Statistiques
| Révision :

root / src / blas / sgemm.f @ 8

Historique | Voir | Annoter | Télécharger (9,39 ko)

1 1 equemene
      SUBROUTINE SGEMM(TRANSA,TRANSB,M,N,K,ALPHA,A,LDA,B,LDB,BETA,C,LDC)
2 1 equemene
*     .. Scalar Arguments ..
3 1 equemene
      REAL ALPHA,BETA
4 1 equemene
      INTEGER K,LDA,LDB,LDC,M,N
5 1 equemene
      CHARACTER TRANSA,TRANSB
6 1 equemene
*     ..
7 1 equemene
*     .. Array Arguments ..
8 1 equemene
      REAL A(LDA,*),B(LDB,*),C(LDC,*)
9 1 equemene
*     ..
10 1 equemene
*
11 1 equemene
*  Purpose
12 1 equemene
*  =======
13 1 equemene
*
14 1 equemene
*  SGEMM  performs one of the matrix-matrix operations
15 1 equemene
*
16 1 equemene
*     C := alpha*op( A )*op( B ) + beta*C,
17 1 equemene
*
18 1 equemene
*  where  op( X ) is one of
19 1 equemene
*
20 1 equemene
*     op( X ) = X   or   op( X ) = X',
21 1 equemene
*
22 1 equemene
*  alpha and beta are scalars, and A, B and C are matrices, with op( A )
23 1 equemene
*  an m by k matrix,  op( B )  a  k by n matrix and  C an m by n matrix.
24 1 equemene
*
25 1 equemene
*  Arguments
26 1 equemene
*  ==========
27 1 equemene
*
28 1 equemene
*  TRANSA - CHARACTER*1.
29 1 equemene
*           On entry, TRANSA specifies the form of op( A ) to be used in
30 1 equemene
*           the matrix multiplication as follows:
31 1 equemene
*
32 1 equemene
*              TRANSA = 'N' or 'n',  op( A ) = A.
33 1 equemene
*
34 1 equemene
*              TRANSA = 'T' or 't',  op( A ) = A'.
35 1 equemene
*
36 1 equemene
*              TRANSA = 'C' or 'c',  op( A ) = A'.
37 1 equemene
*
38 1 equemene
*           Unchanged on exit.
39 1 equemene
*
40 1 equemene
*  TRANSB - CHARACTER*1.
41 1 equemene
*           On entry, TRANSB specifies the form of op( B ) to be used in
42 1 equemene
*           the matrix multiplication as follows:
43 1 equemene
*
44 1 equemene
*              TRANSB = 'N' or 'n',  op( B ) = B.
45 1 equemene
*
46 1 equemene
*              TRANSB = 'T' or 't',  op( B ) = B'.
47 1 equemene
*
48 1 equemene
*              TRANSB = 'C' or 'c',  op( B ) = B'.
49 1 equemene
*
50 1 equemene
*           Unchanged on exit.
51 1 equemene
*
52 1 equemene
*  M      - INTEGER.
53 1 equemene
*           On entry,  M  specifies  the number  of rows  of the  matrix
54 1 equemene
*           op( A )  and of the  matrix  C.  M  must  be at least  zero.
55 1 equemene
*           Unchanged on exit.
56 1 equemene
*
57 1 equemene
*  N      - INTEGER.
58 1 equemene
*           On entry,  N  specifies the number  of columns of the matrix
59 1 equemene
*           op( B ) and the number of columns of the matrix C. N must be
60 1 equemene
*           at least zero.
61 1 equemene
*           Unchanged on exit.
62 1 equemene
*
63 1 equemene
*  K      - INTEGER.
64 1 equemene
*           On entry,  K  specifies  the number of columns of the matrix
65 1 equemene
*           op( A ) and the number of rows of the matrix op( B ). K must
66 1 equemene
*           be at least  zero.
67 1 equemene
*           Unchanged on exit.
68 1 equemene
*
69 1 equemene
*  ALPHA  - REAL            .
70 1 equemene
*           On entry, ALPHA specifies the scalar alpha.
71 1 equemene
*           Unchanged on exit.
72 1 equemene
*
73 1 equemene
*  A      - REAL             array of DIMENSION ( LDA, ka ), where ka is
74 1 equemene
*           k  when  TRANSA = 'N' or 'n',  and is  m  otherwise.
