libvpx: Pull from upstream

source/libvpx/vp8/encoder/arm/neon/fastquantizeb_neon.c

+/*
+ *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <arm_neon.h>
+#include "vp8/encoder/block.h"
+
+static const uint16_t inv_zig_zag[16] = {
+    1,  2,  6,   7,
+    3,  5,  8,  13,
+    4,  9,  12, 14,
+    10, 11, 15, 16
+};
+
+void vp8_fast_quantize_b_neon(BLOCK *b, BLOCKD *d) {
+    const int16x8_t one_q = vdupq_n_s16(-1),
+                    z0 = vld1q_s16(b->coeff),
+                    z1 = vld1q_s16(b->coeff + 8),
+                    round0 = vld1q_s16(b->round),
+                    round1 = vld1q_s16(b->round + 8),
+                    quant0 = vld1q_s16(b->quant_fast),
+                    quant1 = vld1q_s16(b->quant_fast + 8),
+                    dequant0 = vld1q_s16(d->dequant),
+                    dequant1 = vld1q_s16(d->dequant + 8);
+    const uint16x8_t zig_zag0 = vld1q_u16(inv_zig_zag),
+                     zig_zag1 = vld1q_u16(inv_zig_zag + 8);
+    int16x8_t x0, x1, sz0, sz1, y0, y1;
+    uint16x8_t eob0, eob1;
+    uint16x4_t eob_d16;
+    uint32x2_t eob_d32;
+    uint32x4_t eob_q32;
+
+    /* sign of z: z >> 15 */
+    sz0 = vshrq_n_s16(z0, 15);
+    sz1 = vshrq_n_s16(z1, 15);
+
+    /* x = abs(z) */
+    x0 = vabsq_s16(z0);
+    x1 = vabsq_s16(z1);
+
+    /* x += round */
+    x0 = vaddq_s16(x0, round0);
+    x1 = vaddq_s16(x1, round1);
+
+    /* y = 2 * (x * quant) >> 16 */
+    y0 = vqdmulhq_s16(x0, quant0);
+    y1 = vqdmulhq_s16(x1, quant1);
+
+    /* Compensate for doubling in vqdmulhq */
+    y0 = vshrq_n_s16(y0, 1);
+    y1 = vshrq_n_s16(y1, 1);
+
+    /* Restore sign bit */
+    y0 = veorq_s16(y0, sz0);
+    y1 = veorq_s16(y1, sz1);
+    x0 = vsubq_s16(y0, sz0);
+    x1 = vsubq_s16(y1, sz1);
+
+    /* find non-zero elements */
+    eob0 = vtstq_s16(x0, one_q);
+    eob1 = vtstq_s16(x1, one_q);
+
+    /* mask zig zag */
+    eob0 = vandq_u16(eob0, zig_zag0);
+    eob1 = vandq_u16(eob1, zig_zag1);
+
+    /* select the largest value */
+    eob0 = vmaxq_u16(eob0, eob1);
+    eob_d16 = vmax_u16(vget_low_u16(eob0), vget_high_u16(eob0));
+    eob_q32 = vmovl_u16(eob_d16);
+    eob_d32 = vmax_u32(vget_low_u32(eob_q32), vget_high_u32(eob_q32));
+    eob_d32 = vpmax_u32(eob_d32, eob_d32);
+
+    /* qcoeff = x */
+    vst1q_s16(d->qcoeff, x0);
+    vst1q_s16(d->qcoeff + 8, x1);
+
+    /* dqcoeff = x * dequant */
+    vst1q_s16(d->dqcoeff, vmulq_s16(dequant0, x0));
+    vst1q_s16(d->dqcoeff + 8, vmulq_s16(dequant1, x1));
+
+    vst1_lane_s8((int8_t *)d->eob, vreinterpret_s8_u32(eob_d32), 0);
+}