1*4bdc9457SAndroid Build Coastguard Worker // Auto-generated file. Do not edit!
2*4bdc9457SAndroid Build Coastguard Worker // Template: src/f32-raddstoreexpminusmax/sse2-rr2-p5.c.in
3*4bdc9457SAndroid Build Coastguard Worker // Generator: tools/xngen
4*4bdc9457SAndroid Build Coastguard Worker //
5*4bdc9457SAndroid Build Coastguard Worker // Copyright 2019 Google LLC
6*4bdc9457SAndroid Build Coastguard Worker //
7*4bdc9457SAndroid Build Coastguard Worker // This source code is licensed under the BSD-style license found in the
8*4bdc9457SAndroid Build Coastguard Worker // LICENSE file in the root directory of this source tree.
9*4bdc9457SAndroid Build Coastguard Worker
10*4bdc9457SAndroid Build Coastguard Worker #include <assert.h>
11*4bdc9457SAndroid Build Coastguard Worker
12*4bdc9457SAndroid Build Coastguard Worker #include <emmintrin.h>
13*4bdc9457SAndroid Build Coastguard Worker
14*4bdc9457SAndroid Build Coastguard Worker #include <xnnpack/common.h>
15*4bdc9457SAndroid Build Coastguard Worker #include <xnnpack/raddstoreexpminusmax.h>
16*4bdc9457SAndroid Build Coastguard Worker
17*4bdc9457SAndroid Build Coastguard Worker
xnn_f32_raddstoreexpminusmax_ukernel__sse2_rr2_p5_x20_acc5(size_t elements,const float * input,const float * max,float * output,float * sum,const union xnn_f32_expminus_params params[restrict XNN_MIN_ELEMENTS (1)])18*4bdc9457SAndroid Build Coastguard Worker void xnn_f32_raddstoreexpminusmax_ukernel__sse2_rr2_p5_x20_acc5(
19*4bdc9457SAndroid Build Coastguard Worker size_t elements,
20*4bdc9457SAndroid Build Coastguard Worker const float* input,
21*4bdc9457SAndroid Build Coastguard Worker const float* max,
22*4bdc9457SAndroid Build Coastguard Worker float* output,
23*4bdc9457SAndroid Build Coastguard Worker float* sum,
24*4bdc9457SAndroid Build Coastguard Worker const union xnn_f32_expminus_params params[restrict XNN_MIN_ELEMENTS(1)]) XNN_OOB_READS
25*4bdc9457SAndroid Build Coastguard Worker {
26*4bdc9457SAndroid Build Coastguard Worker assert(elements % sizeof(float) == 0);
27*4bdc9457SAndroid Build Coastguard Worker
28*4bdc9457SAndroid Build Coastguard Worker const __m128 vi_max = _mm_load1_ps(max);
29*4bdc9457SAndroid Build Coastguard Worker const __m128 vlog2e = _mm_load_ps(params->sse2_rr2_p5.log2e);
30*4bdc9457SAndroid Build Coastguard Worker const __m128 vmagic_bias = _mm_load_ps(params->sse2_rr2_p5.magic_bias);
31*4bdc9457SAndroid Build Coastguard Worker const __m128 vminus_ln2_hi = _mm_load_ps(params->sse2_rr2_p5.minus_ln2_hi);
32*4bdc9457SAndroid Build Coastguard Worker const __m128 vminus_ln2_lo = _mm_load_ps(params->sse2_rr2_p5.minus_ln2_lo);
33*4bdc9457SAndroid Build Coastguard Worker const __m128 vc5 = _mm_load_ps(params->sse2_rr2_p5.c5);
34*4bdc9457SAndroid Build Coastguard Worker const __m128 vc4 = _mm_load_ps(params->sse2_rr2_p5.c4);
35*4bdc9457SAndroid Build Coastguard Worker const __m128 vc3 = _mm_load_ps(params->sse2_rr2_p5.c3);
36*4bdc9457SAndroid Build Coastguard Worker const __m128 vc2 = _mm_load_ps(params->sse2_rr2_p5.c2);
37*4bdc9457SAndroid Build Coastguard Worker const __m128 vc1 = _mm_load_ps(params->sse2_rr2_p5.c1);
38*4bdc9457SAndroid Build Coastguard Worker const __m128 vdenorm_cutoff = _mm_load_ps(params->sse2_rr2_p5.denorm_cutoff);
39*4bdc9457SAndroid Build Coastguard Worker
40*4bdc9457SAndroid Build Coastguard Worker __m128 vacc0 = _mm_setzero_ps();
41*4bdc9457SAndroid Build Coastguard Worker __m128 vacc1 = _mm_setzero_ps();
42*4bdc9457SAndroid Build Coastguard Worker __m128 vacc2 = _mm_setzero_ps();
43*4bdc9457SAndroid Build Coastguard Worker __m128 vacc3 = _mm_setzero_ps();
44*4bdc9457SAndroid Build Coastguard Worker __m128 vacc4 = _mm_setzero_ps();
45*4bdc9457SAndroid Build Coastguard Worker for (; elements >= 20 * sizeof(float); elements -= 20 * sizeof(float)) {
46*4bdc9457SAndroid Build Coastguard Worker // Load 20 (5x4) inputs at a time.
