Re: [Qemu-devel] [PATCH 3/8] target-ppc: Bug Fix: rlwimi

[Richard Henderson <rth@twiddle.net>]

On 08/11/2014 09:23 AM, Tom Musta wrote:
> Also fix the special case of MB=31 and ME=0 to copy the entire contents
> of the source GPR.

Err, that's not what you did.

>      if (likely(sh == 0 && mb == 0 && me == 31)) {
> +#if defined(TARGET_PPC64)
> +        tcg_gen_mov_i64(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
> +#else
>          tcg_gen_ext32u_tl(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
> +#endif

This is the reverse condition.  Which, true enough, should not be implemented
with ext32u for PPC64.  But a MOV isn't right either, it is

  deposit(ra, rs, 0, 32)

Which does point out that we should probably implement anything MB <= ME and SH
== 31 - ME with the deposit opcode.


r~