvermicelli16Exec(matches[j].val128, buf + i, buf + strlen(t1));
+            const u8 *rv = nvermicelli16Exec(matches[j], buf + i, buf + strlen(t1));
             ASSERT_EQ(buf + j + 18, rv);
         }
     }
 }
 
+TEST(DoubleVermicelli16, ExecNoMatch1) {
+    std::string t1("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches;
+    u64a firsts;
+    flat_set<std::pair<u8, u8>> pairs;
+    for (int i = 0; i < 16; i += 2) {
+      pairs.insert(std::make_pair('a' + i, 'a' + i + 1));
+    }
+    bool ret = vermicelliDouble16Build(pairs, (u8 *)&matches, (u8 *)&firsts);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        for (size_t j = 0; j < 16; j++) {
+            const u8 *rv = vermicelliDouble16Exec(matches, firsts,
+                                      t1_raw + i, t1_raw + t1.length() - i - j);
+            ASSERT_EQ(t1_raw + t1.length() - i - j, rv);
+        }
+    }
+}
+
+TEST(DoubleVermicelli16, ExecNoMatch2) {
+    std::string t1("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches;
+    u64a firsts;
+    flat_set<std::pair<u8, u8>> pairs;
+    pairs.insert(std::make_pair('a', 'b'));
+    pairs.insert(std::make_pair('A', 'B'));
+    pairs.insert(std::make_pair('B', 'A'));
+    pairs.insert(std::make_pair('B', 'B'));
+    bool ret = vermicelliDouble16Build(pairs, (u8 *)&matches, (u8 *)&firsts);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        for (size_t j = 0; j < 16; j++) {
+            const u8 *rv = vermicelliDouble16Exec(matches, firsts,
+                                      t1_raw + i, t1_raw + t1.length() - i - j);
+            ASSERT_EQ(t1_raw + t1.length() - i - j, rv);
+        }
+    }
+}
+
+TEST(DoubleVermicelli16, ExecNoMatch3) {
+    std::string t1("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches;
+    u64a firsts;
+    flat_set<std::pair<u8, u8>> pairs;
+    pairs.insert(std::make_pair('a', 'b'));
+    pairs.insert(std::make_pair('B', 'B'));
+    pairs.insert(std::make_pair('A', 'B'));
+    pairs.insert(std::make_pair('b', 'a'));
+    bool ret = vermicelliDouble16Build(pairs, (u8 *)&matches, (u8 *)&firsts);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        for (size_t j = 0; j < 16; j++) {
+            /* partial match */
+            const u8 *rv = vermicelliDouble16Exec(matches, firsts,
+                                      t1_raw + i, t1_raw + t1.length() - i - j);
+            ASSERT_EQ(t1_raw + t1.length() - i - j - 1, rv);
+        }
+    }
+}
+
+TEST(DoubleVermicelli16, Exec1) {
+    std::string t1("bbbbbbbbbbbbbbbbbbabbbbbbbbbbbbbbbbbbbbbbbbbbbbbbabbbbbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches;
+    u64a firsts;
+    flat_set<std::pair<u8, u8>> pairs;
+    pairs.insert(std::make_pair('a', 'b'));
+    bool ret = vermicelliDouble16Build(pairs, (u8 *)&matches, (u8 *)&firsts);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        const u8 *rv = vermicelliDouble16Exec(matches, firsts,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 18, rv);
+    }
+
+    pairs.insert(std::make_pair('b', 'a'));
+    ret = vermicelliDouble16Build(pairs, (u8 *)&matches, (u8 *)&firsts);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        const u8 *rv = vermicelliDouble16Exec(matches, firsts,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+    }
+}
+
+TEST(DoubleVermicelli16,  Exec2) {
+    std::string t1("bbbbbbbbbbbbbbbbbaaaaaaaaaaaaaaaaaaaaaaaabbbbbbbaaaaabbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches;
+    u64a firsts;
+    flat_set<std::pair<u8, u8>> pairs;
+    pairs.insert(std::make_pair('a', 'a'));
+    bool ret = vermicelliDouble16Build(pairs, (u8 *)&matches, (u8 *)&firsts);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        const u8 *rv = vermicelliDouble16Exec(matches, firsts,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+    }
+}
+
+TEST(DoubleVermicelliMasked16, ExecNoMatch1) {
+    std::string t1("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches1;
+    bool ret = vermicelliDoubleMasked16Build('a', 'b', 0xff, 0xff, (u8 *)&matches1);
+    ASSERT_TRUE(ret);
+    m128 matches2;
+    ret = vermicelliDoubleMasked16Build('B', 'B', 0xff, CASE_CLEAR, (u8 *)&matches2);
+    ASSERT_TRUE(ret);
+    m128 matches3;
+    ret = vermicelliDoubleMasked16Build('A', 'B', CASE_CLEAR, CASE_CLEAR, (u8 *)&matches3);
