Thanks, pushed to trunk.
On Tue, May 9, 2023 at 10:20 AM <juzhe.zh...@rivai.ai> wrote:
>
> From: Juzhe-Zhong <juzhe.zh...@rivai.ai>
>
> This patch is fix dead loop in vsetvl intrinsic avl checking.
>
> vsetvli->get_def () has vsetvli->get_def () has vsetvli.....
> Then it will keep looping in the vsetvli avl checking which is a dead loop.
>
> PR target/109773
>
> gcc/ChangeLog:
>
> * config/riscv/riscv-vsetvl.cc (avl_source_has_vsetvl_p): New
> function.
> (source_equal_p): Fix dead loop in vsetvl avl checking.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/riscv/rvv/vsetvl/pr109773-1.c: New test.
> * gcc.target/riscv/rvv/vsetvl/pr109773-2.c: New test.
>
> ---
> gcc/config/riscv/riscv-vsetvl.cc | 25 ++++++++++++++++++
> .../gcc.target/riscv/rvv/vsetvl/pr109773-1.c | 20 ++++++++++++++
> .../gcc.target/riscv/rvv/vsetvl/pr109773-2.c | 26 +++++++++++++++++++
> 3 files changed, 71 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr109773-1.c
> create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr109773-2.c
>
> diff --git a/gcc/config/riscv/riscv-vsetvl.cc
> b/gcc/config/riscv/riscv-vsetvl.cc
> index 72aa2bfcf6f..2577b2bd9b7 100644
> --- a/gcc/config/riscv/riscv-vsetvl.cc
> +++ b/gcc/config/riscv/riscv-vsetvl.cc
> @@ -1056,6 +1056,24 @@ change_vsetvl_insn (const insn_info *insn, const
> vector_insn_info &info)
> change_insn (rinsn, new_pat);
> }
>
> +static bool
> +avl_source_has_vsetvl_p (set_info *avl_source)
> +{
> + if (!avl_source)
> + return false;
> + if (!avl_source->insn ())
> + return false;
> + if (avl_source->insn ()->is_real ())
> + return vsetvl_insn_p (avl_source->insn ()->rtl ());
> + hash_set<set_info *> sets = get_all_sets (avl_source, true, false, true);
> + for (const auto set : sets)
> + {
> + if (set->insn ()->is_real () && vsetvl_insn_p (set->insn ()->rtl ()))
> + return true;
> + }
> + return false;
> +}
> +
> static bool
> source_equal_p (insn_info *insn1, insn_info *insn2)
> {
> @@ -1098,6 +1116,13 @@ source_equal_p (insn_info *insn1, insn_info *insn2)
> vector_insn_info insn1_info, insn2_info;
> insn1_info.parse_insn (insn1);
> insn2_info.parse_insn (insn2);
> +
> + /* To avoid dead loop, we don't optimize a vsetvli def has vsetvli
> + instructions which will complicate the situation. */
> + if (avl_source_has_vsetvl_p (insn1_info.get_avl_source ())
> + || avl_source_has_vsetvl_p (insn2_info.get_avl_source ()))
> + return false;
> +
> if (insn1_info.same_vlmax_p (insn2_info)
> && insn1_info.compatible_avl_p (insn2_info))
> return true;
> diff --git a/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr109773-1.c
> b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr109773-1.c
> new file mode 100644
> index 00000000000..8656e473117
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr109773-1.c
> @@ -0,0 +1,20 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=rv32gcv -mabi=ilp32 -fno-tree-vectorize
> -fno-schedule-insns -fno-schedule-insns2" } */
> +
> +#include "riscv_vector.h"
> +
> +void f (int32_t *a, int32_t *b, int n)
> +{
> + if (n <= 0)
> + return;
> + int i = n;
> + size_t vl = __riscv_vsetvl_e8mf4 (i);
> + for (; i >= 0; i--)
> + {
> + vint32m1_t v = __riscv_vle32_v_i32m1 (a + i, vl);
> + __riscv_vse32_v_i32m1 (b + i, v, vl);
> + vl = __riscv_vsetvl_e8mf4 (vl);
> + }
> +}
> +
> +/* { dg-final { scan-assembler-times {vsetvli} 3 { target { no-opts "-O0"
> no-opts "-O1" no-opts "-Os" no-opts "-Oz" no-opts "-g" no-opts
> "-funroll-loops" } } } } */
> diff --git a/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr109773-2.c
> b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr109773-2.c
> new file mode 100644
> index 00000000000..7bfbaaf3713
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/riscv/rvv/vsetvl/pr109773-2.c
> @@ -0,0 +1,26 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=rv32gcv -mabi=ilp32 -fno-tree-vectorize
> -fno-schedule-insns -fno-schedule-insns2" } */
> +
> +#include "riscv_vector.h"
> +
> +void f (int32_t * a, int32_t * b, int n)
> +{
> + if (n <= 0)
> + return;
> + int i = n;
> + size_t vl = __riscv_vsetvl_e8mf4 (i);
> + for (; i >= 0; i--)
> + {
> + vint32m1_t v = __riscv_vle32_v_i32m1 (a + i, vl);
> + v = __riscv_vle32_v_i32m1_tu (v, a + i + 100, vl);
> + __riscv_vse32_v_i32m1 (b + i, v, vl);
> +
> + if (i >= vl)
> + continue;
> + if (i == 0)
> + return;
> + vl = __riscv_vsetvl_e8mf4 (vl);
> + }
> +}
> +
> +/* { dg-final { scan-assembler {vsetvli} { target { no-opts "-O0" no-opts
> "-O1" no-opts "-Os" no-opts "-Oz" no-opts "-g" no-opts "-funroll-loops" } } }
> } */
> --
> 2.36.3
>
