1 /* ----------------------------------------------------------------------
2  * Project:      CMSIS DSP Library
3  * Title:        arm_mat_cholesky_f32.c
4  * Description:  Floating-point Cholesky decomposition
5  *
6  * $Date:        23 April 2021
7  * $Revision:    V1.9.0
8  *
9  * Target Processor: Cortex-M and Cortex-A cores
10  * -------------------------------------------------------------------- */
11 /*
12  * Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
13  *
14  * SPDX-License-Identifier: Apache-2.0
15  *
16  * Licensed under the Apache License, Version 2.0 (the License); you may
17  * not use this file except in compliance with the License.
18  * You may obtain a copy of the License at
19  *
20  * www.apache.org/licenses/LICENSE-2.0
21  *
22  * Unless required by applicable law or agreed to in writing, software
23  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
24  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25  * See the License for the specific language governing permissions and
26  * limitations under the License.
27  */
28 
29 #include "dsp/matrix_functions.h"
30 
31 /**
32   @ingroup groupMatrix
33  */
34 
35 /**
36   @defgroup MatrixChol Cholesky and LDLT decompositions
37 
38   Computes the Cholesky or LDL^t decomposition of a matrix.
39 
40 
41   If the input matrix does not have a decomposition, then the
42   algorithm terminates and returns error status ARM_MATH_DECOMPOSITION_FAILURE.
43  */
44 
45 /**
46   @addtogroup MatrixChol
47   @{
48  */
49 
50 /**
51    * @brief Floating-point Cholesky decomposition of positive-definite matrix.
52    * @param[in]  pSrc   points to the instance of the input floating-point matrix structure.
53    * @param[out] pDst   points to the instance of the output floating-point matrix structure.
54    * @return The function returns ARM_MATH_SIZE_MISMATCH, if the dimensions do not match.
55    * @return        execution status
56                    - \ref ARM_MATH_SUCCESS       : Operation successful
57                    - \ref ARM_MATH_SIZE_MISMATCH : Matrix size check failed
58                    - \ref ARM_MATH_DECOMPOSITION_FAILURE      : Input matrix cannot be decomposed
59    * @par
60    * If the matrix is ill conditioned or only semi-definite, then it is better using the LDL^t decomposition.
61    * The decomposition of A is returning a lower triangular matrix U such that A = U U^t
62    */
63 
64 #if defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE)
65 
66 #include "arm_helium_utils.h"
67 
arm_mat_cholesky_f32(const arm_matrix_instance_f32 * pSrc,arm_matrix_instance_f32 * pDst)68 arm_status arm_mat_cholesky_f32(
69   const arm_matrix_instance_f32 * pSrc,
70         arm_matrix_instance_f32 * pDst)
71 {
72 
73   arm_status status;                             /* status of matrix inverse */
74 
75 
76 #ifdef ARM_MATH_MATRIX_CHECK
77 
78   /* Check for matrix mismatch condition */
79   if ((pSrc->numRows != pSrc->numCols) ||
80       (pDst->numRows != pDst->numCols) ||
81       (pSrc->numRows != pDst->numRows)   )
82   {
83     /* Set status as ARM_MATH_SIZE_MISMATCH */
84     status = ARM_MATH_SIZE_MISMATCH;
85   }
86   else
87 
88 #endif /* #ifdef ARM_MATH_MATRIX_CHECK */
89 
90   {
91     int i,j,k;
92     int n = pSrc->numRows;
93     float32_t invSqrtVj;