+    ASSERT_TRUE(ret);
+    m128 matches4;
+    ret = vermicelliDoubleMasked16Build('B', 'B', CASE_CLEAR, 0xff, (u8 *)&matches4);
+    ASSERT_TRUE(ret);
+    m128 matches5;
+    ret = vermicelliDoubleMasked16Build('B', 'A', 0xff, 0xff, (u8 *)&matches5);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        for (size_t j = 0; j < 16; j++) {
+            const u8 *rv = vermicelliDoubleMasked16Exec(matches1, 'a', 0xff,
+                                      t1_raw + i, t1_raw + t1.length() - i - j);
+            ASSERT_EQ(t1_raw + t1.length() - i - j, rv);
+
+            rv = vermicelliDoubleMasked16Exec(matches2, 'B', 0xff, t1_raw + i,
+                                              t1_raw + t1.length() - i - j);
+            ASSERT_EQ(t1_raw + t1.length() - i - j, rv);
+
+            rv = vermicelliDoubleMasked16Exec(matches3, 'A', CASE_CLEAR,
+                                      t1_raw + i, t1_raw + t1.length() - i - j);
+            ASSERT_EQ(t1_raw + t1.length() - i - j, rv);
+
+            /* partial match */
+            rv = vermicelliDoubleMasked16Exec(matches4, 'B', CASE_CLEAR,
+                                      t1_raw + i, t1_raw + t1.length() - i - j);
+            ASSERT_EQ(t1_raw + t1.length() - i - j - 1, rv);
+
+            rv = vermicelliDoubleMasked16Exec(matches5, 'B', 0xff, t1_raw + i,
+                                              t1_raw + t1.length() - i - j);
+            ASSERT_EQ(t1_raw + t1.length() - i - j, rv);
+        }
+    }
+}
+
+TEST(DoubleVermicelliMasked16, Exec1) {
+    std::string t1("bbbbbbbbbbbbbbbbbbabbbbbbbbbbbbbbbbbbbbbbbbbbbbbbabbbbbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches1;
+    bool ret = vermicelliDoubleMasked16Build('a', 'b', 0xff, 0xff, (u8 *)&matches1);
+    ASSERT_TRUE(ret);
+    m128 matches2;
+    ret = vermicelliDoubleMasked16Build('A', 'B', CASE_CLEAR, CASE_CLEAR, (u8 *)&matches2);
+    ASSERT_TRUE(ret);
+    m128 matches3;
+    ret = vermicelliDoubleMasked16Build('a', 'B', 0xff, CASE_CLEAR, (u8 *)&matches3);
+    ASSERT_TRUE(ret);
+    m128 matches4;
+    ret = vermicelliDoubleMasked16Build('A', 'b', CASE_CLEAR, 0xff, (u8 *)&matches4);
+    ASSERT_TRUE(ret);
+    m128 matches5;
+    ret = vermicelliDoubleMasked16Build('b', 'a', 0xff, 0xff, (u8 *)&matches5);
+    ASSERT_TRUE(ret);
+    m128 matches6;
+    ret = vermicelliDoubleMasked16Build('B', 'A', CASE_CLEAR, CASE_CLEAR, (u8 *)&matches6);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        const u8 *rv = vermicelliDoubleMasked16Exec(matches1, 'a', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 18, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches2, 'A', CASE_CLEAR,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 18, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches3, 'a', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 18, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches4, 'A', CASE_CLEAR,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 18, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches5, 'b', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches6, 'B', CASE_CLEAR,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+    }
+}
+
+TEST(DoubleVermicelliMasked16,  Exec2) {
+    std::string t1("bbbbbbbbbbbbbbbbbaaaaaaaaaaaaaaaaaaaaaaaabbbbbbbaaaaabbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches1;
+    bool ret = vermicelliDoubleMasked16Build('a', 'a', 0xff, 0xff, (u8 *)&matches1);
+    ASSERT_TRUE(ret);
+    m128 matches2;
+    ret = vermicelliDoubleMasked16Build('A', 'A', CASE_CLEAR, CASE_CLEAR, (u8 *)&matches2);
+    ASSERT_TRUE(ret);
+    m128 matches3;
+    ret = vermicelliDoubleMasked16Build('a', 'A', 0xff, CASE_CLEAR, (u8 *)&matches3);
+    ASSERT_TRUE(ret);
+    m128 matches4;
+    ret = vermicelliDoubleMasked16Build('A', 'a', CASE_CLEAR, 0xff, (u8 *)&matches4);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        const u8 *rv = vermicelliDoubleMasked16Exec(matches1, 'a', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches2, 'A', CASE_CLEAR,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches3, 'a', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches4, 'A', CASE_CLEAR,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+    }
