Re: [PATCH v5 2/5] x86: move certain MOVSX/MOVZX tests

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Tue, Feb 11, 2020 at 3:55 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 11.02.2020 12:42, H.J. Lu wrote:
> > On Tue, Feb 11, 2020 at 2:25 AM Jan Beulich <jbeulich@suse.com> wrote:
> >>
> >> Some encodings are about to gain a warning - move them from test cases
> >> not expecting any diagnostics to the new, dedicated ones, to allow
> >> better focus on the actual changes in the subsequent patch.
> >>
> >> The new tests added have some wrong expectations right now, which will
> >> be corrected by the next patch. The test is being added here to make
> >> more visible which cases actually were wrong (and hence get changed),
> >> besides demonstrating that in the vast majority of cases the subsequent
> >> change doesn't alter generated code.
> >>
> >> gas/
> >> 2020-02-XX  Jan Beulich  <jbeulich@suse.com>
> >>
> >>         * testsuite/gas/i386/i386.s, testsuite/gas/i386/iamcu-1.s,
> >>         testsuite/gas/i386/ilp32/x86-64.s: Move ambiguous operand size
> >>         tests ...
> >>         * testsuite/gas/i386/noreg16.s, testsuite/gas/i386/noreg32.s,
> >>         testsuite/gas/i386/noreg64.s, testsuite/gas/i386/x86_64.s: ...
> >>         here.
> >>         * testsuite/gas/i386/i386.d, testsuite/gas/i386/i386-intel.d
> >>         testsuite/gas/i386/iamcu-1.d, testsuite/gas/i386/ilp32/x86-64.d,
> >>         testsuite/gas/i386/k1om.d, testsuite/gas/i386/l1om.d,
> >>         testsuite/gas/i386/noreg16.d, testsuite/gas/i386/noreg32.d,
> >>         testsuite/gas/i386/noreg64.d, testsuite/gas/i386/x86_64-intel.d,
> >>         testsuite/gas/i386/x86_64.d: Adjust expectations.
> >>         * testsuite/gas/i386/movx16.s, testsuite/gas/i386/movx16.l,
> >>         testsuite/gas/i386/movx32.s, testsuite/gas/i386/movx32.l,
> >>         testsuite/gas/i386/movx64.s, testsuite/gas/i386/movx64.l: New.
> >>         * testsuite/gas/i386/i386.exp: Run new tests.
> >
> > Please make a separate patch to address MOVSX/MOVZX.
>
> I don't understand what you mean here. This patch simply documents the
> status quo, to make it (much) easier to see what the next patch
> actually adjusts. It doesn't "address" anything. If, for the purpose
> of committing, you'd like to see both patches folded - fine by me. But
> only then, not any earlier.
>
> >  MOVSX and MOVZX
> > should take no suffixes.  AT&T syntax is supported if there is no
> > ambiguity.  AT&T
> > syntax also supports movsXY and movzXY.
>
> Please could you clarify what specifically you'd like to see changed,
> at the very least by pointing out one case each where you think I'm
> moving in the wrong direction (presumably in the next patch really)?
> I'm afraid your response isn't such that I can derive from it what
> exactly you want.

We support

movsx %ax, %ecx
movzx %ax, %ecx
movswl %ax, %ecx
movzwl %ax, %ecx

We disallow

movsxw %ax, %ecx
movzxw %ax, %ecx

> >   We should also improve MOVSX/MOVZX documentation.
>
> Probably, but not here and now.
>
> Jan



-- 
H.J.