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rouault merged 1 commit into from
Apr 24, 2026
Merged

NEON-optimize 9-7 IDWT #1629

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90 changes: 90 additions & 0 deletions src/lib/openjp2/dwt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -55,6 +55,9 @@
#if (defined(__AVX2__) || defined(__AVX512F__))
#include <immintrin.h>
#endif
#ifdef __ARM_NEON
#include <arm_neon.h>
#endif

#if defined(__GNUC__)
#pragma GCC poison malloc calloc realloc free
Expand Down Expand Up @@ -3282,6 +3285,72 @@ static void opj_v8dwt_decode_step2_sse(opj_v8_t* l, opj_v8_t* w,
}
}

#elif defined(__ARM_NEON)

static void opj_v8dwt_decode_step1_neon(opj_v8_t* w,
OPJ_UINT32 start,
OPJ_UINT32 end,
const OPJ_FLOAT32 c)
{
OPJ_FLOAT32* OPJ_RESTRICT fw = (OPJ_FLOAT32*) w;
OPJ_UINT32 i;
float32x4_t vc = vdupq_n_f32(c);
/* To be adapted if NB_ELTS_V8 changes */
fw += 2 * NB_ELTS_V8 * start;
for (i = start; i < end; ++i, fw += 2 * NB_ELTS_V8) {
float32x4_t v0 = vld1q_f32(fw);
float32x4_t v1 = vld1q_f32(fw + 4);
vst1q_f32(fw, vmulq_f32(v0, vc));
vst1q_f32(fw + 4, vmulq_f32(v1, vc));
}
}

static void opj_v8dwt_decode_step2_neon(opj_v8_t* l, opj_v8_t* w,
OPJ_UINT32 start,
OPJ_UINT32 end,
OPJ_UINT32 m,
OPJ_FLOAT32 c)
{
OPJ_FLOAT32* fl = (OPJ_FLOAT32*) l;
OPJ_FLOAT32* fw = (OPJ_FLOAT32*) w;
OPJ_UINT32 i;
OPJ_UINT32 imax = opj_uint_min(end, m);
float32x4_t vc;
if (start > 0) {
fw += 2 * NB_ELTS_V8 * start;
fl = fw - 2 * NB_ELTS_V8;
}
/* To be adapted if NB_ELTS_V8 changes */
vc = vdupq_n_f32(c);
for (i = start; i < imax; ++i) {
float32x4_t fl0 = vld1q_f32(fl);
float32x4_t fl1 = vld1q_f32(fl + 4);
float32x4_t fw0 = vld1q_f32(fw);
float32x4_t fw1 = vld1q_f32(fw + 4);
float32x4_t fwm8 = vld1q_f32(fw - 8);
float32x4_t fwm4 = vld1q_f32(fw - 4);
fwm8 = vmlaq_f32(fwm8, vaddq_f32(fl0, fw0), vc);
fwm4 = vmlaq_f32(fwm4, vaddq_f32(fl1, fw1), vc);
vst1q_f32(fw - 8, fwm8);
vst1q_f32(fw - 4, fwm4);
fl = fw;
fw += 2 * NB_ELTS_V8;
}
if (m < end) {
float32x4_t vc2, fl0, fl1, fwm8, fwm4;
assert(m + 1 == end);
vc2 = vaddq_f32(vc, vc);
fl0 = vld1q_f32(fl);
fl1 = vld1q_f32(fl + 4);
fwm8 = vld1q_f32(fw - 8);
fwm4 = vld1q_f32(fw - 4);
fwm8 = vmlaq_f32(fwm8, fl0, vc2);
fwm4 = vmlaq_f32(fwm4, fl1, vc2);
vst1q_f32(fw - 8, fwm8);
vst1q_f32(fw - 4, fwm4);
}
}

#else

static void opj_v8dwt_decode_step1(opj_v8_t* w,
Expand Down Expand Up @@ -3395,6 +3464,27 @@ static void opj_v8dwt_decode(opj_v8dwt_t* OPJ_RESTRICT dwt)
dwt->win_h_x0, dwt->win_h_x1,
(OPJ_UINT32)opj_int_min(dwt->dn, dwt->sn - b),
_mm_set1_ps(-opj_dwt_alpha));
#elif defined(__ARM_NEON)
opj_v8dwt_decode_step1_neon(dwt->wavelet + a, dwt->win_l_x0, dwt->win_l_x1,
opj_K);
opj_v8dwt_decode_step1_neon(dwt->wavelet + b, dwt->win_h_x0, dwt->win_h_x1,
two_invK);
opj_v8dwt_decode_step2_neon(dwt->wavelet + b, dwt->wavelet + a + 1,
dwt->win_l_x0, dwt->win_l_x1,
(OPJ_UINT32)opj_int_min(dwt->sn, dwt->dn - a),
-opj_dwt_delta);
opj_v8dwt_decode_step2_neon(dwt->wavelet + a, dwt->wavelet + b + 1,
dwt->win_h_x0, dwt->win_h_x1,
(OPJ_UINT32)opj_int_min(dwt->dn, dwt->sn - b),
-opj_dwt_gamma);
opj_v8dwt_decode_step2_neon(dwt->wavelet + b, dwt->wavelet + a + 1,
dwt->win_l_x0, dwt->win_l_x1,
(OPJ_UINT32)opj_int_min(dwt->sn, dwt->dn - a),
-opj_dwt_beta);
opj_v8dwt_decode_step2_neon(dwt->wavelet + a, dwt->wavelet + b + 1,
dwt->win_h_x0, dwt->win_h_x1,
(OPJ_UINT32)opj_int_min(dwt->dn, dwt->sn - b),
-opj_dwt_alpha);
#else
opj_v8dwt_decode_step1(dwt->wavelet + a, dwt->win_l_x0, dwt->win_l_x1,
opj_K);
Expand Down
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