cgebd2.c

#include<math.h>
#include<stdlib.h>
#include<string.h>
#include<stdio.h>
#include<complex.h>
#ifdefcomplex
#undef complex
#endif
#ifdefI
#undef I
#endif

#if defined(_WIN64)
typedeflong longBLASLONG;
typedefunsigned long longBLASULONG;
#else
typedeflongBLASLONG;
typedefunsigned longBLASULONG;
#endif

#ifdefLAPACK_ILP64
typedefBLASLONGblasint;
#if defined(_WIN64)
#defineblasabs(x) llabs(x)
#else
#defineblasabs(x) labs(x)
#endif
#else
typedefintblasint;
#defineblasabs(x) abs(x)
#endif

typedefblasintinteger;

typedefunsigned intuinteger;
typedefchar*address;
typedefshort intshortint;
typedeffloatreal;
typedefdoubledoublereal;
typedefstruct { realr, i; } complex;
typedefstruct { doublerealr, i; } doublecomplex;
#ifdef_MSC_VER
staticinline_FcomplexCf(complex*z) {_Fcomplexzz={z->r , z->i}; returnzz;}
staticinline_DcomplexCd(doublecomplex*z) {_Dcomplexzz={z->r , z->i};returnzz;}
staticinline_Fcomplex*_pCf(complex*z) {return (_Fcomplex*)z;}
staticinline_Dcomplex*_pCd(doublecomplex*z) {return (_Dcomplex*)z;}
#else
staticinline_ComplexfloatCf(complex*z) {returnz->r+z->i*_Complex_I;}
staticinline_ComplexdoubleCd(doublecomplex*z) {returnz->r+z->i*_Complex_I;}
staticinline_Complexfloat*_pCf(complex*z) {return (_Complexfloat*)z;}
staticinline_Complexdouble*_pCd(doublecomplex*z) {return (_Complexdouble*)z;}
#endif
#definepCf(z) (*_pCf(z))
#definepCd(z) (*_pCd(z))
typedefintlogical;
typedefshort intshortlogical;
typedefcharlogical1;
typedefcharinteger1;

#defineTRUE_ (1)
#defineFALSE_ (0)

/* Extern is for use with -E */
#ifndefExtern
#defineExtern extern
#endif

/* I/O stuff */

typedefintflag;
typedefintftnlen;
typedefintftnint;

/*external read, write*/
typedefstruct
{ flagcierr;
ftnintciunit;
flagciend;
char*cifmt;
ftnintcirec;
} cilist;

/*internal read, write*/
typedefstruct
{ flagicierr;
char*iciunit;
flagiciend;
char*icifmt;
ftninticirlen;
ftninticirnum;
} icilist;

/*open*/
typedefstruct
{ flagoerr;
ftnintounit;
char*ofnm;
ftnlenofnmlen;
char*osta;
char*oacc;
char*ofm;
ftnintorl;
char*oblnk;
} olist;

/*close*/
typedefstruct
{ flagcerr;
ftnintcunit;
char*csta;
} cllist;

/*rewind, backspace, endfile*/
typedefstruct
{ flagaerr;
ftnintaunit;
} alist;

/* inquire */
typedefstruct
{ flaginerr;
ftnintinunit;
char*infile;
ftnleninfilen;
ftnint*inex; /*parameters in standard's order*/
ftnint*inopen;
ftnint*innum;
ftnint*innamed;
char*inname;
ftnleninnamlen;
char*inacc;
ftnleninacclen;
char*inseq;
ftnleninseqlen;
char*indir;
ftnlenindirlen;
char*infmt;
ftnleninfmtlen;
char*inform;
ftnintinformlen;
char*inunf;
ftnleninunflen;
ftnint*inrecl;
ftnint*innrec;
char*inblank;
ftnleninblanklen;
} inlist;

#defineVOID void

unionMultitype { /* for multiple entry points */
integer1g;
shortinth;
integeri;
/* longint j; */
realr;
doublereald;
complexc;
doublecomplexz;
 };

typedefunionMultitypeMultitype;

structVardesc { /* for Namelist */
char*name;
char*addr;
ftnlen*dims;
inttype;
 };
typedefstructVardescVardesc;

structNamelist {
char*name;
Vardesc**vars;
intnvars;
 };
typedefstructNamelistNamelist;