75 1 equemene
*           Before entry with  TRANSA = 'N' or 'n',  the leading  m by k
76 1 equemene
*           part of the array  A  must contain the matrix  A,  otherwise
77 1 equemene
*           the leading  k by m  part of the array  A  must contain  the
78 1 equemene
*           matrix A.
79 1 equemene
*           Unchanged on exit.
80 1 equemene
*
81 1 equemene
*  LDA    - INTEGER.
82 1 equemene
*           On entry, LDA specifies the first dimension of A as declared
83 1 equemene
*           in the calling (sub) program. When  TRANSA = 'N' or 'n' then
84 1 equemene
*           LDA must be at least  max( 1, m ), otherwise  LDA must be at
85 1 equemene
*           least  max( 1, k ).
86 1 equemene
*           Unchanged on exit.
87 1 equemene
*
88 1 equemene
*  B      - REAL             array of DIMENSION ( LDB, kb ), where kb is
89 1 equemene
*           n  when  TRANSB = 'N' or 'n',  and is  k  otherwise.
90 1 equemene
*           Before entry with  TRANSB = 'N' or 'n',  the leading  k by n
91 1 equemene
*           part of the array  B  must contain the matrix  B,  otherwise
92 1 equemene
*           the leading  n by k  part of the array  B  must contain  the
93 1 equemene
*           matrix B.
94 1 equemene
*           Unchanged on exit.
95 1 equemene
*
96 1 equemene
*  LDB    - INTEGER.
97 1 equemene
*           On entry, LDB specifies the first dimension of B as declared
98 1 equemene
*           in the calling (sub) program. When  TRANSB = 'N' or 'n' then
99 1 equemene
*           LDB must be at least  max( 1, k ), otherwise  LDB must be at
100 1 equemene
*           least  max( 1, n ).
101 1 equemene
*           Unchanged on exit.
102 1 equemene
*
103 1 equemene
*  BETA   - REAL            .
104 1 equemene
*           On entry,  BETA  specifies the scalar  beta.  When  BETA  is
105 1 equemene
*           supplied as zero then C need not be set on input.
106 1 equemene
*           Unchanged on exit.
107 1 equemene
*
108 1 equemene
*  C      - REAL             array of DIMENSION ( LDC, n ).
109 1 equemene
*           Before entry, the leading  m by n  part of the array  C must
110 1 equemene
*           contain the matrix  C,  except when  beta  is zero, in which
111 1 equemene
*           case C need not be set on entry.
112 1 equemene
*           On exit, the array  C  is overwritten by the  m by n  matrix
113 1 equemene
*           ( alpha*op( A )*op( B ) + beta*C ).
114 1 equemene
*
115 1 equemene
*  LDC    - INTEGER.
116 1 equemene
*           On entry, LDC specifies the first dimension of C as declared
117 1 equemene
*           in  the  calling  (sub)  program.   LDC  must  be  at  least
118 1 equemene
*           max( 1, m ).
119 1 equemene
*           Unchanged on exit.
120 1 equemene
*
121 1 equemene
*
122 1 equemene
*  Level 3 Blas routine.
123 1 equemene
*
124 1 equemene
*  -- Written on 8-February-1989.
125 1 equemene
*     Jack Dongarra, Argonne National Laboratory.
126 1 equemene
*     Iain Duff, AERE Harwell.
127 1 equemene
*     Jeremy Du Croz, Numerical Algorithms Group Ltd.
128 1 equemene
*     Sven Hammarling, Numerical Algorithms Group Ltd.
129 1 equemene
*
130 1 equemene
*
131 1 equemene
*     .. External Functions ..
132 1 equemene
      LOGICAL LSAME
133 1 equemene
      EXTERNAL LSAME
134 1 equemene
*     ..
135 1 equemene
*     .. External Subroutines ..
136 1 equemene
      EXTERNAL XERBLA
137 1 equemene
*     ..
138 1 equemene
*     .. Intrinsic Functions ..
139 1 equemene
      INTRINSIC MAX
140 1 equemene
*     ..
141 1 equemene
*     .. Local Scalars ..
142 1 equemene
      REAL TEMP
143 1 equemene
      INTEGER I,INFO,J,L,NCOLA,NROWA,NROWB
144 1 equemene
      LOGICAL NOTA,NOTB
145 1 equemene
*     ..
146 1 equemene
*     .. Parameters ..
147 1 equemene
      REAL ONE,ZERO
148 1 equemene
      PARAMETER (ONE=1.0E+0,ZERO=0.0E+0)
149 1 equemene
*     ..
