Re: [PATCH] x86: Add {load}/{store} tests for apx instructions.

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

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On Wed, Jul 3, 2024, 10:41 AM Cui, Lili <lili.cui@intel.com> wrote:

> > > On 02.07.2024 12:29, Cui, Lili wrote:
> > > >>>>>> Having reached the end of the file: What about CTESTcc and
> > CCMPcc?
> > > >>>>>>
> > > >>>>>
> > > >>>
> > > >>> When adding swap test cases for CTESTcc, I found that it does not
> > > >>> support
> > > >> swapping operands, but test, {evex} test and ctest template insns
> > > >> all have D, which does not match the SDM/APX spec, I want to remove
> > > >> D for them. I'm a bit unsure if there's any particular reason why
> > > >> the legacy test
> > > added D ?
> > > >>
> > > >> Did you look at the commit doing so?
> > > >>
> > > >
> > > > Ok, I found the commit this time, but I'm even more confused because
> > > > I
> > > didn't find the basis for the second test from SDM.
> > > >
> > > > -test, 0x84, None, 0, W|CheckRegSize|Modrm|No_sSuf, {
> > > > Reg8|Reg16|Reg32|Reg64,
> > > >
> > >
> > Reg8|Reg16|Reg32|Reg64|Unspecified|Byte|Word|Dword|Qword|BaseInde
> > > x }
> > > > -test, 0x84, None, 0, W|CheckRegSize|Modrm|No_sSuf, {
> > > > Byte|Word|Dword|Qword|Unspecified|BaseIndex,
> > > Reg8|Reg16|Reg32|Reg64 }
> > > > +test, 0x84, None, 0, D|W|C|CheckRegSize|Modrm|No_sSuf, {
> > > > +Reg8|Reg16|Reg32|Reg64,
> > > Reg8|Reg16|Reg32|Reg64|Unspecified|BaseIndex
> > > > +}
> > >
> > > "basis for the second test"? What do you mean? Are you referring to
> > > the SDM spelling out only one operand order? That's surely a (very
> > > minor) shortcoming there. TEST is commutative, and hence whatever
> > > order the programmer likes should be accepted by an assembler.
> >
> > Yes, I only found "test %ax, (%bx)" and didn't find "test (%bx), %ax" in
> the
> > SDM. And APX spec also doesn’t say " ctest {def=} (%bx), %ax " is
> supported.
> > Anyway, their assemblers are same.
> > I will support "ctestb(%rax),%ecx" and "{evex} test(%rax),%ecx" in
> assembler,
> > currently "ctestb(%rax),%ecx" does not work, I need to fix it first.
> >
> $ cat test.s
> test (%edx), %eax
> test %eax, (%edx)
>
> $ as --64  test.s -o test.o
> $ objdump  -dw -Msuffix test.o
> 0000000000000000 <_start>:
>    0:   67 85 02                testl  %eax,(%edx)
>    3:   67 85 02                testl  %eax,(%edx)
>
> Hi HJ,
>
> Do you remember why we supported "test (%edx), %eax" in the original
> version? I'm curious about it.


I don't remember why.  I think we should follow SDM.


>
> Thanks,
> Lili.
>