#defineabs(x) ((x) >= 0 ? (x) : -(x))
#definedabs(x) (fabs(x))
#definef2cmin(a,b) ((a) <= (b) ? (a) : (b))
#definef2cmax(a,b) ((a) >= (b) ? (a) : (b))
#definedmin(a,b) (f2cmin(a,b))
#definedmax(a,b) (f2cmax(a,b))
#definebit_test(a,b) ((a) >> (b) & 1)
#definebit_clear(a,b) ((a) & ~((uinteger)1 << (b)))
#definebit_set(a,b) ((a) | ((uinteger)1 << (b)))

#defineabort_() { sig_die("Fortran abort routine called", 1); }
#definec_abs(z) (cabsf(Cf(z)))
#definec_cos(R,Z) { pCf(R)=ccos(Cf(Z)); }
#ifdef_MSC_VER
#definec_div(c, a, b) {Cf(c)._Val[0] = (Cf(a)._Val[0]/Cf(b)._Val[0]); Cf(c)._Val[1]=(Cf(a)._Val[1]/Cf(b)._Val[1]);}
#definez_div(c, a, b) {Cd(c)._Val[0] = (Cd(a)._Val[0]/Cd(b)._Val[0]); Cd(c)._Val[1]=(Cd(a)._Val[1]/df(b)._Val[1]);}
#else
#definec_div(c, a, b) {pCf(c) = Cf(a)/Cf(b);}
#definez_div(c, a, b) {pCd(c) = Cd(a)/Cd(b);}
#endif
#definec_exp(R, Z) {pCf(R) = cexpf(Cf(Z));}
#definec_log(R, Z) {pCf(R) = clogf(Cf(Z));}
#definec_sin(R, Z) {pCf(R) = csinf(Cf(Z));}
//#define c_sqrt(R, Z) {*(R) = csqrtf(Cf(Z));}
#definec_sqrt(R, Z) {pCf(R) = csqrtf(Cf(Z));}
#defined_abs(x) (fabs(*(x)))
#defined_acos(x) (acos(*(x)))
#defined_asin(x) (asin(*(x)))
#defined_atan(x) (atan(*(x)))
#defined_atn2(x, y) (atan2(*(x),*(y)))
#defined_cnjg(R, Z) { pCd(R) = conj(Cd(Z)); }
#definer_cnjg(R, Z) { pCf(R) = conjf(Cf(Z)); }
#defined_cos(x) (cos(*(x)))
#defined_cosh(x) (cosh(*(x)))
#defined_dim(__a, __b) ( *(__a) > *(__b) ? *(__a) - *(__b) : 0.0 )
#defined_exp(x) (exp(*(x)))
#defined_imag(z) (cimag(Cd(z)))
#definer_imag(z) (cimagf(Cf(z)))
#defined_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))
#definer_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))
#defined_lg10(x) ( 0.43429448190325182765 * log(*(x)) )
#definer_lg10(x) ( 0.43429448190325182765 * log(*(x)) )
#defined_log(x) (log(*(x)))
#defined_mod(x, y) (fmod(*(x), *(y)))
#defineu_nint(__x) ((__x)>=0 ? floor((__x) + .5) : -floor(.5 - (__x)))
#defined_nint(x) u_nint(*(x))
#defineu_sign(__a,__b) ((__b) >= 0 ? ((__a) >= 0 ? (__a) : -(__a)) : -((__a) >= 0 ? (__a) : -(__a)))
#defined_sign(a,b) u_sign(*(a),*(b))
#definer_sign(a,b) u_sign(*(a),*(b))
#defined_sin(x) (sin(*(x)))
#defined_sinh(x) (sinh(*(x)))
#defined_sqrt(x) (sqrt(*(x)))
#defined_tan(x) (tan(*(x)))
#defined_tanh(x) (tanh(*(x)))
#definei_abs(x) abs(*(x))
#definei_dnnt(x) ((integer)u_nint(*(x)))
#definei_len(s, n) (n)
#definei_nint(x) ((integer)u_nint(*(x)))
#definei_sign(a,b) ((integer)u_sign((integer)*(a),(integer)*(b)))
#definepow_dd(ap, bp) ( pow(*(ap), *(bp)))
#definepow_si(B,E) spow_ui(*(B),*(E))
#definepow_ri(B,E) spow_ui(*(B),*(E))
#definepow_di(B,E) dpow_ui(*(B),*(E))
#definepow_zi(p, a, b) {pCd(p) = zpow_ui(Cd(a), *(b));}
#definepow_ci(p, a, b) {pCf(p) = cpow_ui(Cf(a), *(b));}
#definepow_zz(R,A,B) {pCd(R) = cpow(Cd(A),*(B));}
#defines_cat(lpp, rpp, rnp, np, llp) { ftnlen i, nc, ll; char *f__rp, *lp; ll = (llp); lp = (lpp); for(i=0; i < (int)*(np); ++i) { nc = ll; if((rnp)[i] < nc) nc = (rnp)[i]; ll -= nc; f__rp = (rpp)[i]; while(--nc >= 0) *lp++ = *(f__rp)++; } while(--ll >= 0) *lp++ = ' '; }
#defines_cmp(a,b,c,d) ((integer)strncmp((a),(b),f2cmin((c),(d))))
#defines_copy(A,B,C,D) { int __i,__m; for (__i=0, __m=f2cmin((C),(D)); __i<__m && (B)[__i] != 0; ++__i) (A)[__i] = (B)[__i]; }
#definesig_die(s, kill) { exit(1); }
#defines_stop(s, n) {exit(0);}
staticcharjunk[] ="\n@(#)LIBF77 VERSION 19990503\n";
#definez_abs(z) (cabs(Cd(z)))
#definez_exp(R, Z) {pCd(R) = cexp(Cd(Z));}
#definez_sqrt(R, Z) {pCd(R) = csqrt(Cd(Z));}
#definemyexit_() break;
#definemycycle() continue;
#definemyceiling(w) {ceil(w)}
#definemyhuge(w) {HUGE_VAL}
//#define mymaxloc_(w,s,e,n) {if (sizeof(*(w)) == sizeof(double)) dmaxloc_((w),*(s),*(e),n); else dmaxloc_((w),*(s),*(e),n);}
#definemymaxloc(w,s,e,n) {dmaxloc_(w,*(s),*(e),n)}

