root / src / blas / zher2k.f @ 10
Historique | Voir | Annoter | Télécharger (12,86 ko)
| 1 |
SUBROUTINE ZHER2K(UPLO,TRANS,N,K,ALPHA,A,LDA,B,LDB,BETA,C,LDC) |
|---|---|
| 2 |
* .. Scalar Arguments .. |
| 3 |
DOUBLE COMPLEX ALPHA |
| 4 |
DOUBLE PRECISION BETA |
| 5 |
INTEGER K,LDA,LDB,LDC,N |
| 6 |
CHARACTER TRANS,UPLO |
| 7 |
* .. |
| 8 |
* .. Array Arguments .. |
| 9 |
DOUBLE COMPLEX A(LDA,*),B(LDB,*),C(LDC,*) |
| 10 |
* .. |
| 11 |
* |
| 12 |
* Purpose |
| 13 |
* ======= |
| 14 |
* |
| 15 |
* ZHER2K performs one of the hermitian rank 2k operations |
| 16 |
* |
| 17 |
* C := alpha*A*conjg( B' ) + conjg( alpha )*B*conjg( A' ) + beta*C, |
| 18 |
* |
| 19 |
* or |
| 20 |
* |
| 21 |
* C := alpha*conjg( A' )*B + conjg( alpha )*conjg( B' )*A + beta*C, |
| 22 |
* |
| 23 |
* where alpha and beta are scalars with beta real, C is an n by n |
| 24 |
* hermitian matrix and A and B are n by k matrices in the first case |
| 25 |
* and k by n matrices in the second case. |
| 26 |
* |
| 27 |
* Arguments |
| 28 |
* ========== |
| 29 |
* |
| 30 |
* UPLO - CHARACTER*1. |
| 31 |
* On entry, UPLO specifies whether the upper or lower |
| 32 |
* triangular part of the array C is to be referenced as |
| 33 |
* follows: |
| 34 |
* |
| 35 |
* UPLO = 'U' or 'u' Only the upper triangular part of C |
| 36 |
* is to be referenced. |
| 37 |
* |
| 38 |
* UPLO = 'L' or 'l' Only the lower triangular part of C |
| 39 |
* is to be referenced. |
| 40 |
* |
| 41 |
* Unchanged on exit. |
| 42 |
* |
| 43 |
* TRANS - CHARACTER*1. |
| 44 |
* On entry, TRANS specifies the operation to be performed as |
| 45 |
* follows: |
| 46 |
* |
| 47 |
* TRANS = 'N' or 'n' C := alpha*A*conjg( B' ) + |
| 48 |
* conjg( alpha )*B*conjg( A' ) + |
| 49 |
* beta*C. |
| 50 |
* |
| 51 |
* TRANS = 'C' or 'c' C := alpha*conjg( A' )*B + |
| 52 |
* conjg( alpha )*conjg( B' )*A + |
| 53 |
* beta*C. |
| 54 |
* |
| 55 |
* Unchanged on exit. |
| 56 |
* |
| 57 |
* N - INTEGER. |
| 58 |
* On entry, N specifies the order of the matrix C. N must be |
| 59 |
* at least zero. |
| 60 |
* Unchanged on exit. |
| 61 |
* |
| 62 |
* K - INTEGER. |
| 63 |
* On entry with TRANS = 'N' or 'n', K specifies the number |
| 64 |
* of columns of the matrices A and B, and on entry with |
| 65 |
* TRANS = 'C' or 'c', K specifies the number of rows of the |
| 66 |
* matrices A and B. K must be at least zero. |
| 67 |
* Unchanged on exit. |
| 68 |
* |
| 69 |