47*4bdc9457SAndroid Build Coastguard Worker const __m128 vi0123 = _mm_loadu_ps(input);
48*4bdc9457SAndroid Build Coastguard Worker const __m128 vi4567 = _mm_loadu_ps(input + 4);
49*4bdc9457SAndroid Build Coastguard Worker const __m128 vi89AB = _mm_loadu_ps(input + 8);
50*4bdc9457SAndroid Build Coastguard Worker const __m128 viCDEF = _mm_loadu_ps(input + 12);
51*4bdc9457SAndroid Build Coastguard Worker const __m128 viGHIJ = _mm_loadu_ps(input + 16);
52*4bdc9457SAndroid Build Coastguard Worker input += 20;
53*4bdc9457SAndroid Build Coastguard Worker
54*4bdc9457SAndroid Build Coastguard Worker // Subtract maximum input x := i - i_max. This implies x <= 0.
55*4bdc9457SAndroid Build Coastguard Worker const __m128 vx0123 = _mm_sub_ps(vi0123, vi_max);
56*4bdc9457SAndroid Build Coastguard Worker const __m128 vx4567 = _mm_sub_ps(vi4567, vi_max);
57*4bdc9457SAndroid Build Coastguard Worker const __m128 vx89AB = _mm_sub_ps(vi89AB, vi_max);
58*4bdc9457SAndroid Build Coastguard Worker const __m128 vxCDEF = _mm_sub_ps(viCDEF, vi_max);
59*4bdc9457SAndroid Build Coastguard Worker const __m128 vxGHIJ = _mm_sub_ps(viGHIJ, vi_max);
60*4bdc9457SAndroid Build Coastguard Worker
61*4bdc9457SAndroid Build Coastguard Worker // Compute reduced argument elements := round(x / log(2)).
62*4bdc9457SAndroid Build Coastguard Worker __m128 vn0123 = _mm_add_ps(_mm_mul_ps(vx0123, vlog2e), vmagic_bias);
63*4bdc9457SAndroid Build Coastguard Worker __m128 vn4567 = _mm_add_ps(_mm_mul_ps(vx4567, vlog2e), vmagic_bias);
64*4bdc9457SAndroid Build Coastguard Worker __m128 vn89AB = _mm_add_ps(_mm_mul_ps(vx89AB, vlog2e), vmagic_bias);
65*4bdc9457SAndroid Build Coastguard Worker __m128 vnCDEF = _mm_add_ps(_mm_mul_ps(vxCDEF, vlog2e), vmagic_bias);
66*4bdc9457SAndroid Build Coastguard Worker __m128 vnGHIJ = _mm_add_ps(_mm_mul_ps(vxGHIJ, vlog2e), vmagic_bias);
67*4bdc9457SAndroid Build Coastguard Worker
68*4bdc9457SAndroid Build Coastguard Worker // Create a floating-point number s (scale) such that s == 2**elements for inputs which don't cause underflow, i.e.
69*4bdc9457SAndroid Build Coastguard Worker // -87.33642 <= x <= 0.0, and -126 <= elements <= 0 accordingly.
