[llvm-dev] BUILD_VECTOR disambiguation

[Cameron McInally via llvm-dev]

Sorry. Being pedantic, how do we end up with a mixed operand type BUILD_VECTOR?

On Tue, Jul 7, 2020 at 11:10 AM Cameron McInally
<cameron.mcinally at nyu.edu> wrote:
>
> Thanks for the clarification. The `except` seemed dangling to me, but
> it's early here.
>
> Just curious... how do we end up with a mixed type BUILD_VECTOR?
> That's counterintuitive.
>
> On Tue, Jul 7, 2020 at 10:58 AM Krzysztof Parzyszek via llvm-dev
> <llvm-dev at lists.llvm.org> wrote:
> >
> > Mixed integer types are ok, but the values will get truncated to the element type of the output value.  It's pretty much what the comment says.
> >
> > --
> > Krzysztof Parzyszek  kparzysz at quicinc.com   AI tools development
> >
> > > -----Original Message-----
> > > From: llvm-dev <llvm-dev-bounces at lists.llvm.org> On Behalf Of Cameron
> > > McInally via llvm-dev
> > > Sent: Tuesday, July 7, 2020 9:53 AM
> > > To: LLVM Developers Mailing List <llvm-dev at lists.llvm.org>
> > > Subject: [EXT] [llvm-dev] BUILD_VECTOR disambiguation
> > >
> > > Hey devs,
> > >
> > > From ISDOpcodes.h...
> > >
> > > /// BUILD_VECTOR(ELT0, ELT1, ELT2, ELT3,...) - Return a fixed-width vector
> > > /// with the specified, possibly variable, elements. The number of elements
> > > /// is required to be a power of two. The types of the operands must all be
> > > /// the same and must match the vector element type, except that integer
> > > types /// are allowed to be larger than the element type, in which case the
> > > operands /// are implicitly truncated.
> > > BUILD_VECTOR,
> > >
> > > Must the operand types always be the same? Or could we see a BUILD_VECTOR
> > > with mixed integer types? E.g.:
> > >
> > > BUILD_VECTOR(i32, i32, i64, i32)
> > >
> > > Thanks,
> > > Cam