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stgsharp/StgSharp.Native/sn-src/m.solve.x86.c
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2026-01-14 18:01:03 +08:00

130 lines
4.7 KiB
C

#include "sn_target.h"
#if SN_IS_ARCH(SN_ARCH_X86_64)
#include "sn_intrinsic.h"
#include <math.h>
DECLARE_KER_PROC_LEFT_RIGHT_ANS_SCALAR(float, sse, , try_plu)
{
/* Aliases */
MAT_KERNEL(float) *upper = left; /* U */
MAT_KERNEL(float) *lower = right; /* L (unit diag) */
MAT_KERNEL(float) *source = ans; /* A */
unsigned char *pivot = (unsigned char *)&scalar->data[0]; /* length = 4 */
int *success = (int *)&scalar->data[1];
/* Init permutation and outputs */
pivot[0] = 0;
pivot[1] = 1;
pivot[2] = 2;
pivot[3] = 3;
*success = 1;
/* Working copy of A in column-major a[col][row], load via SIMD view */
MAT_KERNEL(float) a;
const __m128 z = _mm_setzero_ps();
for (int c = 0; c < 4; ++c) {
__m128 col = _mm_load_ps((float *)&source->f32_x[c]);
_mm_storeu_ps((float *)&a.f32_x[c], col);
_mm_store_ps((float *)&upper->f32_x[c], z);
_mm_store_ps((float *)&lower->f32_x[c], z);
}
const float eps = 1e-12f;
for (int k = 0; k < 4; ++k) {
/* Pivot search on column k, rows k..3 */
int p = k;
float maxabs = fabsf(a.m[k][p]);
for (int r = k + 1; r < 4; ++r) {
float v = fabsf(a.m[k][r]);
if (v > maxabs) {
maxabs = v;
p = r;
}
}
if (maxabs < eps) {
*success = 0;
/* leave outputs zeroed */
return;
}
/* Swap rows if needed */
if (p != k) {
for (int c = 0; c < 4; ++c) {
float tmp = a.m[c][k];
a.m[c][k] = a.m[c][p];
a.m[c][p] = tmp;
}
unsigned char tmpi = pivot[k];
pivot[k] = pivot[p];
pivot[p] = tmpi;
}
float pivot_val = a.m[k][k];
/* Eliminate below pivot: store multipliers in L column k */
for (int r = k + 1; r < 4; ++r) {
float factor = a.m[k][r] / pivot_val;
lower->m[k][r] = factor;
for (int c = k; c < 4; ++c) {
a.m[c][r] -= factor * a.m[c][k];
}
}
/* Set U row k (columns k..3) and L diagonal */
lower->m[k][k] = 1.0f;
for (int c = k; c < 4; ++c) {
upper->m[c][k] = a.m[c][k];
}
}
/* Ensure remaining diagonal ones for L */
for (int d = 0; d < 4; ++d) {
if (lower->m[d][d] == 0.0f)
lower->m[d][d] = 1.0f;
}
}
DECLARE_KER_PROC_RIGHT_ANS(float, sse, , quality)
{
static const __m128 abs_mask_source = { .m128_i32 = { 0x80000000, 0x80000000, 0x80000000,
0x80000000 } };
register __m128 abs_mask = _mm_load_ps(abs_mask_source.m128_i32);
register __m128 col0 = _mm_andnot_ps(abs_mask, _mm_load_ps((float *)&right->f32_x[0]));
register __m128 col1 = _mm_andnot_ps(abs_mask, _mm_load_ps((float *)&right->f32_x[1]));
register __m128 col2 = _mm_andnot_ps(abs_mask, _mm_load_ps((float *)&right->f32_x[2]));
register __m128 col3 = _mm_andnot_ps(abs_mask, _mm_load_ps((float *)&right->f32_x[3]));
// norm
register __m128 row_sum = _mm_add_ps(col0, col1);
row_sum = _mm_add_ps(row_sum, col2);
row_sum = _mm_add_ps(row_sum, col3);
// max(0,2) and max(1,3)
register __m128 max = _mm_max_ps(row_sum, _mm_movehl_ps(row_sum, row_sum));
max = _mm_max_ps(max, _mm_shuffle_ps(max, max, _MM_SHUFFLE(2, 3, 0, 1)));
float norm = _mm_cvtss_f32(max);
ans->f32_x[0].m128_f32[0] = norm;
// min on cross
col1 = _mm_shuffle_ps(col1, col1, _MM_SHUFFLE(0, 3, 2, 1));
col2 = _mm_shuffle_ps(col2, col2, _MM_SHUFFLE(1, 0, 3, 2));
col3 = _mm_shuffle_ps(col3, col3, _MM_SHUFFLE(2, 1, 0, 3));
max = _mm_min_ps(col0, col2);
register max0 = _mm_min_ps(max, col1);
max = _mm_min_ps(max0, max);
float min_val = _mm_cvtss_f32(max);
ans->f32_x[0].m128_f32[1] = min_val;
float quality = min_val / (norm + 1e-20f);
ans->f32_x[0].m128_f32[2] = quality;
}
#endif