On Thu, 2022-04-07 at 17:29 +0800, Kewen.Lin wrote:
> 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.
>
> Bootstrapped and regtested on powerpc64-linux-gnu P8 and
> powerpc64le-linux-gnu P9 and P10.
>
> v1: https://gcc.gnu.org/pipermail/gcc-patches/2022-March/591150.html
>
> v2: Polish some comments and add one test case as Will and Peter suggested.
Thanks.
>
> Is it ok for trunk or upcoming stage1?
>
> 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/testsuite/ChangeLog:
>
> * gcc.target/powerpc/pr103353.c: New test.
> ---
> gcc/config/rs6000/mma.md | 42 ++++++++++++++++++---
> gcc/testsuite/gcc.target/powerpc/pr103353.c | 22 +++++++++++
> 2 files changed, 58 insertions(+), 6 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/powerpc/pr103353.c
>
> diff --git a/gcc/config/rs6000/mma.md b/gcc/config/rs6000/mma.md
> index 907c9d6d516..746a77a0957 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, 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 ();
> })
ok
>
> (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, even if we have already emitted error messages about some
> + missing required conditions. As shown in that PR, without one
> + explicit mov optab on XOmode 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 ();
> })
ok
>
> (define_insn_and_split "*movxo"
> diff --git a/gcc/testsuite/gcc.target/powerpc/pr103353.c
> b/gcc/testsuite/gcc.target/powerpc/pr103353.c
> new file mode 100644
> index 00000000000..6b0bedbb958
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/pr103353.c
> @@ -0,0 +1,22 @@
> +/* { dg-require-effective-target powerpc_altivec_ok } */
> +/* If the default cpu type is power10 or later, MMA is enabled by default.
> + To keep the test point available all the time, this case specifies
> + -mdejagnu-cpu=power6 to make it be tested without MMA. */
> +/* { dg-options "-maltivec -mdejagnu-cpu=power6" } */
> +
> +/* Verify there is no ICE and don't check the error messages on MMA
> + requirement since they could be fragile and are not test points
> + of this case. */
> +
> +void
> +foo (__vector_pair *dst, double *x)
> +{
> + dst[0] = __builtin_vsx_lxvp (0, (__vector_pair *)(void *)x);
> + /* { dg-error ".*" "pr103353" { target *-*-* } .-1 } */
ok
> +}
> +
> +void
> +bar (__vector_pair *src, double *x)
> +{
> + __builtin_vsx_stxvp (src[0], 0, (__vector_pair *)(void *)x);
> +}
lgtm,
thanks
-Will
> --
> 2.27.0
