Re: [Qemu-devel] [PATCH 14/15] tcg-mips: Use mipsr6 instructions in branches

[Richard Henderson]

On 02/10/2016 03:22 AM, James Hogan wrote:
> So to be correct + efficient, it should only put the nop in if the next
> generated instruction is a CTI. I imagine that would be a bit messy /
> fragile, but maybe doable? I haven't looked too deeply.

Ouch, I didn't notice this about these insns.

I suppose this might be rare enough that it's still worth thinking about.  Off 
the top of my head I can't think of any way to save extra state, but perhaps 
just looking back at the previous insn's major opcode is enough when emitting 
any forbidden insn.

For the moment, let's just drop this patch (and probably the one for calls too, 
for the same reason?)


r~