xref: /aosp_15_r20/external/XNNPACK/src/f32-vsigmoid/gen/vsigmoid-sse2-rr2-lut64-p2-div-x16.c (revision 4bdc94577ba0e567308109d787f7fec7b531ce36)
1 // Auto-generated file. Do not edit!
2 //   Template: src/f32-vsigmoid/sse-rr2-lut64-p2-div.c.in
3 //   Generator: tools/xngen
4 //
5 // Copyright 2020 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 
12 #include <emmintrin.h>
13 
14 #include <xnnpack/common.h>
15 #include <xnnpack/vunary.h>
16 
17 
18 extern XNN_INTERNAL const float xnn_table_exp2minus_k_over_64[64];
19 
xnn_f32_vsigmoid_ukernel__sse2_rr2_lut64_p2_div_x16(size_t n,const float * x,float * y,const union xnn_f32_sigmoid_params params[restrict XNN_MIN_ELEMENTS (1)])20 void xnn_f32_vsigmoid_ukernel__sse2_rr2_lut64_p2_div_x16(
21     size_t n,
22     const float* x,
23     float* y,
24     const union xnn_f32_sigmoid_params params[restrict XNN_MIN_ELEMENTS(1)]) XNN_OOB_READS
25 {
26   assert(n % sizeof(float) == 0);
27 
28   const __m128 vsign_mask = _mm_load_ps(params->sse2_rr2_lut64_p2.sign_mask);
29   const __m128 vmagic_bias = _mm_load_ps(params->sse2_rr2_lut64_p2.magic_bias);
30   const __m128 vlog2e = _mm_load_ps(params->sse2_rr2_lut64_p2.log2e);
31   const __m128i vindex_mask = _mm_load_si128((const __m128i*) params->sse2_rr2_lut64_p2.index_mask);
32   const __m128 vminus_ln2_hi = _mm_load_ps(params->sse2_rr2_lut64_p2.minus_ln2_hi);
33   const __m128 vminus_ln2_lo = _mm_load_ps(params->sse2_rr2_lut64_p2.minus_ln2_lo);
34   const __m128 vc2 = _mm_load_ps(params->sse2_rr2_lut64_p2.c2);
35   const __m128 vone = _mm_load_ps(params->sse2_rr2_lut64_p2.one);
36   const __m128 vdenorm_cutoff = _mm_load_ps(params->sse2_rr2_lut64_p2.denorm_cutoff);
37 
38   for (; n >= 16 * sizeof(float); n -= 16 * sizeof(float)) {
39     const __m128 vx0123 = _mm_loadu_ps(x);
40     const __m128 vx4567 = _mm_loadu_ps(x + 4);
41     const __m128 vx89AB = _mm_loadu_ps(x + 8);
42     const __m128 vxCDEF = _mm_loadu_ps(x + 12);
43     x += 16;
44 
45     const __m128 vz0123 = _mm_or_ps(vx0123, vsign_mask);
46     const __m128 vz4567 = _mm_or_ps(vx4567, vsign_mask);
47     const __m128 vz89AB = _mm_or_ps(vx89AB, vsign_mask);
48     const __m128 vzCDEF = _mm_or_ps(vxCDEF, vsign_mask);
49 
50     __m128 vn0123 = _mm_add_ps(_mm_mul_ps(vz0123, vlog2e), vmagic_bias);
51     __m128 vn4567 = _mm_add_ps(_mm_mul_ps(vz4567, vlog2e), vmagic_bias);
52     __m128 vn89AB = _mm_add_ps(_mm_mul_ps(vz89AB, vlog2e), vmagic_bias);
53     __m128 vnCDEF = _mm_add_ps(_mm_mul_ps(vzCDEF, vlog2e), vmagic_bias);
54 
55     const __m128i ve0123 = _mm_slli_epi32(_mm_castps_si128(vn0123), 17);
56     const __m128i ve4567 = _mm_slli_epi32(_mm_castps_si128(vn4567), 17);
57     const __m128i ve89AB = _mm_slli_epi32(_mm_castps_si128(vn89AB), 17);
58     const __m128i veCDEF = _mm_slli_epi32(_mm_castps_si128(vnCDEF), 17);
59 
60     const __m128i vidx0123 = _mm_slli_epi32(_mm_and_si128(_mm_castps_si128(vn0123), vindex_mask), 2);
61     const __m128i vidx4567 = _mm_slli_epi32(_mm_and_si128(_mm_castps_si128(vn4567), vindex_mask), 2);
62     const __m128i vidx89AB = _mm_slli_epi32(_mm_and_si128(_mm_castps_si128(vn89AB), vindex_mask), 2);