150 1 equemene
*
151 1 equemene
*     Set  NOTA  and  NOTB  as  true if  A  and  B  respectively are not
152 1 equemene
*     transposed and set  NROWA, NCOLA and  NROWB  as the number of rows
153 1 equemene
*     and  columns of  A  and the  number of  rows  of  B  respectively.
154 1 equemene
*
155 1 equemene
      NOTA = LSAME(TRANSA,'N')
156 1 equemene
      NOTB = LSAME(TRANSB,'N')
157 1 equemene
      IF (NOTA) THEN
158 1 equemene
          NROWA = M
159 1 equemene
          NCOLA = K
160 1 equemene
      ELSE
161 1 equemene
          NROWA = K
162 1 equemene
          NCOLA = M
163 1 equemene
      END IF
164 1 equemene
      IF (NOTB) THEN
165 1 equemene
          NROWB = K
166 1 equemene
      ELSE
167 1 equemene
          NROWB = N
168 1 equemene
      END IF
169 1 equemene
*
170 1 equemene
*     Test the input parameters.
171 1 equemene
*
172 1 equemene
      INFO = 0
173 1 equemene
      IF ((.NOT.NOTA) .AND. (.NOT.LSAME(TRANSA,'C')) .AND.
174 1 equemene
     +    (.NOT.LSAME(TRANSA,'T'))) THEN
175 1 equemene
          INFO = 1
176 1 equemene
      ELSE IF ((.NOT.NOTB) .AND. (.NOT.LSAME(TRANSB,'C')) .AND.
177 1 equemene
     +         (.NOT.LSAME(TRANSB,'T'))) THEN
178 1 equemene
          INFO = 2
179 1 equemene
      ELSE IF (M.LT.0) THEN
180 1 equemene
          INFO = 3
181 1 equemene
      ELSE IF (N.LT.0) THEN
182 1 equemene
          INFO = 4
183 1 equemene
      ELSE IF (K.LT.0) THEN
184 1 equemene
          INFO = 5
185 1 equemene
      ELSE IF (LDA.LT.MAX(1,NROWA)) THEN
186 1 equemene
          INFO = 8
187 1 equemene
      ELSE IF (LDB.LT.MAX(1,NROWB)) THEN
188 1 equemene
          INFO = 10
189 1 equemene
      ELSE IF (LDC.LT.MAX(1,M)) THEN
190 1 equemene
          INFO = 13
191 1 equemene
      END IF
192 1 equemene
      IF (INFO.NE.0) THEN
193 1 equemene
          CALL XERBLA('SGEMM ',INFO)
194 1 equemene
          RETURN
195 1 equemene
      END IF
196 1 equemene
*
197 1 equemene
*     Quick return if possible.
198 1 equemene
*
199 1 equemene
      IF ((M.EQ.0) .OR. (N.EQ.0) .OR.
200 1 equemene
     +    (((ALPHA.EQ.ZERO).OR. (K.EQ.0)).AND. (BETA.EQ.ONE))) RETURN
201 1 equemene
*
202 1 equemene
*     And if  alpha.eq.zero.
203 1 equemene
*
204 1 equemene
      IF (ALPHA.EQ.ZERO) THEN
205 1 equemene
          IF (BETA.EQ.ZERO) THEN
206 1 equemene
              DO 20 J = 1,N
207 1 equemene
                  DO 10 I = 1,M
208 1 equemene
                      C(I,J) = ZERO
209 1 equemene
   10             CONTINUE
210 1 equemene
   20         CONTINUE
211 1 equemene
          ELSE
212 1 equemene
              DO 40 J = 1,N
213 1 equemene
                  DO 30 I = 1,M
214 1 equemene
                      C(I,J) = BETA*C(I,J)
215 1 equemene
   30             CONTINUE
216 1 equemene
   40         CONTINUE
217 1 equemene
          END IF
218 1 equemene
          RETURN
219 1 equemene
      END IF
220 1 equemene
*
221 1 equemene
*     Start the operations.
222 1 equemene
*
223 1 equemene
      IF (NOTB) THEN
224 1 equemene
          IF (NOTA) THEN
225 1 equemene
*
226 1 equemene
*           Form  C := alpha*A*B + beta*C.
