Squashed 'third_party/eigen/' content from commit 61d72f6

Change-Id: Iccc90fa0b55ab44037f018046d2fcffd90d9d025
git-subtree-dir: third_party/eigen
git-subtree-split: 61d72f6383cfa842868c53e30e087b0258177257
diff --git a/blas/ctbmv.f b/blas/ctbmv.f
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+      SUBROUTINE CTBMV(UPLO,TRANS,DIAG,N,K,A,LDA,X,INCX)
+*     .. Scalar Arguments ..
+      INTEGER INCX,K,LDA,N
+      CHARACTER DIAG,TRANS,UPLO
+*     ..
+*     .. Array Arguments ..
+      COMPLEX A(LDA,*),X(*)
+*     ..
+*
+*  Purpose
+*  =======
+*
+*  CTBMV  performs one of the matrix-vector operations
+*
+*     x := A*x,   or   x := A'*x,   or   x := conjg( A' )*x,
+*
+*  where x is an n element vector and  A is an n by n unit, or non-unit,
+*  upper or lower triangular band matrix, with ( k + 1 ) diagonals.
+*
+*  Arguments
+*  ==========
+*
+*  UPLO   - CHARACTER*1.
+*           On entry, UPLO specifies whether the matrix is an upper or
+*           lower triangular matrix as follows:
+*
+*              UPLO = 'U' or 'u'   A is an upper triangular matrix.
+*
+*              UPLO = 'L' or 'l'   A is a lower triangular matrix.
+*
+*           Unchanged on exit.
+*
+*  TRANS  - CHARACTER*1.
+*           On entry, TRANS specifies the operation to be performed as
+*           follows:
+*
+*              TRANS = 'N' or 'n'   x := A*x.
+*
+*              TRANS = 'T' or 't'   x := A'*x.
+*
+*              TRANS = 'C' or 'c'   x := conjg( A' )*x.
+*
+*           Unchanged on exit.
+*
+*  DIAG   - CHARACTER*1.
+*           On entry, DIAG specifies whether or not A is unit
+*           triangular as follows:
+*
+*              DIAG = 'U' or 'u'   A is assumed to be unit triangular.
+*
+*              DIAG = 'N' or 'n'   A is not assumed to be unit
+*                                  triangular.
+*
+*           Unchanged on exit.
+*
+*  N      - INTEGER.
+*           On entry, N specifies the order of the matrix A.
+*           N must be at least zero.
+*           Unchanged on exit.
+*
+*  K      - INTEGER.
+*           On entry with UPLO = 'U' or 'u', K specifies the number of
+*           super-diagonals of the matrix A.
+*           On entry with UPLO = 'L' or 'l', K specifies the number of
+*           sub-diagonals of the matrix A.
+*           K must satisfy  0 .le. K.
+*           Unchanged on exit.
+*
+*  A      - COMPLEX          array of DIMENSION ( LDA, n ).
+*           Before entry with UPLO = 'U' or 'u', the leading ( k + 1 )
+*           by n part of the array A must contain the upper triangular
+*           band part of the matrix of coefficients, supplied column by
+*           column, with the leading diagonal of the matrix in row
+*           ( k + 1 ) of the array, the first super-diagonal starting at
+*           position 2 in row k, and so on. The top left k by k triangle
+*           of the array A is not referenced.
+*           The following program segment will transfer an upper
+*           triangular band matrix from conventional full matrix storage
+*           to band storage:
+*
+*                 DO 20, J = 1, N
+*                    M = K + 1 - J
+*                    DO 10, I = MAX( 1, J - K ), J
+*                       A( M + I, J ) = matrix( I, J )
+*              10    CONTINUE
+*              20 CONTINUE
+*
+*           Before entry with UPLO = 'L' or 'l', the leading ( k + 1 )
+*           by n part of the array A must contain the lower triangular
+*           band part of the matrix of coefficients, supplied column by
+*           column, with the leading diagonal of the matrix in row 1 of
+*           the array, the first sub-diagonal starting at position 1 in
+*           row 2, and so on. The bottom right k by k triangle of the
+*           array A is not referenced.
+*           The following program segment will transfer a lower
+*           triangular band matrix from conventional full matrix storage
+*           to band storage:
+*
+*                 DO 20, J = 1, N
+*                    M = 1 - J
+*                    DO 10, I = J, MIN( N, J + K )
+*                       A( M + I, J ) = matrix( I, J )
+*              10    CONTINUE
+*              20 CONTINUE
+*
+*           Note that when DIAG = 'U' or 'u' the elements of the array A
+*           corresponding to the diagonal elements of the matrix are not
+*           referenced, but are assumed to be unity.
+*           Unchanged on exit.
+*
+*  LDA    - INTEGER.
+*           On entry, LDA specifies the first dimension of A as declared
+*           in the calling (sub) program. LDA must be at least
+*           ( k + 1 ).
+*           Unchanged on exit.
