xref: /aosp_15_r20/external/XNNPACK/src/f32-raddextexp/gen/avx512f-p5-scalef-x128-acc2.c (revision 4bdc94577ba0e567308109d787f7fec7b531ce36)
1 // Auto-generated file. Do not edit!
2 //   Template: src/f32-raddextexp/avx512f-p5-scalef.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 <immintrin.h>
14 
15 #include <xnnpack/common.h>
16 #include <xnnpack/intrinsics-polyfill.h>
17 #include <xnnpack/raddextexp.h>
18 
19 
xnn_f32_raddextexp_ukernel__avx512f_p5_scalef_x128_acc2(size_t elements,const float * x,float * sum)20 void xnn_f32_raddextexp_ukernel__avx512f_p5_scalef_x128_acc2(
21     size_t elements,
22     const float* x,
23     float* sum)
24 {
25   assert(elements % sizeof(float) == 0);
26 
27   const __m512 vlog2e = _mm512_set1_ps(0x1.715476p+0f);
28   const __m512 vminus_ln2_hi = _mm512_set1_ps(-0x1.62E43p-1f);
29   const __m512 vminus_ln2_lo = _mm512_set1_ps(0x1.05C61p-29f);
30 
31   const __m512 vc0 = _mm512_set1_ps(1.0f);
32   const __m512 vc1 = _mm512_set1_ps(0x1.FFFFF6p-1f);
33   const __m512 vc2 = _mm512_set1_ps(0x1.FFFDC6p-2f);
34   const __m512 vc3 = _mm512_set1_ps(0x1.555A80p-3f);
35   const __m512 vc4 = _mm512_set1_ps(0x1.573A1Ap-5f);
36   const __m512 vc5 = _mm512_set1_ps(0x1.0F9F9Cp-7f);
37 
38   const __m512 vminus_inf = _mm512_set1_ps(-INFINITY);
39 
40   __m512 vaccv0 = _mm512_setzero_ps();
41   __m512 vaccv1 = _mm512_setzero_ps();
42   __m512 vacce0 = vminus_inf;
43   __m512 vacce1 = vminus_inf;
44   for (; elements >= 128 * sizeof(float); elements -= 128 * sizeof(float)) {
45     // Load 128 (8x16) inputs at a time.
46     const __m512 vx0 = _mm512_loadu_ps(x);
47     const __m512 vx1 = _mm512_loadu_ps(x + 16);
48     const __m512 vx2 = _mm512_loadu_ps(x + 32);
49     const __m512 vx3 = _mm512_loadu_ps(x + 48);
50     const __m512 vx4 = _mm512_loadu_ps(x + 64);
51     const __m512 vx5 = _mm512_loadu_ps(x + 80);
52     const __m512 vx6 = _mm512_loadu_ps(x + 96);
53     const __m512 vx7 = _mm512_loadu_ps(x + 112);
54     x += 128;
55 
56     // Compute reduced argument elements := round(x / log(2)).
57     const __m512 vn0 = _mm512_roundscale_ps(_mm512_mul_ps(vx0, vlog2e), 0);
58     const __m512 vn1 = _mm512_roundscale_ps(_mm512_mul_ps(vx1, vlog2e), 0);
59     const __m512 vn2 = _mm512_roundscale_ps(_mm512_mul_ps(vx2, vlog2e), 0);
60     const __m512 vn3 = _mm512_roundscale_ps(_mm512_mul_ps(vx3, vlog2e), 0);
61     const __m512 vn4 = _mm512_roundscale_ps(_mm512_mul_ps(vx4, vlog2e), 0);
62     const __m512 vn5 = _mm512_roundscale_ps(_mm512_mul_ps(vx5, vlog2e), 0);
63     const __m512 vn6 = _mm512_roundscale_ps(_mm512_mul_ps(vx6, vlog2e), 0);
64     const __m512 vn7 = _mm512_roundscale_ps(_mm512_mul_ps(vx7, vlog2e), 0);
65 
66     // Compute reduced argument t := x - elements * log(2).
67     // Use Cody-Waite range reduction method (note two constants to represent log(2)) to improve accuracy.
