Cleaning up loopfilter code.

Lower case variable names, removing redundant variables, declaration and
initialization on the same line.

Change-Id: Ie0c6c95b14103990eb6a9d7784f8259c662e1251

1 files changed, 117 insertions, 180 deletions

diff --git a/vp9/common/vp9_loopfilter_filters.c b/vp9/common/vp9_loopfilter_filters.c
index 6f434dafe..a473cf742 100644
--- a/vp9/common/vp9_loopfilter_filters.c
+++ b/vp9/common/vp9_loopfilter_filters.c
@@ -49,47 +49,36 @@ static INLINE int8_t hevmask(uint8_t thresh, uint8_t p1, uint8_t p0,
 
 static INLINE void filter(int8_t mask, uint8_t hev, uint8_t *op1,
                           uint8_t *op0, uint8_t *oq0, uint8_t *oq1) {
-  int8_t ps0, qs0;
-  int8_t ps1, qs1;
-  int8_t filter, Filter1, Filter2;
-  int8_t u;
-
-  ps1 = (int8_t) *op1 ^ 0x80;
-  ps0 = (int8_t) *op0 ^ 0x80;
-  qs0 = (int8_t) *oq0 ^ 0x80;
-  qs1 = (int8_t) *oq1 ^ 0x80;
-
-  /* add outer taps if we have high edge variance */
-  filter = signed_char_clamp(ps1 - qs1);
-  filter &= hev;
-
-  /* inner taps */
-  filter = signed_char_clamp(filter + 3 * (qs0 - ps0));
-  filter &= mask;
+  int8_t filter1, filter2;
 
-  /* save bottom 3 bits so that we round one side +4 and the other +3
-   * if it equals 4 we'll set to adjust by -1 to account for the fact
-   * we'd round 3 the other way
-   */
-  Filter1 = signed_char_clamp(filter + 4);
-  Filter2 = signed_char_clamp(filter + 3);
-  Filter1 >>= 3;
-  Filter2 >>= 3;
-  u = signed_char_clamp(qs0 - Filter1);
-  *oq0 = u ^ 0x80;
-  u = signed_char_clamp(ps0 + Filter2);
-  *op0 = u ^ 0x80;
-  filter = Filter1;
-
-  /* outer tap adjustments */
+  const int8_t ps1 = (int8_t) *op1 ^ 0x80;
+  const int8_t ps0 = (int8_t) *op0 ^ 0x80;
+  const int8_t qs0 = (int8_t) *oq0 ^ 0x80;
+  const int8_t qs1 = (int8_t) *oq1 ^ 0x80;
+
+  // add outer taps if we have high edge variance
+  int8_t filter = signed_char_clamp(ps1 - qs1) & hev;
+
+  // inner taps
+  filter = signed_char_clamp(filter + 3 * (qs0 - ps0)) & mask;
+
+  // save bottom 3 bits so that we round one side +4 and the other +3
+  // if it equals 4 we'll set to adjust by -1 to account for the fact
+  // we'd round 3 the other way
+  filter1 = signed_char_clamp(filter + 4) >> 3;
+  filter2 = signed_char_clamp(filter + 3) >> 3;
+
+  *oq0 = signed_char_clamp(qs0 - filter1) ^ 0x80;
+  *op0 = signed_char_clamp(ps0 + filter2) ^ 0x80;
+  filter = filter1;
+
+  // outer tap adjustments
   filter += 1;
   filter >>= 1;
   filter &= ~hev;
 
-  u = signed_char_clamp(qs1 - filter);
-  *oq1 = u ^ 0x80;
-  u = signed_char_clamp(ps1 + filter);
-  *op1 = u ^ 0x80;
+  *oq1 = signed_char_clamp(qs1 - filter) ^ 0x80;
+  *op1 = signed_char_clamp(ps1 + filter) ^ 0x80;
 }
 
