shithub: libvpx

Download patch

ref: d18477b449ad4aaff6e56ae977c35c9a1030c871
parent: c244a862341826713c4ad17b1f7c637e8395cdfc
author: Linfeng Zhang <[email protected]>
date: Mon Mar 5 11:14:35 EST 2018 

Fix a bug in vp9_iht16x16_256_add_neon()

This bug was introduced in 88c23864.

BUG=webm:1403

Change-Id: If96fd6f102be6b9bda866e55e574257287746f4a


--- a/test/dct_test.cc
+++ b/test/dct_test.cc
@@ -639,12 +639,8 @@
 #endif
 #endif
   { &vp9_fht4x4_c, &iht_wrapper<vp9_iht4x4_16_add_neon>, 4, 1 },
-  // TODO(linfengz): reenable these functions once test vector failures are
-  // addressed.
   { &vp9_fht8x8_c, &iht_wrapper<vp9_iht8x8_64_add_neon>, 8, 1 },
-#if 0
   { &vp9_fht16x16_c, &iht_wrapper<vp9_iht16x16_256_add_neon>, 16, 1 }
-#endif
 };
 
 INSTANTIATE_TEST_CASE_P(
--- a/vp9/common/arm/neon/vp9_iht16x16_add_neon.c
+++ b/vp9/common/arm/neon/vp9_iht16x16_add_neon.c
@@ -221,30 +221,10 @@
   x[15] = sub_dct_const_round_shift_low_8(s13, s15);
 
   // stage 4
-  {
-    const int16x8_t sum = vaddq_s16(x[2], x[3]);
-    const int16x8_t sub = vsubq_s16(x[2], x[3]);
-    x[2] = iadst_half_butterfly_neg_neon(sum, c_16_n16_8_24);
-    x[3] = iadst_half_butterfly_pos_neon(sub, c_16_n16_8_24);
-  }
-  {
-    const int16x8_t sum = vaddq_s16(x[7], x[6]);
-    const int16x8_t sub = vsubq_s16(x[7], x[6]);
-    x[6] = iadst_half_butterfly_pos_neon(sum, c_16_n16_8_24);
-    x[7] = iadst_half_butterfly_pos_neon(sub, c_16_n16_8_24);
-  }
-  {
-    const int16x8_t sum = vaddq_s16(x[11], x[10]);
-    const int16x8_t sub = vsubq_s16(x[11], x[10]);
-    x[10] = iadst_half_butterfly_pos_neon(sum, c_16_n16_8_24);
-    x[11] = iadst_half_butterfly_pos_neon(sub, c_16_n16_8_24);
-  }
-  {
-    const int16x8_t sum = vaddq_s16(x[14], x[15]);
-    const int16x8_t sub = vsubq_s16(x[14], x[15]);
-    x[14] = iadst_half_butterfly_neg_neon(sum, c_16_n16_8_24);
-    x[15] = iadst_half_butterfly_pos_neon(sub, c_16_n16_8_24);
-  }
+  iadst_half_butterfly_neg_neon(&x[3], &x[2], c_16_n16_8_24);
+  iadst_half_butterfly_pos_neon(&x[7], &x[6], c_16_n16_8_24);
+  iadst_half_butterfly_pos_neon(&x[11], &x[10], c_16_n16_8_24);
+  iadst_half_butterfly_neg_neon(&x[15], &x[14], c_16_n16_8_24);
 
   out[0] = x[0];
   out[1] = vnegq_s16(x[8]);
--- a/vp9/common/arm/neon/vp9_iht_neon.h
+++ b/vp9/common/arm/neon/vp9_iht_neon.h
@@ -74,22 +74,40 @@
   x[1] = dct_const_round_shift_low_8(t1);
 }
 
-static INLINE int16x8_t iadst_half_butterfly_neg_neon(const int16x8_t in,
-                                                      const int16x4_t c) {
-  int32x4_t t[2];
+static INLINE void iadst_half_butterfly_neg_neon(int16x8_t *const x0,
+                                                 int16x8_t *const x1,
+                                                 const int16x4_t c) {
+  // Don't add/sub before multiply, which will overflow in iadst8.
+  const int32x4_t x0_lo = vmull_lane_s16(vget_low_s16(*x0), c, 1);
+  const int32x4_t x0_hi = vmull_lane_s16(vget_high_s16(*x0), c, 1);
+  const int32x4_t x1_lo = vmull_lane_s16(vget_low_s16(*x1), c, 1);
+  const int32x4_t x1_hi = vmull_lane_s16(vget_high_s16(*x1), c, 1);
+  int32x4_t t0[2], t1[2];
 
-  t[0] = vmull_lane_s16(vget_low_s16(in), c, 1);
-  t[1] = vmull_lane_s16(vget_high_s16(in), c, 1);
-  return dct_const_round_shift_low_8(t);
+  t0[0] = vaddq_s32(x0_lo, x1_lo);
+  t0[1] = vaddq_s32(x0_hi, x1_hi);
+  t1[0] = vsubq_s32(x0_lo, x1_lo);
+  t1[1] = vsubq_s32(x0_hi, x1_hi);
+  *x1 = dct_const_round_shift_low_8(t0);
+  *x0 = dct_const_round_shift_low_8(t1);
 }
 
-static INLINE int16x8_t iadst_half_butterfly_pos_neon(const int16x8_t in,
-                                                      const int16x4_t c) {
-  int32x4_t t[2];
+static INLINE void iadst_half_butterfly_pos_neon(int16x8_t *const x0,
+                                                 int16x8_t *const x1,
+                                                 const int16x4_t c) {
+  // Don't add/sub before multiply, which will overflow in iadst8.
+  const int32x4_t x0_lo = vmull_lane_s16(vget_low_s16(*x0), c, 0);
+  const int32x4_t x0_hi = vmull_lane_s16(vget_high_s16(*x0), c, 0);
+  const int32x4_t x1_lo = vmull_lane_s16(vget_low_s16(*x1), c, 0);
+  const int32x4_t x1_hi = vmull_lane_s16(vget_high_s16(*x1), c, 0);
+  int32x4_t t0[2], t1[2];
 
-  t[0] = vmull_lane_s16(vget_low_s16(in), c, 0);
-  t[1] = vmull_lane_s16(vget_high_s16(in), c, 0);
-  return dct_const_round_shift_low_8(t);
+  t0[0] = vaddq_s32(x0_lo, x1_lo);
+  t0[1] = vaddq_s32(x0_hi, x1_hi);
+  t1[0] = vsubq_s32(x0_lo, x1_lo);
+  t1[1] = vsubq_s32(x0_hi, x1_hi);
+  *x1 = dct_const_round_shift_low_8(t0);
+  *x0 = dct_const_round_shift_low_8(t1);
 }
 
 static INLINE void iadst_butterfly_lane_0_1_neon(const int16x8_t in0,
--- a/vp9/common/vp9_rtcd_defs.pl
+++ b/vp9/common/vp9_rtcd_defs.pl
@@ -69,7 +69,7 @@
   # CONFIG_VP9_HIGHBITDEPTH is off.
   specialize qw/vp9_iht4x4_16_add neon sse2/;
   specialize qw/vp9_iht8x8_64_add neon sse2/;
-  specialize qw/vp9_iht16x16_256_add sse2/;
+  specialize qw/vp9_iht16x16_256_add neon sse2/;
   if (vpx_config("CONFIG_VP9_HIGHBITDEPTH") ne "yes") {
     # Note that these specializations are appended to the above ones.
     specialize qw/vp9_iht4x4_16_add dspr2 msa/;