On Thu, 2022-03-03 at 16:38 +0800, Kewen.Lin via Gcc-patches wrote:
> Hi,
>
Hi
> As PR103353 shows, we may want to continue to expand a MMA built-in
> function like a normal function, even if we have already emitted
> error messages about some missing required conditions. As shown in
> that PR, without one explicit mov optab on OOmode provided, it would
> call emit_move_insn recursively.
>
> So this patch is to allow the mov pattern to be generated when we are
> expanding to RTL and have seen errors even without MMA supported, it's
> expected that the generated pattern would not cause further ICEs as the
> compilation would stop soon after expanding.
Is there a testcase, new or existing, that illustrates this error path?
>
> Bootstrapped and regtested on powerpc64-linux-gnu P8 and
> powerpc64le-linux-gnu P9 and P10.
>
> Is it ok for trunk?
>
> BR,
> Kewen
> ------
>
> PR target/103353
>
> gcc/ChangeLog:
>
> * config/rs6000/mma.md (define_expand movoo): Move TARGET_MMA condition
> check to preparation statements and add handlings for !TARGET_MMA.
> (define_expand movxo): Likewise.
> > ---
> > gcc/config/rs6000/mma.md | 42 ++++++++++++++++++++++++++++++++++------
> > 1 file changed, 36 insertions(+), 6 deletions(-)
> >
> > diff --git a/gcc/config/rs6000/mma.md b/gcc/config/rs6000/mma.md
> > index 907c9d6d516..f76a87b4a21 100644
> > --- a/gcc/config/rs6000/mma.md
> > +++ b/gcc/config/rs6000/mma.md
> > @@ -268,10 +268,25 @@ (define_int_attr avvi4i4i4
> > [(UNSPEC_MMA_PMXVI8GER4PP "pmxvi8ger4pp")
> > (define_expand "movoo"
> > [(set (match_operand:OO 0 "nonimmediate_operand")
> > (match_operand:OO 1 "input_operand"))]
> > - "TARGET_MMA"
> > + ""
> > {
> > - rs6000_emit_move (operands[0], operands[1], OOmode);
> > - DONE;
> > + if (TARGET_MMA) {
> > + rs6000_emit_move (operands[0], operands[1], OOmode);
> > + DONE;
> > + }
> > + /* Opaque modes are only expected to be available when MMA is supported,
> > + but PR103353 shows we may want to continue to expand a MMA built-in
> > + function like a normal function, even if we have already emitted
> > + error messages about some missing required conditions.
perhaps drop "like a normal function".
> > + As shown in that PR, without one explicit mov optab on OOmode
> > provided,
> > + it would call emit_move_insn recursively. So we allow this pattern to
> > + be generated when we are expanding to RTL and have seen errors, even
> > + though there is no MMA support. It would not cause further ICEs as
> > + the compilation would stop soon after expanding. */
Testcase would be particularly helpful to illustrate this, i think.
TH
anks,
-Will
> > + else if (currently_expanding_to_rtl && seen_error ())
> > + ;
> > + else
> > + gcc_unreachable ();
> > })
> >
> > (define_insn_and_split "*movoo"
> > @@ -300,10 +315,25 @@ (define_insn_and_split "*movoo"
> > (define_expand "movxo"
> > [(set (match_operand:XO 0 "nonimmediate_operand")
> > (match_operand:XO 1 "input_operand"))]
> > - "TARGET_MMA"
> > + ""
> > {
> > - rs6000_emit_move (operands[0], operands[1], XOmode);
> > - DONE;
> > + if (TARGET_MMA) {
> > + rs6000_emit_move (operands[0], operands[1], XOmode);
> > + DONE;
> > + }
> > + /* Opaque modes are only expected to be available when MMA is supported,
> > + but PR103353 shows we may want to continue to expand a MMA built-in
> > + function like a normal function, even if we have already emitted
> > + error messages about some missing required conditions.
> > + As shown in that PR, without one explicit mov optab on OOmode
> > provided,
> > + it would call emit_move_insn recursively. So we allow this pattern to
> > + be generated when we are expanding to RTL and have seen errors, even
> > + though there is no MMA support. It would not cause further ICEs as
> > + the compilation would stop soon after expanding. */
> > + else if (currently_expanding_to_rtl && seen_error ())
> > + ;
> > + else
> > + gcc_unreachable ();
> > })
> >
> > (define_insn_and_split "*movxo"
> > --
> > 2.25.1
> >