+*
+*  X      - COMPLEX          array of dimension at least
+*           ( 1 + ( n - 1 )*abs( INCX ) ).
+*           Before entry, the incremented array X must contain the n
+*           element vector x. On exit, X is overwritten with the
+*           tranformed vector x.
+*
+*  INCX   - INTEGER.
+*           On entry, INCX specifies the increment for the elements of
+*           X. INCX must not be zero.
+*           Unchanged on exit.
+*
+*  Further Details
+*  ===============
+*
+*  Level 2 Blas routine.
+*
+*  -- Written on 22-October-1986.
+*     Jack Dongarra, Argonne National Lab.
+*     Jeremy Du Croz, Nag Central Office.
+*     Sven Hammarling, Nag Central Office.
+*     Richard Hanson, Sandia National Labs.
+*
+*  =====================================================================
+*
+*     .. Parameters ..
+      COMPLEX ZERO
+      PARAMETER (ZERO= (0.0E+0,0.0E+0))
+*     ..
+*     .. Local Scalars ..
+      COMPLEX TEMP
+      INTEGER I,INFO,IX,J,JX,KPLUS1,KX,L
+      LOGICAL NOCONJ,NOUNIT
+*     ..
+*     .. External Functions ..
+      LOGICAL LSAME
+      EXTERNAL LSAME
+*     ..
+*     .. External Subroutines ..
+      EXTERNAL XERBLA
+*     ..
+*     .. Intrinsic Functions ..
+      INTRINSIC CONJG,MAX,MIN
+*     ..
+*
+*     Test the input parameters.
+*
+      INFO = 0
+      IF (.NOT.LSAME(UPLO,'U') .AND. .NOT.LSAME(UPLO,'L')) THEN
+          INFO = 1
+      ELSE IF (.NOT.LSAME(TRANS,'N') .AND. .NOT.LSAME(TRANS,'T') .AND.
+     +         .NOT.LSAME(TRANS,'C')) THEN
+          INFO = 2
+      ELSE IF (.NOT.LSAME(DIAG,'U') .AND. .NOT.LSAME(DIAG,'N')) THEN
+          INFO = 3
+      ELSE IF (N.LT.0) THEN
+          INFO = 4
+      ELSE IF (K.LT.0) THEN
+          INFO = 5
+      ELSE IF (LDA.LT. (K+1)) THEN
+          INFO = 7
+      ELSE IF (INCX.EQ.0) THEN
+          INFO = 9
+      END IF
+      IF (INFO.NE.0) THEN
+          CALL XERBLA('CTBMV ',INFO)
+          RETURN
+      END IF
+*
+*     Quick return if possible.
+*
+      IF (N.EQ.0) RETURN
+*
+      NOCONJ = LSAME(TRANS,'T')
+      NOUNIT = LSAME(DIAG,'N')
+*
+*     Set up the start point in X if the increment is not unity. This
+*     will be  ( N - 1 )*INCX   too small for descending loops.
+*
+      IF (INCX.LE.0) THEN
+          KX = 1 - (N-1)*INCX
+      ELSE IF (INCX.NE.1) THEN
+          KX = 1
+      END IF
+*
+*     Start the operations. In this version the elements of A are
+*     accessed sequentially with one pass through A.
+*
+      IF (LSAME(TRANS,'N')) THEN
+*
+*         Form  x := A*x.
+*
+          IF (LSAME(UPLO,'U')) THEN
+              KPLUS1 = K + 1
+              IF (INCX.EQ.1) THEN
+                  DO 20 J = 1,N
+                      IF (X(J).NE.ZERO) THEN
+                          TEMP = X(J)
+                          L = KPLUS1 - J
+                          DO 10 I = MAX(1,J-K),J - 1
+                              X(I) = X(I) + TEMP*A(L+I,J)
+   10                     CONTINUE
+                          IF (NOUNIT) X(J) = X(J)*A(KPLUS1,J)
+                      END IF
+   20             CONTINUE
+              ELSE
+                  JX = KX
+                  DO 40 J = 1,N
+                      IF (X(JX).NE.ZERO) THEN
+                          TEMP = X(JX)
+                          IX = KX
+                          L = KPLUS1 - J
+                          DO 30 I = MAX(1,J-K),J - 1
+                              X(IX) = X(IX) + TEMP*A(L+I,J)
+                              IX = IX + INCX
+   30                     CONTINUE
+                          IF (NOUNIT) X(JX) = X(JX)*A(KPLUS1,J)
+                      END IF
+                      JX = JX + INCX
+                      IF (J.GT.K) KX = KX + INCX
+   40             CONTINUE
+              END IF
+          ELSE
+              IF (INCX.EQ.1) THEN
+                  DO 60 J = N,1,-1
+                      IF (X(J).NE.ZERO) THEN
+                          TEMP = X(J)
+                          L = 1 - J
+                          DO 50 I = MIN(N,J+K),J + 1,-1
+                              X(I) = X(I) + TEMP*A(L+I,J)
+   50                     CONTINUE
+                          IF (NOUNIT) X(J) = X(J)*A(1,J)
+                      END IF
+   60             CONTINUE
+              ELSE
+                  KX = KX + (N-1)*INCX
+                  JX = KX
+                  DO 80 J = N,1,-1
+                      IF (X(JX).NE.ZERO) THEN
+                          TEMP = X(JX)
+                          IX = KX
+                          L = 1 - J
+                          DO 70 I = MIN(N,J+K),J + 1,-1
+                              X(IX) = X(IX) + TEMP*A(L+I,J)
+                              IX = IX - INCX
+   70                     CONTINUE
+                          IF (NOUNIT) X(JX) = X(JX)*A(1,J)
+                      END IF
+                      JX = JX - INCX
+                      IF ((N-J).GE.K) KX = KX - INCX
+   80             CONTINUE
+              END IF
+          END IF
+      ELSE
+*
+*        Form  x := A'*x  or  x := conjg( A' )*x.
