Re: [Qemu-devel] [PATCH] tcg/mips: fix add2

2015-07-31 Thread Richard Henderson
On 07/31/2015 08:31 AM, Aurelien Jarno wrote: The add2 code in the tcg_out_addsub2 function doesn't take into account the case where rl == al == bl. In that case we can't compute the carry after the addition. As it corresponds to a multiplication by 2, the carry bit is the bit 31. While this is

[Qemu-devel] [PATCH] tcg/mips: fix add2

2015-07-31 Thread Aurelien Jarno
The add2 code in the tcg_out_addsub2 function doesn't take into account the case where rl == al == bl. In that case we can't compute the carry after the addition. As it corresponds to a multiplication by 2, the carry bit is the bit 31. While this is a corner case, this prevents x86-64 guests to bo