Harold Grovesteen wrote:

>The chart and words do not match.

Oops.  Sorry for that ...

>Due to the inconsitency, this leads to three questions:
>
>   1. Has the ABI changed for floating point between s/390 and zSeries
>      versions?

Yes.  We did this because the S/390 ABI was originally supposed to
work on old machines with only 4 floating-point registers (2 saved,
and 2 volatile), and the 12 additional registers of new machines
could only be added as volatile registers.  The zSeries ABI from
the beginning assumes 16 registers, and making half of them saved
and half volatile seems to work out well ...

>   2. What is correct usage and volatility for zSeries (or is the s/390
>      really wrong)?

S/390 is correct.  For zSeries, the correct situation is as described
in Table 8:

Call-saved: f8 - f15
Volatile:   f0 - f7

(The text below that table is wrong.)

>   3. How does the inconsistency in the zSeries ELF ABI get fixed?

I'll see to get this fixed.


Thanks for reporting the problem!

Bye,
Ulrich

--
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  [EMAIL PROTECTED]

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