63     const __m128i vidxCDEF = _mm_slli_epi32(_mm_and_si128(_mm_castps_si128(vnCDEF), vindex_mask), 2);
64 
65     #if XNN_ARCH_X86_64
66       const uint64_t vidx01 = (uint64_t) _mm_cvtsi128_si64(vidx0123);
67       const uint64_t vidx23 = (uint64_t) _mm_cvtsi128_si64(_mm_unpackhi_epi64(vidx0123, vidx0123));
68       const __m128i vl0   = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidx01)));
69       const __m128i vl2 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidx23)));
70       const __m128i vl1 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidx01 >> 32))));
71       const __m128i vl01 = _mm_unpacklo_epi32(vl0, vl1);
72       const __m128i vl3 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidx23 >> 32))));
73       const __m128i vl23 = _mm_unpacklo_epi32(vl2, vl3);
74       const __m128i vl0123 = _mm_unpacklo_epi64(vl01, vl23);
75       const uint64_t vidx45 = (uint64_t) _mm_cvtsi128_si64(vidx4567);
76       const uint64_t vidx67 = (uint64_t) _mm_cvtsi128_si64(_mm_unpackhi_epi64(vidx4567, vidx4567));
77       const __m128i vl4   = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidx45)));
78       const __m128i vl6 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidx67)));
79       const __m128i vl5 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidx45 >> 32))));
80       const __m128i vl45 = _mm_unpacklo_epi32(vl4, vl5);
81       const __m128i vl7 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidx67 >> 32))));
82       const __m128i vl67 = _mm_unpacklo_epi32(vl6, vl7);
83       const __m128i vl4567 = _mm_unpacklo_epi64(vl45, vl67);
84       const uint64_t vidx89 = (uint64_t) _mm_cvtsi128_si64(vidx89AB);
85       const uint64_t vidxAB = (uint64_t) _mm_cvtsi128_si64(_mm_unpackhi_epi64(vidx89AB, vidx89AB));
86       const __m128i vl8   = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidx89)));
87       const __m128i vlA = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidxAB)));
88       const __m128i vl9 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidx89 >> 32))));
89       const __m128i vl89 = _mm_unpacklo_epi32(vl8, vl9);
90       const __m128i vlB = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidxAB >> 32))));
91       const __m128i vlAB = _mm_unpacklo_epi32(vlA, vlB);
92       const __m128i vl89AB = _mm_unpacklo_epi64(vl89, vlAB);
93       const uint64_t vidxCD = (uint64_t) _mm_cvtsi128_si64(vidxCDEF);
94       const uint64_t vidxEF = (uint64_t) _mm_cvtsi128_si64(_mm_unpackhi_epi64(vidxCDEF, vidxCDEF));
95       const __m128i vlC   = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidxCD)));
96       const __m128i vlE = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidxEF)));
97       const __m128i vlD = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidxCD >> 32))));
98       const __m128i vlCD = _mm_unpacklo_epi32(vlC, vlD);
99       const __m128i vlF = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidxEF >> 32))));
100       const __m128i vlEF = _mm_unpacklo_epi32(vlE, vlF);
101       const __m128i vlCDEF = _mm_unpacklo_epi64(vlCD, vlEF);
102     #else  // !XNN_ARCH_X86_64