* ALPHA - COMPLEX*16 . |
| 70 |
* On entry, ALPHA specifies the scalar alpha. |
| 71 |
* Unchanged on exit. |
| 72 |
* |
| 73 |
* A - COMPLEX*16 array of DIMENSION ( LDA, ka ), where ka is |
| 74 |
* k when TRANS = 'N' or 'n', and is n otherwise. |
| 75 |
* Before entry with TRANS = 'N' or 'n', the leading n by k |
| 76 |
* part of the array A must contain the matrix A, otherwise |
| 77 |
* the leading k by n part of the array A must contain the |
| 78 |
* matrix A. |
| 79 |
* Unchanged on exit. |
| 80 |
* |
| 81 |
* LDA - INTEGER. |
| 82 |
* On entry, LDA specifies the first dimension of A as declared |
| 83 |
* in the calling (sub) program. When TRANS = 'N' or 'n' |
| 84 |
* then LDA must be at least max( 1, n ), otherwise LDA must |
| 85 |
* be at least max( 1, k ). |
| 86 |
* Unchanged on exit. |
| 87 |
* |
| 88 |
* B - COMPLEX*16 array of DIMENSION ( LDB, kb ), where kb is |
| 89 |
* k when TRANS = 'N' or 'n', and is n otherwise. |
| 90 |
* Before entry with TRANS = 'N' or 'n', the leading n by k |
| 91 |
* part of the array B must contain the matrix B, otherwise |
| 92 |
* the leading k by n part of the array B must contain the |
| 93 |
* matrix B. |
| 94 |
* Unchanged on exit. |
| 95 |
* |
| 96 |
* LDB - INTEGER. |
| 97 |
* On entry, LDB specifies the first dimension of B as declared |
| 98 |
* in the calling (sub) program. When TRANS = 'N' or 'n' |
| 99 |
* then LDB must be at least max( 1, n ), otherwise LDB must |
| 100 |
* be at least max( 1, k ). |
| 101 |
* Unchanged on exit. |
| 102 |
* |
| 103 |
* BETA - DOUBLE PRECISION . |
| 104 |
* On entry, BETA specifies the scalar beta. |
| 105 |
* Unchanged on exit. |
| 106 |
* |
| 107 |
* C - COMPLEX*16 array of DIMENSION ( LDC, n ). |
| 108 |
* Before entry with UPLO = 'U' or 'u', the leading n by n |
| 109 |
* upper triangular part of the array C must contain the upper |
| 110 |
* triangular part of the hermitian matrix and the strictly |
| 111 |
* lower triangular part of C is not referenced. On exit, the |
| 112 |
* upper triangular part of the array C is overwritten by the |
| 113 |
* upper triangular part of the updated matrix. |
| 114 |
* Before entry with UPLO = 'L' or 'l', the leading n by n |
| 115 |
* lower triangular part of the array C must contain the lower |
| 116 |
* triangular part of the hermitian matrix and the strictly |
| 117 |
* upper triangular part of C is not referenced. On exit, the |