68     __m512 vt0 = _mm512_fmadd_ps(vn0, vminus_ln2_hi, vx0);
69     __m512 vt1 = _mm512_fmadd_ps(vn1, vminus_ln2_hi, vx1);
70     __m512 vt2 = _mm512_fmadd_ps(vn2, vminus_ln2_hi, vx2);
71     __m512 vt3 = _mm512_fmadd_ps(vn3, vminus_ln2_hi, vx3);
72     __m512 vt4 = _mm512_fmadd_ps(vn4, vminus_ln2_hi, vx4);
73     __m512 vt5 = _mm512_fmadd_ps(vn5, vminus_ln2_hi, vx5);
74     __m512 vt6 = _mm512_fmadd_ps(vn6, vminus_ln2_hi, vx6);
75     __m512 vt7 = _mm512_fmadd_ps(vn7, vminus_ln2_hi, vx7);
76 
77     vt0 = _mm512_fmadd_ps(vn0, vminus_ln2_lo, vt0);
78     vt1 = _mm512_fmadd_ps(vn1, vminus_ln2_lo, vt1);
79     vt2 = _mm512_fmadd_ps(vn2, vminus_ln2_lo, vt2);
80     vt3 = _mm512_fmadd_ps(vn3, vminus_ln2_lo, vt3);
81     vt4 = _mm512_fmadd_ps(vn4, vminus_ln2_lo, vt4);
82     vt5 = _mm512_fmadd_ps(vn5, vminus_ln2_lo, vt5);
83     vt6 = _mm512_fmadd_ps(vn6, vminus_ln2_lo, vt6);
84     vt7 = _mm512_fmadd_ps(vn7, vminus_ln2_lo, vt7);
85 
86     // Compute degree-5 polynomial approximation for exp(t) on [-log(2)/2, log(2)/2].
87     __m512 vp0 = _mm512_fmadd_ps(vc5, vt0, vc4);
88     __m512 vp1 = _mm512_fmadd_ps(vc5, vt1, vc4);
89     __m512 vp2 = _mm512_fmadd_ps(vc5, vt2, vc4);
90     __m512 vp3 = _mm512_fmadd_ps(vc5, vt3, vc4);
91     __m512 vp4 = _mm512_fmadd_ps(vc5, vt4, vc4);
92     __m512 vp5 = _mm512_fmadd_ps(vc5, vt5, vc4);
93     __m512 vp6 = _mm512_fmadd_ps(vc5, vt6, vc4);
94     __m512 vp7 = _mm512_fmadd_ps(vc5, vt7, vc4);
95 
96     vp0 = _mm512_fmadd_ps(vp0, vt0, vc3);
97     vp1 = _mm512_fmadd_ps(vp1, vt1, vc3);
98     vp2 = _mm512_fmadd_ps(vp2, vt2, vc3);
99     vp3 = _mm512_fmadd_ps(vp3, vt3, vc3);
100     vp4 = _mm512_fmadd_ps(vp4, vt4, vc3);
101     vp5 = _mm512_fmadd_ps(vp5, vt5, vc3);
102     vp6 = _mm512_fmadd_ps(vp6, vt6, vc3);
103     vp7 = _mm512_fmadd_ps(vp7, vt7, vc3);
104 
105     vp0 = _mm512_fmadd_ps(vp0, vt0, vc2);
106     vp1 = _mm512_fmadd_ps(vp1, vt1, vc2);
107     vp2 = _mm512_fmadd_ps(vp2, vt2, vc2);
108     vp3 = _mm512_fmadd_ps(vp3, vt3, vc2);
109     vp4 = _mm512_fmadd_ps(vp4, vt4, vc2);
110     vp5 = _mm512_fmadd_ps(vp5, vt5, vc2);
111     vp6 = _mm512_fmadd_ps(vp6, vt6, vc2);
112     vp7 = _mm512_fmadd_ps(vp7, vt7, vc2);
113 
114     vp0 = _mm512_fmadd_ps(vp0, vt0, vc1);
115     vp1 = _mm512_fmadd_ps(vp1, vt1, vc1);
116     vp2 = _mm512_fmadd_ps(vp2, vt2, vc1);
117     vp3 = _mm512_fmadd_ps(vp3, vt3, vc1);
118     vp4 = _mm512_fmadd_ps(vp4, vt4, vc1);
119     vp5 = _mm512_fmadd_ps(vp5, vt5, vc1);
120     vp6 = _mm512_fmadd_ps(vp6, vt6, vc1);
121     vp7 = _mm512_fmadd_ps(vp7, vt7, vc1);
122 
123     vp0 = _mm512_fmadd_ps(vp0, vt0, vc0);
124     vp1 = _mm512_fmadd_ps(vp1, vt1, vc0);
125     vp2 = _mm512_fmadd_ps(vp2, vt2, vc0);
126     vp3 = _mm512_fmadd_ps(vp3, vt3, vc0);
127     vp4 = _mm512_fmadd_ps(vp4, vt4, vc0);
128     vp5 = _mm512_fmadd_ps(vp5, vt5, vc0);
129     vp6 = _mm512_fmadd_ps(vp6, vt6, vc0);
130     vp7 = _mm512_fmadd_ps(vp7, vt7, vc0);
131 
132     // Accumulate "extended" floating-point numbers in ("mantissa", "exponent") representation where
133     //  - vnX is "exponent"
134     //  - vpX is "mantissa"
135     //
136     // exp2(ae) * av + exp2(be) * bv =
137     //   = exp2(max(ae, be)) * exp2(ae - max(ae, be)) * av + exp2(max(ae, be)) * exp2(be - max(ae, be)) * bv
138     //   = exp2(max_e) * (exp2(ae - max_e) * av + exp2(be - max_e) * bv)
139     //   = exp2(max_e) * (exp2(delta_ae) * av + exp2(delta_be) * bv)
140     //
141     // For computational efficiency we add three "extended" floating-point numbers at a time.
