dtrmm.f.html

来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 371 行 · 第 1/2 页

          INFO = 4
      ELSE IF (M.LT.0) THEN
          INFO = 5
      ELSE IF (N.LT.0) THEN
          INFO = 6
      ELSE IF (LDA.LT.MAX(1,NROWA)) THEN
          INFO = 9
      ELSE IF (LDB.LT.MAX(1,M)) THEN
          INFO = 11
      END IF
      IF (INFO.NE.0) THEN
          CALL <a name="XERBLA.179"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>(<span class="string">'<a name="DTRMM.179"></a><a href="dtrmm.f.html#DTRMM.1">DTRMM</a> '</span>,INFO)
          RETURN
      END IF
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     Quick return if possible.
</span><span class="comment">*</span><span class="comment">
</span>      IF (N.EQ.0) RETURN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     And when  alpha.eq.zero.
</span><span class="comment">*</span><span class="comment">
</span>      IF (ALPHA.EQ.ZERO) THEN
          DO 20 J = 1,N
              DO 10 I = 1,M
                  B(I,J) = ZERO
   10         CONTINUE
   20     CONTINUE
          RETURN
      END IF
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     Start the operations.
</span><span class="comment">*</span><span class="comment">
</span>      IF (LSIDE) THEN
          IF (<a name="LSAME.201"></a><a href="lsame.f.html#LSAME.1">LSAME</a>(TRANSA,<span class="string">'N'</span>)) THEN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">           Form  B := alpha*A*B.
</span><span class="comment">*</span><span class="comment">
</span>              IF (UPPER) THEN
                  DO 50 J = 1,N
                      DO 40 K = 1,M
                          IF (B(K,J).NE.ZERO) THEN
                              TEMP = ALPHA*B(K,J)
                              DO 30 I = 1,K - 1
                                  B(I,J) = B(I,J) + TEMP*A(I,K)
   30                         CONTINUE
                              IF (NOUNIT) TEMP = TEMP*A(K,K)
                              B(K,J) = TEMP
                          END IF
   40                 CONTINUE
   50             CONTINUE
              ELSE
                  DO 80 J = 1,N
                      DO 70 K = M,1,-1
                          IF (B(K,J).NE.ZERO) THEN
                              TEMP = ALPHA*B(K,J)
                              B(K,J) = TEMP
                              IF (NOUNIT) B(K,J) = B(K,J)*A(K,K)
                              DO 60 I = K + 1,M
                                  B(I,J) = B(I,J) + TEMP*A(I,K)
   60                         CONTINUE
                          END IF
   70                 CONTINUE
   80             CONTINUE
              END IF
          ELSE
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">           Form  B := alpha*A'*B.
</span><span class="comment">*</span><span class="comment">
</span>              IF (UPPER) THEN
                  DO 110 J = 1,N
                      DO 100 I = M,1,-1
                          TEMP = B(I,J)
                          IF (NOUNIT) TEMP = TEMP*A(I,I)
                          DO 90 K = 1,I - 1
                              TEMP = TEMP + A(K,I)*B(K,J)
   90                     CONTINUE
                          B(I,J) = ALPHA*TEMP
  100                 CONTINUE
  110             CONTINUE
              ELSE
                  DO 140 J = 1,N
                      DO 130 I = 1,M
                          TEMP = B(I,J)
                          IF (NOUNIT) TEMP = TEMP*A(I,I)
                          DO 120 K = I + 1,M
                              TEMP = TEMP + A(K,I)*B(K,J)
  120                     CONTINUE
                          B(I,J) = ALPHA*TEMP
  130                 CONTINUE
  140             CONTINUE
              END IF
          END IF
      ELSE
          IF (<a name="LSAME.261"></a><a href="lsame.f.html#LSAME.1">LSAME</a>(TRANSA,<span class="string">'N'</span>)) THEN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">           Form  B := alpha*B*A.
</span><span class="comment">*</span><span class="comment">
</span>              IF (UPPER) THEN
                  DO 180 J = N,1,-1
                      TEMP = ALPHA
                      IF (NOUNIT) TEMP = TEMP*A(J,J)
                      DO 150 I = 1,M
                          B(I,J) = TEMP*B(I,J)
  150                 CONTINUE
                      DO 170 K = 1,J - 1
                          IF (A(K,J).NE.ZERO) THEN
                              TEMP = ALPHA*A(K,J)
                              DO 160 I = 1,M
                                  B(I,J) = B(I,J) + TEMP*B(I,K)
  160                         CONTINUE
                          END IF
  170                 CONTINUE
  180             CONTINUE
              ELSE
                  DO 220 J = 1,N
                      TEMP = ALPHA
                      IF (NOUNIT) TEMP = TEMP*A(J,J)
                      DO 190 I = 1,M
                          B(I,J) = TEMP*B(I,J)
  190                 CONTINUE
                      DO 210 K = J + 1,N
                          IF (A(K,J).NE.ZERO) THEN
                              TEMP = ALPHA*A(K,J)
                              DO 200 I = 1,M
                                  B(I,J) = B(I,J) + TEMP*B(I,K)
  200                         CONTINUE
                          END IF
  210                 CONTINUE
  220             CONTINUE
              END IF
          ELSE
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">           Form  B := alpha*B*A'.
</span><span class="comment">*</span><span class="comment">
</span>              IF (UPPER) THEN
                  DO 260 K = 1,N
                      DO 240 J = 1,K - 1
                          IF (A(J,K).NE.ZERO) THEN
                              TEMP = ALPHA*A(J,K)
                              DO 230 I = 1,M
                                  B(I,J) = B(I,J) + TEMP*B(I,K)
  230                         CONTINUE
                          END IF
  240                 CONTINUE
                      TEMP = ALPHA
                      IF (NOUNIT) TEMP = TEMP*A(K,K)
                      IF (TEMP.NE.ONE) THEN
                          DO 250 I = 1,M
                              B(I,K) = TEMP*B(I,K)
  250                     CONTINUE
                      END IF
  260             CONTINUE
              ELSE
                  DO 300 K = N,1,-1
                      DO 280 J = K + 1,N
                          IF (A(J,K).NE.ZERO) THEN
                              TEMP = ALPHA*A(J,K)
                              DO 270 I = 1,M
                                  B(I,J) = B(I,J) + TEMP*B(I,K)
  270                         CONTINUE
                          END IF
  280                 CONTINUE
                      TEMP = ALPHA
                      IF (NOUNIT) TEMP = TEMP*A(K,K)
                      IF (TEMP.NE.ONE) THEN
                          DO 290 I = 1,M
                              B(I,K) = TEMP*B(I,K)
  290                     CONTINUE
                      END IF
  300             CONTINUE
              END IF
          END IF
      END IF
<span class="comment">*</span><span class="comment">
</span>      RETURN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     End of <a name="DTRMM.344"></a><a href="dtrmm.f.html#DTRMM.1">DTRMM</a> .
</span><span class="comment">*</span><span class="comment">
</span>      END

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