| 118 |
* lower triangular part of the array C is overwritten by the |
| 119 |
* lower triangular part of the updated matrix. |
| 120 |
* Note that the imaginary parts of the diagonal elements need |
| 121 |
* not be set, they are assumed to be zero, and on exit they |
| 122 |
* are set to zero. |
| 123 |
* |
| 124 |
* LDC - INTEGER. |
| 125 |
* On entry, LDC specifies the first dimension of C as declared |
| 126 |
* in the calling (sub) program. LDC must be at least |
| 127 |
* max( 1, n ). |
| 128 |
* Unchanged on exit. |
| 129 |
* |
| 130 |
* |
| 131 |
* Level 3 Blas routine. |
| 132 |
* |
| 133 |
* -- Written on 8-February-1989. |
| 134 |
* Jack Dongarra, Argonne National Laboratory. |
| 135 |
* Iain Duff, AERE Harwell. |
| 136 |
* Jeremy Du Croz, Numerical Algorithms Group Ltd. |
| 137 |
* Sven Hammarling, Numerical Algorithms Group Ltd. |
| 138 |
* |
| 139 |
* -- Modified 8-Nov-93 to set C(J,J) to DBLE( C(J,J) ) when BETA = 1. |
| 140 |
* Ed Anderson, Cray Research Inc. |
| 141 |
* |
| 142 |
* |
| 143 |
* .. External Functions .. |
| 144 |
LOGICAL LSAME |
| 145 |
EXTERNAL LSAME |
| 146 |
* .. |
| 147 |
* .. External Subroutines .. |
| 148 |
EXTERNAL XERBLA |
| 149 |
* .. |
| 150 |
* .. Intrinsic Functions .. |
| 151 |
INTRINSIC DBLE,DCONJG,MAX |
| 152 |
* .. |
| 153 |
* .. Local Scalars .. |
| 154 |
DOUBLE COMPLEX TEMP1,TEMP2 |
| 155 |
INTEGER I,INFO,J,L,NROWA |
| 156 |
LOGICAL UPPER |
| 157 |
* .. |
| 158 |
* .. Parameters .. |
| 159 |
DOUBLE PRECISION ONE |
| 160 |
PARAMETER (ONE=1.0D+0) |
| 161 |
DOUBLE COMPLEX ZERO |
| 162 |
PARAMETER (ZERO= (0.0D+0,0.0D+0)) |
| 163 |
* .. |
| 164 |
* |
| 165 |
* Test the input parameters. |
| 166 |
* |
| 167 |
IF (LSAME(TRANS,'N')) THEN |
| 168 |
NROWA = N |
| 169 |
ELSE |
| 170 |
NROWA = K |
| 171 |
END IF |
| 172 |
UPPER = LSAME(UPLO,'U') |
| 173 |
* |
| 174 |
INFO = 0 |
| 175 |
IF ((.NOT.UPPER) .AND. (.NOT.LSAME(UPLO,'L'))) THEN |
| 176 |
INFO = 1 |
| 177 |
ELSE IF ((.NOT.LSAME(TRANS,'N')) .AND. |
| 178 |
+ (.NOT.LSAME(TRANS,'C'))) THEN |
| 179 |
INFO = 2 |
| 180 |
ELSE IF (N.LT.0) THEN |
| 181 |
INFO = 3 |
| 182 |
ELSE IF (K.LT.0) THEN |
| 183 |
INFO = 4 |
| 184 |
ELSE IF (LDA.LT.MAX(1,NROWA)) THEN |
| 185 |
INFO = 7 |
| 186 |
ELSE IF (LDB.LT.MAX(1,NROWA)) THEN |
| 187 |
INFO = 9 |
| 188 |
ELSE IF (LDC.LT.MAX(1,N)) THEN |
| 189 |
INFO = 12 |
| 190 |
END IF |
| 191 |
IF (INFO.NE.0) THEN |
| 192 |
