Remove unit tests for no-op filter in convolutions

Unit tests loop across the whole list of filters for each filter type,
which includes the no-op filter when sub_x or sub_y = 0. In practice,
however, the convolution functions are never called for such filters
(convolve_copy will be used instead), so remove these test cases. The
code accommodating this special no-op filter in the Neon paths will be
removed in a subsequent patch.

Change-Id: Ib363f15b35b1bdec796e4e8f490b9fae45328f54

test/av1_convolve_test.cc

diff --git a/test/av1_convolve_test.cc b/test/av1_convolve_test.cc
index 26a4b5e..382a2fe 100644
--- a/test/av1_convolve_test.cc
+++ b/test/av1_convolve_test.cc
@@ -325,7 +325,8 @@
 class AV1ConvolveXTest : public AV1ConvolveTest<convolve_x_func> {
  public:
   void RunTest() {
-    for (int sub_x = 0; sub_x < 16; ++sub_x) {
+    // Do not test the no-op filter.
+    for (int sub_x = 1; sub_x < 16; ++sub_x) {
       for (int filter = EIGHTTAP_REGULAR; filter <= INTERP_FILTERS_ALL;
            ++filter) {
         InterpFilter f = static_cast<InterpFilter>(filter);
@@ -530,7 +531,8 @@
 class AV1ConvolveXHighbdTest : public AV1ConvolveTest<highbd_convolve_x_func> {
  public:
   void RunTest() {
-    for (int sub_x = 0; sub_x < 16; ++sub_x) {
+    // Do not test the no-op filter.
+    for (int sub_x = 1; sub_x < 16; ++sub_x) {
       for (int filter = EIGHTTAP_REGULAR; filter <= INTERP_FILTERS_ALL;
            ++filter) {
         InterpFilter f = static_cast<InterpFilter>(filter);
@@ -737,7 +739,8 @@
 class AV1ConvolveYTest : public AV1ConvolveTest<convolve_y_func> {
  public:
   void RunTest() {
-    for (int sub_y = 0; sub_y < 16; ++sub_y) {
+    // Do not test the no-op filter.
+    for (int sub_y = 1; sub_y < 16; ++sub_y) {
       for (int filter = EIGHTTAP_REGULAR; filter <= INTERP_FILTERS_ALL;
            ++filter) {
         InterpFilter f = static_cast<InterpFilter>(filter);
@@ -923,7 +926,8 @@
 class AV1ConvolveYHighbdTest : public AV1ConvolveTest<highbd_convolve_y_func> {
  public:
   void RunTest() {
-    for (int sub_y = 0; sub_y < 16; ++sub_y) {
+    // Do not test the no-op filter.
+    for (int sub_y = 1; sub_y < 16; ++sub_y) {
       for (int filter = EIGHTTAP_REGULAR; filter <= INTERP_FILTERS_ALL;
            ++filter) {
         InterpFilter f = static_cast<InterpFilter>(filter);
@@ -1203,8 +1207,9 @@
 class AV1Convolve2DTest : public AV1ConvolveTest<convolve_2d_func> {
  public:
   void RunTest() {
-    for (int sub_x = 0; sub_x < 16; ++sub_x) {
-      for (int sub_y = 0; sub_y < 16; ++sub_y) {
+    // Do not test the no-op filter.
+    for (int sub_x = 1; sub_x < 16; ++sub_x) {
+      for (int sub_y = 1; sub_y < 16; ++sub_y) {
         for (int h_f = EIGHTTAP_REGULAR; h_f <= INTERP_FILTERS_ALL; ++h_f) {
           for (int v_f = EIGHTTAP_REGULAR; v_f <= INTERP_FILTERS_ALL; ++v_f) {
             if (((h_f == MULTITAP_SHARP2) && (v_f < MULTITAP_SHARP2)) ||
@@ -1429,8 +1434,9 @@
     : public AV1ConvolveTest<highbd_convolve_2d_func> {
  public:
   void RunTest() {
-    for (int sub_x = 0; sub_x < 16; ++sub_x) {
-      for (int sub_y = 0; sub_y < 16; ++sub_y) {
+    // Do not test the no-op filter.
+    for (int sub_x = 1; sub_x < 16; ++sub_x) {
+      for (int sub_y = 1; sub_y < 16; ++sub_y) {
         for (int h_f = EIGHTTAP_REGULAR; h_f <= INTERP_FILTERS_ALL; ++h_f) {
           for (int v_f = EIGHTTAP_REGULAR; v_f <= INTERP_FILTERS_ALL; ++v_f) {
             if (((h_f == MULTITAP_SHARP2) && (v_f < MULTITAP_SHARP2)) ||
@@ -1781,7 +1787,8 @@
  public:
   void RunTest() {
     auto compound_params = GetCompoundParams();
-    for (int sub_pix = 0; sub_pix < 16; ++sub_pix) {
+    // Do not test the no-op filter.
+    for (int sub_pix = 1; sub_pix < 16; ++sub_pix) {
       for (int f = EIGHTTAP_REGULAR; f < INTERP_FILTERS_ALL; ++f) {
         for (const auto &c : compound_params) {
           TestConvolve(sub_pix, static_cast<InterpFilter>(f), c);
@@ -1883,7 +1890,8 @@
  public:
   void RunTest() {
     auto compound_params = GetCompoundParams();
-    for (int sub_pix = 0; sub_pix < 16; ++sub_pix) {
+    // Do not test the no-op filter.
+    for (int sub_pix = 1; sub_pix < 16; ++sub_pix) {
       for (int f = EIGHTTAP_REGULAR; f < INTERP_FILTERS_ALL; ++f) {
         for (const auto &c : compound_params) {
           TestConvolve(sub_pix, static_cast<InterpFilter>(f), c);
@@ -2282,8 +2290,9 @@
     auto compound_params = GetCompoundParams();
     for (int h_f = EIGHTTAP_REGULAR; h_f < INTERP_FILTERS_ALL; ++h_f) {
       for (int v_f = EIGHTTAP_REGULAR; v_f < INTERP_FILTERS_ALL; ++v_f) {
-        for (int sub_x = 0; sub_x < 16; ++sub_x) {
-          for (int sub_y = 0; sub_y < 16; ++sub_y) {
+        // Do not test the no-op filter.
+        for (int sub_x = 1; sub_x < 16; ++sub_x) {
+          for (int sub_y = 1; sub_y < 16; ++sub_y) {
             for (const auto &compound : compound_params) {
               TestConvolve(static_cast<InterpFilter>(h_f),
                            static_cast<InterpFilter>(v_f), sub_x, sub_y,
@@ -2388,8 +2397,9 @@
     auto compound_params = GetCompoundParams();
     for (int h_f = EIGHTTAP_REGULAR; h_f < INTERP_FILTERS_ALL; ++h_f) {
       for (int v_f = EIGHTTAP_REGULAR; v_f < INTERP_FILTERS_ALL; ++v_f) {
-        for (int sub_x = 0; sub_x < 16; ++sub_x) {
-          for (int sub_y = 0; sub_y < 16; ++sub_y) {
+        // Do not test the no-op filter.
+        for (int sub_x = 1; sub_x < 16; ++sub_x) {
+          for (int sub_y = 1; sub_y < 16; ++sub_y) {
             for (const auto &compound : compound_params) {
               TestConvolve(static_cast<InterpFilter>(h_f),
                            static_cast<InterpFilter>(v_f), sub_x, sub_y,