/* procedure parameter types for -A and -C++ */

#defineF2C_proc_par_types 1
#ifdef__cplusplus
typedeflogical (*L_fp)(...);
#else
typedeflogical (*L_fp)();
#endif

staticfloatspow_ui(floatx, integern) {
floatpow=1.0; unsigned long intu;
if(n!=0) {
if(n<0) n=-n, x=1/x;
for(u=n; ; ) {
if(u&01) pow *= x;
if(u >>= 1) x *= x;
elsebreak;
 }
 }
returnpow;
}
staticdoubledpow_ui(doublex, integern) {
doublepow=1.0; unsigned long intu;
if(n!=0) {
if(n<0) n=-n, x=1/x;
for(u=n; ; ) {
if(u&01) pow *= x;
if(u >>= 1) x *= x;
elsebreak;
 }
 }
returnpow;
}
#ifdef_MSC_VER
static_Fcomplexcpow_ui(complexx, integern) {
complexpow={1.0,0.0}; unsigned long intu;
if(n!=0) {
if(n<0) n=-n, x.r=1/x.r, x.i=1/x.i;
for(u=n; ; ) {
if(u&01) pow.r *= x.r, pow.i *= x.i;
if(u >>= 1) x.r *= x.r, x.i *= x.i;
elsebreak;
 }
 }
_Fcomplexp={pow.r, pow.i};
returnp;
}
#else
static_Complexfloatcpow_ui(_Complexfloatx, integern) {
_Complexfloatpow=1.0; unsigned long intu;
if(n!=0) {
if(n<0) n=-n, x=1/x;
for(u=n; ; ) {
if(u&01) pow *= x;
if(u >>= 1) x *= x;
elsebreak;
 }
 }
returnpow;
}
#endif
#ifdef_MSC_VER
static_Dcomplexzpow_ui(_Dcomplexx, integern) {
_Dcomplexpow={1.0,0.0}; unsigned long intu;
if(n!=0) {
if(n<0) n=-n, x._Val[0] =1/x._Val[0], x._Val[1] =1/x._Val[1];
for(u=n; ; ) {
if(u&01) pow._Val[0] *= x._Val[0], pow._Val[1] *= x._Val[1];
if(u >>= 1) x._Val[0] *= x._Val[0], x._Val[1] *= x._Val[1];
elsebreak;
 }
 }
_Dcomplexp= {pow._Val[0], pow._Val[1]};
returnp;
}
#else
static_Complexdoublezpow_ui(_Complexdoublex, integern) {
_Complexdoublepow=1.0; unsigned long intu;
if(n!=0) {
if(n<0) n=-n, x=1/x;
for(u=n; ; ) {
if(u&01) pow *= x;
if(u >>= 1) x *= x;
elsebreak;
 }
 }
returnpow;
}
#endif
staticintegerpow_ii(integerx, integern) {
integerpow; unsigned long intu;
if (n <= 0) {
if (n==0||x==1) pow=1;
elseif (x!=-1) pow=x==0 ? 1/x : 0;
elsen=-n;
 }
if ((n>0) || !(n==0||x==1||x!=-1)) {
u=n;
for(pow=1; ; ) {
if(u&01) pow *= x;
if(u >>= 1) x *= x;
elsebreak;
 }
 }
returnpow;
}
staticintegerdmaxloc_(double*w, integers, integere, integer*n)
{
doublem; integeri, mi;
for(m=w[s-1], mi=s, i=s+1; i<=e; i++)
if (w[i-1]>m) mi=i ,m=w[i-1];
returnmi-s+1;
}
staticintegersmaxloc_(float*w, integers, integere, integer*n)
{
floatm; integeri, mi;
for(m=w[s-1], mi=s, i=s+1; i<=e; i++)
if (w[i-1]>m) mi=i ,m=w[i-1];
returnmi-s+1;
}
staticinlinevoidcdotc_(complex*z, integer*n_, complex*x, integer*incx_, complex*y, integer*incy_) {
integern=*n_, incx=*incx_, incy=*incy_, i;
#ifdef_MSC_VER
_Fcomplexzdotc= {0.0, 0.0};
if (incx==1&&incy==1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] +=conjf(Cf(&x[i]))._Val[0] *Cf(&y[i])._Val[0];
zdotc._Val[1] +=conjf(Cf(&x[i]))._Val[1] *Cf(&y[i])._Val[1];
 }
 } else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] +=conjf(Cf(&x[i*incx]))._Val[0] *Cf(&y[i*incy])._Val[0];
zdotc._Val[1] +=conjf(Cf(&x[i*incx]))._Val[1] *Cf(&y[i*incy])._Val[1];
 }
 }
pCf(z) =zdotc;
}
#else
_Complexfloatzdotc=0.0;