CALL XERBLA('ZHER2K',INFO)
|
| 193 |
RETURN |
| 194 |
END IF |
| 195 |
* |
| 196 |
* Quick return if possible. |
| 197 |
* |
| 198 |
IF ((N.EQ.0) .OR. (((ALPHA.EQ.ZERO).OR. |
| 199 |
+ (K.EQ.0)).AND. (BETA.EQ.ONE))) RETURN |
| 200 |
* |
| 201 |
* And when alpha.eq.zero. |
| 202 |
* |
| 203 |
IF (ALPHA.EQ.ZERO) THEN |
| 204 |
IF (UPPER) THEN |
| 205 |
IF (BETA.EQ.DBLE(ZERO)) THEN |
| 206 |
DO 20 J = 1,N |
| 207 |
DO 10 I = 1,J |
| 208 |
C(I,J) = ZERO |
| 209 |
10 CONTINUE |
| 210 |
20 CONTINUE |
| 211 |
ELSE |
| 212 |
DO 40 J = 1,N |
| 213 |
DO 30 I = 1,J - 1 |
| 214 |
C(I,J) = BETA*C(I,J) |
| 215 |
30 CONTINUE |
| 216 |
C(J,J) = BETA*DBLE(C(J,J)) |
| 217 |
40 CONTINUE |
| 218 |
END IF |
| 219 |
ELSE |
| 220 |
IF (BETA.EQ.DBLE(ZERO)) THEN |
| 221 |
DO 60 J = 1,N |
| 222 |
DO 50 I = J,N |
| 223 |
C(I,J) = ZERO |
| 224 |
50 CONTINUE |
| 225 |
60 CONTINUE |
| 226 |
ELSE |
| 227 |
DO 80 J = 1,N |
| 228 |
C(J,J) = BETA*DBLE(C(J,J)) |
| 229 |
DO 70 I = J + 1,N |
| 230 |
C(I,J) = BETA*C(I,J) |
| 231 |
70 CONTINUE |
| 232 |
80 CONTINUE |
| 233 |
END IF |
| 234 |
END IF |
| 235 |
RETURN |
| 236 |
END IF |
| 237 |
* |
| 238 |
* Start the operations. |
| 239 |
* |
| 240 |
IF (LSAME(TRANS,'N')) THEN |
| 241 |
* |
| 242 |
* Form C := alpha*A*conjg( B' ) + conjg( alpha )*B*conjg( A' ) + |
| 243 |
* C. |
| 244 |
* |
| 245 |
IF (UPPER) THEN |
| 246 |
DO 130 J = 1,N |
| 247 |
IF (BETA.EQ.DBLE(ZERO)) THEN |
| 248 |
DO 90 I = 1,J |
| 249 |
C(I,J) = ZERO |
| 250 |
90 CONTINUE |
| 251 |
ELSE IF (BETA.NE.ONE) THEN |
| 252 |
DO 100 I = 1,J - 1 |
| 253 |
C(I,J) = BETA*C(I,J) |
| 254 |
100 CONTINUE |
| 255 |
C(J,J) = BETA*DBLE(C(J,J)) |
| 256 |
ELSE |
| 257 |
C(J,J) = DBLE(C(J,J)) |
| 258 |
END IF |
| 259 |
DO 120 L = 1,K |
| 260 |
IF ((A(J,L).NE.ZERO) .OR. (B(J,L).NE.ZERO)) THEN |
| 261 |
TEMP1 = ALPHA*DCONJG(B(J,L)) |
| 262 |
TEMP2 = DCONJG(ALPHA*A(J,L)) |
| 263 |
DO 110 I = 1,J - 1 |
| 264 |
C(I,J) = C(I,J) + A(I,L)*TEMP1 + |
| 265 |
+ B(I,L)*TEMP2 |
| 266 |
110 CONTINUE |
| 267 |
C(J,J) = DBLE(C(J,J)) + |
| 268 |
+ DBLE(A(J,L)*TEMP1+B(J,L)*TEMP2) |
| 269 |
END IF |
| 270 |
120 CONTINUE |
| 271 |
130 CONTINUE |
| 272 |
ELSE |
| 273 |
DO 180 J = 1,N |
| 274 |
IF (BETA.EQ.DBLE(ZERO)) THEN |
| 275 |
DO 140 I = J,N |
| 276 |
C(I,J) = ZERO |
| 277 |
140 CONTINUE |
| 278 |
ELSE IF (BETA.NE.ONE) THEN |
| 279 |
DO 150 I = J + 1,N |
| 280 |
C(I,J) = BETA*C(I,J) |
| 281 |
150 CONTINUE |
| 282 |