70*4bdc9457SAndroid Build Coastguard Worker const __m128 vs0123 = _mm_castsi128_ps(_mm_slli_epi32(_mm_castps_si128(vn0123), 23));
71*4bdc9457SAndroid Build Coastguard Worker const __m128 vs4567 = _mm_castsi128_ps(_mm_slli_epi32(_mm_castps_si128(vn4567), 23));
72*4bdc9457SAndroid Build Coastguard Worker const __m128 vs89AB = _mm_castsi128_ps(_mm_slli_epi32(_mm_castps_si128(vn89AB), 23));
73*4bdc9457SAndroid Build Coastguard Worker const __m128 vsCDEF = _mm_castsi128_ps(_mm_slli_epi32(_mm_castps_si128(vnCDEF), 23));
74*4bdc9457SAndroid Build Coastguard Worker const __m128 vsGHIJ = _mm_castsi128_ps(_mm_slli_epi32(_mm_castps_si128(vnGHIJ), 23));
75*4bdc9457SAndroid Build Coastguard Worker
76*4bdc9457SAndroid Build Coastguard Worker // Subtract the large number back to get final elements := round(x / log(2)).
77*4bdc9457SAndroid Build Coastguard Worker vn0123 = _mm_sub_ps(vn0123, vmagic_bias);
78*4bdc9457SAndroid Build Coastguard Worker vn4567 = _mm_sub_ps(vn4567, vmagic_bias);
79*4bdc9457SAndroid Build Coastguard Worker vn89AB = _mm_sub_ps(vn89AB, vmagic_bias);
80*4bdc9457SAndroid Build Coastguard Worker vnCDEF = _mm_sub_ps(vnCDEF, vmagic_bias);
81*4bdc9457SAndroid Build Coastguard Worker vnGHIJ = _mm_sub_ps(vnGHIJ, vmagic_bias);
82*4bdc9457SAndroid Build Coastguard Worker
83*4bdc9457SAndroid Build Coastguard Worker // Compute reduced argument t := x - elements * log(2).
84*4bdc9457SAndroid Build Coastguard Worker // Use Cody-Waite range reduction method (note two constants to represent log(2)) to improve accuracy.
85*4bdc9457SAndroid Build Coastguard Worker __m128 vt0123 = _mm_add_ps(_mm_mul_ps(vn0123, vminus_ln2_hi), vx0123);
86*4bdc9457SAndroid Build Coastguard Worker __m128 vt4567 = _mm_add_ps(_mm_mul_ps(vn4567, vminus_ln2_hi), vx4567);
87*4bdc9457SAndroid Build Coastguard Worker __m128 vt89AB = _mm_add_ps(_mm_mul_ps(vn89AB, vminus_ln2_hi), vx89AB);
88*4bdc9457SAndroid Build Coastguard Worker __m128 vtCDEF = _mm_add_ps(_mm_mul_ps(vnCDEF, vminus_ln2_hi), vxCDEF);
89*4bdc9457SAndroid Build Coastguard Worker __m128 vtGHIJ = _mm_add_ps(_mm_mul_ps(vnGHIJ, vminus_ln2_hi), vxGHIJ);
90*4bdc9457SAndroid Build Coastguard Worker
91*4bdc9457SAndroid Build Coastguard Worker vt0123 = _mm_add_ps(_mm_mul_ps(vn0123, vminus_ln2_lo), vt0123);
92*4bdc9457SAndroid Build Coastguard Worker vt4567 = _mm_add_ps(_mm_mul_ps(vn4567, vminus_ln2_lo), vt4567);
93*4bdc9457SAndroid Build Coastguard Worker vt89AB = _mm_add_ps(_mm_mul_ps(vn89AB, vminus_ln2_lo), vt89AB);
94*4bdc9457SAndroid Build Coastguard Worker vtCDEF = _mm_add_ps(_mm_mul_ps(vnCDEF, vminus_ln2_lo), vtCDEF);
95*4bdc9457SAndroid Build Coastguard Worker vtGHIJ = _mm_add_ps(_mm_mul_ps(vnGHIJ, vminus_ln2_lo), vtGHIJ);
96*4bdc9457SAndroid Build Coastguard Worker
97*4bdc9457SAndroid Build Coastguard Worker // Compute degree-5 polynomial approximation for exp(t) on [-log(2)/2, log(2)/2].
