RE: [PATCH] arm: Restrict support of vectors of boolean immediates (PR target/104662)

[Kyrylo Tkachov <Kyrylo.Tkachov@arm.com>]

> -----Original Message-----
> From: Gcc-patches <gcc-patches-
> bounces+kyrylo.tkachov=arm.com@gcc.gnu.org> On Behalf Of Christophe
> Lyon via Gcc-patches
> Sent: Wednesday, May 4, 2022 8:51 AM
> To: gcc-patches@gcc.gnu.org
> Subject: Re: [PATCH] arm: Restrict support of vectors of boolean immediates
> (PR target/104662)
> 
> ping?
> 
> On 4/20/22 10:50, Christophe Lyon wrote:
> > This simple patch avoids the ICE described in the PR:
> > internal compiler error: in simd_valid_immediate, at
> config/arm/arm.cc:12866
> >
> > with an early exit from simd_valid_immediate if we are trying to
> > handle a vector of booleans and MVE is not enabled.
> >
> > We still get an ICE when compiling the existing
> > gcc.dg/rtl/arm/mve-vxbi.c without -march=armv8.1-m.main+mve:
> >
> > error: unrecognizable insn:
> > (insn 7 5 8 2 (set (reg:V4BI 114)
> >          (const_vector:V4BI [
> >                  (const_int 1 [0x1])
> >                  (const_int 0 [0]) repeated x2
> >                  (const_int 1 [0x1])
> >              ])) -1
> >       (nil))
> > during RTL pass: ira
> >
> > but there's little we can do since the testcase explicitly creates
> > vectors of booleans which do need MVE.
> >
> > That is the reason why I do not add a testcase.

Ok if testing is fine.
Thanks,
Kyrill

> >
> > 2022-04-19  Christophe Lyon  <christophe.lyon@arm.com>
> >
> > 	PR target/104662
> > 	* config/arm/arm.cc (simd_valid_immediate): Exit when input is a
> > 	vector of booleans and MVE is not enabled.
> > ---
> >   gcc/config/arm/arm.cc | 3 +++
> >   1 file changed, 3 insertions(+)
> >
> > diff --git a/gcc/config/arm/arm.cc b/gcc/config/arm/arm.cc
> > index 14e2fdfeafa..69a18c2f157 100644
> > --- a/gcc/config/arm/arm.cc
> > +++ b/gcc/config/arm/arm.cc
> > @@ -12849,6 +12849,9 @@ simd_valid_immediate (rtx op, machine_mode
> mode, int inverse,
> >   	  || n_elts * innersize != 16))
> >       return -1;
> >
> > +  if (!TARGET_HAVE_MVE && GET_MODE_CLASS (mode) ==
> MODE_VECTOR_BOOL)
> > +    return -1;
> > +
> >     /* Vectors of float constants.  */
> >     if (GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
> >       {