C(J,J) = BETA*DBLE(C(J,J)) |
| 283 |
ELSE |
| 284 |
C(J,J) = DBLE(C(J,J)) |
| 285 |
END IF |
| 286 |
DO 170 L = 1,K |
| 287 |
IF ((A(J,L).NE.ZERO) .OR. (B(J,L).NE.ZERO)) THEN |
| 288 |
TEMP1 = ALPHA*DCONJG(B(J,L)) |
| 289 |
TEMP2 = DCONJG(ALPHA*A(J,L)) |
| 290 |
DO 160 I = J + 1,N |
| 291 |
C(I,J) = C(I,J) + A(I,L)*TEMP1 + |
| 292 |
+ B(I,L)*TEMP2 |
| 293 |
160 CONTINUE |
| 294 |
C(J,J) = DBLE(C(J,J)) + |
| 295 |
+ DBLE(A(J,L)*TEMP1+B(J,L)*TEMP2) |
| 296 |
END IF |
| 297 |
170 CONTINUE |
| 298 |
180 CONTINUE |
| 299 |
END IF |
| 300 |
ELSE |
| 301 |
* |
| 302 |
* Form C := alpha*conjg( A' )*B + conjg( alpha )*conjg( B' )*A + |
| 303 |
* C. |
| 304 |
* |
| 305 |
IF (UPPER) THEN |
| 306 |
DO 210 J = 1,N |
| 307 |
DO 200 I = 1,J |
| 308 |
TEMP1 = ZERO |
| 309 |
TEMP2 = ZERO |
| 310 |
DO 190 L = 1,K |
| 311 |
TEMP1 = TEMP1 + DCONJG(A(L,I))*B(L,J) |
| 312 |
TEMP2 = TEMP2 + DCONJG(B(L,I))*A(L,J) |
| 313 |
190 CONTINUE |
| 314 |
IF (I.EQ.J) THEN |
| 315 |
IF (BETA.EQ.DBLE(ZERO)) THEN |
| 316 |
C(J,J) = DBLE(ALPHA*TEMP1+ |
| 317 |
+ DCONJG(ALPHA)*TEMP2) |
| 318 |
ELSE |
| 319 |
C(J,J) = BETA*DBLE(C(J,J)) + |
| 320 |
+ DBLE(ALPHA*TEMP1+ |
| 321 |
+ DCONJG(ALPHA)*TEMP2) |
| 322 |
END IF |
| 323 |
ELSE |
| 324 |
IF (BETA.EQ.DBLE(ZERO)) THEN |
| 325 |
C(I,J) = ALPHA*TEMP1 + DCONJG(ALPHA)*TEMP2 |
| 326 |
ELSE |
| 327 |
C(I,J) = BETA*C(I,J) + ALPHA*TEMP1 + |
| 328 |
+ DCONJG(ALPHA)*TEMP2 |
| 329 |
END IF |
| 330 |
END IF |
| 331 |
200 CONTINUE |
| 332 |
210 CONTINUE |
| 333 |
ELSE |
| 334 |
DO 240 J = 1,N |
| 335 |
DO 230 I = J,N |
| 336 |
TEMP1 = ZERO |
| 337 |
TEMP2 = ZERO |
| 338 |
DO 220 L = 1,K |
| 339 |
TEMP1 = TEMP1 + DCONJG(A(L,I))*B(L,J) |
| 340 |
TEMP2 = TEMP2 + DCONJG(B(L,I))*A(L,J) |
| 341 |
220 CONTINUE |
| 342 |
IF (I.EQ.J) THEN |
| 343 |
IF (BETA.EQ.DBLE(ZERO)) THEN |
| 344 |
C(J,J) = DBLE(ALPHA*TEMP1+ |
| 345 |
+ DCONJG(ALPHA)*TEMP2) |
| 346 |
ELSE |
| 347 |
C(J,J) = BETA*DBLE(C(J,J)) + |
| 348 |
+ DBLE(ALPHA*TEMP1+ |
| 349 |
+ DCONJG(ALPHA)*TEMP2) |
| 350 |
END IF |
| 351 |
ELSE |
| 352 |
IF (BETA.EQ.DBLE(ZERO)) THEN |
| 353 |
C(I,J) = ALPHA*TEMP1 + DCONJG(ALPHA)*TEMP2 |
| 354 |
ELSE |
| 355 |
C(I,J) = BETA*C(I,J) + ALPHA*TEMP1 + |
| 356 |
+ DCONJG(ALPHA)*TEMP2 |
| 357 |
END IF |
| 358 |
END IF |
| 359 |
230 CONTINUE |
| 360 |
240 CONTINUE |
| 361 |
END IF |
| 362 |
END IF |
| 363 |
* |
| 364 |
RETURN |
| 365 |
* |
| 366 |
* End of ZHER2K. |
| 367 |
* |
| 368 |
END |