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// Auto-generated file. Do not edit!
// Template: src/f32-raddstoreexpminusmax/wasmsimd-p5.c.in
// Generator: tools/xngen
//
// Copyright 2020 Google LLC
//
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree.
#include <assert.h>
#include <wasm_simd128.h>
#include <xnnpack/common.h>
#include <xnnpack/raddstoreexpminusmax.h>
void xnn_f32_raddstoreexpminusmax_ukernel__wasmsimd_p5_x16_acc4(
size_t elements,
const float* input,
float* output,
float* sum,
float max) XNN_DISABLE_TSAN
{
assert(elements % sizeof(float) == 0);
const v128_t vmagic_bias = wasm_f32x4_splat(0x1.8000FEp23f);
// The smallest x for which expf(x) is normalized.
const v128_t vdenorm_cutoff = wasm_f32x4_splat(-0x1.5D589Ep6f);
const v128_t vlog2e = wasm_f32x4_splat(0x1.715476p+0f);
// Last 7 bits are zeroes
const v128_t vminus_ln2_hi = wasm_f32x4_splat(-0x1.62E400p-1f);
const v128_t vminus_ln2_lo = wasm_f32x4_splat(-0x1.7F7D1Cp-20f);
const v128_t vc1 = wasm_f32x4_splat(0x1.FFFFF6p-1f);
const v128_t vc2 = wasm_f32x4_splat(0x1.FFFDC6p-2f);
const v128_t vc3 = wasm_f32x4_splat(0x1.555A80p-3f);
const v128_t vc4 = wasm_f32x4_splat(0x1.573A1Ap-5f);
const v128_t vc5 = wasm_f32x4_splat(0x1.0F9F9Cp-7f);
const v128_t vi_max = wasm_f32x4_splat(max);
v128_t vacc0 = wasm_f32x4_splat(0.0f);
v128_t vacc1 = vacc0;
v128_t vacc2 = vacc0;
v128_t vacc3 = vacc0;
for (; elements >= 16 * sizeof(float); elements -= 16 * sizeof(float)) {
// Load 16 (4x4) inputs at a time.
const v128_t vi0123 = wasm_v128_load(input);
const v128_t vi4567 = wasm_v128_load(input + 4);
const v128_t vi89AB = wasm_v128_load(input + 8);
const v128_t viCDEF = wasm_v128_load(input + 12);
input += 16;
// Subtract maximum input x := i - i_max. This implies x <= 0.
const v128_t vx0123 = wasm_f32x4_sub(vi0123, vi_max);
const v128_t vx4567 = wasm_f32x4_sub(vi4567, vi_max);
const v128_t vx89AB = wasm_f32x4_sub(vi89AB, vi_max);
const v128_t vxCDEF = wasm_f32x4_sub(viCDEF, vi_max);
// Compute reduced argument elements := round(x / log(2)).
v128_t vn0123 = wasm_f32x4_add(vmagic_bias, wasm_f32x4_mul(vx0123, vlog2e));
v128_t vn4567 = wasm_f32x4_add(vmagic_bias, wasm_f32x4_mul(vx4567, vlog2e));
v128_t vn89AB = wasm_f32x4_add(vmagic_bias, wasm_f32x4_mul(vx89AB, vlog2e));
v128_t vnCDEF = wasm_f32x4_add(vmagic_bias, wasm_f32x4_mul(vxCDEF, vlog2e));
// Create a floating-point number s (scale) such that s == 2**elements for inputs which don't cause underflow, i.e.
// -87.33642 <= x <= 0.0, and -126 <= elements <= 0 accordingly.
const v128_t vs0123 = wasm_i32x4_shl(vn0123, 23);
const v128_t vs4567 = wasm_i32x4_shl(vn4567, 23);
const v128_t vs89AB = wasm_i32x4_shl(vn89AB, 23);
const v128_t vsCDEF = wasm_i32x4_shl(vnCDEF, 23);
// Subtract the large number back to get final elements := round(x / log(2)).
vn0123 = wasm_f32x4_sub(vn0123, vmagic_bias);
vn4567 = wasm_f32x4_sub(vn4567, vmagic_bias);
vn89AB = wasm_f32x4_sub(vn89AB, vmagic_bias);
vnCDEF = wasm_f32x4_sub(vnCDEF, vmagic_bias);
// Compute reduced argument t := x - elements * log(2).