103       const uint32_t vidx0 = (uint32_t) _mm_cvtsi128_si32(vidx0123);
104       const uint32_t vidx1 = (uint32_t) _mm_extract_epi16(vidx0123, 2);
105       const uint32_t vidx2 = (uint32_t) _mm_extract_epi16(vidx0123, 4);
106       const uint32_t vidx3 = (uint32_t) _mm_extract_epi16(vidx0123, 6);
107       const __m128i vl0   = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidx0)));
108       const __m128i vl2 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidx2)));
109       const __m128i vl1 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidx1)));
110       const __m128i vl01 = _mm_unpacklo_epi32(vl0, vl1);
111       const __m128i vl3 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidx3)));
112       const __m128i vl23 = _mm_unpacklo_epi32(vl2, vl3);
113       const __m128i vl0123 = _mm_unpacklo_epi64(vl01, vl23);
114       const uint32_t vidx4 = (uint32_t) _mm_cvtsi128_si32(vidx4567);
115       const uint32_t vidx5 = (uint32_t) _mm_extract_epi16(vidx4567, 2);
116       const uint32_t vidx6 = (uint32_t) _mm_extract_epi16(vidx4567, 4);
117       const uint32_t vidx7 = (uint32_t) _mm_extract_epi16(vidx4567, 6);
118       const __m128i vl4   = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidx4)));
119       const __m128i vl6 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidx6)));
120       const __m128i vl5 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidx5)));
121       const __m128i vl45 = _mm_unpacklo_epi32(vl4, vl5);
122       const __m128i vl7 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidx7)));
123       const __m128i vl67 = _mm_unpacklo_epi32(vl6, vl7);
124       const __m128i vl4567 = _mm_unpacklo_epi64(vl45, vl67);
125       const uint32_t vidx8 = (uint32_t) _mm_cvtsi128_si32(vidx89AB);
126       const uint32_t vidx9 = (uint32_t) _mm_extract_epi16(vidx89AB, 2);
127       const uint32_t vidxA = (uint32_t) _mm_extract_epi16(vidx89AB, 4);
128       const uint32_t vidxB = (uint32_t) _mm_extract_epi16(vidx89AB, 6);
129       const __m128i vl8   = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidx8)));
130       const __m128i vlA = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidxA)));
131       const __m128i vl9 = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidx9)));
132       const __m128i vl89 = _mm_unpacklo_epi32(vl8, vl9);
133       const __m128i vlB = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidxB)));
134       const __m128i vlAB = _mm_unpacklo_epi32(vlA, vlB);
135       const __m128i vl89AB = _mm_unpacklo_epi64(vl89, vlAB);
136       const uint32_t vidxC = (uint32_t) _mm_cvtsi128_si32(vidxCDEF);
137       const uint32_t vidxD = (uint32_t) _mm_extract_epi16(vidxCDEF, 2);
138       const uint32_t vidxE = (uint32_t) _mm_extract_epi16(vidxCDEF, 4);
139       const uint32_t vidxF = (uint32_t) _mm_extract_epi16(vidxCDEF, 6);
140       const __m128i vlC   = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidxC)));
141       const __m128i vlE = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidxE)));
142       const __m128i vlD = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidxD)));