if (incx==1&&incy==1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc+=conjf(Cf(&x[i])) *Cf(&y[i]);
 }
 } else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc+=conjf(Cf(&x[i*incx])) *Cf(&y[i*incy]);
 }
 }
pCf(z) =zdotc;
}
#endif
staticinlinevoidzdotc_(doublecomplex*z, integer*n_, doublecomplex*x, integer*incx_, doublecomplex*y, integer*incy_) {
integern=*n_, incx=*incx_, incy=*incy_, i;
#ifdef_MSC_VER
_Dcomplexzdotc= {0.0, 0.0};
if (incx==1&&incy==1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] +=conj(Cd(&x[i]))._Val[0] *Cd(&y[i])._Val[0];
zdotc._Val[1] +=conj(Cd(&x[i]))._Val[1] *Cd(&y[i])._Val[1];
 }
 } else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] +=conj(Cd(&x[i*incx]))._Val[0] *Cd(&y[i*incy])._Val[0];
zdotc._Val[1] +=conj(Cd(&x[i*incx]))._Val[1] *Cd(&y[i*incy])._Val[1];
 }
 }
pCd(z) =zdotc;
}
#else
_Complexdoublezdotc=0.0;
if (incx==1&&incy==1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc+=conj(Cd(&x[i])) *Cd(&y[i]);
 }
 } else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc+=conj(Cd(&x[i*incx])) *Cd(&y[i*incy]);
 }
 }
pCd(z) =zdotc;
}
#endif
staticinlinevoidcdotu_(complex*z, integer*n_, complex*x, integer*incx_, complex*y, integer*incy_) {
integern=*n_, incx=*incx_, incy=*incy_, i;
#ifdef_MSC_VER
_Fcomplexzdotc= {0.0, 0.0};
if (incx==1&&incy==1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] +=Cf(&x[i])._Val[0] *Cf(&y[i])._Val[0];
zdotc._Val[1] +=Cf(&x[i])._Val[1] *Cf(&y[i])._Val[1];
 }
 } else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] +=Cf(&x[i*incx])._Val[0] *Cf(&y[i*incy])._Val[0];
zdotc._Val[1] +=Cf(&x[i*incx])._Val[1] *Cf(&y[i*incy])._Val[1];
 }
 }
pCf(z) =zdotc;
}
#else
_Complexfloatzdotc=0.0;
if (incx==1&&incy==1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc+=Cf(&x[i]) *Cf(&y[i]);
 }
 } else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc+=Cf(&x[i*incx]) *Cf(&y[i*incy]);
 }
 }
pCf(z) =zdotc;
}
#endif
staticinlinevoidzdotu_(doublecomplex*z, integer*n_, doublecomplex*x, integer*incx_, doublecomplex*y, integer*incy_) {
integern=*n_, incx=*incx_, incy=*incy_, i;
#ifdef_MSC_VER
_Dcomplexzdotc= {0.0, 0.0};
if (incx==1&&incy==1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] +=Cd(&x[i])._Val[0] *Cd(&y[i])._Val[0];
zdotc._Val[1] +=Cd(&x[i])._Val[1] *Cd(&y[i])._Val[1];
 }
 } else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc._Val[0] +=Cd(&x[i*incx])._Val[0] *Cd(&y[i*incy])._Val[0];
zdotc._Val[1] +=Cd(&x[i*incx])._Val[1] *Cd(&y[i*incy])._Val[1];
 }
 }
pCd(z) =zdotc;
}
#else
_Complexdoublezdotc=0.0;
if (incx==1&&incy==1) {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc+=Cd(&x[i]) *Cd(&y[i]);
 }
 } else {
for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
zdotc+=Cd(&x[i*incx]) *Cd(&y[i*incy]);
 }
 }
pCd(z) =zdotc;
}
#endif
/* -- translated by f2c (version 20000121).
 You must link the resulting object file with the libraries:
 -lf2c -lm (in that order)
*/


