Comment 8 for bug 1841990

Sorry I didn't get a chance to look at this before I went away on holiday, however I've just posted a patchset at https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg05577.html which should resolve the issue for you.

With the above patchset applied I now see the following results with your test program:

LE host:
$ ../qemu-ppc64le -L /usr/powerpc64le-linux-gnu -cpu power9 test-denbcdqle
0x00000000000000000000000000000000
0x0000000000000000000000000000000c
0x22080000000000000000000000000000
$ ../qemu-ppc64le -L /usr/powerpc64le-linux-gnu -cpu power9 test-denbcdqle 1
0x00000000000000000000000000000001
0x0000000000000000000000000000001c
0x22080000000000000000000000000001
$ ../qemu-ppc64le -L /usr/powerpc64le-linux-gnu -cpu power9 test-denbcdqle $(seq 0 99)
0x00000000000000000000000000000064
0x0000000000000000000000000000100c
0x22080000000000000000000000000080

BE host:
$ ../qemu-ppc64 -L /usr/powerpc64-linux-gnu -cpu power9 test-denbcdq
0x00000000000000000000000000000000
0x000000000000000c0000000000000000
0x00000000000000002208000000000000
$ ../qemu-ppc64 -L /usr/powerpc64-linux-gnu -cpu power9 test-denbcdq 1
0x00000000000000010000000000000000
0x000000000000001c0000000000000000
0x00000000000000012208000000000000
$ ../qemu-ppc64 -L /usr/powerpc64-linux-gnu -cpu power9 test-denbcdq $(seq 0 99)
0x00000000000000640000000000000000
0x000000000000100c0000000000000000
0x00000000000000802208000000000000

If you could confirm that the BE host results above match those on real hardware then that would be great as I've switched over to use macros that should do the right thing regardless of host endian.

Finally if you have access to a more comprehensive test suite then that would be helpful to test more of the 64-bit DFP number paths and some of more esoteric DFP instructions.