143       const __m128i vlCD = _mm_unpacklo_epi32(vlC, vlD);
144       const __m128i vlF = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + vidxF)));
145       const __m128i vlEF = _mm_unpacklo_epi32(vlE, vlF);
146       const __m128i vlCDEF = _mm_unpacklo_epi64(vlCD, vlEF);
147     #endif  // XNN_ARCH_X86_64
148 
149     const __m128 vs0123 = _mm_castsi128_ps(_mm_add_epi32(vl0123, ve0123));
150     const __m128 vs4567 = _mm_castsi128_ps(_mm_add_epi32(vl4567, ve4567));
151     const __m128 vs89AB = _mm_castsi128_ps(_mm_add_epi32(vl89AB, ve89AB));
152     const __m128 vsCDEF = _mm_castsi128_ps(_mm_add_epi32(vlCDEF, veCDEF));
153 
154     vn0123 = _mm_sub_ps(vn0123, vmagic_bias);
155     vn4567 = _mm_sub_ps(vn4567, vmagic_bias);
156     vn89AB = _mm_sub_ps(vn89AB, vmagic_bias);
157     vnCDEF = _mm_sub_ps(vnCDEF, vmagic_bias);
158 
159     __m128 vt0123 = _mm_add_ps(vz0123, _mm_mul_ps(vn0123, vminus_ln2_hi));
160     __m128 vt4567 = _mm_add_ps(vz4567, _mm_mul_ps(vn4567, vminus_ln2_hi));
161     __m128 vt89AB = _mm_add_ps(vz89AB, _mm_mul_ps(vn89AB, vminus_ln2_hi));
162     __m128 vtCDEF = _mm_add_ps(vzCDEF, _mm_mul_ps(vnCDEF, vminus_ln2_hi));
163 
164     vt0123 = _mm_add_ps(vt0123, _mm_mul_ps(vn0123, vminus_ln2_lo));
165     vt4567 = _mm_add_ps(vt4567, _mm_mul_ps(vn4567, vminus_ln2_lo));
166     vt89AB = _mm_add_ps(vt89AB, _mm_mul_ps(vn89AB, vminus_ln2_lo));
167     vtCDEF = _mm_add_ps(vtCDEF, _mm_mul_ps(vnCDEF, vminus_ln2_lo));
168 
169     __m128 vp0123 = _mm_mul_ps(vt0123, vc2);
170     __m128 vp4567 = _mm_mul_ps(vt4567, vc2);
171     __m128 vp89AB = _mm_mul_ps(vt89AB, vc2);
172     __m128 vpCDEF = _mm_mul_ps(vtCDEF, vc2);
173 
174     vp0123 = _mm_add_ps(vt0123, _mm_mul_ps(vp0123, vt0123));
175     vp4567 = _mm_add_ps(vt4567, _mm_mul_ps(vp4567, vt4567));
176     vp89AB = _mm_add_ps(vt89AB, _mm_mul_ps(vp89AB, vt89AB));
177     vpCDEF = _mm_add_ps(vtCDEF, _mm_mul_ps(vpCDEF, vtCDEF));
178 
179     const __m128 vy0123 = _mm_add_ps(vs0123, _mm_mul_ps(vs0123, vp0123));
180     const __m128 vy4567 = _mm_add_ps(vs4567, _mm_mul_ps(vs4567, vp4567));
181     const __m128 vy89AB = _mm_add_ps(vs89AB, _mm_mul_ps(vs89AB, vp89AB));
182     const __m128 vyCDEF = _mm_add_ps(vsCDEF, _mm_mul_ps(vsCDEF, vpCDEF));
183 
184     __m128 vf0123 = _mm_div_ps(vy0123, _mm_add_ps(vy0123, vone));
185     __m128 vf4567 = _mm_div_ps(vy4567, _mm_add_ps(vy4567, vone));
186     __m128 vf89AB = _mm_div_ps(vy89AB, _mm_add_ps(vy89AB, vone));
187     __m128 vfCDEF = _mm_div_ps(vyCDEF, _mm_add_ps(vyCDEF, vone));
188 
189     vf0123 = _mm_andnot_ps(_mm_cmplt_ps(vz0123, vdenorm_cutoff), vf0123);
190     vf4567 = _mm_andnot_ps(_mm_cmplt_ps(vz4567, vdenorm_cutoff), vf4567);
191     vf89AB = _mm_andnot_ps(_mm_cmplt_ps(vz89AB, vdenorm_cutoff), vf89AB);
192     vfCDEF = _mm_andnot_ps(_mm_cmplt_ps(vzCDEF, vdenorm_cutoff), vfCDEF);
193 
194     const __m128 vm0123 = _mm_castsi128_ps(_mm_cmpgt_epi32(_mm_setzero_si128(), _mm_castps_si128(vx0123)));
195     const __m128 vm4567 = _mm_castsi128_ps(_mm_cmpgt_epi32(_mm_setzero_si128(), _mm_castps_si128(vx4567)));
196     const __m128 vm89AB = _mm_castsi128_ps(_mm_cmpgt_epi32(_mm_setzero_si128(), _mm_castps_si128(vx89AB)));