94     float32_t *pA,*pG;
95     int kCnt;
96 
97     mve_pred16_t p0;
98 
99     f32x4_t acc, acc0, acc1, acc2, acc3;
100     f32x4_t vecGi;
101     f32x4_t vecGj,vecGj0,vecGj1,vecGj2,vecGj3;
102 
103 
104     pA = pSrc->pData;
105     pG = pDst->pData;
106 
107     for(i=0 ;i < n ; i++)
108     {
109        for(j=i ; j+3 < n ; j+=4)
110        {
111           pG[(j + 0) * n + i] = pA[(j + 0) * n + i];
112           pG[(j + 1) * n + i] = pA[(j + 1) * n + i];
113           pG[(j + 2) * n + i] = pA[(j + 2) * n + i];
114           pG[(j + 3) * n + i] = pA[(j + 3) * n + i];
115 
116           kCnt = i;
117           acc0 = vdupq_n_f32(0.0f);
118           acc1 = vdupq_n_f32(0.0f);
119           acc2 = vdupq_n_f32(0.0f);
120           acc3 = vdupq_n_f32(0.0f);
121 
122           for(k=0; k < i ; k+=4)
123           {
124              p0 = vctp32q(kCnt);
125 
126              vecGi=vldrwq_z_f32(&pG[i * n + k],p0);
127 
128              vecGj0=vldrwq_z_f32(&pG[(j + 0) * n + k],p0);
129              vecGj1=vldrwq_z_f32(&pG[(j + 1) * n + k],p0);
130              vecGj2=vldrwq_z_f32(&pG[(j + 2) * n + k],p0);
131              vecGj3=vldrwq_z_f32(&pG[(j + 3) * n + k],p0);
132 
133              acc0 = vfmaq_m(acc0, vecGi, vecGj0, p0);
134              acc1 = vfmaq_m(acc1, vecGi, vecGj1, p0);
135              acc2 = vfmaq_m(acc2, vecGi, vecGj2, p0);
136              acc3 = vfmaq_m(acc3, vecGi, vecGj3, p0);
137 
138              kCnt -= 4;
139           }
140           pG[(j + 0) * n + i] -= vecAddAcrossF32Mve(acc0);
141           pG[(j + 1) * n + i] -= vecAddAcrossF32Mve(acc1);
142           pG[(j + 2) * n + i] -= vecAddAcrossF32Mve(acc2);
143           pG[(j + 3) * n + i] -= vecAddAcrossF32Mve(acc3);
144        }
145 
146        for(; j < n ; j++)
147        {
148           pG[j * n + i] = pA[j * n + i];
149 
150           kCnt = i;
151           acc = vdupq_n_f32(0.0f);
152 
153           for(k=0; k < i ; k+=4)
154           {
155              p0 = vctp32q(kCnt);
156 
157              vecGi=vldrwq_z_f32(&pG[i * n + k],p0);
158              vecGj=vldrwq_z_f32(&pG[j * n + k],p0);
159 
160              acc = vfmaq_m(acc, vecGi, vecGj,p0);
161 
162              kCnt -= 4;
163           }
164           pG[j * n + i] -= vecAddAcrossF32Mve(acc);
165        }
166 
167        if (pG[i * n + i] <= 0.0f)
168        {
169          return(ARM_MATH_DECOMPOSITION_FAILURE);
170        }
171 
172        invSqrtVj = 1.0f/sqrtf(pG[i * n + i]);
173        for(j=i; j < n ; j++)
174        {
175          pG[j * n + i] = pG[j * n + i] * invSqrtVj ;
176        }
177     }
178 
179     status = ARM_MATH_SUCCESS;
180 
181   }
182 
183 
184   /* Return to application */
185   return (status);
186 }
187 
188 #else
189 #if defined(ARM_MATH_NEON) && !defined(ARM_MATH_AUTOVECTORIZE)
190 
arm_mat_cholesky_f32(const arm_matrix_instance_f32 * pSrc,arm_matrix_instance_f32 * pDst)191 arm_status arm_mat_cholesky_f32(
192   const arm_matrix_instance_f32 * pSrc,
193         arm_matrix_instance_f32 * pDst)
194 {
195 
196   arm_status status;                             /* status of matrix inverse */
197 
198 
199 #ifdef ARM_MATH_MATRIX_CHECK
200 
201   /* Check for matrix mismatch condition */
202   if ((pSrc->numRows != pSrc->numCols) ||
203       (pDst->numRows != pDst->numCols) ||
204       (pSrc->numRows != pDst->numRows)   )