 void vp9_loop_filter_horizontal_edge_c(uint8_t *s,
@@ -176,21 +165,16 @@ static INLINE void mbfilter(int8_t mask, uint8_t hev, uint8_t flat,
                             uint8_t *op1, uint8_t *op0,
                             uint8_t *oq0, uint8_t *oq1,
                             uint8_t *oq2, uint8_t *oq3) {
-  /* use a 7 tap filter [1, 1, 1, 2, 1, 1, 1] for flat line */
+  // use a 7 tap filter [1, 1, 1, 2, 1, 1, 1] for flat line
   if (flat && mask) {
-    uint8_t p0, q0;
-    uint8_t p1, q1;
-    uint8_t p2, q2;
-    uint8_t p3, q3;
-
-    p3 = *op3;
-    p2 = *op2;
-    p1 = *op1;
-    p0 = *op0;
-    q0 = *oq0;
-    q1 = *oq1;
-    q2 = *oq2;
-    q3 = *oq3;
+    const uint8_t p3 = *op3;
+    const uint8_t p2 = *op2;
+    const uint8_t p1 = *op1;
+    const uint8_t p0 = *op0;
+    const uint8_t q0 = *oq0;
+    const uint8_t q1 = *oq1;
+    const uint8_t q2 = *oq2;
+    const uint8_t q3 = *oq3;
 
     *op2 = (p3 + p3 + p3 + p2 + p2 + p1 + p0 + q0 + 4) >> 3;
     *op1 = (p3 + p3 + p2 + p1 + p1 + p0 + q0 + q1 + 4) >> 3;
@@ -199,44 +183,33 @@ static INLINE void mbfilter(int8_t mask, uint8_t hev, uint8_t flat,
     *oq1 = (p1 + p0 + q0 + q1 + q1 + q2 + q3 + q3 + 4) >> 3;
     *oq2 = (p0 + q0 + q1 + q2 + q2 + q3 + q3 + q3 + 4) >> 3;
   } else {
-    int8_t ps0, qs0;
-    int8_t ps1, qs1;
-    int8_t filter, Filter1, Filter2;
-    int8_t u;
-
-    ps1 = (int8_t) *op1 ^ 0x80;
-    ps0 = (int8_t) *op0 ^ 0x80;
-    qs0 = (int8_t) *oq0 ^ 0x80;
-    qs1 = (int8_t) *oq1 ^ 0x80;
-
-    /* add outer taps if we have high edge variance */
-    filter = signed_char_clamp(ps1 - qs1);
-    filter &= hev;
-
-    /* inner taps */
-    filter = signed_char_clamp(filter + 3 * (qs0 - ps0));
-    filter &= mask;
-
-    Filter1 = signed_char_clamp(filter + 4);
-    Filter2 = signed_char_clamp(filter + 3);
-    Filter1 >>= 3;
-    Filter2 >>= 3;
-
-    u = signed_char_clamp(qs0 - Filter1);
-    *oq0 = u ^ 0x80;
-    u = signed_char_clamp(ps0 + Filter2);
-    *op0 = u ^ 0x80;
-    filter = Filter1;
-
-    /* outer tap adjustments */
+    int8_t filter1, filter2;
+
+    const int8_t ps1 = (int8_t) *op1 ^ 0x80;
+    const int8_t ps0 = (int8_t) *op0 ^ 0x80;
+    const int8_t qs0 = (int8_t) *oq0 ^ 0x80;
+    const int8_t qs1 = (int8_t) *oq1 ^ 0x80;
+
+    // add outer taps if we have high edge variance
+    int8_t filter = signed_char_clamp(ps1 - qs1) & hev;
+
+    // inner taps
+    filter = signed_char_clamp(filter + 3 * (qs0 - ps0)) & mask;
+
+    filter1 = signed_char_clamp(filter + 4) >> 3;
+    filter2 = signed_char_clamp(filter + 3) >> 3;
+
+    *oq0 = signed_char_clamp(qs0 - filter1) ^ 0x80;
+    *op0 = signed_char_clamp(ps0 + filter2) ^ 0x80;
+    filter = filter1;
+
+    // outer tap adjustments
     filter += 1;
     filter >>= 1;
     filter &= ~hev;
 
-    u = signed_char_clamp(qs1 - filter);
-    *oq1 = u ^ 0x80;
-    u = signed_char_clamp(ps1 + filter);
-    *op1 = u ^ 0x80;
+    *oq1 = signed_char_clamp(qs1 - filter) ^ 0x80;
+    *op1 = signed_char_clamp(ps1 + filter) ^ 0x80;
   }
 }
 