+*
+          IF (LSAME(UPLO,'U')) THEN
+              KPLUS1 = K + 1
+              IF (INCX.EQ.1) THEN
+                  DO 110 J = N,1,-1
+                      TEMP = X(J)
+                      L = KPLUS1 - J
+                      IF (NOCONJ) THEN
+                          IF (NOUNIT) TEMP = TEMP*A(KPLUS1,J)
+                          DO 90 I = J - 1,MAX(1,J-K),-1
+                              TEMP = TEMP + A(L+I,J)*X(I)
+   90                     CONTINUE
+                      ELSE
+                          IF (NOUNIT) TEMP = TEMP*CONJG(A(KPLUS1,J))
+                          DO 100 I = J - 1,MAX(1,J-K),-1
+                              TEMP = TEMP + CONJG(A(L+I,J))*X(I)
+  100                     CONTINUE
+                      END IF
+                      X(J) = TEMP
+  110             CONTINUE
+              ELSE
+                  KX = KX + (N-1)*INCX
+                  JX = KX
+                  DO 140 J = N,1,-1
+                      TEMP = X(JX)
+                      KX = KX - INCX
+                      IX = KX
+                      L = KPLUS1 - J
+                      IF (NOCONJ) THEN
+                          IF (NOUNIT) TEMP = TEMP*A(KPLUS1,J)
+                          DO 120 I = J - 1,MAX(1,J-K),-1
+                              TEMP = TEMP + A(L+I,J)*X(IX)
+                              IX = IX - INCX
+  120                     CONTINUE
+                      ELSE
+                          IF (NOUNIT) TEMP = TEMP*CONJG(A(KPLUS1,J))
+                          DO 130 I = J - 1,MAX(1,J-K),-1
+                              TEMP = TEMP + CONJG(A(L+I,J))*X(IX)
+                              IX = IX - INCX
+  130                     CONTINUE
+                      END IF
+                      X(JX) = TEMP
+                      JX = JX - INCX
+  140             CONTINUE
+              END IF
+          ELSE
+              IF (INCX.EQ.1) THEN
+                  DO 170 J = 1,N
+                      TEMP = X(J)
+                      L = 1 - J
+                      IF (NOCONJ) THEN
+                          IF (NOUNIT) TEMP = TEMP*A(1,J)
+                          DO 150 I = J + 1,MIN(N,J+K)
+                              TEMP = TEMP + A(L+I,J)*X(I)
+  150                     CONTINUE
+                      ELSE
+                          IF (NOUNIT) TEMP = TEMP*CONJG(A(1,J))
+                          DO 160 I = J + 1,MIN(N,J+K)
+                              TEMP = TEMP + CONJG(A(L+I,J))*X(I)
+  160                     CONTINUE
+                      END IF
+                      X(J) = TEMP
+  170             CONTINUE
+              ELSE
+                  JX = KX
+                  DO 200 J = 1,N
+                      TEMP = X(JX)
+                      KX = KX + INCX
+                      IX = KX
+                      L = 1 - J
+                      IF (NOCONJ) THEN
+                          IF (NOUNIT) TEMP = TEMP*A(1,J)
+                          DO 180 I = J + 1,MIN(N,J+K)
+                              TEMP = TEMP + A(L+I,J)*X(IX)
+                              IX = IX + INCX
+  180                     CONTINUE
+                      ELSE
+                          IF (NOUNIT) TEMP = TEMP*CONJG(A(1,J))
+                          DO 190 I = J + 1,MIN(N,J+K)
+                              TEMP = TEMP + CONJG(A(L+I,J))*X(IX)
+                              IX = IX + INCX
+  190                     CONTINUE
+                      END IF
+                      X(JX) = TEMP
+                      JX = JX + INCX
+  200             CONTINUE
+              END IF
+          END IF
+      END IF
+*
+      RETURN
+*
+*     End of CTBMV .
+*
+      END