// Use Cody-Waite range reduction method (note two constants to represent log(2)) to improve accuracy.
v128_t vt0123 = wasm_f32x4_add(vx0123, wasm_f32x4_mul(vn0123, vminus_ln2_hi));
v128_t vt4567 = wasm_f32x4_add(vx4567, wasm_f32x4_mul(vn4567, vminus_ln2_hi));
v128_t vt89AB = wasm_f32x4_add(vx89AB, wasm_f32x4_mul(vn89AB, vminus_ln2_hi));
v128_t vtCDEF = wasm_f32x4_add(vxCDEF, wasm_f32x4_mul(vnCDEF, vminus_ln2_hi));
vt0123 = wasm_f32x4_add(vt0123, wasm_f32x4_mul(vn0123, vminus_ln2_lo));
vt4567 = wasm_f32x4_add(vt4567, wasm_f32x4_mul(vn4567, vminus_ln2_lo));
vt89AB = wasm_f32x4_add(vt89AB, wasm_f32x4_mul(vn89AB, vminus_ln2_lo));
vtCDEF = wasm_f32x4_add(vtCDEF, wasm_f32x4_mul(vnCDEF, vminus_ln2_lo));
// Compute degree-5 polynomial approximation for exp(t) on [-log(2)/2, log(2)/2].
v128_t vp0123 = wasm_f32x4_add(vc4, wasm_f32x4_mul(vc5, vt0123));
v128_t vp4567 = wasm_f32x4_add(vc4, wasm_f32x4_mul(vc5, vt4567));
v128_t vp89AB = wasm_f32x4_add(vc4, wasm_f32x4_mul(vc5, vt89AB));
v128_t vpCDEF = wasm_f32x4_add(vc4, wasm_f32x4_mul(vc5, vtCDEF));
vp0123 = wasm_f32x4_add(vc3, wasm_f32x4_mul(vp0123, vt0123));
vp4567 = wasm_f32x4_add(vc3, wasm_f32x4_mul(vp4567, vt4567));
vp89AB = wasm_f32x4_add(vc3, wasm_f32x4_mul(vp89AB, vt89AB));
vpCDEF = wasm_f32x4_add(vc3, wasm_f32x4_mul(vpCDEF, vtCDEF));
vp0123 = wasm_f32x4_add(vc2, wasm_f32x4_mul(vp0123, vt0123));
vp4567 = wasm_f32x4_add(vc2, wasm_f32x4_mul(vp4567, vt4567));
vp89AB = wasm_f32x4_add(vc2, wasm_f32x4_mul(vp89AB, vt89AB));
vpCDEF = wasm_f32x4_add(vc2, wasm_f32x4_mul(vpCDEF, vtCDEF));
vp0123 = wasm_f32x4_add(vc1, wasm_f32x4_mul(vp0123, vt0123));
vp4567 = wasm_f32x4_add(vc1, wasm_f32x4_mul(vp4567, vt4567));
vp89AB = wasm_f32x4_add(vc1, wasm_f32x4_mul(vp89AB, vt89AB));
vpCDEF = wasm_f32x4_add(vc1, wasm_f32x4_mul(vpCDEF, vtCDEF));
// Reconstruct the final f value:
// f = s * (1 + t * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5)))))
// = s + (t * s) * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5))))
// = s + (t * s) * p
vt0123 = wasm_f32x4_mul(vt0123, vs0123);
vt4567 = wasm_f32x4_mul(vt4567, vs4567);
vt89AB = wasm_f32x4_mul(vt89AB, vs89AB);
vtCDEF = wasm_f32x4_mul(vtCDEF, vsCDEF);
v128_t vf0123 = wasm_f32x4_add(vs0123, wasm_f32x4_mul(vt0123, vp0123));
v128_t vf4567 = wasm_f32x4_add(vs4567, wasm_f32x4_mul(vt4567, vp4567));
v128_t vf89AB = wasm_f32x4_add(vs89AB, wasm_f32x4_mul(vt89AB, vp89AB));
v128_t vfCDEF = wasm_f32x4_add(vsCDEF, wasm_f32x4_mul(vtCDEF, vpCDEF));
// For inputs below zero cutoff, replace output with +0.0f.
