struct fpreg

From: Patrick Alken <psa22(at)drexel.edu>
Date: Thu Aug 28 2003 - 17:41:45 EDT

Hello,

  I am using OpenBSD 3.3-release and have a question about the struct fpreg defined in /usr/include/machine/reg.h. The only element of the struct is a 108 byte character array: __data[]. I need to know which fpu registers correspond to which indices of this array.

  I initially assumed it was set up as:

fctrl = __data[0-3]
fstat = __data[4-7]
ftag = __data[8-11]

...

st0 = __data[28-37]
st1 = __data[38-47]
...

st7 = __data[98-107]

which is sort of similar to freebsd's setup, but I do not think this is correct after trying it for a bit.

Before assuming my code is wrong, I want to confirm the correct structure of __data[]. Can anyone point me to documentation on which indices of __data[] correspond to which fpu registers?

Thank you in advance,
Patrick Alken Received on Thu Aug 28 17:47:26 2003