daala_tx: Add CONFIG_DAALA_TX_DST8 build flag.

Change-Id: Ie39b11d0cfda205df95650cdced616db148be80a
diff --git a/av1/common/daala_tx.c b/av1/common/daala_tx.c
index ab5f9ec..d9de9fc 100644
--- a/av1/common/daala_tx.c
+++ b/av1/common/daala_tx.c
@@ -5854,7 +5854,7 @@
   x[7*xstride] = (od_coeff)r7;
 }
 
-#if 1
+#if !CONFIG_DAALA_TX_DST8
 void od_bin_fdst8(od_coeff y[8], const od_coeff *x, int xstride) {
   int r0;
   int r1;
diff --git a/av1/common/x86/daala_inv_txfm_avx2.c b/av1/common/x86/daala_inv_txfm_avx2.c
index bdedfa5..73f8029 100644
--- a/av1/common/x86/daala_inv_txfm_avx2.c
+++ b/av1/common/x86/daala_inv_txfm_avx2.c
@@ -1443,7 +1443,12 @@
   { od_row_idct4_avx2, od_row_idst4_avx2, od_row_flip_idst4_avx2,
     od_row_iidtx4_avx2 },
   // 8-point transforms
-  { od_row_idct8_avx2, od_row_idst8_avx2, od_row_flip_idst8_avx2,
+  { od_row_idct8_avx2,
+#if CONFIG_DAALA_TX_DST8
+    NULL, NULL,
+#else
+    od_row_idst8_avx2, od_row_flip_idst8_avx2,
+#endif
     od_row_iidtx8_avx2 },
   // 16-point transforms
   { od_row_idct16_avx2, od_row_idst16_avx2, od_row_flip_idst16_avx2,
@@ -1478,8 +1483,13 @@
       { od_col_idct4_add_hbd_avx2, od_col_idst4_add_hbd_avx2,
         od_col_flip_idst4_add_hbd_avx2, od_col_iidtx4_add_hbd_avx2 },
       // 8-point transforms
-      { od_col_idct8_add_hbd_avx2, od_col_idst8_add_hbd_avx2,
-        od_col_flip_idst8_add_hbd_avx2, od_col_iidtx8_add_hbd_avx2 },
+      { od_col_idct8_add_hbd_avx2,
+#if CONFIG_DAALA_TX_DST8
+        NULL, NULL,
+#else
+        od_col_idst8_add_hbd_avx2, od_col_flip_idst8_add_hbd_avx2,
+#endif
+        od_col_iidtx8_add_hbd_avx2 },
       // 16-point transforms
       { od_col_idct16_add_hbd_avx2, od_col_idst16_add_hbd_avx2,
         od_col_flip_idst16_add_hbd_avx2, od_col_iidtx16_add_hbd_avx2 },
diff --git a/build/cmake/aom_config_defaults.cmake b/build/cmake/aom_config_defaults.cmake
index a37f86f..de35525 100644
--- a/build/cmake/aom_config_defaults.cmake
+++ b/build/cmake/aom_config_defaults.cmake
@@ -120,6 +120,7 @@
 set(CONFIG_DAALA_TX4 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_DAALA_TX64 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_DAALA_TX8 0 CACHE NUMBER "AV1 experiment flag.")
+set(CONFIG_DAALA_TX_DST8 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_DCT_ONLY 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_DEBLOCK_13TAP 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_DEPENDENT_HORZTILES 0 CACHE NUMBER "AV1 experiment flag.")
diff --git a/build/cmake/aom_experiment_deps.cmake b/build/cmake/aom_experiment_deps.cmake
index 0555c63..f2707c2 100644
--- a/build/cmake/aom_experiment_deps.cmake
+++ b/build/cmake/aom_experiment_deps.cmake
@@ -53,6 +53,13 @@
      set(CONFIG_DAALA_TX64 1)
   endif ()
 
+  if (CONFIG_DAALA_TX_DST8)
+    if (NOT CONFIG_DAALA_TX8)
+      set(CONFIG_DAALA_TX_DST8 0)
+      message("--- DAALA_TX_DST8 requires DAALA_TX8: disabled DAALA_TX_DST8")
+    endif ()
+  endif ()
+
   if (CONFIG_DAALA_TX64)
     if (NOT CONFIG_TX64X64)
       set(CONFIG_DAALA_TX64 0)
diff --git a/configure b/configure
index bcac33f..31dab6f 100755
--- a/configure
+++ b/configure
@@ -279,6 +279,7 @@
     daala_tx16
     daala_tx32
     daala_tx64
+    daala_tx_dst8
     frame_size
     ext_delta_q
     adapt_scan
@@ -564,6 +565,10 @@
       log_echo "daala_tx64 requires tx64x64, so disabling daala_tx64"
       disable_feature daala_tx64
     fi
+    if enabled daala_tx_dst8 && ! enabled daala_tx8; then
+      log_echo "daala_tx_dst8 requires daala_tx8, so disabling daala_tx_dst8"
+      disable_feature daala_tx_dst8
+    fi
     if enabled daala_tx4 || enabled daala_tx8 || enabled daala_tx16 ||
         enabled daala_tx32 || enabled daala_tx64; then
       disable_feature txmg