// Note that for NaN inputs, comparison result is false, and outputs are left unchanged.
vf0123 = wasm_v128_andnot(vf0123, wasm_f32x4_lt(vx0123, vdenorm_cutoff));
vf4567 = wasm_v128_andnot(vf4567, wasm_f32x4_lt(vx4567, vdenorm_cutoff));
vf89AB = wasm_v128_andnot(vf89AB, wasm_f32x4_lt(vx89AB, vdenorm_cutoff));
vfCDEF = wasm_v128_andnot(vfCDEF, wasm_f32x4_lt(vxCDEF, vdenorm_cutoff));
// Store 16 (4x4) outputs at a time.
wasm_v128_store(output, vf0123);
wasm_v128_store(output + 4, vf4567);
wasm_v128_store(output + 8, vf89AB);
wasm_v128_store(output + 12, vfCDEF);
output += 16;
// Accumulate computed exponents.
vacc0 = wasm_f32x4_add(vacc0, vf0123);
vacc0 = wasm_f32x4_add(vacc0, vf4567);
vacc0 = wasm_f32x4_add(vacc0, vf89AB);
vacc0 = wasm_f32x4_add(vacc0, vfCDEF);
}
// Add up all accumulators to vacc0
vacc0 = wasm_f32x4_add(vacc0, vacc1);
vacc2 = wasm_f32x4_add(vacc2, vacc3);
vacc0 = wasm_f32x4_add(vacc0, vacc2);
v128_t vacc = vacc0;
for (; elements >= 4 * sizeof(float); elements -= 4 * sizeof(float)) {
// Load 4 inputs at a time.
const v128_t vi = wasm_v128_load(input);
input += 4;
// Subtract maximum input x := i - i_max. This implies x <= 0.
const v128_t vx = wasm_f32x4_sub(vi, vi_max);
// Compute reduced argument elements := round(x / log(2)).
v128_t vn = wasm_f32x4_add(vmagic_bias, wasm_f32x4_mul(vx, vlog2e));
// Create a floating-point number s (scale) such that s == 2**elements for inputs which don't cause underflow, i.e.
// -87.33642 <= x <= 0.0, and -126 <= elements <= 0 accordingly.
const v128_t vs = wasm_i32x4_shl(vn, 23);
// Subtract the large number back to get final elements := round(x / log(2)).
vn = wasm_f32x4_sub(vn, vmagic_bias);
// Compute reduced argument t := x - elements * log(2).
// Use Cody-Waite range reduction method (note two constants to represent log(2)) to improve accuracy.
v128_t vt = wasm_f32x4_add(vx, wasm_f32x4_mul(vn, vminus_ln2_hi));
vt = wasm_f32x4_add(vt, wasm_f32x4_mul(vn, vminus_ln2_lo));
// Compute degree-5 polynomial approximation for exp(t) on [-log(2)/2, log(2)/2].
v128_t vp = wasm_f32x4_add(vc4, wasm_f32x4_mul(vc5, vt));
vp = wasm_f32x4_add(vc3, wasm_f32x4_mul(vp, vt));
vp = wasm_f32x4_add(vc2, wasm_f32x4_mul(vp, vt));
vp = wasm_f32x4_add(vc1, wasm_f32x4_mul(vp, vt));
// Reconstruct the final f value:
// f = s * (1 + t * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5)))))
// = s + (t * s) * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5))))
// = s + (t * s) * p
vt = wasm_f32x4_mul(vt, vs);
v128_t vf = wasm_f32x4_add(vs, wasm_f32x4_mul(vt, vp));
// For inputs below zero cutoff, replace output with +0.0f.
