On 24/08/2021 21:11, matheus.fe...@eldorado.org.br wrote:
From: Matheus Ferst <matheus.fe...@eldorado.org.br>
The definition of struct Int128 is currently independent of the host
endianness, causing different results when using the member s128 of
union ppc_vsr_t in big-endian builds with CONFIG_INT128 or
!CONFIG_INT128.
The only PPC instructions that seem to be affected by this issue are the
"Vector Extract Unsigned Byte/Halfword/Word to GPR using GPR-specified
Left/Right-Index." Even on builds with Int128 support, however, their
helpers give the wrong result on big-endian hosts.
The first patch in this series changes the definition of struct Int128
to allow its use in the ppc_vsr_t union. The second patch fixes the
helper definition.
Matheus Ferst (2):
include/qemu/int128.h: define struct Int128 according to the host
endianness
target/ppc: fix vextu[bhw][lr]x helpers
include/qemu/int128.h | 19 ++++++++++++-------
target/ppc/int_helper.c | 38 ++++++++++----------------------------
2 files changed, 22 insertions(+), 35 deletions(-)
Hi Matheus,
Slightly unrelated to this patchset, however I see you've managed to make some good
efforts in consolidating the functionality between big-endian and little-endian host
systems.
When I first worked on adding host vector support for PPC I noticed there were some
further places in target/ppc/int_helper.c that could be improved from accessing
ppc_avr_t fields such as u64 directly and instead using the relevant Vsr*() macros.
If you feel suitably motivated, it would be amazing to see more patches to help this
further along: basically look in target/ppc/int_helper.c for individual elements such
as u64 (and also the VECTOR_FOR_INORDER_I macro) and determine which ones are better
replaced by the relevant Vsr*() macro.
ATB,
Mark.
