Re: [Qemu-devel] [Bug 1308381] Re: illegal instructions for AArch64ARMv88

[Janne Grunau]

On 2014-04-16 11:59:58 +0100, Peter Maydell wrote:
> On 16 April 2014 11:55, Alex Bennée <address@hidden> wrote:
> >
> > Peter Maydell <address@hidden> writes:
> >
> >> Can you attach a statically linked test case binary, please?
> >
> > I can reproduce with the source file. It looks like:
> >
> > @@ -7553,12 +7555,9 @@ static void 
> > disas_simd_scalar_two_reg_misc(DisasContext *s, uint32_t insn)
> >          }
> >          break;
> >      case 0x12: /* SQXTUN */
> > -        if (u) {
> > -            unallocated_encoding(s);
> > -            return;
> > -        }
> >          /* fall through */
> >
> > Fixes it.
> 
> However the ARM ARM, unless I'm misreading it, requires scalar-2-misc
> SQXTUN to have U==1, so the correct fix should be to turn that "if (u)"
> into "if (!u)" I think. (Opcode 0x12 u==0 isn't in the table so should undef.)

agree, was about to send a patch

> Better check we didn't make the same mistake in the vector-2-misc
> decode as well.

The vector sqxtun2? halfword to byte is used in libav and works as
expected.

Janne