// Note that for NaN inputs, comparison result is false, and outputs are left unchanged.
vf = wasm_v128_andnot(vf, wasm_f32x4_lt(vx, vdenorm_cutoff));
// Store 4 outputs at a time.
wasm_v128_store(output, vf);
output += 4;
// Accumulate computed exponents.
vacc = wasm_f32x4_add(vacc, vf);
}
vacc = wasm_f32x4_add(vacc, wasm_v32x4_shuffle(vacc, vacc, 2, 3, 2, 3));
float vsum = wasm_f32x4_extract_lane(vacc, 0) + wasm_f32x4_extract_lane(vacc, 1);
if (elements != 0) {
assert(elements >= 1 * sizeof(float));
assert(elements <= 3 * sizeof(float));
// Load 4 inputs at a time.
const v128_t vi = wasm_v128_load(input);
// Subtract maximum input x := i - i_max. This implies x <= 0.
const v128_t vx = wasm_f32x4_sub(vi, vi_max);
// Compute reduced argument elements := round(x / log(2)).
v128_t vn = wasm_f32x4_add(vmagic_bias, wasm_f32x4_mul(vx, vlog2e));
// Create a floating-point number s (scale) such that s == 2**elements for inputs which don't cause underflow, i.e.
// -87.33642 <= x <= 0.0, and -126 <= elements <= 0 accordingly.
const v128_t vs = wasm_i32x4_shl(vn, 23);
// Subtract the large number back to get final elements := round(x / log(2)).
vn = wasm_f32x4_sub(vn, vmagic_bias);
// Compute reduced argument t := x - elements * log(2).
// Use Cody-Waite range reduction method (note two constants to represent log(2)) to improve accuracy.
v128_t vt = wasm_f32x4_add(vx, wasm_f32x4_mul(vn, vminus_ln2_hi));
vt = wasm_f32x4_add(vt, wasm_f32x4_mul(vn, vminus_ln2_lo));
// Compute degree-5 polynomial approximation for exp(t) on [-log(2)/2, log(2)/2].
v128_t vp = wasm_f32x4_add(vc4, wasm_f32x4_mul(vc5, vt));
vp = wasm_f32x4_add(vc3, wasm_f32x4_mul(vp, vt));
vp = wasm_f32x4_add(vc2, wasm_f32x4_mul(vp, vt));
vp = wasm_f32x4_add(vc1, wasm_f32x4_mul(vp, vt));
// Reconstruct the final f value:
// f = s * (1 + t * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5)))))
// = s + (t * s) * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5))))
// = s + (t * s) * p
vt = wasm_f32x4_mul(vt, vs);
v128_t vf = wasm_f32x4_add(vs, wasm_f32x4_mul(vt, vp));
// For inputs below zero cutoff, replace output with +0.0f.
// Note that for NaN inputs, comparison result is false, and outputs are left unchanged.
vf = wasm_v128_andnot(vf, wasm_f32x4_lt(vx, vdenorm_cutoff));
if (elements & (2 * sizeof(float))) {
// Store and accumulate 2 outputs at a time.
const float vf0 = wasm_f32x4_extract_lane(vf, 0);
output[0] = vf0;
vsum += vf0;
const float vf1 = wasm_f32x4_extract_lane(vf, 1);
output[1] = vf1;
vsum += vf1;
vf = wasm_v32x4_shuffle(vf, vf, 2, 3, 2, 3);
output += 2;
}
if (elements & (1 * sizeof(float))) {
// Store 1 output at a time.
const float vf0 = wasm_f32x4_extract_lane(vf, 0);
*output = vf0;
vsum += vf0;
}
}
// Reduce 4 elements in the SIMD register
*sum = vsum;
}