[Bug libc/6411] PowerPC: Extend fpu fenv operations to operate on 64-bit FPSCR

["rsa at us dot ibm dot com" <sourceware-bugzilla at sourceware dot org>]

------- Additional Comments From rsa at us dot ibm dot com  2008-11-13 21:06 -------
Created an attachment (id=3061)
 --> (http://sourceware.org/bugzilla/attachment.cgi?id=3061&action=view)
Respin of the patch with a test case verifying correct behavior.

This patch has an added test case and a hwcap accessor fix.

The test case verifies the behavior of [set|get|swap]context in the following
scenarios:

power5 -m32 --enable-kernel=2.4.21 [no-altivec, 32-bit FPSCR]
power5 -m64 --enable-kernel=2.4.21 [no-altivec, 32-bit FPSCR]
power5 -m32 --enable-kernel=2.6.16 [no-altivec, 32-bit FPSCR]
power5 -m64 --enable-kernel=2.6.16 [no-altivec, 32-bit FPSCR]

power6 -m32 --enable-kernel=2.4.21 [altivec, 64-bit FPSCR]
power6 -m64 --enable-kernel=2.4.21 [altivec, 64-bit FPSCR]
power6 -m32 --enable-kernel=2.6.16 [altivec, 64-bit FPSCR]
power6 -m64 --enable-kernel=2.6.16 [altivec, 64-bit FPSCR]


power6 -mcpu=power6 -m32 --enable-kernel=2.4.21 [altivec, 64-bit FPSCR]
power6 -mcpu=power6 -m64 --enable-kernel=2.4.21 [altivec, 64-bit FPSCR]
power6 -mcpu=power6 -m32 --enable-kernel=2.6.16 [altivec, 64-bit FPSCR]
power6 -mcpu=power6 -m64 --enable-kernel=2.6.16 [altivec, 64-bit FPSCR]

So I've verified with the test case that the given scenarios pass.

2.4.21 is prior to the swapcontext syscall so it tests the
[get|set|swap]context-common code path.

2.6.16 contains the swapcontext syscall so it test the syscall path for said
function invocations.

The -mcpu=power6 switch indicates that this GLIBC is built for ISA 2.05
compliance at a minimum, whereby a dynamic check for the 64-bit FPSCR doesn't
need to be made since ISA 2.05 and later have a 64-bit FPSCR by default.

This testcase can be added to in the future for testing any special register
preservation across context calls.

Please consider for check-in.  Everything is behaving properly as verified by
the patch and the build passes make check.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
Attachment #3005 is|0                           |1
           obsolete|                            |


http://sourceware.org/bugzilla/show_bug.cgi?id=6411

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.