[Lightning] jit_movr broken on MIPS

[Paul Cercueil]

Hi,

I have a problem when compiling for MIPS.

Very rarely, one call to jit_movr() is optimized out even though the 
source and destination registers differ. This also happens with 
jit_retval_i() (as it calls jit_movr internally).

As a result my generated code is wrong and fails at runtime. I currently 
work around that by patching the references to jit_movr(dest, src) with 
jit_orr(dest, _ZERO, src); then my program runs fine.

It is fully reproductible but it happens only once or twice in my 
disassembly log (which is ~6 MiB); I couldn't manage to create a simple 
test case which reproduces the issue.

Did anybody run into a similar issue?
Any pointers to what could be the cause?

Thanks,
Paul