dtrsv.c

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                            x[i__] -= temp * a[i__ + j * a_dim1];
/*<    10                CONTINUE >*/
/* L10: */
                        }
/*<                   END IF >*/
                    }
/*<    20          CONTINUE >*/
/* L20: */
                }
/*<             ELSE >*/
            } else {
/*<                JX = KX + ( N - 1 )*INCX >*/
                jx = kx + (*n - 1) * *incx;
/*<                DO 40, J = N, 1, -1 >*/
                for (j = *n; j >= 1; --j) {
/*<                   IF( X( JX ).NE.ZERO )THEN >*/
                    if (x[jx] != 0.) {
/*<    >*/
                        if (nounit) {
                            x[jx] /= a[j + j * a_dim1];
                        }
/*<                      TEMP = X( JX ) >*/
                        temp = x[jx];
/*<                      IX   = JX >*/
                        ix = jx;
/*<                      DO 30, I = J - 1, 1, -1 >*/
                        for (i__ = j - 1; i__ >= 1; --i__) {
/*<                         IX      = IX      - INCX >*/
                            ix -= *incx;
/*<                         X( IX ) = X( IX ) - TEMP*A( I, J ) >*/
                            x[ix] -= temp * a[i__ + j * a_dim1];
/*<    30                CONTINUE >*/
/* L30: */
                        }
/*<                   END IF >*/
                    }
/*<                   JX = JX - INCX >*/
                    jx -= *incx;
/*<    40          CONTINUE >*/
/* L40: */
                }
/*<             END IF >*/
            }
/*<          ELSE >*/
        } else {
/*<             IF( INCX.EQ.1 )THEN >*/
            if (*incx == 1) {
/*<                DO 60, J = 1, N >*/
                i__1 = *n;
                for (j = 1; j <= i__1; ++j) {
/*<                   IF( X( J ).NE.ZERO )THEN >*/
                    if (x[j] != 0.) {
/*<    >*/
                        if (nounit) {
                            x[j] /= a[j + j * a_dim1];
                        }
/*<                      TEMP = X( J ) >*/
                        temp = x[j];
/*<                      DO 50, I = J + 1, N >*/
                        i__2 = *n;
                        for (i__ = j + 1; i__ <= i__2; ++i__) {
/*<                         X( I ) = X( I ) - TEMP*A( I, J ) >*/
                            x[i__] -= temp * a[i__ + j * a_dim1];
/*<    50                CONTINUE >*/
/* L50: */
                        }
/*<                   END IF >*/
                    }
/*<    60          CONTINUE >*/
/* L60: */
                }
/*<             ELSE >*/
            } else {
/*<                JX = KX >*/
                jx = kx;
/*<                DO 80, J = 1, N >*/
                i__1 = *n;
                for (j = 1; j <= i__1; ++j) {
/*<                   IF( X( JX ).NE.ZERO )THEN >*/
                    if (x[jx] != 0.) {
/*<    >*/
                        if (nounit) {
                            x[jx] /= a[j + j * a_dim1];
                        }
/*<                      TEMP = X( JX ) >*/
                        temp = x[jx];
/*<                      IX   = JX >*/
                        ix = jx;
/*<                      DO 70, I = J + 1, N >*/
                        i__2 = *n;
                        for (i__ = j + 1; i__ <= i__2; ++i__) {
/*<                         IX      = IX      + INCX >*/
                            ix += *incx;
/*<                         X( IX ) = X( IX ) - TEMP*A( I, J ) >*/
                            x[ix] -= temp * a[i__ + j * a_dim1];
/*<    70                CONTINUE >*/
/* L70: */
                        }
/*<                   END IF >*/
                    }
/*<                   JX = JX + INCX >*/
                    jx += *incx;
/*<    80          CONTINUE >*/
/* L80: */
                }
/*<             END IF >*/
            }
/*<          END IF >*/
        }
/*<       ELSE >*/
    } else {

