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1 // Auto-generated file. Do not edit!
2 //   Template: src/f32-vsigmoid/scalar-rr2-lut2048-p1-div.c.in
3 //   Generator: tools/xngen
4 //
5 // Copyright 2019 Google LLC
6 //
7 // This source code is licensed under the BSD-style license found in the
8 // LICENSE file in the root directory of this source tree.
9 
10 #include <assert.h>
11 #include <math.h>
12 
13 #include <xnnpack/common.h>
14 #include <xnnpack/vunary.h>
15 
16 #include <fp16/bitcasts.h>
17 
18 
19 // Note redefine as uint32[] to avoid redundant bitcasts.
20 extern XNN_INTERNAL const uint32_t xnn_table_exp2minus_k_over_2048[2048];
21 
xnn_f32_vsigmoid_ukernel__scalar_rr2_lut2048_p1_div_x2(size_t n,const float * x,float * y,const union xnn_f32_sigmoid_params params[restrict XNN_MIN_ELEMENTS (1)])22 void xnn_f32_vsigmoid_ukernel__scalar_rr2_lut2048_p1_div_x2(
23     size_t n,
24     const float* x,
25     float* y,
26     const union xnn_f32_sigmoid_params params[restrict XNN_MIN_ELEMENTS(1)])
27 {
28   assert(n % sizeof(float) == 0);
29 
30   const float vmagic_bias = params->scalar_rr2_lut2048_p1.magic_bias;
31   const float vminus_log2e = params->scalar_rr2_lut2048_p1.minus_log2e;
32   const uint32_t vindex_mask = UINT32_C(0x7FF);
33   const float vln2_hi = params->scalar_rr2_lut2048_p1.ln2_hi;
34   const float vln2_lo = params->scalar_rr2_lut2048_p1.ln2_lo;
35   const float vc1 = params->scalar_rr2_lut2048_p1.c1;
36   const float vone = params->scalar_rr2_lut2048_p1.one;
37   const float vdenorm_cutoff = params->scalar_rr2_lut2048_p1.denorm_cutoff;
38 
39   for (; n >= 2 * sizeof(float); n -= 2 * sizeof(float)) {
40     const float vx0 = x[0];
41     const float vx1 = x[1];
42     x += 2;
43 
44     const float vz0 = fabsf(vx0);
45     const float vz1 = fabsf(vx1);
46 
47     float vn0 = vz0 * vminus_log2e + vmagic_bias;
48     float vn1 = vz1 * vminus_log2e + vmagic_bias;
49 
50     const uint32_t ve0 = fp32_to_bits(vn0) << 12;
51     const uint32_t ve1 = fp32_to_bits(vn1) << 12;
52 
53     const uint32_t vidx0 = fp32_to_bits(vn0) & vindex_mask;
54     const float vs0 = fp32_from_bits(xnn_table_exp2minus_k_over_2048[vidx0] + ve0);
55     const uint32_t vidx1 = fp32_to_bits(vn1) & vindex_mask;
56     const float vs1 = fp32_from_bits(xnn_table_exp2minus_k_over_2048[vidx1] + ve1);
57 
58     vn0 -= vmagic_bias;
59     vn1 -= vmagic_bias;
60 
61     float vt0 = vn0 * vln2_hi + vz0;
62     float vt1 = vn1 * vln2_hi + vz1;
63 
64     vt0 = vn0 * vln2_lo + vt0;
65     vt1 = vn1 * vln2_lo + vt1;
66 
67     const float vp0 = vt0 * vc1;
68     const float vp1 = vt1 * vc1;
69 
70     const float vy0 = vp0 * vs0 + vs0;
71     const float vy1 = vp1 * vs1 + vs1;
72 
73     const float vd0 = vy0 + vone;
74     const float vd1 = vy1 + vone;
75 
76     float vf0 = vy0 / vd0;
77     float vf1 = vy1 / vd1;
78 
79     if XNN_UNPREDICTABLE(vz0 > vdenorm_cutoff) {
80       vf0 = 0.0f;
81     }
82     if XNN_UNPREDICTABLE(vz1 > vdenorm_cutoff) {
83       vf1 = 0.0f;
84     }
85 
86     if XNN_UNPREDICTABLE(vx0 > 0.0f) {
87       vf0 = vone - vf0;
88     }
89     if XNN_UNPREDICTABLE(vx1 > 0.0f) {
90       vf1 = vone - vf1;
91     }
92 
93     y[0] = vf0;
94     y[1] = vf1;
95     y += 2;
96   }
97   if XNN_UNLIKELY(n != 0) {
98     const float vx = *x;
99 
100     const float vz = fabsf(vx);
101 
102     float vn = vz * vminus_log2e + vmagic_bias;
103     const uint32_t ve = fp32_to_bits(vn) << 12;
104     const uint32_t vidx = fp32_to_bits(vn) & vindex_mask;
105     const float vs = fp32_from_bits(xnn_table_exp2minus_k_over_2048[vidx] + ve);
106     vn -= vmagic_bias;
107 
108     float vt = vn * vln2_hi + vz;
109     vt = vn * vln2_lo + vt;
110 
111     const float vp = vt * vc1;
112     const float vy = vp * vs + vs;
113 
114     const float vd = vy + vone;
115     float vf = vy / vd;
116     if XNN_UNPREDICTABLE(vz > vdenorm_cutoff) {
117       vf = 0.0f;
118     }
119     if XNN_UNPREDICTABLE(vx > 0.0f) {
120       vf = vone - vf;
121     }
122 
123     *y = vf;
124   }
125 }
126