197     const __m128 vmCDEF = _mm_castsi128_ps(_mm_cmpgt_epi32(_mm_setzero_si128(), _mm_castps_si128(vxCDEF)));
198 
199     vf0123 = _mm_or_ps(_mm_and_ps(vf0123, vm0123), _mm_andnot_ps(vm0123, _mm_sub_ps(vone, vf0123)));
200     vf4567 = _mm_or_ps(_mm_and_ps(vf4567, vm4567), _mm_andnot_ps(vm4567, _mm_sub_ps(vone, vf4567)));
201     vf89AB = _mm_or_ps(_mm_and_ps(vf89AB, vm89AB), _mm_andnot_ps(vm89AB, _mm_sub_ps(vone, vf89AB)));
202     vfCDEF = _mm_or_ps(_mm_and_ps(vfCDEF, vmCDEF), _mm_andnot_ps(vmCDEF, _mm_sub_ps(vone, vfCDEF)));
203 
204     _mm_storeu_ps(y, vf0123);
205     _mm_storeu_ps(y + 4, vf4567);
206     _mm_storeu_ps(y + 8, vf89AB);
207     _mm_storeu_ps(y + 12, vfCDEF);
208     y += 16;
209   }
210   for (; n >= 4 * sizeof(float); n -= 4 * sizeof(float)) {
211     const __m128 vx = _mm_loadu_ps(x);
212     x += 4;
213 
214     const __m128 vz = _mm_or_ps(vx, vsign_mask);
215 
216     __m128 vn = _mm_add_ps(_mm_mul_ps(vz, vlog2e), vmagic_bias);
217     const __m128i ve = _mm_slli_epi32(_mm_castps_si128(vn), 17);
218 
219     const __m128i vidx = _mm_slli_epi32(_mm_and_si128(_mm_castps_si128(vn), vindex_mask), 2);
220     #if XNN_ARCH_X86_64
221       const uint64_t vidx_lo = (uint64_t) _mm_cvtsi128_si64(vidx);
222       const uint64_t vidx_hi = (uint64_t) _mm_cvtsi128_si64(_mm_unpackhi_epi64(vidx, vidx));
223       const __m128i vl_ll   = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidx_lo)));
224       const __m128i vl_hl = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidx_hi)));
225       const __m128i vl_lh = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidx_lo >> 32))));
226       const __m128i vl_lo = _mm_unpacklo_epi32(vl_ll, vl_lh);
227       const __m128i vl_hh = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidx_hi >> 32))));
228       const __m128i vl_hi = _mm_unpacklo_epi32(vl_hl, vl_hh);
229     #else  // !XNN_ARCH_X86_64
230       const __m128i vl_ll = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) _mm_cvtsi128_si32(vidx))));
231       const __m128i vl_hl = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) _mm_extract_epi16(vidx, 4))));
232       const __m128i vl_lh = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) _mm_extract_epi16(vidx, 2))));
233       const __m128i vl_lo = _mm_unpacklo_epi32(vl_ll, vl_lh);
234       const __m128i vl_hh = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) _mm_extract_epi16(vidx, 6))));
235       const __m128i vl_hi = _mm_unpacklo_epi32(vl_hl, vl_hh);
236     #endif  // XNN_ARCH_X86_64
237     const __m128i vl = _mm_unpacklo_epi64(vl_lo, vl_hi);
238 
239     const __m128 vs = _mm_castsi128_ps(_mm_add_epi32(vl, ve));
240     vn = _mm_sub_ps(vn, vmagic_bias);
241 
242     __m128 vt = _mm_add_ps(vz, _mm_mul_ps(vn, vminus_ln2_hi));
243     vt = _mm_add_ps(vt, _mm_mul_ps(vn, vminus_ln2_lo));
244 
245     __m128 vp = _mm_mul_ps(vt, vc2);
246     vp = _mm_add_ps(vt, _mm_mul_ps(vp, vt));
247 
248     const __m128 vy = _mm_add_ps(vs, _mm_mul_ps(vs, vp));
249 
250     __m128 vf = _mm_div_ps(vy, _mm_add_ps(vy, vone));