/*        Form  x := inv( A' )*x. */

/*<          IF( LSAME( UPLO, 'U' ) )THEN >*/
        if (lsame_(uplo, "U", (ftnlen)1, (ftnlen)1)) {
/*<             IF( INCX.EQ.1 )THEN >*/
            if (*incx == 1) {
/*<                DO 100, J = 1, N >*/
                i__1 = *n;
                for (j = 1; j <= i__1; ++j) {
/*<                   TEMP = X( J ) >*/
                    temp = x[j];
/*<                   DO 90, I = 1, J - 1 >*/
                    i__2 = j - 1;
                    for (i__ = 1; i__ <= i__2; ++i__) {
/*<                      TEMP = TEMP - A( I, J )*X( I ) >*/
                        temp -= a[i__ + j * a_dim1] * x[i__];
/*<    90             CONTINUE >*/
/* L90: */
                    }
/*<    >*/
                    if (nounit) {
                        temp /= a[j + j * a_dim1];
                    }
/*<                   X( J ) = TEMP >*/
                    x[j] = temp;
/*<   100          CONTINUE >*/
/* L100: */
                }
/*<             ELSE >*/
            } else {
/*<                JX = KX >*/
                jx = kx;
/*<                DO 120, J = 1, N >*/
                i__1 = *n;
                for (j = 1; j <= i__1; ++j) {
/*<                   TEMP = X( JX ) >*/
                    temp = x[jx];
/*<                   IX   = KX >*/
                    ix = kx;
/*<                   DO 110, I = 1, J - 1 >*/
                    i__2 = j - 1;
                    for (i__ = 1; i__ <= i__2; ++i__) {
/*<                      TEMP = TEMP - A( I, J )*X( IX ) >*/
                        temp -= a[i__ + j * a_dim1] * x[ix];
/*<                      IX   = IX   + INCX >*/
                        ix += *incx;
/*<   110             CONTINUE >*/
/* L110: */
                    }
/*<    >*/
                    if (nounit) {
                        temp /= a[j + j * a_dim1];
                    }
/*<                   X( JX ) = TEMP >*/
                    x[jx] = temp;
/*<                   JX      = JX   + INCX >*/
                    jx += *incx;
/*<   120          CONTINUE >*/
/* L120: */
                }
/*<             END IF >*/
            }
/*<          ELSE >*/
        } else {
/*<             IF( INCX.EQ.1 )THEN >*/
            if (*incx == 1) {
/*<                DO 140, J = N, 1, -1 >*/
                for (j = *n; j >= 1; --j) {
/*<                   TEMP = X( J ) >*/
                    temp = x[j];
/*<                   DO 130, I = N, J + 1, -1 >*/
                    i__1 = j + 1;
                    for (i__ = *n; i__ >= i__1; --i__) {
/*<                      TEMP = TEMP - A( I, J )*X( I ) >*/
                        temp -= a[i__ + j * a_dim1] * x[i__];
/*<   130             CONTINUE >*/
/* L130: */
                    }
/*<    >*/
                    if (nounit) {
                        temp /= a[j + j * a_dim1];
                    }
/*<                   X( J ) = TEMP >*/
                    x[j] = temp;
/*<   140          CONTINUE >*/
/* L140: */
                }
/*<             ELSE >*/
            } else {
/*<                KX = KX + ( N - 1 )*INCX >*/
                kx += (*n - 1) * *incx;
/*<                JX = KX >*/
                jx = kx;
/*<                DO 160, J = N, 1, -1 >*/
                for (j = *n; j >= 1; --j) {
/*<                   TEMP = X( JX ) >*/
                    temp = x[jx];
/*<                   IX   = KX >*/
                    ix = kx;
/*<                   DO 150, I = N, J + 1, -1 >*/
                    i__1 = j + 1;
                    for (i__ = *n; i__ >= i__1; --i__) {
/*<                      TEMP = TEMP - A( I, J )*X( IX ) >*/
                        temp -= a[i__ + j * a_dim1] * x[ix];
/*<                      IX   = IX   - INCX >*/
                        ix -= *incx;
/*<   150             CONTINUE >*/
/* L150: */
                    }
/*<    >*/
                    if (nounit) {
                        temp /= a[j + j * a_dim1];
                    }
/*<                   X( JX ) = TEMP >*/
                    x[jx] = temp;
/*<                   JX      = JX   - INCX >*/
                    jx -= *incx;
/*<   160          CONTINUE >*/
/* L160: */
                }
/*<             END IF >*/
            }
/*<          END IF >*/
        }
/*<       END IF >*/
    }

/*<       RETURN >*/
    return 0;

/*     End of DTRSV . */

/*<       END >*/
} /* dtrsv_ */

#ifdef __cplusplus
        }
#endif