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Diffstat (limited to 'eigen/blas/f2c/srotmg.c')
-rw-r--r-- | eigen/blas/f2c/srotmg.c | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/eigen/blas/f2c/srotmg.c b/eigen/blas/f2c/srotmg.c new file mode 100644 index 0000000..75f789f --- /dev/null +++ b/eigen/blas/f2c/srotmg.c @@ -0,0 +1,295 @@ +/* srotmg.f -- translated by f2c (version 20100827). + You must link the resulting object file with libf2c: + on Microsoft Windows system, link with libf2c.lib; + on Linux or Unix systems, link with .../path/to/libf2c.a -lm + or, if you install libf2c.a in a standard place, with -lf2c -lm + -- in that order, at the end of the command line, as in + cc *.o -lf2c -lm + Source for libf2c is in /netlib/f2c/libf2c.zip, e.g., + + http://www.netlib.org/f2c/libf2c.zip +*/ + +#include "datatypes.h" + +/* Subroutine */ int srotmg_(real *sd1, real *sd2, real *sx1, real *sy1, real + *sparam) +{ + /* Initialized data */ + + static real zero = 0.f; + static real one = 1.f; + static real two = 2.f; + static real gam = 4096.f; + static real gamsq = 16777200.f; + static real rgamsq = 5.96046e-8f; + + /* Format strings */ + static char fmt_120[] = ""; + static char fmt_150[] = ""; + static char fmt_180[] = ""; + static char fmt_210[] = ""; + + /* System generated locals */ + real r__1; + + /* Local variables */ + real su, sp1, sp2, sq1, sq2, sh11, sh12, sh21, sh22; + integer igo; + real sflag, stemp; + + /* Assigned format variables */ + static char *igo_fmt; + +/* .. Scalar Arguments .. */ +/* .. */ +/* .. Array Arguments .. */ +/* .. */ + +/* Purpose */ +/* ======= */ + +/* CONSTRUCT THE MODIFIED GIVENS TRANSFORMATION MATRIX H WHICH ZEROS */ +/* THE SECOND COMPONENT OF THE 2-VECTOR (SQRT(SD1)*SX1,SQRT(SD2)* */ +/* SY2)**T. */ +/* WITH SPARAM(1)=SFLAG, H HAS ONE OF THE FOLLOWING FORMS.. */ + +/* SFLAG=-1.E0 SFLAG=0.E0 SFLAG=1.E0 SFLAG=-2.E0 */ + +/* (SH11 SH12) (1.E0 SH12) (SH11 1.E0) (1.E0 0.E0) */ +/* H=( ) ( ) ( ) ( ) */ +/* (SH21 SH22), (SH21 1.E0), (-1.E0 SH22), (0.E0 1.E0). */ +/* LOCATIONS 2-4 OF SPARAM CONTAIN SH11,SH21,SH12, AND SH22 */ +/* RESPECTIVELY. (VALUES OF 1.E0, -1.E0, OR 0.E0 IMPLIED BY THE */ +/* VALUE OF SPARAM(1) ARE NOT STORED IN SPARAM.) */ + +/* THE VALUES OF GAMSQ AND RGAMSQ SET IN THE DATA STATEMENT MAY BE */ +/* INEXACT. THIS IS OK AS THEY ARE ONLY USED FOR TESTING THE SIZE */ +/* OF SD1 AND SD2. ALL ACTUAL SCALING OF DATA IS DONE USING GAM. */ + + +/* Arguments */ +/* ========= */ + + +/* SD1 (input/output) REAL */ + +/* SD2 (input/output) REAL */ + +/* SX1 (input/output) REAL */ + +/* SY1 (input) REAL */ + + +/* SPARAM (input/output) REAL array, dimension 5 */ +/* SPARAM(1)=SFLAG */ +/* SPARAM(2)=SH11 */ +/* SPARAM(3)=SH21 */ +/* SPARAM(4)=SH12 */ +/* SPARAM(5)=SH22 */ + +/* ===================================================================== */ + +/* .. Local Scalars .. */ +/* .. */ +/* .. Intrinsic Functions .. */ +/* .. */ +/* .. Data statements .. */ + + /* Parameter adjustments */ + --sparam; + + /* Function Body */ +/* .. */ + if (! (*sd1 < zero)) { + goto L10; + } +/* GO ZERO-H-D-AND-SX1.. */ + goto L60; +L10: +/* CASE-SD1-NONNEGATIVE */ + sp2 = *sd2 * *sy1; + if (! (sp2 == zero)) { + goto L20; + } + sflag = -two; + goto L260; +/* REGULAR-CASE.. */ +L20: + sp1 = *sd1 * *sx1; + sq2 = sp2 * *sy1; + sq1 = sp1 * *sx1; + + if (! (dabs(sq1) > dabs(sq2))) { + goto L40; + } + sh21 = -(*sy1) / *sx1; + sh12 = sp2 / sp1; + + su = one - sh12 * sh21; + + if (! (su <= zero)) { + goto L30; + } +/* GO ZERO-H-D-AND-SX1.. */ + goto L60; +L30: + sflag = zero; + *sd1 /= su; + *sd2 /= su; + *sx1 *= su; +/* GO SCALE-CHECK.. */ + goto L100; +L40: + if (! (sq2 < zero)) { + goto L50; + } +/* GO ZERO-H-D-AND-SX1.. */ + goto L60; +L50: + sflag = one; + sh11 = sp1 / sp2; + sh22 = *sx1 / *sy1; + su = one + sh11 * sh22; + stemp = *sd2 / su; + *sd2 = *sd1 / su; + *sd1 = stemp; + *sx1 = *sy1 * su; +/* GO SCALE-CHECK */ + goto L100; +/* PROCEDURE..ZERO-H-D-AND-SX1.. */ +L60: + sflag = -one; + sh11 = zero; + sh12 = zero; + sh21 = zero; + sh22 = zero; + + *sd1 = zero; + *sd2 = zero; + *sx1 = zero; +/* RETURN.. */ + goto L220; +/* PROCEDURE..FIX-H.. */ +L70: + if (! (sflag >= zero)) { + goto L90; + } + + if (! (sflag == zero)) { + goto L80; + } + sh11 = one; + sh22 = one; + sflag = -one; + goto L90; +L80: + sh21 = -one; + sh12 = one; + sflag = -one; +L90: + switch (igo) { + case 0: goto L120; + case 1: goto L150; + case 2: goto L180; + case 3: goto L210; + } +/* PROCEDURE..SCALE-CHECK */ +L100: +L110: + if (! (*sd1 <= rgamsq)) { + goto L130; + } + if (*sd1 == zero) { + goto L160; + } + igo = 0; + igo_fmt = fmt_120; +/* FIX-H.. */ + goto L70; +L120: +/* Computing 2nd power */ + r__1 = gam; + *sd1 *= r__1 * r__1; + *sx1 /= gam; + sh11 /= gam; + sh12 /= gam; + goto L110; +L130: +L140: + if (! (*sd1 >= gamsq)) { + goto L160; + } + igo = 1; + igo_fmt = fmt_150; +/* FIX-H.. */ + goto L70; +L150: +/* Computing 2nd power */ + r__1 = gam; + *sd1 /= r__1 * r__1; + *sx1 *= gam; + sh11 *= gam; + sh12 *= gam; + goto L140; +L160: +L170: + if (! (dabs(*sd2) <= rgamsq)) { + goto L190; + } + if (*sd2 == zero) { + goto L220; + } + igo = 2; + igo_fmt = fmt_180; +/* FIX-H.. */ + goto L70; +L180: +/* Computing 2nd power */ + r__1 = gam; + *sd2 *= r__1 * r__1; + sh21 /= gam; + sh22 /= gam; + goto L170; +L190: +L200: + if (! (dabs(*sd2) >= gamsq)) { + goto L220; + } + igo = 3; + igo_fmt = fmt_210; +/* FIX-H.. */ + goto L70; +L210: +/* Computing 2nd power */ + r__1 = gam; + *sd2 /= r__1 * r__1; + sh21 *= gam; + sh22 *= gam; + goto L200; +L220: + if (sflag < 0.f) { + goto L250; + } else if (sflag == 0) { + goto L230; + } else { + goto L240; + } +L230: + sparam[3] = sh21; + sparam[4] = sh12; + goto L260; +L240: + sparam[2] = sh11; + sparam[5] = sh22; + goto L260; +L250: + sparam[2] = sh11; + sparam[3] = sh21; + sparam[4] = sh12; + sparam[5] = sh22; +L260: + sparam[1] = sflag; + return 0; +} /* srotmg_ */ + |