251     vf = _mm_andnot_ps(_mm_cmplt_ps(vz, vdenorm_cutoff), vf);
252     const __m128 vm = _mm_castsi128_ps(_mm_cmpgt_epi32(_mm_setzero_si128(), _mm_castps_si128(vx)));
253     vf = _mm_or_ps(_mm_and_ps(vf, vm), _mm_andnot_ps(vm, _mm_sub_ps(vone, vf)));
254 
255     _mm_storeu_ps(y, vf);
256     y += 4;
257   }
258   if XNN_UNLIKELY(n != 0) {
259     const __m128 vx = _mm_loadu_ps(x);
260 
261     const __m128 vz = _mm_or_ps(vx, vsign_mask);
262 
263     __m128 vn = _mm_add_ps(_mm_mul_ps(vz, vlog2e), vmagic_bias);
264     const __m128i ve = _mm_slli_epi32(_mm_castps_si128(vn), 17);
265 
266     const __m128i vidx = _mm_slli_epi32(_mm_and_si128(_mm_castps_si128(vn), vindex_mask), 2);
267     #if XNN_ARCH_X86_64
268       const uint64_t vidx_lo = (uint64_t) _mm_cvtsi128_si64(vidx);
269       const uint64_t vidx_hi = (uint64_t) _mm_cvtsi128_si64(_mm_unpackhi_epi64(vidx, vidx));
270       const __m128i vl_ll   = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidx_lo)));
271       const __m128i vl_hl = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) vidx_hi)));
272       const __m128i vl_lh = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidx_lo >> 32))));
273       const __m128i vl_lo = _mm_unpacklo_epi32(vl_ll, vl_lh);
274       const __m128i vl_hh = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) (vidx_hi >> 32))));
275       const __m128i vl_hi = _mm_unpacklo_epi32(vl_hl, vl_hh);
276     #else  // !XNN_ARCH_X86_64
277       const __m128i vl_ll = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) _mm_cvtsi128_si32(vidx))));
278       const __m128i vl_hl = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) _mm_extract_epi16(vidx, 4))));
279       const __m128i vl_lh = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) _mm_extract_epi16(vidx, 2))));
280       const __m128i vl_lo = _mm_unpacklo_epi32(vl_ll, vl_lh);
281       const __m128i vl_hh = _mm_cvtsi32_si128(*((const int*) ((uintptr_t) xnn_table_exp2minus_k_over_64 + (uint32_t) _mm_extract_epi16(vidx, 6))));
282       const __m128i vl_hi = _mm_unpacklo_epi32(vl_hl, vl_hh);
283     #endif  // XNN_ARCH_X86_64
284     const __m128i vl = _mm_unpacklo_epi64(vl_lo, vl_hi);
285 
286     const __m128 vs = _mm_castsi128_ps(_mm_add_epi32(vl, ve));
287     vn = _mm_sub_ps(vn, vmagic_bias);
288 
289     __m128 vt = _mm_add_ps(vz, _mm_mul_ps(vn, vminus_ln2_hi));
290     vt = _mm_add_ps(vt, _mm_mul_ps(vn, vminus_ln2_lo));
291 
292     __m128 vp = _mm_mul_ps(vt, vc2);
293     vp = _mm_add_ps(vt, _mm_mul_ps(vp, vt));
294 
295     const __m128 vy = _mm_add_ps(vs, _mm_mul_ps(vs, vp));
296 
297     __m128 vf = _mm_div_ps(vy, _mm_add_ps(vy, vone));
298     vf = _mm_andnot_ps(_mm_cmplt_ps(vz, vdenorm_cutoff), vf);
299     const __m128 vm = _mm_castsi128_ps(_mm_cmpgt_epi32(_mm_setzero_si128(), _mm_castps_si128(vx)));
300     vf = _mm_or_ps(_mm_and_ps(vf, vm), _mm_andnot_ps(vm, _mm_sub_ps(vone, vf)));
301 
302     if (n & (2 * sizeof(float))) {
303       _mm_storel_pi((__m64*) y, vf);
304       vf = _mm_movehl_ps(vf, vf);
305       y += 2;
306     }
307     if (n & (1 * sizeof(float))) {
308       _mm_store_ss(y, vf);
309     }
310   }
311 }
312