98*4bdc9457SAndroid Build Coastguard Worker __m128 vp0123 = _mm_add_ps(_mm_mul_ps(vc5, vt0123), vc4);
99*4bdc9457SAndroid Build Coastguard Worker __m128 vp4567 = _mm_add_ps(_mm_mul_ps(vc5, vt4567), vc4);
100*4bdc9457SAndroid Build Coastguard Worker __m128 vp89AB = _mm_add_ps(_mm_mul_ps(vc5, vt89AB), vc4);
101*4bdc9457SAndroid Build Coastguard Worker __m128 vpCDEF = _mm_add_ps(_mm_mul_ps(vc5, vtCDEF), vc4);
102*4bdc9457SAndroid Build Coastguard Worker __m128 vpGHIJ = _mm_add_ps(_mm_mul_ps(vc5, vtGHIJ), vc4);
103*4bdc9457SAndroid Build Coastguard Worker
104*4bdc9457SAndroid Build Coastguard Worker vp0123 = _mm_add_ps(_mm_mul_ps(vp0123, vt0123), vc3);
105*4bdc9457SAndroid Build Coastguard Worker vp4567 = _mm_add_ps(_mm_mul_ps(vp4567, vt4567), vc3);
106*4bdc9457SAndroid Build Coastguard Worker vp89AB = _mm_add_ps(_mm_mul_ps(vp89AB, vt89AB), vc3);
107*4bdc9457SAndroid Build Coastguard Worker vpCDEF = _mm_add_ps(_mm_mul_ps(vpCDEF, vtCDEF), vc3);
108*4bdc9457SAndroid Build Coastguard Worker vpGHIJ = _mm_add_ps(_mm_mul_ps(vpGHIJ, vtGHIJ), vc3);
109*4bdc9457SAndroid Build Coastguard Worker
110*4bdc9457SAndroid Build Coastguard Worker vp0123 = _mm_add_ps(_mm_mul_ps(vp0123, vt0123), vc2);
111*4bdc9457SAndroid Build Coastguard Worker vp4567 = _mm_add_ps(_mm_mul_ps(vp4567, vt4567), vc2);
112*4bdc9457SAndroid Build Coastguard Worker vp89AB = _mm_add_ps(_mm_mul_ps(vp89AB, vt89AB), vc2);
113*4bdc9457SAndroid Build Coastguard Worker vpCDEF = _mm_add_ps(_mm_mul_ps(vpCDEF, vtCDEF), vc2);
114*4bdc9457SAndroid Build Coastguard Worker vpGHIJ = _mm_add_ps(_mm_mul_ps(vpGHIJ, vtGHIJ), vc2);
115*4bdc9457SAndroid Build Coastguard Worker
116*4bdc9457SAndroid Build Coastguard Worker vp0123 = _mm_add_ps(_mm_mul_ps(vp0123, vt0123), vc1);
117*4bdc9457SAndroid Build Coastguard Worker vp4567 = _mm_add_ps(_mm_mul_ps(vp4567, vt4567), vc1);
118*4bdc9457SAndroid Build Coastguard Worker vp89AB = _mm_add_ps(_mm_mul_ps(vp89AB, vt89AB), vc1);
119*4bdc9457SAndroid Build Coastguard Worker vpCDEF = _mm_add_ps(_mm_mul_ps(vpCDEF, vtCDEF), vc1);
120*4bdc9457SAndroid Build Coastguard Worker vpGHIJ = _mm_add_ps(_mm_mul_ps(vpGHIJ, vtGHIJ), vc1);
121*4bdc9457SAndroid Build Coastguard Worker
122*4bdc9457SAndroid Build Coastguard Worker // Reconstruct the final f value:
123*4bdc9457SAndroid Build Coastguard Worker // f = s * (1 + t * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5)))))
124*4bdc9457SAndroid Build Coastguard Worker // = s + (t * s) * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5))))
125*4bdc9457SAndroid Build Coastguard Worker // = s + (t * s) * p
126*4bdc9457SAndroid Build Coastguard Worker vt0123 = _mm_mul_ps(vt0123, vs0123);
127*4bdc9457SAndroid Build Coastguard Worker vt4567 = _mm_mul_ps(vt4567, vs4567);
128*4bdc9457SAndroid Build Coastguard Worker vt89AB = _mm_mul_ps(vt89AB, vs89AB);
129*4bdc9457SAndroid Build Coastguard Worker vtCDEF = _mm_mul_ps(vtCDEF, vsCDEF);
130*4bdc9457SAndroid Build Coastguard Worker vtGHIJ = _mm_mul_ps(vtGHIJ, vsGHIJ);
131*4bdc9457SAndroid Build Coastguard Worker
132*4bdc9457SAndroid Build Coastguard Worker __m128 vf0123 = _mm_add_ps(_mm_mul_ps(vt0123, vp0123), vs0123);