/* -- translated by f2c (version 20000121).
 You must link the resulting object file with the libraries:
 -lf2c -lm (in that order)
*/



/* -- translated by f2c (version 20000121).
 You must link the resulting object file with the libraries:
 -lf2c -lm (in that order)
*/



/* Table of constant values */

staticintegerc__1=1;

/* > \brief \b CGEBD2 reduces a general matrix to bidiagonal form using an unblocked algorithm. */

/* =========== DOCUMENTATION =========== */

/* Online html documentation available at */
/* http://www.netlib.org/lapack/explore-html/ */

/* > \htmlonly */
/* > Download CGEBD2 + dependencies */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/cgebd2.
f"> */
/* > [TGZ]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/cgebd2.
f"> */
/* > [ZIP]</a> */
/* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/cgebd2.
f"> */
/* > [TXT]</a> */
/* > \endhtmlonly */

/* Definition: */
/* =========== */

/* SUBROUTINE CGEBD2( M, N, A, LDA, D, E, TAUQ, TAUP, WORK, INFO ) */

/* INTEGER INFO, LDA, M, N */
/* REAL D( * ), E( * ) */
/* COMPLEX A( LDA, * ), TAUP( * ), TAUQ( * ), WORK( * ) */


/* > \par Purpose: */
/* ============= */
/* > */
/* > \verbatim */
/* > */
/* > CGEBD2 reduces a complex general m by n matrix A to upper or lower */
/* > real bidiagonal form B by a unitary transformation: Q**H * A * P = B. */
/* > */
/* > If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal. */
/* > \endverbatim */

