On 10/10/25 08:50, Philippe Mathieu-Daudé wrote:
> Per commit a2f827ff4f4 ("target/riscv: accessors to registers upper
> part and 128-bit load/store") description:
>
> > The 128-bit ISA adds ldu, lq and sq. We provide support for these
> > instructions. Note that (a) we compute only 64-bit addresses to
> > actually access memory, cowardly utilizing the existing address
> > translation mechanism of QEMU, and (b) we assume for now
> > little-endian memory accesses.
>
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> However this commit used MO_TE (target endianness) for the
> gen_load_i128() and gen_store_i128() helpers. Likely it was
> unnoticed because current targets are only built using little
> endianness:
>
> $ git grep -L TARGET_BIG_ENDIAN=y configs/targets/riscv*
> configs/targets/riscv32-linux-user.mak
> configs/targets/riscv32-softmmu.mak
> configs/targets/riscv64-bsd-user.mak
> configs/targets/riscv64-linux-user.mak
> configs/targets/riscv64-softmmu.mak
>
> Replace by MO_TE -> MO_LE to really use little endianness.
>
> Cc: Fabien Portas <fabien.portas@grenoble-inp.org>
> Cc: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
> Fixes: a2f827ff4f4 ("target/riscv: accessors to registers upper part and 128-bit load/store")
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
> target/riscv/insn_trans/trans_rvi.c.inc | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/target/riscv/insn_trans/trans_rvi.c.inc b/target/riscv/insn_trans/trans_rvi.c.inc
> index b9c71604687..df0b555176a 100644
> --- a/target/riscv/insn_trans/trans_rvi.c.inc
> +++ b/target/riscv/insn_trans/trans_rvi.c.inc
> @@ -389,9 +389,11 @@ static bool gen_load_i128(DisasContext *ctx, arg_lb *a, MemOp memop)
> }
> } else {
> /* assume little-endian memory access for now */
> - tcg_gen_qemu_ld_tl(destl, addrl, ctx->mem_idx, MO_TEUQ);
> + MemOp memop = MO_LEUQ;
> +
> + tcg_gen_qemu_ld_tl(destl, addrl, ctx->mem_idx, memop);
> tcg_gen_addi_tl(addrl, addrl, 8);
> - tcg_gen_qemu_ld_tl(desth, addrl, ctx->mem_idx, MO_TEUQ);
> + tcg_gen_qemu_ld_tl(desth, addrl, ctx->mem_idx, memop);
> }
>
> gen_set_gpr128(ctx, a->rd, destl, desth);
> @@ -494,9 +496,11 @@ static bool gen_store_i128(DisasContext *ctx, arg_sb *a, MemOp memop)
> tcg_gen_qemu_st_tl(src2l, addrl, ctx->mem_idx, memop);
> } else {
> /* little-endian memory access assumed for now */
> - tcg_gen_qemu_st_tl(src2l, addrl, ctx->mem_idx, MO_TEUQ);
> + MemOp memop = MO_LEUQ;
> +
> + tcg_gen_qemu_st_tl(src2l, addrl, ctx->mem_idx, memop);
> tcg_gen_addi_tl(addrl, addrl, 8);
> - tcg_gen_qemu_st_tl(src2h, addrl, ctx->mem_idx, MO_TEUQ);
> + tcg_gen_qemu_st_tl(src2h, addrl, ctx->mem_idx, memop);
> }
> return true;
> }
We fix this to use tcg_gen_qemu_{ld,st}_i128.
r~