Re: [PATCH v3 09/30] tcg/loongarch64: Implement tcg_out_mov and tcg_out_movi

[WANG Xuerui]

Hi Richard,

On 9/23/21 02:39, Richard Henderson wrote:
> On 9/22/21 11:09 AM, WANG Xuerui wrote:
> > +    if (pc_offset == (int32_t)pc_offset) {
> > +        tcg_target_long lo = sextreg(pc_offset, 0, 12);
> > +        tcg_target_long hi = pc_offset - lo;
> > +        tcg_out_opc_pcaddu12i(s, rd, hi >> 12);
> > +        tcg_out_opc_addi_d(s, rd, rd, lo);
>
> pc_offset = 0x7ffff800 will fail:
>
> lo = 0xfffffffffffff800
> hi = 0x0000000080000000
>
> but hi will be interpreted as negative by pcaddu12i.
>
> This is the same problem I pointed out with tcg_out_call, but with 
> different constants.
Hmm, I think I'll have to look into this, but not now (it's again 3 am 
here)... I'll try to come up with something tomorrow.
> r~