/* Arguments: */
/* ========== */

/* > \param[in] M */
/* > \verbatim */
/* > M is INTEGER */
/* > The number of rows in the matrix A. M >= 0. */
/* > \endverbatim */
/* > */
/* > \param[in] N */
/* > \verbatim */
/* > N is INTEGER */
/* > The number of columns in the matrix A. N >= 0. */
/* > \endverbatim */
/* > */
/* > \param[in,out] A */
/* > \verbatim */
/* > A is COMPLEX array, dimension (LDA,N) */
/* > On entry, the m by n general matrix to be reduced. */
/* > On exit, */
/* > if m >= n, the diagonal and the first superdiagonal are */
/* > overwritten with the upper bidiagonal matrix B; the */
/* > elements below the diagonal, with the array TAUQ, represent */
/* > the unitary matrix Q as a product of elementary */
/* > reflectors, and the elements above the first superdiagonal, */
/* > with the array TAUP, represent the unitary matrix P as */
/* > a product of elementary reflectors; */
/* > if m < n, the diagonal and the first subdiagonal are */
/* > overwritten with the lower bidiagonal matrix B; the */
/* > elements below the first subdiagonal, with the array TAUQ, */
/* > represent the unitary matrix Q as a product of */
/* > elementary reflectors, and the elements above the diagonal, */
/* > with the array TAUP, represent the unitary matrix P as */
/* > a product of elementary reflectors. */
/* > See Further Details. */
/* > \endverbatim */
/* > */
/* > \param[in] LDA */
/* > \verbatim */
/* > LDA is INTEGER */
/* > The leading dimension of the array A. LDA >= f2cmax(1,M). */
/* > \endverbatim */
/* > */
/* > \param[out] D */
/* > \verbatim */
/* > D is REAL array, dimension (f2cmin(M,N)) */
/* > The diagonal elements of the bidiagonal matrix B: */
/* > D(i) = A(i,i). */
/* > \endverbatim */
/* > */
/* > \param[out] E */
/* > \verbatim */
/* > E is REAL array, dimension (f2cmin(M,N)-1) */
/* > The off-diagonal elements of the bidiagonal matrix B: */
/* > if m >= n, E(i) = A(i,i+1) for i = 1,2,...,n-1; */
/* > if m < n, E(i) = A(i+1,i) for i = 1,2,...,m-1. */
/* > \endverbatim */
/* > */
/* > \param[out] TAUQ */
/* > \verbatim */
/* > TAUQ is COMPLEX array, dimension (f2cmin(M,N)) */
/* > The scalar factors of the elementary reflectors which */
/* > represent the unitary matrix Q. See Further Details. */
/* > \endverbatim */
/* > */
/* > \param[out] TAUP */
/* > \verbatim */
/* > TAUP is COMPLEX array, dimension (f2cmin(M,N)) */
/* > The scalar factors of the elementary reflectors which */
/* > represent the unitary matrix P. See Further Details. */
/* > \endverbatim */
/* > */
/* > \param[out] WORK */
/* > \verbatim */
/* > WORK is COMPLEX array, dimension (f2cmax(M,N)) */
/* > \endverbatim */
/* > */
/* > \param[out] INFO */
/* > \verbatim */
/* > INFO is INTEGER */
/* > = 0: successful exit */
/* > < 0: if INFO = -i, the i-th argument had an illegal value. */
/* > \endverbatim */

/* Authors: */
/* ======== */

/* > \author Univ. of Tennessee */
/* > \author Univ. of California Berkeley */
/* > \author Univ. of Colorado Denver */
/* > \author NAG Ltd. */

