checkasm: add proper restrictions for h/w_pad in ipred.cfl_ac[444/422]

h_pad and w_pad can only be even if ss_ver=0 or ss_hor=0, respectively.
This means certain special cases don't need to be implemented in SIMD
while still guaranteeing correct decoding, and thus we don't want to
test for these special cases in the checkasm test either.

1 files changed, 10 insertions, 3 deletions

diff --git a/tests/checkasm/ipred.c b/tests/checkasm/ipred.c
index d5955d2..65edcdc 100644
--- a/tests/checkasm/ipred.c
+++ b/tests/checkasm/ipred.c
@@ -142,14 +142,21 @@ static void check_cfl_ac(Dav1dIntraPredDSPContext *const c) {
     for (int layout = 1; layout <= DAV1D_PIXEL_LAYOUT_I444; layout++) {
         const int ss_ver = layout == DAV1D_PIXEL_LAYOUT_I420;
         const int ss_hor = layout != DAV1D_PIXEL_LAYOUT_I444;
+        const int h_step = 2 >> ss_hor, v_step = 2 >> ss_ver;
         for (int w = 4; w <= (32 >> ss_hor); w <<= 1)
             if (check_func(c->cfl_ac[layout - 1], "cfl_ac_%s_w%d_%dbpc",
                 cfl_ac_names[layout - 1], w, BITDEPTH))
             {
-                for (int h = imax(w / 4, 4); h <= imin(w * 4, (32 >> ss_ver)); h <<= 1) {
+                for (int h = imax(w / 4, 4);
+                     h <= imin(w * 4, (32 >> ss_ver)); h <<= 1)
+                {
                     const ptrdiff_t stride = 32 * sizeof(pixel);
-                    for (int w_pad = (w >> 2) - 1; w_pad >= 0; w_pad--) {
-                        for (int h_pad = (h >> 2) - 1; h_pad >= 0; h_pad--) {
+                    for (int w_pad = imax((w >> 2) - h_step, 0);
+                         w_pad >= 0; w_pad -= h_step)
+                    {
+                        for (int h_pad = imax((h >> 2) - v_step, 0);
+                             h_pad >= 0; h_pad -= v_step)
+                        {
 #if BITDEPTH == 16
                             const int bitdepth_max = rnd() & 1 ? 0x3ff : 0xfff;
 #else