133*4bdc9457SAndroid Build Coastguard Worker __m128 vf4567 = _mm_add_ps(_mm_mul_ps(vt4567, vp4567), vs4567);
134*4bdc9457SAndroid Build Coastguard Worker __m128 vf89AB = _mm_add_ps(_mm_mul_ps(vt89AB, vp89AB), vs89AB);
135*4bdc9457SAndroid Build Coastguard Worker __m128 vfCDEF = _mm_add_ps(_mm_mul_ps(vtCDEF, vpCDEF), vsCDEF);
136*4bdc9457SAndroid Build Coastguard Worker __m128 vfGHIJ = _mm_add_ps(_mm_mul_ps(vtGHIJ, vpGHIJ), vsGHIJ);
137*4bdc9457SAndroid Build Coastguard Worker
138*4bdc9457SAndroid Build Coastguard Worker // For inputs below zero cutoff, replace output with +0.0f.
139*4bdc9457SAndroid Build Coastguard Worker // Note that for NaN inputs, comparison result is false, and outputs are left unchanged.
140*4bdc9457SAndroid Build Coastguard Worker vf0123 = _mm_andnot_ps(_mm_cmplt_ps(vx0123, vdenorm_cutoff), vf0123);
141*4bdc9457SAndroid Build Coastguard Worker vf4567 = _mm_andnot_ps(_mm_cmplt_ps(vx4567, vdenorm_cutoff), vf4567);
142*4bdc9457SAndroid Build Coastguard Worker vf89AB = _mm_andnot_ps(_mm_cmplt_ps(vx89AB, vdenorm_cutoff), vf89AB);
143*4bdc9457SAndroid Build Coastguard Worker vfCDEF = _mm_andnot_ps(_mm_cmplt_ps(vxCDEF, vdenorm_cutoff), vfCDEF);
144*4bdc9457SAndroid Build Coastguard Worker vfGHIJ = _mm_andnot_ps(_mm_cmplt_ps(vxGHIJ, vdenorm_cutoff), vfGHIJ);
145*4bdc9457SAndroid Build Coastguard Worker
146*4bdc9457SAndroid Build Coastguard Worker // Store 20 (5x4) outputs at a time.
147*4bdc9457SAndroid Build Coastguard Worker _mm_storeu_ps(output, vf0123);
148*4bdc9457SAndroid Build Coastguard Worker _mm_storeu_ps(output + 4, vf4567);
149*4bdc9457SAndroid Build Coastguard Worker _mm_storeu_ps(output + 8, vf89AB);
150*4bdc9457SAndroid Build Coastguard Worker _mm_storeu_ps(output + 12, vfCDEF);
151*4bdc9457SAndroid Build Coastguard Worker _mm_storeu_ps(output + 16, vfGHIJ);
152*4bdc9457SAndroid Build Coastguard Worker output += 20;
153*4bdc9457SAndroid Build Coastguard Worker
154*4bdc9457SAndroid Build Coastguard Worker // Accumulate computed exponents.
155*4bdc9457SAndroid Build Coastguard Worker vacc0 = _mm_add_ps(vacc0, vf0123);
156*4bdc9457SAndroid Build Coastguard Worker vacc4 = _mm_add_ps(vacc4, vf4567);
157*4bdc9457SAndroid Build Coastguard Worker vacc3 = _mm_add_ps(vacc3, vf89AB);
158*4bdc9457SAndroid Build Coastguard Worker vacc2 = _mm_add_ps(vacc2, vfCDEF);
159*4bdc9457SAndroid Build Coastguard Worker vacc1 = _mm_add_ps(vacc1, vfGHIJ);
160*4bdc9457SAndroid Build Coastguard Worker }
161*4bdc9457SAndroid Build Coastguard Worker // Add up all accumulators to vacc0
162*4bdc9457SAndroid Build Coastguard Worker vacc0 = _mm_add_ps(vacc0, vacc1);
163*4bdc9457SAndroid Build Coastguard Worker vacc2 = _mm_add_ps(vacc2, vacc3);
164*4bdc9457SAndroid Build Coastguard Worker vacc0 = _mm_add_ps(vacc0, vacc2);
165*4bdc9457SAndroid Build Coastguard Worker vacc0 = _mm_add_ps(vacc0, vacc4);
166*4bdc9457SAndroid Build Coastguard Worker
167*4bdc9457SAndroid Build Coastguard Worker __m128 vacc = vacc0;
168*4bdc9457SAndroid Build Coastguard Worker for (; elements >= 4 * sizeof(float); elements -= 4 * sizeof(float)) {
169*4bdc9457SAndroid Build Coastguard Worker // Load 4 inputs at a time.