/* > \date June 2017 */

/* > \ingroup complexGEcomputational */
/* @precisions normal c -> s d z */

/* > \par Further Details: */
/* ===================== */
/* > */
/* > \verbatim */
/* > */
/* > The matrices Q and P are represented as products of elementary */
/* > reflectors: */
/* > */
/* > If m >= n, */
/* > */
/* > Q = H(1) H(2) . . . H(n) and P = G(1) G(2) . . . G(n-1) */
/* > */
/* > Each H(i) and G(i) has the form: */
/* > */
/* > H(i) = I - tauq * v * v**H and G(i) = I - taup * u * u**H */
/* > */
/* > where tauq and taup are complex scalars, and v and u are complex */
/* > vectors; v(1:i-1) = 0, v(i) = 1, and v(i+1:m) is stored on exit in */
/* > A(i+1:m,i); u(1:i) = 0, u(i+1) = 1, and u(i+2:n) is stored on exit in */
/* > A(i,i+2:n); tauq is stored in TAUQ(i) and taup in TAUP(i). */
/* > */
/* > If m < n, */
/* > */
/* > Q = H(1) H(2) . . . H(m-1) and P = G(1) G(2) . . . G(m) */
/* > */
/* > Each H(i) and G(i) has the form: */
/* > */
/* > H(i) = I - tauq * v * v**H and G(i) = I - taup * u * u**H */
/* > */
/* > where tauq and taup are complex scalars, v and u are complex vectors; */
/* > v(1:i) = 0, v(i+1) = 1, and v(i+2:m) is stored on exit in A(i+2:m,i); */
/* > u(1:i-1) = 0, u(i) = 1, and u(i+1:n) is stored on exit in A(i,i+1:n); */
/* > tauq is stored in TAUQ(i) and taup in TAUP(i). */
/* > */
/* > The contents of A on exit are illustrated by the following examples: */
/* > */
/* > m = 6 and n = 5 (m > n): m = 5 and n = 6 (m < n): */
/* > */
/* > ( d e u1 u1 u1 ) ( d u1 u1 u1 u1 u1 ) */
/* > ( v1 d e u2 u2 ) ( e d u2 u2 u2 u2 ) */
/* > ( v1 v2 d e u3 ) ( v1 e d u3 u3 u3 ) */
/* > ( v1 v2 v3 d e ) ( v1 v2 e d u4 u4 ) */
/* > ( v1 v2 v3 v4 d ) ( v1 v2 v3 e d u5 ) */
/* > ( v1 v2 v3 v4 v5 ) */
/* > */
/* > where d and e denote diagonal and off-diagonal elements of B, vi */
/* > denotes an element of the vector defining H(i), and ui an element of */
/* > the vector defining G(i). */
/* > \endverbatim */
/* > */
/* ===================================================================== */
/* Subroutine */voidcgebd2_(integer*m, integer*n, complex*a, integer*lda,
real*d__, real*e, complex*tauq, complex*taup, complex*work, 
integer*info)
{
/* System generated locals */
integera_dim1, a_offset, i__1, i__2, i__3;
complexq__1;

/* Local variables */
integeri__;
complexalpha;
extern/* Subroutine */voidclarf_(char*, integer*, integer*, complex*
 , integer*, complex*, complex*, integer*, complex*), 
clarfg_(integer*, complex*, complex*, integer*, complex*), 
clacgv_(integer*, complex*, integer*);
externintxerbla_(char*, integer*, ftnlen);


/* -- LAPACK computational routine (version 3.7.1) -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* June 2017 */


/* ===================================================================== */


/* Test the input parameters */

/* Parameter adjustments */
a_dim1=*lda;
a_offset=1+a_dim1*1;
a-=a_offset;
--d__;
--e;
--tauq;
--taup;
--work;

/* Function Body */
*info=0;
if (*m<0) {
*info=-1;
 } elseif (*n<0) {
*info=-2;
 } elseif (*lda<f2cmax(1,*m)) {
*info=-4;
 }
if (*info<0) {
i__1=-(*info);
xerbla_("CGEBD2", &i__1, (ftnlen)6);
return;
 }

if (*m >= *n) {

/* Reduce to upper bidiagonal form */

i__1=*n;
for (i__=1; i__ <= i__1; ++i__) {

/* Generate elementary reflector H(i) to annihilate A(i+1:m,i) */

i__2=i__+i__*a_dim1;
alpha.r=a[i__2].r, alpha.i=a[i__2].i;
i__2=*m-i__+1;
/* Computing MIN */
i__3=i__+1;
clarfg_(&i__2, &alpha, &a[f2cmin(i__3,*m) +i__*a_dim1], &c__1, &
tauq[i__]);
i__2=i__;
d__[i__2] =alpha.r;
i__2=i__+i__*a_dim1;
a[i__2].r=1.f, a[i__2].i=0.f;