205   {
206     /* Set status as ARM_MATH_SIZE_MISMATCH */
207     status = ARM_MATH_SIZE_MISMATCH;
208   }
209   else
210 
211 #endif /* #ifdef ARM_MATH_MATRIX_CHECK */
212 
213   {
214     int i,j,k;
215     int n = pSrc->numRows;
216     float32_t invSqrtVj;
217     float32_t *pA,*pG;
218     int kCnt;
219 
220 
221     f32x4_t acc, acc0, acc1, acc2, acc3;
222     f32x4_t vecGi;
223     f32x4_t vecGj,vecGj0,vecGj1,vecGj2,vecGj3;
224     f32x2_t tmp = vdup_n_f32(0);
225     float32_t sum=0.0f;
226     float32_t sum0=0.0f,sum1=0.0f,sum2=0.0f,sum3=0.0f;
227 
228 
229     pA = pSrc->pData;
230     pG = pDst->pData;
231 
232     for(i=0 ;i < n ; i++)
233     {
234        for(j=i ; j+3 < n ; j+=4)
235        {
236           pG[(j + 0) * n + i] = pA[(j + 0) * n + i];
237           pG[(j + 1) * n + i] = pA[(j + 1) * n + i];
238           pG[(j + 2) * n + i] = pA[(j + 2) * n + i];
239           pG[(j + 3) * n + i] = pA[(j + 3) * n + i];
240 
241           acc0 = vdupq_n_f32(0.0f);
242           acc1 = vdupq_n_f32(0.0f);
243           acc2 = vdupq_n_f32(0.0f);
244           acc3 = vdupq_n_f32(0.0f);
245 
246           kCnt = i >> 2;
247           k=0;
248           while(kCnt > 0)
249           {
250 
251              vecGi=vld1q_f32(&pG[i * n + k]);
252 
253              vecGj0=vld1q_f32(&pG[(j + 0) * n + k]);
254              vecGj1=vld1q_f32(&pG[(j + 1) * n + k]);
255              vecGj2=vld1q_f32(&pG[(j + 2) * n + k]);
256              vecGj3=vld1q_f32(&pG[(j + 3) * n + k]);
257 
258              acc0 = vfmaq_f32(acc0, vecGi, vecGj0);
259              acc1 = vfmaq_f32(acc1, vecGi, vecGj1);
260              acc2 = vfmaq_f32(acc2, vecGi, vecGj2);
261              acc3 = vfmaq_f32(acc3, vecGi, vecGj3);
262 
263              kCnt--;
264              k+=4;
265           }
266 
267 #if __aarch64__
268           sum0 = vpadds_f32(vpadd_f32(vget_low_f32(acc0), vget_high_f32(acc0)));
269           sum1 = vpadds_f32(vpadd_f32(vget_low_f32(acc1), vget_high_f32(acc1)));
270           sum2 = vpadds_f32(vpadd_f32(vget_low_f32(acc2), vget_high_f32(acc2)));
271           sum3 = vpadds_f32(vpadd_f32(vget_low_f32(acc3), vget_high_f32(acc3)));
272 
273 #else
274           tmp = vpadd_f32(vget_low_f32(acc0), vget_high_f32(acc0));
275           sum0 = vget_lane_f32(tmp, 0) + vget_lane_f32(tmp, 1);
276 
277           tmp = vpadd_f32(vget_low_f32(acc1), vget_high_f32(acc1));
278           sum1 = vget_lane_f32(tmp, 0) + vget_lane_f32(tmp, 1);
279 
280           tmp = vpadd_f32(vget_low_f32(acc2), vget_high_f32(acc2));
281           sum2 = vget_lane_f32(tmp, 0) + vget_lane_f32(tmp, 1);
282 
283           tmp = vpadd_f32(vget_low_f32(acc3), vget_high_f32(acc3));
284           sum3 = vget_lane_f32(tmp, 0) + vget_lane_f32(tmp, 1);
285 #endif
286 
287           kCnt = i & 3;
288           while(kCnt > 0)
289           {
290 
291              sum0 = sum0 + pG[i * n + k] * pG[(j + 0) * n + k];
292              sum1 = sum1 + pG[i * n + k] * pG[(j + 1) * n + k];
293              sum2 = sum2 + pG[i * n + k] * pG[(j + 2) * n + k];
294              sum3 = sum3 + pG[i * n + k] * pG[(j + 3) * n + k];
295              kCnt--;
296              k++;
297           }
298 
299           pG[(j + 0) * n + i] -= sum0;
300           pG[(j + 1) * n + i] -= sum1;
301           pG[(j + 2) * n + i] -= sum2;