+}
+
+TEST(DoubleVermicelliMasked16,  Exec3) {
+    /*              012345678901234567890123 */
+    std::string t1("bbbbbbbbbbbbbbbbbaAaaAAaaaaaaaaaaaaaaaaaabbbbbbbaaaaabbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches1;
+    bool ret = vermicelliDoubleMasked16Build('A', 'a', 0xff, 0xff, (u8 *)&matches1);
+    ASSERT_TRUE(ret);
+    m128 matches2;
+    ret = vermicelliDoubleMasked16Build('A', 'A', CASE_CLEAR, CASE_CLEAR, (u8 *)&matches2);
+    ASSERT_TRUE(ret);
+    m128 matches3;
+    ret = vermicelliDoubleMasked16Build('A', 'A', 0xff, 0xff, (u8 *)&matches3);
+    ASSERT_TRUE(ret);
+    m128 matches4;
+    ret = vermicelliDoubleMasked16Build('a', 'A', 0xff, 0xff, (u8 *)&matches4);
+    ASSERT_TRUE(ret);
+    m128 matches5;
+    ret = vermicelliDoubleMasked16Build('a', 'A', 0xff, CASE_CLEAR, (u8 *)&matches5);
+    ASSERT_TRUE(ret);
+    m128 matches6;
+    ret = vermicelliDoubleMasked16Build('A', 'a', CASE_CLEAR, 0xff, (u8 *)&matches6);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        const u8 *rv = vermicelliDoubleMasked16Exec(matches1, 'A', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 18, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches2, 'A', CASE_CLEAR,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches3, 'A', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 21, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches4, 'a', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches5, 'a', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches6, 'A', CASE_CLEAR,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 18, rv);
+    }
+}
+
+TEST(DoubleVermicelliMasked16, Exec4) {
+    std::string t1("bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches1;
+    bool ret = vermicelliDoubleMasked16Build('a', 'a', 0xff, 0xff, (u8 *)&matches1);
+    ASSERT_TRUE(ret);
+    m128 matches2;
+    ret = vermicelliDoubleMasked16Build('A', 'A', CASE_CLEAR, CASE_CLEAR, (u8 *)&matches2);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 31; i++) {
+        t1[48 - i] = 'a';
+        t1[48 - i + 1] = 'a';
+        const u8 *rv = vermicelliDoubleMasked16Exec(matches1, 'a', 0xff, t1_raw,
+                                                    t1_raw + t1.length());
+        ASSERT_EQ(t1_raw + 48 - i, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches2, 'A', CASE_CLEAR, t1_raw,
+                                          t1_raw + t1.length());
+        ASSERT_EQ(t1_raw + 48 - i, rv);
+    }
+}
+
+TEST(DoubleVermicelliMasked16,  Exec5) {
+    std::string t1("bbbbbbbbbbbbbbbbbaCaGaOCaChBfcNgBFGiLbbbbbbbbbbbbbbbbbbbbbbbb");
+    const u8 *t1_raw = (const u8 *)t1.c_str();
+
+    m128 matches1;
+    bool ret = vermicelliDoubleMasked16Build('a', 'B', 0xff, 0xde, (u8 *)&matches1);
+    ASSERT_TRUE(ret);
+    m128 matches2;
+    ret = vermicelliDoubleMasked16Build('a', 'D', 0xff, 0xdc, (u8 *)&matches2);
+    ASSERT_TRUE(ret);
+    m128 matches3;
+    ret = vermicelliDoubleMasked16Build('D', 'a', 0xdc, 0xff, (u8 *)&matches3);
+    ASSERT_TRUE(ret);
+    m128 matches4;
+    ret = vermicelliDoubleMasked16Build('A', 'B', 0xdf, 0xde, (u8 *)&matches4);
+    ASSERT_TRUE(ret);
+    m128 matches5;
+    ret = vermicelliDoubleMasked16Build('B', 'a', 0xde, 0xff, (u8 *)&matches5);
+    ASSERT_TRUE(ret);
+    m128 matches6;
+    ret = vermicelliDoubleMasked16Build('B', 'A', 0xde, 0xdf, (u8 *)&matches6);
+    ASSERT_TRUE(ret);
+
+    for (size_t i = 0; i < 16; i++) {
+        const u8 *rv = vermicelliDoubleMasked16Exec(matches1, 'a', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches2, 'a', 0xff,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 19, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches3, 'D', 0xdc,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 20, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches4, 'A', 0xdf,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 17, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches5, 'B', 0xde,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 16, rv);
+
+        rv = vermicelliDoubleMasked16Exec(matches6, 'B', 0xde,
+                                          t1_raw + i, t1_raw + t1.length() - i);
+        ASSERT_EQ(t1_raw + 16, rv);
+    }
+}
+
 #endif // HAVE_SVE2
\ No newline at end of file