[v2] tree-ssa-pre.c/115214(ICE in find_or_generate_expression, at tree-ssa-pre.c:2780): Return NULL_TREE when deal special cases.

Return NULL_TREE when match the POLY_INT case.
https://gcc.gnu.org/pipermail/gcc-patches/2024-May/652641.html

gcc/ChangeLog:

        * tree-ssa-pre.cc (create_component_ref_by_pieces_1): New
        * conditions.

gcc/testsuite/ChangeLog:

        * gcc.target/riscv/rvv/vsetvl/pr115214.c: New test.

---
 .../gcc.target/riscv/rvv/vsetvl/pr115214.c    | 51 +++++++++++++++++++
 gcc/tree-ssa-pre.cc                           | 13 +++--
 2 files changed, 61 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr115214.c

On Fri, May 24, 2024 at 5:33 PM Jiawei <jiawei@iscas.ac.cn> wrote:
>
> Return NULL_TREE when match the POLY_INT case.
> https://gcc.gnu.org/pipermail/gcc-patches/2024-May/652641.html
>
> gcc/ChangeLog:
>
>         * tree-ssa-pre.cc (create_component_ref_by_pieces_1): New
>         * conditions.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.target/riscv/rvv/vsetvl/pr115214.c: New test.
>
> ---
>  .../gcc.target/riscv/rvv/vsetvl/pr115214.c    | 51 +++++++++++++++++++
>  gcc/tree-ssa-pre.cc                           | 13 +++--
>  2 files changed, 61 insertions(+), 3 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr115214.c
>
> diff --git a/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr115214.c b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr115214.c
> new file mode 100644
> index 00000000000..9d19641196f
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr115214.c
> @@ -0,0 +1,51 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mrvv-vector-bits=scalable -march=rv64gcv -mabi=lp64d -O3 -w" } */
> +/* { dg-skip-if "" { *-*-* } { "-flto" } } */
> +
> +#include <riscv_vector.h>
> +
> +static inline __attribute__(()) int vaddq_f32();
> +static inline __attribute__(()) int vload_tillz_f32(int nlane) {
> +  vint32m1_t __trans_tmp_9;
> +  {
> +    int __trans_tmp_0 = nlane;
> +    {
> +      vint64m1_t __trans_tmp_1;
> +      vint64m1_t __trans_tmp_2;
> +      vint64m1_t __trans_tmp_3;
> +      vint64m1_t __trans_tmp_4;
> +      if (__trans_tmp_0 == 1) {
> +        {
> +          __trans_tmp_3 =
> +              __riscv_vslideup_vx_i64m1(__trans_tmp_1, __trans_tmp_2, 1, 2);
> +        }
> +        __trans_tmp_4 = __trans_tmp_2;
> +      }
> +      __trans_tmp_4 = __trans_tmp_3;
> +      __trans_tmp_9 = __riscv_vreinterpret_v_i64m1_i32m1(__trans_tmp_3);
> +    }
> +  }
> +  return vaddq_f32(__trans_tmp_9); /* { dg-error {RVV type 'vint32m1_t' cannot be passed to an unprototyped function} } */
> +}
> +
> +char CFLOAT_add_args[3];
> +const int *CFLOAT_add_steps;
> +const int CFLOAT_steps;
> +
> +__attribute__(()) void CFLOAT_add() {
> +  char *b_src0 = &CFLOAT_add_args[0], *b_src1 = &CFLOAT_add_args[1],
> +       *b_dst = &CFLOAT_add_args[2];
> +  const float *src1 = (float *)b_src1;
> +  float *dst = (float *)b_dst;
> +  const int ssrc1 = CFLOAT_add_steps[1] / sizeof(float);
> +  const int sdst = CFLOAT_add_steps[2] / sizeof(float);
> +  const int hstep = 4 / 2;
> +  vfloat32m1x2_t a;
> +  int len = 255;
> +  for (; len > 0; len -= hstep, src1 += 4, dst += 4) {
> +    int b = vload_tillz_f32(len);
> +    int r = vaddq_f32(a.__val[0], b); /* { dg-error {RVV type '__rvv_float32m1_t' cannot be passed to an unprototyped function} } */
> +  }
> +  for (; len > 0; --len, b_src0 += CFLOAT_steps,
> +                  b_src1 += CFLOAT_add_steps[1], b_dst += CFLOAT_add_steps[2])
> +    ;
> +}
> \ No newline at end of file
> diff --git a/gcc/tree-ssa-pre.cc b/gcc/tree-ssa-pre.cc
> index 75217f5cde1..b185f858c7f 100644
> --- a/gcc/tree-ssa-pre.cc
> +++ b/gcc/tree-ssa-pre.cc
> @@ -2685,11 +2685,18 @@ create_component_ref_by_pieces_1 (basic_block block, vn_reference_t ref,
>                here as the element alignment may be not visible.  See
>                PR43783.  Simply drop the element size for constant
>                sizes.  */
> -           if (TREE_CODE (genop3) == INTEGER_CST
> +           if ((TREE_CODE (genop3) == INTEGER_CST
>                 && TREE_CODE (TYPE_SIZE_UNIT (elmt_type)) == INTEGER_CST
>                 && wi::eq_p (wi::to_offset (TYPE_SIZE_UNIT (elmt_type)),
> -                            (wi::to_offset (genop3)
> -                             * vn_ref_op_align_unit (currop))))
> +                 (wi::to_offset (genop3) * vn_ref_op_align_unit (currop))))
> +               || (TREE_CODE (genop3) == POLY_INT_CST
> +                 && TREE_CODE (TYPE_SIZE_UNIT (elmt_type)) == POLY_INT_CST
> +                 && wi::eq_p (wi::to_offset (TYPE_SIZE_UNIT (elmt_type)),
> +                   (wi::to_offset (genop3) * vn_ref_op_align_unit (currop))))

The above doesn't work, you can't convert a POLY_INT_CST to a wide_int, instead
it would need to be wi::to_poly_offset, I'm not sure of the wi::eq_p -
there should be
something like a wi::must_eq_p or so?

Btw, I'm fine with simply not implementing this case but only ...

> +               || (TREE_CODE (genop3) == EXACT_DIV_EXPR
> +                 && TREE_CODE (TREE_OPERAND (genop3, 1)) == INTEGER_CST
> +                 && wi::eq_p (wi::to_offset (TREE_OPERAND (genop3, 1)),
> +                   vn_ref_op_align_unit (currop))))

... this - but note here you miss to compare the denominator:

                      && operand_equal_p (TREE_OPERAND (genop3, 0),
TYPE_SIZE_UNIT (elmt_type))

The patch is OK with the above case removed (it's not exercised by the
test) and the below
case amended as suggested.

Thanks,
Richard.

>               genop3 = NULL_TREE;
>             else
>               {
> --
> 2.25.1
>