170*4bdc9457SAndroid Build Coastguard Worker const __m128 vi = _mm_loadu_ps(input);
171*4bdc9457SAndroid Build Coastguard Worker input += 4;
172*4bdc9457SAndroid Build Coastguard Worker
173*4bdc9457SAndroid Build Coastguard Worker // Subtract maximum input x := i - i_max. This implies x <= 0.
174*4bdc9457SAndroid Build Coastguard Worker const __m128 vx = _mm_sub_ps(vi, vi_max);
175*4bdc9457SAndroid Build Coastguard Worker
176*4bdc9457SAndroid Build Coastguard Worker // Compute reduced argument elements := round(x / log(2)).
177*4bdc9457SAndroid Build Coastguard Worker __m128 vn = _mm_add_ps(_mm_mul_ps(vx, vlog2e), vmagic_bias);
178*4bdc9457SAndroid Build Coastguard Worker
179*4bdc9457SAndroid Build Coastguard Worker // Create a floating-point number s (scale) such that s == 2**elements for inputs which don't cause underflow, i.e.
180*4bdc9457SAndroid Build Coastguard Worker // -87.33642 <= x <= 0.0, and -126 <= elements <= 0 accordingly.
181*4bdc9457SAndroid Build Coastguard Worker const __m128 vs = _mm_castsi128_ps(_mm_slli_epi32(_mm_castps_si128(vn), 23));
182*4bdc9457SAndroid Build Coastguard Worker
183*4bdc9457SAndroid Build Coastguard Worker // Subtract the large number back to get final elements := round(x / log(2)).
184*4bdc9457SAndroid Build Coastguard Worker vn = _mm_sub_ps(vn, vmagic_bias);
185*4bdc9457SAndroid Build Coastguard Worker
186*4bdc9457SAndroid Build Coastguard Worker // Compute reduced argument t := x - elements * log(2).
187*4bdc9457SAndroid Build Coastguard Worker // Use Cody-Waite range reduction method (note two constants to represent log(2)) to improve accuracy.
188*4bdc9457SAndroid Build Coastguard Worker __m128 vt = _mm_add_ps(_mm_mul_ps(vn, vminus_ln2_hi), vx);
189*4bdc9457SAndroid Build Coastguard Worker vt = _mm_add_ps(_mm_mul_ps(vn, vminus_ln2_lo), vt);
190*4bdc9457SAndroid Build Coastguard Worker
191*4bdc9457SAndroid Build Coastguard Worker // Compute degree-5 polynomial approximation for exp(t) on [-log(2)/2, log(2)/2].
192*4bdc9457SAndroid Build Coastguard Worker __m128 vp = _mm_add_ps(_mm_mul_ps(vc5, vt), vc4);
193*4bdc9457SAndroid Build Coastguard Worker vp = _mm_add_ps(_mm_mul_ps(vp, vt), vc3);
194*4bdc9457SAndroid Build Coastguard Worker vp = _mm_add_ps(_mm_mul_ps(vp, vt), vc2);
195*4bdc9457SAndroid Build Coastguard Worker vp = _mm_add_ps(_mm_mul_ps(vp, vt), vc1);
196*4bdc9457SAndroid Build Coastguard Worker
197*4bdc9457SAndroid Build Coastguard Worker // Reconstruct the final f value:
198*4bdc9457SAndroid Build Coastguard Worker // f = s * (1 + t * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5)))))
199*4bdc9457SAndroid Build Coastguard Worker // = s + (t * s) * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5))))
200*4bdc9457SAndroid Build Coastguard Worker // = s + (t * s) * p
201*4bdc9457SAndroid Build Coastguard Worker vt = _mm_mul_ps(vt, vs);
202*4bdc9457SAndroid Build Coastguard Worker __m128 vf = _mm_add_ps(_mm_mul_ps(vt, vp), vs);
203*4bdc9457SAndroid Build Coastguard Worker
204*4bdc9457SAndroid Build Coastguard Worker // For inputs below zero cutoff, replace output with +0.0f.