227 1 equemene
*
228 1 equemene
              DO 90 J = 1,N
229 1 equemene
                  IF (BETA.EQ.ZERO) THEN
230 1 equemene
                      DO 50 I = 1,M
231 1 equemene
                          C(I,J) = ZERO
232 1 equemene
   50                 CONTINUE
233 1 equemene
                  ELSE IF (BETA.NE.ONE) THEN
234 1 equemene
                      DO 60 I = 1,M
235 1 equemene
                          C(I,J) = BETA*C(I,J)
236 1 equemene
   60                 CONTINUE
237 1 equemene
                  END IF
238 1 equemene
                  DO 80 L = 1,K
239 1 equemene
                      IF (B(L,J).NE.ZERO) THEN
240 1 equemene
                          TEMP = ALPHA*B(L,J)
241 1 equemene
                          DO 70 I = 1,M
242 1 equemene
                              C(I,J) = C(I,J) + TEMP*A(I,L)
243 1 equemene
   70                     CONTINUE
244 1 equemene
                      END IF
245 1 equemene
   80             CONTINUE
246 1 equemene
   90         CONTINUE
247 1 equemene
          ELSE
248 1 equemene
*
249 1 equemene
*           Form  C := alpha*A'*B + beta*C
250 1 equemene
*
251 1 equemene
              DO 120 J = 1,N
252 1 equemene
                  DO 110 I = 1,M
253 1 equemene
                      TEMP = ZERO
254 1 equemene
                      DO 100 L = 1,K
255 1 equemene
                          TEMP = TEMP + A(L,I)*B(L,J)
256 1 equemene
  100                 CONTINUE
257 1 equemene
                      IF (BETA.EQ.ZERO) THEN
258 1 equemene
                          C(I,J) = ALPHA*TEMP
259 1 equemene
                      ELSE
260 1 equemene
                          C(I,J) = ALPHA*TEMP + BETA*C(I,J)
261 1 equemene
                      END IF
262 1 equemene
  110             CONTINUE
263 1 equemene
  120         CONTINUE
264 1 equemene
          END IF
265 1 equemene
      ELSE
266 1 equemene
          IF (NOTA) THEN
267 1 equemene
*
268 1 equemene
*           Form  C := alpha*A*B' + beta*C
269 1 equemene
*
270 1 equemene
              DO 170 J = 1,N
271 1 equemene
                  IF (BETA.EQ.ZERO) THEN
272 1 equemene
                      DO 130 I = 1,M
273 1 equemene
                          C(I,J) = ZERO
274 1 equemene
  130                 CONTINUE
275 1 equemene
                  ELSE IF (BETA.NE.ONE) THEN
276 1 equemene
                      DO 140 I = 1,M
277 1 equemene
                          C(I,J) = BETA*C(I,J)
278 1 equemene
  140                 CONTINUE
279 1 equemene
                  END IF
280 1 equemene
                  DO 160 L = 1,K
281 1 equemene
                      IF (B(J,L).NE.ZERO) THEN
282 1 equemene
                          TEMP = ALPHA*B(J,L)
283 1 equemene
                          DO 150 I = 1,M
284 1 equemene
                              C(I,J) = C(I,J) + TEMP*A(I,L)
285 1 equemene
  150                     CONTINUE
286 1 equemene
                      END IF
287 1 equemene
  160             CONTINUE
288 1 equemene
  170         CONTINUE
289 1 equemene
          ELSE
290 1 equemene
*
291 1 equemene
*           Form  C := alpha*A'*B' + beta*C
292 1 equemene
*
293 1 equemene
              DO 200 J = 1,N
294 1 equemene
                  DO 190 I = 1,M
295 1 equemene
                      TEMP = ZERO
296 1 equemene
                      DO 180 L = 1,K
297 1 equemene
                          TEMP = TEMP + A(L,I)*B(J,L)
298 1 equemene
  180                 CONTINUE
299 1 equemene
                      IF (BETA.EQ.ZERO) THEN
300 1 equemene
                          C(I,J) = ALPHA*TEMP
301 1 equemene
                      ELSE
302 1 equemene
                          C(I,J) = ALPHA*TEMP + BETA*C(I,J)
303 1 equemene
                      END IF
304 1 equemene
  190             CONTINUE
305 1 equemene
  200         CONTINUE
306 1 equemene
          END IF
307 1 equemene
      END IF
308 1 equemene
*
309 1 equemene
      RETURN
310 1 equemene
*
311 1 equemene
*     End of SGEMM .
312 1 equemene
*
313 1 equemene
      END