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1 // Auto-generated file. Do not edit!
2 //   Template: src/f32-vsqrt/fma3-nr1fma1adj.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 <immintrin.h>
13 
14 #include <xnnpack/common.h>
15 #include <xnnpack/vunary.h>
16 
17 
18 static const int32_t mask_table[14] = {-1, -1, -1, -1, -1, -1, -1, 0, 0, 0, 0, 0, 0, 0};
19 
xnn_f32_vsqrt_ukernel__fma3_nr1fma1adj_x16(size_t n,const float * x,float * y,const union xnn_f32_sqrt_params params[restrict XNN_MIN_ELEMENTS (1)])20 void xnn_f32_vsqrt_ukernel__fma3_nr1fma1adj_x16(
21     size_t n,
22     const float* x,
23     float* y,
24     const union xnn_f32_sqrt_params params[restrict XNN_MIN_ELEMENTS(1)])
25 {
26   assert(n != 0);
27   assert(n % sizeof(float) == 0);
28 
29   const __m256 vhalf = _mm256_broadcast_ss(&params->fma.half);
30   for (; n >= 16 * sizeof(float); n -= 16 * sizeof(float)) {
31     const __m256 vx0 = _mm256_loadu_ps(x);
32     const __m256 vx1 = _mm256_loadu_ps(x + 8);
33     x += 16;
34 
35     const __m256 vrsqrtx0 = _mm256_rsqrt_ps(vx0);
36     const __m256 vrsqrtx1 = _mm256_rsqrt_ps(vx1);
37 
38     __m256 vsqrtx0 = _mm256_mul_ps(vrsqrtx0, vx0);
39     __m256 vhalfrsqrtx0 = _mm256_mul_ps(vrsqrtx0, vhalf);
40     __m256 vsqrtx1 = _mm256_mul_ps(vrsqrtx1, vx1);
41     __m256 vhalfrsqrtx1 = _mm256_mul_ps(vrsqrtx1, vhalf);
42 
43     const __m256 vresidual0 = _mm256_fnmadd_ps(vsqrtx0, vhalfrsqrtx0, vhalf);
44     const __m256 vresidual1 = _mm256_fnmadd_ps(vsqrtx1, vhalfrsqrtx1, vhalf);
45 
46     vhalfrsqrtx0 = _mm256_fmadd_ps(vhalfrsqrtx0, vresidual0, vhalfrsqrtx0);
47     vsqrtx0 = _mm256_fmadd_ps(vsqrtx0, vresidual0, vsqrtx0);
48     vhalfrsqrtx1 = _mm256_fmadd_ps(vhalfrsqrtx1, vresidual1, vhalfrsqrtx1);
49     vsqrtx1 = _mm256_fmadd_ps(vsqrtx1, vresidual1, vsqrtx1);
50 
51     const __m256 vadjustment0 = _mm256_fnmadd_ps(vsqrtx0, vsqrtx0, vx0);
52     const __m256 vadjustment1 = _mm256_fnmadd_ps(vsqrtx1, vsqrtx1, vx1);
53 
54     const __m256 vy0 = _mm256_fmadd_ps(vhalfrsqrtx0, vadjustment0, vsqrtx0);
55     const __m256 vy1 = _mm256_fmadd_ps(vhalfrsqrtx1, vadjustment1, vsqrtx1);
56 
57     _mm256_storeu_ps(y, vy0);
58     _mm256_storeu_ps(y + 8, vy1);
59     y += 16;
60   }
61   for (; n >= 8 * sizeof(float); n -= 8 * sizeof(float)) {
62     const __m256 vx = _mm256_loadu_ps(x);
63     x += 8;
64 
65     const __m256 vrsqrtx = _mm256_rsqrt_ps(vx);
66     __m256 vsqrtx = _mm256_mul_ps(vrsqrtx, vx);
67     __m256 vhalfrsqrtx = _mm256_mul_ps(vrsqrtx, vhalf);
68     const __m256 vresidual = _mm256_fnmadd_ps(vsqrtx, vhalfrsqrtx, vhalf);
69     vhalfrsqrtx = _mm256_fmadd_ps(vhalfrsqrtx, vresidual, vhalfrsqrtx);
70     vsqrtx = _mm256_fmadd_ps(vsqrtx, vresidual, vsqrtx);
71     const __m256 vadjustment = _mm256_fnmadd_ps(vsqrtx, vsqrtx, vx);
72     const __m256 vy = _mm256_fmadd_ps(vhalfrsqrtx, vadjustment, vsqrtx);
73 
74     _mm256_storeu_ps(y, vy);
75     y += 8;
76   }
77   if XNN_UNLIKELY(n != 0) {
78     assert(n >= 1 * sizeof(float));
79     assert(n <= 7 * sizeof(float));
80     __m256i vmask = _mm256_loadu_si256((const __m256i*) ((uintptr_t) &mask_table[7] - n));
81 
82     const __m256 vx = _mm256_maskload_ps(x, vmask);
83 
84     const __m256 vrsqrtx = _mm256_rsqrt_ps(vx);
85     __m256 vsqrtx = _mm256_mul_ps(vrsqrtx, vx);
86     __m256 vhalfrsqrtx = _mm256_mul_ps(vrsqrtx, vhalf);
87     const __m256 vresidual = _mm256_fnmadd_ps(vsqrtx, vhalfrsqrtx, vhalf);
88     vhalfrsqrtx = _mm256_fmadd_ps(vhalfrsqrtx, vresidual, vhalfrsqrtx);
89     vsqrtx = _mm256_fmadd_ps(vsqrtx, vresidual, vsqrtx);
90     const __m256 vadjustment = _mm256_fnmadd_ps(vsqrtx, vsqrtx, vx);
91     const __m256 vy = _mm256_fmadd_ps(vhalfrsqrtx, vadjustment, vsqrtx);
92 
93     // _mm256_maskstore_ps(y, vmask, vy) could be used here, but triggers msan failures (probably an msan bug).
94     __m128 vy_lo = _mm256_castps256_ps128(vy);
95     if (n & (4 * sizeof(float))) {
96       _mm_storeu_ps(y, vy_lo);
97       vy_lo = _mm256_extractf128_ps(vy, 1);
98       y += 4;
99     }
100     if (n & (2 * sizeof(float))) {
101       _mm_storel_pi((__m64*) y, vy_lo);
102       vy_lo = _mm_movehl_ps(vy_lo, vy_lo);
103       y += 2;
104     }
105     if (n & (1 * sizeof(float))) {
106       _mm_store_ss(y, vy_lo);
107     }
108   }
109 }
110