Re: QR test failure with --enable-64

[John W. Eaton]

On 19-Feb-2010, Jaroslav Hajek wrote:

| On Fri, Feb 19, 2010 at 6:19 PM, John W. Eaton <address@hidden> wrote:
| > When I compile Octave with --enable-64 on an amd64 system, the
| > following test from qr.cc fails because the computed norm is exactly
| > equal to 10*eps.  On the same system without --enable-64, the test
| > passes.  I don't know exactly why changing the  size of integer
| > indexes would change the result.  My best guess is that the additional
| > memory required by the index values forces the compiler to store some
| > floating point values that are otherwise kept in registers.
| 
| Interesting. Is it just qrdelete that makes the difference, or is the
| qr result also different?

The test I quoted in the original message is the only one in qr.cc
that is failing for me with --enable-64.

jwe