@@ -304,38 +277,28 @@ void vp9_mbloop_filter_vertical_edge_c(uint8_t *s,
 static INLINE int8_t simple_filter_mask(uint8_t blimit,
                                         uint8_t p1, uint8_t p0,
                                         uint8_t q0, uint8_t q1) {
-  /* Why does this cause problems for win32?
-   * error C2143: syntax error : missing ';' before 'type'
-   *  (void) limit;
-   */
-  int8_t mask = (abs(p0 - q0) * 2 + abs(p1 - q1) / 2  <= blimit) * -1;
-  return mask;
+  return (abs(p0 - q0) * 2 + abs(p1 - q1) / 2  <= blimit) * -1;
 }
 
 static INLINE void simple_filter(int8_t mask,
                                  uint8_t *op1, uint8_t *op0,
                                  uint8_t *oq0, uint8_t *oq1) {
-  int8_t filter, Filter1, Filter2;
-  int8_t p1 = (int8_t) *op1 ^ 0x80;
-  int8_t p0 = (int8_t) *op0 ^ 0x80;
-  int8_t q0 = (int8_t) *oq0 ^ 0x80;
-  int8_t q1 = (int8_t) *oq1 ^ 0x80;
-  int8_t u;
-
-  filter = signed_char_clamp(p1 - q1);
+  int8_t filter1, filter2;
+  const int8_t p1 = (int8_t) *op1 ^ 0x80;
+  const int8_t p0 = (int8_t) *op0 ^ 0x80;
+  const int8_t q0 = (int8_t) *oq0 ^ 0x80;
+  const int8_t q1 = (int8_t) *oq1 ^ 0x80;
+
+  int8_t filter = signed_char_clamp(p1 - q1);
   filter = signed_char_clamp(filter + 3 * (q0 - p0));
   filter &= mask;
 
-  /* save bottom 3 bits so that we round one side +4 and the other +3 */
-  Filter1 = signed_char_clamp(filter + 4);
-  Filter1 >>= 3;
-  u = signed_char_clamp(q0 - Filter1);
-  *oq0  = u ^ 0x80;
+  // save bottom 3 bits so that we round one side +4 and the other +3
+  filter1 = signed_char_clamp(filter + 4) >> 3;
+  *oq0  = signed_char_clamp(q0 - filter1) ^ 0x80;
 
-  Filter2 = signed_char_clamp(filter + 3);
-  Filter2 >>= 3;
-  u = signed_char_clamp(p0 + Filter2);
-  *op0 = u ^ 0x80;
+  filter2 = signed_char_clamp(filter + 3) >> 3;
+  *op0 = signed_char_clamp(p0 + filter2) ^ 0x80;
 }
 
 void vp9_loop_filter_simple_horizontal_edge_c(uint8_t *s,
@@ -495,33 +458,24 @@ static INLINE void wide_mbfilter(int8_t mask, uint8_t hev,
                                  uint8_t *oq1, uint8_t *oq2, uint8_t *oq3,
                                  uint8_t *oq4, uint8_t *oq5, uint8_t *oq6,
                                  uint8_t *oq7) {
-  /* use a 15 tap filter [1,1,1,1,1,1,1,2,1,1,1,1,1,1,1] for flat line */
+  // use a 15 tap filter [1,1,1,1,1,1,1,2,1,1,1,1,1,1,1] for flat line
   if (flat2 && flat && mask) {
-    uint8_t p0, q0;
-    uint8_t p1, q1;
-    uint8_t p2, q2;
-    uint8_t p3, q3;
-    uint8_t p4, q4;
-    uint8_t p5, q5;
-    uint8_t p6, q6;
-    uint8_t p7, q7;
-
-    p7 = *op7;
-    p6 = *op6;
-    p5 = *op5;
-    p4 = *op4;
-    p3 = *op3;
-    p2 = *op2;
-    p1 = *op1;
-    p0 = *op0;
-    q0 = *oq0;
-    q1 = *oq1;
-    q2 = *oq2;
-    q3 = *oq3;
-    q4 = *oq4;
-    q5 = *oq5;
-    q6 = *oq6;
-    q7 = *oq7;
+    const uint8_t p7 = *op7;
+    const uint8_t p6 = *op6;
+    const uint8_t p5 = *op5;
+    const uint8_t p4 = *op4;
+    const uint8_t p3 = *op3;
+    const uint8_t p2 = *op2;
+    const uint8_t p1 = *op1;
+    const uint8_t p0 = *op0;
+    const uint8_t q0 = *oq0;
+    const uint8_t q1 = *oq1;
+    const uint8_t q2 = *oq2;
+    const uint8_t q3 = *oq3;
+    const uint8_t q4 = *oq4;
+    const uint8_t q5 = *oq5;
+    const uint8_t q6 = *oq6;
+    const uint8_t q7 = *oq7;
 