205*4bdc9457SAndroid Build Coastguard Worker // Note that for NaN inputs, comparison result is false, and outputs are left unchanged.
206*4bdc9457SAndroid Build Coastguard Worker vf = _mm_andnot_ps(_mm_cmplt_ps(vx, vdenorm_cutoff), vf);
207*4bdc9457SAndroid Build Coastguard Worker
208*4bdc9457SAndroid Build Coastguard Worker // Store 4 outputs at a time.
209*4bdc9457SAndroid Build Coastguard Worker _mm_storeu_ps(output, vf);
210*4bdc9457SAndroid Build Coastguard Worker output += 4;
211*4bdc9457SAndroid Build Coastguard Worker
212*4bdc9457SAndroid Build Coastguard Worker // Accumulate computed exponents.
213*4bdc9457SAndroid Build Coastguard Worker vacc = _mm_add_ps(vacc, vf);
214*4bdc9457SAndroid Build Coastguard Worker }
215*4bdc9457SAndroid Build Coastguard Worker if (elements != 0) {
216*4bdc9457SAndroid Build Coastguard Worker assert(elements >= 1 * sizeof(float));
217*4bdc9457SAndroid Build Coastguard Worker assert(elements <= 3 * sizeof(float));
218*4bdc9457SAndroid Build Coastguard Worker // Load 4 inputs at a time.
219*4bdc9457SAndroid Build Coastguard Worker const __m128 vi = _mm_loadu_ps(input);
220*4bdc9457SAndroid Build Coastguard Worker
221*4bdc9457SAndroid Build Coastguard Worker // Subtract maximum input x := i - i_max. This implies x <= 0.
222*4bdc9457SAndroid Build Coastguard Worker const __m128 vx = _mm_sub_ps(vi, vi_max);
223*4bdc9457SAndroid Build Coastguard Worker
224*4bdc9457SAndroid Build Coastguard Worker // Compute reduced argument elements := round(x / log(2)).
225*4bdc9457SAndroid Build Coastguard Worker __m128 vn = _mm_add_ps(_mm_mul_ps(vx, vlog2e), vmagic_bias);
226*4bdc9457SAndroid Build Coastguard Worker
227*4bdc9457SAndroid Build Coastguard Worker // Create a floating-point number s (scale) such that s == 2**elements for inputs which don't cause underflow, i.e.
228*4bdc9457SAndroid Build Coastguard Worker // -87.33642 <= x <= 0.0, and -126 <= elements <= 0 accordingly.
229*4bdc9457SAndroid Build Coastguard Worker const __m128 vs = _mm_castsi128_ps(_mm_slli_epi32(_mm_castps_si128(vn), 23));
230*4bdc9457SAndroid Build Coastguard Worker
231*4bdc9457SAndroid Build Coastguard Worker // Subtract the large number back to get final elements := round(x / log(2)).
232*4bdc9457SAndroid Build Coastguard Worker vn = _mm_sub_ps(vn, vmagic_bias);
233*4bdc9457SAndroid Build Coastguard Worker
234*4bdc9457SAndroid Build Coastguard Worker // Compute reduced argument t := x - elements * log(2).
235*4bdc9457SAndroid Build Coastguard Worker // Use Cody-Waite range reduction method (note two constants to represent log(2)) to improve accuracy.
236*4bdc9457SAndroid Build Coastguard Worker __m128 vt = _mm_add_ps(_mm_mul_ps(vn, vminus_ln2_hi), vx);
237*4bdc9457SAndroid Build Coastguard Worker vt = _mm_add_ps(_mm_mul_ps(vn, vminus_ln2_lo), vt);
238*4bdc9457SAndroid Build Coastguard Worker
239*4bdc9457SAndroid Build Coastguard Worker // Compute degree-5 polynomial approximation for exp(t) on [-log(2)/2, log(2)/2].