142     __m512 vmax_e0 = _mm512_max_ps(vacce0, vn0);
143     __m512 vmax_e1 = _mm512_max_ps(vacce1, vn1);
144     vmax_e0 = _mm512_max_ps(vmax_e0, vn2);
145     vmax_e1 = _mm512_max_ps(vmax_e1, vn3);
146     vmax_e0 = _mm512_max_ps(vmax_e0, vn4);
147     vmax_e1 = _mm512_max_ps(vmax_e1, vn5);
148     vmax_e0 = _mm512_max_ps(vmax_e0, vn6);
149     vmax_e1 = _mm512_max_ps(vmax_e1, vn7);
150 
151     const __m512 vdelta_acce0 = _mm512_sub_ps(vacce0, vmax_e0);
152     const __m512 vdelta_acce1 = _mm512_sub_ps(vacce1, vmax_e1);
153     const __m512 vdelta_e0 = _mm512_sub_ps(vn0, vmax_e0);
154     const __m512 vdelta_e1 = _mm512_sub_ps(vn1, vmax_e1);
155     const __m512 vdelta_e2 = _mm512_sub_ps(vn2, vmax_e0);
156     const __m512 vdelta_e3 = _mm512_sub_ps(vn3, vmax_e1);
157     const __m512 vdelta_e4 = _mm512_sub_ps(vn4, vmax_e0);
158     const __m512 vdelta_e5 = _mm512_sub_ps(vn5, vmax_e1);
159     const __m512 vdelta_e6 = _mm512_sub_ps(vn6, vmax_e0);
160     const __m512 vdelta_e7 = _mm512_sub_ps(vn7, vmax_e1);
161 
162     // Update accumulated "mantissa" and "exponent" values
163     vaccv0 = _mm512_scalef_ps(vaccv0, vdelta_acce0);
164     vaccv1 = _mm512_scalef_ps(vaccv1, vdelta_acce1);
165     vaccv0 = _mm512_add_ps(vaccv0, _mm512_scalef_ps(vp0, vdelta_e0));
166     vaccv1 = _mm512_add_ps(vaccv1, _mm512_scalef_ps(vp1, vdelta_e1));
167     vaccv0 = _mm512_add_ps(vaccv0, _mm512_scalef_ps(vp2, vdelta_e2));
168     vaccv1 = _mm512_add_ps(vaccv1, _mm512_scalef_ps(vp3, vdelta_e3));
169     vaccv0 = _mm512_add_ps(vaccv0, _mm512_scalef_ps(vp4, vdelta_e4));
170     vaccv1 = _mm512_add_ps(vaccv1, _mm512_scalef_ps(vp5, vdelta_e5));
171     vaccv0 = _mm512_add_ps(vaccv0, _mm512_scalef_ps(vp6, vdelta_e6));
172     vaccv1 = _mm512_add_ps(vaccv1, _mm512_scalef_ps(vp7, vdelta_e7));
173 
174     vacce0 = vmax_e0;
175     vacce1 = vmax_e1;
176   }
177 
178   // Reduce partial sums of "extended" floating-point numbers into a single "extended" SIMD vector of sums.
179   const __m512 vmax_acce01 = _mm512_max_ps(vacce0, vacce1);
180 
181   const __m512 vdelta_acce0 = _mm512_sub_ps(vacce0, vmax_acce01);
182   const __m512 vdelta_acce1 = _mm512_sub_ps(vacce1, vmax_acce01);
183 
184   __m512 vaccv = _mm512_scalef_ps(vaccv0, vdelta_acce0);
185   vaccv = _mm512_add_ps(vaccv, _mm512_scalef_ps(vaccv1, vdelta_acce1));
186   __m512 vacce = vmax_acce01;
187 
188   for (; elements >= 16 * sizeof(float); elements -= 16 * sizeof(float)) {
189     // Load 16 inputs at a time.