     *op6 = (p7 * 7 + p6 * 2 +
             p5 + p4 + p3 + p2 + p1 + p0 + q0 + 8) >> 4;
@@ -552,19 +506,14 @@ static INLINE void wide_mbfilter(int8_t mask, uint8_t hev,
     *oq6 = (p0 + q0 + q1 + q2 + q3 + q4 + q5 + q6 * 2 +
             q7 * 7 + 8) >> 4;
   } else if (flat && mask) {
-    unsigned char p0, q0;
-    unsigned char p1, q1;
-    unsigned char p2, q2;
-    unsigned char p3, q3;
-
-    p3 = *op3;
-    p2 = *op2;
-    p1 = *op1;
-    p0 = *op0;
-    q0 = *oq0;
-    q1 = *oq1;
-    q2 = *oq2;
-    q3 = *oq3;
+    const uint8_t p3 = *op3;
+    const uint8_t p2 = *op2;
+    const uint8_t p1 = *op1;
+    const uint8_t p0 = *op0;
+    const uint8_t q0 = *oq0;
+    const uint8_t q1 = *oq1;
+    const uint8_t q2 = *oq2;
+    const uint8_t q3 = *oq3;
 
     *op2 = (p3 + p3 + p3 + p2 + p2 + p1 + p0 + q0 + 4) >> 3;
     *op1 = (p3 + p3 + p2 + p1 + p1 + p0 + q0 + q1 + 4) >> 3;
@@ -573,44 +522,32 @@ static INLINE void wide_mbfilter(int8_t mask, uint8_t hev,
     *oq1 = (p1 + p0 + q0 + q1 + q1 + q2 + q3 + q3 + 4) >> 3;
     *oq2 = (p0 + q0 + q1 + q2 + q2 + q3 + q3 + q3 + 4) >> 3;
   } else {
-    signed char ps0, qs0;
-    signed char ps1, qs1;
-    signed char filter, Filter1, Filter2;
-    signed char u;
-
-    ps1 = (signed char) * op1 ^ 0x80;
-    ps0 = (signed char) * op0 ^ 0x80;
-    qs0 = (signed char) * oq0 ^ 0x80;
-    qs1 = (signed char) * oq1 ^ 0x80;
-
-    /* add outer taps if we have high edge variance */
-    filter = signed_char_clamp(ps1 - qs1);
-    filter &= hev;
-
-    /* inner taps */
-    filter = signed_char_clamp(filter + 3 * (qs0 - ps0));
-    filter &= mask;
-
-    Filter1 = signed_char_clamp(filter + 4);
-    Filter2 = signed_char_clamp(filter + 3);
-    Filter1 >>= 3;
-    Filter2 >>= 3;
-
-    u = signed_char_clamp(qs0 - Filter1);
-    *oq0 = u ^ 0x80;
-    u = signed_char_clamp(ps0 + Filter2);
-    *op0 = u ^ 0x80;
-    filter = Filter1;
-
-    /* outer tap adjustments */
+    int8_t filter1, filter2;
+
+    const int8_t ps1 = (int8_t) * op1 ^ 0x80;
+    const int8_t ps0 = (int8_t) * op0 ^ 0x80;
+    const int8_t qs0 = (int8_t) * oq0 ^ 0x80;
+    const int8_t qs1 = (int8_t) * oq1 ^ 0x80;
+
+    // add outer taps if we have high edge variance
+    int8_t filter = signed_char_clamp(ps1 - qs1) & hev;
+
+    // inner taps
+    filter = signed_char_clamp(filter + 3 * (qs0 - ps0)) & mask;
+    filter1 = signed_char_clamp(filter + 4) >> 3;
+    filter2 = signed_char_clamp(filter + 3) >> 3;
+
+    *oq0 = signed_char_clamp(qs0 - filter1) ^ 0x80;
+    *op0 = signed_char_clamp(ps0 + filter2) ^ 0x80;
+    filter = filter1;
+
+    // outer tap adjustments
     filter += 1;
     filter >>= 1;
     filter &= ~hev;
 
-    u = signed_char_clamp(qs1 - filter);
-    *oq1 = u ^ 0x80;
-    u = signed_char_clamp(ps1 + filter);
-    *op1 = u ^ 0x80;
+    *oq1 = signed_char_clamp(qs1 - filter) ^ 0x80;
+    *op1 = signed_char_clamp(ps1 + filter) ^ 0x80;
   }
 }