240*4bdc9457SAndroid Build Coastguard Worker __m128 vp = _mm_add_ps(_mm_mul_ps(vc5, vt), vc4);
241*4bdc9457SAndroid Build Coastguard Worker vp = _mm_add_ps(_mm_mul_ps(vp, vt), vc3);
242*4bdc9457SAndroid Build Coastguard Worker vp = _mm_add_ps(_mm_mul_ps(vp, vt), vc2);
243*4bdc9457SAndroid Build Coastguard Worker vp = _mm_add_ps(_mm_mul_ps(vp, vt), vc1);
244*4bdc9457SAndroid Build Coastguard Worker
245*4bdc9457SAndroid Build Coastguard Worker // Reconstruct the final f value:
246*4bdc9457SAndroid Build Coastguard Worker // f = s * (1 + t * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5)))))
247*4bdc9457SAndroid Build Coastguard Worker // = s + (t * s) * (c1 + t * (c2 + t * (c3 + t * (c4 + t * c5))))
248*4bdc9457SAndroid Build Coastguard Worker // = s + (t * s) * p
249*4bdc9457SAndroid Build Coastguard Worker vt = _mm_mul_ps(vt, vs);
250*4bdc9457SAndroid Build Coastguard Worker __m128 vf = _mm_add_ps(_mm_mul_ps(vt, vp), vs);
251*4bdc9457SAndroid Build Coastguard Worker
252*4bdc9457SAndroid Build Coastguard Worker // For inputs below zero cutoff, replace output with +0.0f.
253*4bdc9457SAndroid Build Coastguard Worker // Note that for NaN inputs, comparison result is false, and outputs are left unchanged.
254*4bdc9457SAndroid Build Coastguard Worker vf = _mm_andnot_ps(_mm_cmplt_ps(vx, vdenorm_cutoff), vf);
255*4bdc9457SAndroid Build Coastguard Worker
256*4bdc9457SAndroid Build Coastguard Worker if (elements & (2 * sizeof(float))) {
257*4bdc9457SAndroid Build Coastguard Worker // Store 2 outputs at a time.
258*4bdc9457SAndroid Build Coastguard Worker _mm_storel_pi((__m64*) output, vf);
259*4bdc9457SAndroid Build Coastguard Worker output += 2;
260*4bdc9457SAndroid Build Coastguard Worker
261*4bdc9457SAndroid Build Coastguard Worker // Accumulate 2 computed exponents.
262*4bdc9457SAndroid Build Coastguard Worker vacc = _mm_add_ps(vacc, _mm_movelh_ps(vf, _mm_setzero_ps()));
263*4bdc9457SAndroid Build Coastguard Worker
264*4bdc9457SAndroid Build Coastguard Worker vf = _mm_movehl_ps(vf, vf);
265*4bdc9457SAndroid Build Coastguard Worker }
266*4bdc9457SAndroid Build Coastguard Worker if (elements & (1 * sizeof(float))) {
267*4bdc9457SAndroid Build Coastguard Worker // Store 1 output at a time.
268*4bdc9457SAndroid Build Coastguard Worker _mm_store_ss(output, vf);
269*4bdc9457SAndroid Build Coastguard Worker
270*4bdc9457SAndroid Build Coastguard Worker // Accumulate 1 computed exponent.
271*4bdc9457SAndroid Build Coastguard Worker vacc = _mm_add_ss(vacc, vf);
272*4bdc9457SAndroid Build Coastguard Worker }
273*4bdc9457SAndroid Build Coastguard Worker }
274*4bdc9457SAndroid Build Coastguard Worker // Reduce 4 elements in the SIMD register
275*4bdc9457SAndroid Build Coastguard Worker vacc = _mm_add_ps(vacc, _mm_movehl_ps(vacc, vacc));
276*4bdc9457SAndroid Build Coastguard Worker vacc = _mm_add_ss(vacc, _mm_shuffle_ps(vacc, vacc, _MM_SHUFFLE(2, 3, 0, 1)));
277*4bdc9457SAndroid Build Coastguard Worker _mm_store_ss(sum, vacc);
278*4bdc9457SAndroid Build Coastguard Worker }
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