/* Apply H(i)**H to A(i:m,i+1:n) from the left */

if (i__<*n) {
i__2=*m-i__+1;
i__3=*n-i__;
r_cnjg(&q__1, &tauq[i__]);
clarf_("Left", &i__2, &i__3, &a[i__+i__*a_dim1], &c__1, &
q__1, &a[i__+ (i__+1) *a_dim1], lda, &work[1]);
 }
i__2=i__+i__*a_dim1;
i__3=i__;
a[i__2].r=d__[i__3], a[i__2].i=0.f;

if (i__<*n) {

/* Generate elementary reflector G(i) to annihilate */
/* A(i,i+2:n) */

i__2=*n-i__;
clacgv_(&i__2, &a[i__+ (i__+1) *a_dim1], lda);
i__2=i__+ (i__+1) *a_dim1;
alpha.r=a[i__2].r, alpha.i=a[i__2].i;
i__2=*n-i__;
/* Computing MIN */
i__3=i__+2;
clarfg_(&i__2, &alpha, &a[i__+f2cmin(i__3,*n) *a_dim1], lda, &
taup[i__]);
i__2=i__;
e[i__2] =alpha.r;
i__2=i__+ (i__+1) *a_dim1;
a[i__2].r=1.f, a[i__2].i=0.f;

/* Apply G(i) to A(i+1:m,i+1:n) from the right */

i__2=*m-i__;
i__3=*n-i__;
clarf_("Right", &i__2, &i__3, &a[i__+ (i__+1) *a_dim1], 
lda, &taup[i__], &a[i__+1+ (i__+1) *a_dim1], 
lda, &work[1]);
i__2=*n-i__;
clacgv_(&i__2, &a[i__+ (i__+1) *a_dim1], lda);
i__2=i__+ (i__+1) *a_dim1;
i__3=i__;
a[i__2].r=e[i__3], a[i__2].i=0.f;
 } else {
i__2=i__;
taup[i__2].r=0.f, taup[i__2].i=0.f;
 }
/* L10: */
 }
 } else {

/* Reduce to lower bidiagonal form */

i__1=*m;
for (i__=1; i__ <= i__1; ++i__) {

/* Generate elementary reflector G(i) to annihilate A(i,i+1:n) */

i__2=*n-i__+1;
clacgv_(&i__2, &a[i__+i__*a_dim1], lda);
i__2=i__+i__*a_dim1;
alpha.r=a[i__2].r, alpha.i=a[i__2].i;
i__2=*n-i__+1;
/* Computing MIN */
i__3=i__+1;
clarfg_(&i__2, &alpha, &a[i__+f2cmin(i__3,*n) *a_dim1], lda, &
taup[i__]);
i__2=i__;
d__[i__2] =alpha.r;
i__2=i__+i__*a_dim1;
a[i__2].r=1.f, a[i__2].i=0.f;

/* Apply G(i) to A(i+1:m,i:n) from the right */

if (i__<*m) {
i__2=*m-i__;
i__3=*n-i__+1;
clarf_("Right", &i__2, &i__3, &a[i__+i__*a_dim1], lda, &
taup[i__], &a[i__+1+i__*a_dim1], lda, &work[1]);
 }
i__2=*n-i__+1;
clacgv_(&i__2, &a[i__+i__*a_dim1], lda);
i__2=i__+i__*a_dim1;
i__3=i__;
a[i__2].r=d__[i__3], a[i__2].i=0.f;

if (i__<*m) {

/* Generate elementary reflector H(i) to annihilate */
/* A(i+2:m,i) */

i__2=i__+1+i__*a_dim1;
alpha.r=a[i__2].r, alpha.i=a[i__2].i;
i__2=*m-i__;
/* Computing MIN */
i__3=i__+2;
clarfg_(&i__2, &alpha, &a[f2cmin(i__3,*m) +i__*a_dim1], &c__1,
&tauq[i__]);
i__2=i__;
e[i__2] =alpha.r;
i__2=i__+1+i__*a_dim1;
a[i__2].r=1.f, a[i__2].i=0.f;

/* Apply H(i)**H to A(i+1:m,i+1:n) from the left */

i__2=*m-i__;
i__3=*n-i__;
r_cnjg(&q__1, &tauq[i__]);
clarf_("Left", &i__2, &i__3, &a[i__+1+i__*a_dim1], &
c__1, &q__1, &a[i__+1+ (i__+1) *a_dim1], lda, &
work[1]);
i__2=i__+1+i__*a_dim1;
i__3=i__;
a[i__2].r=e[i__3], a[i__2].i=0.f;
 } else {
i__2=i__;
tauq[i__2].r=0.f, tauq[i__2].i=0.f;
 }
/* L20: */
 }
 }
return;

/* End of CGEBD2 */

} /* cgebd2_ */