Mercurial > octave-nkf
comparison libcruft/blas/cswap.f @ 7789:82be108cc558
First attempt at single precision tyeps
* * *
corrections to qrupdate single precision routines
* * *
prefer demotion to single over promotion to double
* * *
Add single precision support to log2 function
* * *
Trivial PROJECT file update
* * *
Cache optimized hermitian/transpose methods
* * *
Add tests for tranpose/hermitian and ChangeLog entry for new transpose code
| author | David Bateman <dbateman@free.fr> |
|---|---|
| date | Sun, 27 Apr 2008 22:34:17 +0200 |
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| children |
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| 7788:45f5faba05a2 | 7789:82be108cc558 |
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| 1 SUBROUTINE CSWAP(N,CX,INCX,CY,INCY) | |
| 2 * .. Scalar Arguments .. | |
| 3 INTEGER INCX,INCY,N | |
| 4 * .. | |
| 5 * .. Array Arguments .. | |
| 6 COMPLEX CX(*),CY(*) | |
| 7 * .. | |
| 8 * | |
| 9 * Purpose | |
| 10 * ======= | |
| 11 * | |
| 12 * interchanges two vectors. | |
| 13 * jack dongarra, linpack, 3/11/78. | |
| 14 * modified 12/3/93, array(1) declarations changed to array(*) | |
| 15 * | |
| 16 * | |
| 17 * .. Local Scalars .. | |
| 18 COMPLEX CTEMP | |
| 19 INTEGER I,IX,IY | |
| 20 * .. | |
| 21 IF (N.LE.0) RETURN | |
| 22 IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20 | |
| 23 * | |
| 24 * code for unequal increments or equal increments not equal | |
| 25 * to 1 | |
| 26 * | |
| 27 IX = 1 | |
| 28 IY = 1 | |
| 29 IF (INCX.LT.0) IX = (-N+1)*INCX + 1 | |
| 30 IF (INCY.LT.0) IY = (-N+1)*INCY + 1 | |
| 31 DO 10 I = 1,N | |
| 32 CTEMP = CX(IX) | |
| 33 CX(IX) = CY(IY) | |
| 34 CY(IY) = CTEMP | |
| 35 IX = IX + INCX | |
| 36 IY = IY + INCY | |
| 37 10 CONTINUE | |
| 38 RETURN | |
| 39 * | |
| 40 * code for both increments equal to 1 | |
| 41 20 DO 30 I = 1,N | |
| 42 CTEMP = CX(I) | |
| 43 CX(I) = CY(I) | |
| 44 CY(I) = CTEMP | |
| 45 30 CONTINUE | |
| 46 RETURN | |
| 47 END |