190     const __m512 vx = _mm512_loadu_ps(x);
191     x += 16;
192 
193     // Compute reduced argument elements := round(x / log(2)).
194     const __m512 vn = _mm512_roundscale_ps(_mm512_mul_ps(vx, vlog2e), 0);
195 
196     // Compute reduced argument t := x - elements * log(2).
197     // Use Cody-Waite range reduction method (note two constants to represent log(2)) to improve accuracy.
198     __m512 vt = _mm512_fmadd_ps(vn, vminus_ln2_hi, vx);
199     vt = _mm512_fmadd_ps(vn, vminus_ln2_lo, vt);
200 
201     // Compute degree-5 polynomial approximation for exp(t) on [-log(2)/2, log(2)/2].
202     __m512 vp = _mm512_fmadd_ps(vc5, vt, vc4);
203     vp = _mm512_fmadd_ps(vp, vt, vc3);
204     vp = _mm512_fmadd_ps(vp, vt, vc2);
205     vp = _mm512_fmadd_ps(vp, vt, vc1);
206     vp = _mm512_fmadd_ps(vp, vt, vc0);
207 
208     // Accumulate "extended" floating-point numbers in ("mantissa", "exponent") representation.
209     const __m512 vmax_e = _mm512_max_ps(vacce, vn);
210     const __m512 vdelta_acce = _mm512_sub_ps(vacce, vmax_e);
211     const __m512 vdelta_e = _mm512_sub_ps(vn, vmax_e);
212     vaccv = _mm512_scalef_ps(vaccv, vdelta_acce);
213     vaccv = _mm512_add_ps(vaccv, _mm512_scalef_ps(vp, vdelta_e));
214 
215     vacce = vmax_e;
216   }
217   if XNN_UNLIKELY(elements != 0) {
218     // Prepare mask for valid 32-bit elements (depends on elements).
219     elements >>= 2 /* log2(sizeof(float)) */;
220     const __mmask16 vmask = _cvtu32_mask16((uint16_t) ((uint32_t) (UINT32_C(1) << elements) - UINT32_C(1)));
221 
222     // Load up to 15 inputs at a time.
223     const __m512 vx = _mm512_maskz_loadu_ps(vmask, x);
224 
225     // Compute reduced argument elements := round(x / log(2)).
226     const __m512 vn = _mm512_roundscale_ps(_mm512_mul_ps(vx, vlog2e), 0);
227 
228     // Compute reduced argument t := x - elements * log(2).
229     // Use Cody-Waite range reduction method (note two constants to represent log(2)) to improve accuracy.
230     __m512 vt = _mm512_fmadd_ps(vn, vminus_ln2_hi, vx);
231     vt = _mm512_fmadd_ps(vn, vminus_ln2_lo, vt);
232 
233     // Compute degree-5 polynomial approximation for exp(t) on [-log(2)/2, log(2)/2].
234     __m512 vp = _mm512_fmadd_ps(vc5, vt, vc4);
235     vp = _mm512_fmadd_ps(vp, vt, vc3);
236     vp = _mm512_fmadd_ps(vp, vt, vc2);
237     vp = _mm512_fmadd_ps(vp, vt, vc1);
238     vp = _mm512_fmadd_ps(vp, vt, vc0);
239 
240     // Accumulate "extended" floating-point numbers in ("mantissa", "exponent") representation.
241     const __m512 vmax_e = _mm512_mask_max_ps(vacce, vmask, vacce, vn);
242     const __m512 vdelta_acce = _mm512_sub_ps(vacce, vmax_e);
243     const __m512 vdelta_e = _mm512_sub_ps(vn, vmax_e);
244     vaccv = _mm512_mask_scalef_ps(vaccv, vmask, vaccv, vdelta_acce);
245     vaccv = _mm512_mask_add_ps(vaccv, vmask, vaccv, _mm512_maskz_scalef_ps(vmask, vp, vdelta_e));
246     vacce = vmax_e;
247   }
248 
249   // Reduce partial sums of "extended" floating-point numbers into a single "extended" floating-point sum.
250   const float vmax_acce = _mm512_reduce_max_ps(vacce);
251   const __m512 vdelta_acce = _mm512_sub_ps(vacce, _mm512_set1_ps(vmax_acce));
252 
253   sum[0] = _mm512_reduce_add_ps(_mm512_scalef_ps(vaccv, vdelta_acce));
254   sum[1] = vmax_acce;
255 
256   _mm256_zeroupper();
257 }
258