302           pG[(j + 3) * n + i] -= sum3;
303        }
304 
305        for(; j < n ; j++)
306        {
307           pG[j * n + i] = pA[j * n + i];
308 
309           acc = vdupq_n_f32(0.0f);
310 
311           kCnt = i >> 2;
312           k=0;
313           while(kCnt > 0)
314           {
315 
316              vecGi=vld1q_f32(&pG[i * n + k]);
317              vecGj=vld1q_f32(&pG[j * n + k]);
318 
319              acc = vfmaq_f32(acc, vecGi, vecGj);
320 
321              kCnt--;
322              k+=4;
323           }
324 
325 #if __aarch64__
326           sum = vpadds_f32(vpadd_f32(vget_low_f32(acc), vget_high_f32(acc)));
327 #else
328           tmp = vpadd_f32(vget_low_f32(acc), vget_high_f32(acc));
329           sum = vget_lane_f32(tmp, 0) + vget_lane_f32(tmp, 1);
330 #endif
331 
332           kCnt = i & 3;
333           while(kCnt > 0)
334           {
335              sum = sum + pG[i * n + k] * pG[(j + 0) * n + k];
336 
337 
338              kCnt--;
339              k++;
340           }
341 
342           pG[j * n + i] -= sum;
343        }
344 
345        if (pG[i * n + i] <= 0.0f)
346        {
347          return(ARM_MATH_DECOMPOSITION_FAILURE);
348        }
349 
350        invSqrtVj = 1.0f/sqrtf(pG[i * n + i]);
351        for(j=i; j < n ; j++)
352        {
353          pG[j * n + i] = pG[j * n + i] * invSqrtVj ;
354        }
355     }
356 
357     status = ARM_MATH_SUCCESS;
358 
359   }
360 
361 
362   /* Return to application */
363   return (status);
364 }
365 
366 #else
arm_mat_cholesky_f32(const arm_matrix_instance_f32 * pSrc,arm_matrix_instance_f32 * pDst)367 arm_status arm_mat_cholesky_f32(
368   const arm_matrix_instance_f32 * pSrc,
369         arm_matrix_instance_f32 * pDst)
370 {
371 
372   arm_status status;                             /* status of matrix inverse */
373 
374 
375 #ifdef ARM_MATH_MATRIX_CHECK
376 
377   /* Check for matrix mismatch condition */
378   if ((pSrc->numRows != pSrc->numCols) ||
379       (pDst->numRows != pDst->numCols) ||
380       (pSrc->numRows != pDst->numRows)   )
381   {
382     /* Set status as ARM_MATH_SIZE_MISMATCH */
383     status = ARM_MATH_SIZE_MISMATCH;
384   }
385   else
386 
387 #endif /* #ifdef ARM_MATH_MATRIX_CHECK */
388 
389   {
390     int i,j,k;
391     int n = pSrc->numRows;
392     float32_t invSqrtVj;
393     float32_t *pA,*pG;
394 
395     pA = pSrc->pData;
396     pG = pDst->pData;
397 
398 
399     for(i=0 ; i < n ; i++)
400     {
401        for(j=i ; j < n ; j++)
402        {
403           pG[j * n + i] = pA[j * n + i];
404 
405           for(k=0; k < i ; k++)
406           {
407              pG[j * n + i] = pG[j * n + i] - pG[i * n + k] * pG[j * n + k];
408           }
409        }
410 
411        if (pG[i * n + i] <= 0.0f)
412        {
413          return(ARM_MATH_DECOMPOSITION_FAILURE);
414        }
415 
416        invSqrtVj = 1.0f/sqrtf(pG[i * n + i]);
417        for(j=i ; j < n ; j++)
418        {
419          pG[j * n + i] = pG[j * n + i] * invSqrtVj ;
420        }
421     }
422 
423     status = ARM_MATH_SUCCESS;
424 
425   }
426 
427 
428   /* Return to application */
429   return (status);
430 }
431 #endif /* #if defined(ARM_MATH_NEON) */
432 #endif /* defined(ARM_MATH_MVEF) && !defined(ARM_MATH_AUTOVECTORIZE) */
433 
434 /**
435   @} end of MatrixChol group
436  */
437