Re: [PATCH] RISC-V: Add probability model of each block to prevent endless loop of Phase 3
committed, thanks.
On Tue, Jan 10, 2023 at 7:17 AM wrote:
> From: Ju-Zhe Zhong
>
> Notice that the PASS is just simpily pick the probability >= 50%
> to do the backward fusion which will create endless loop on Phase 3.
>
> Adding this probability to fix this bug.
> gcc/ChangeLog:
>
> * config/riscv/riscv-vsetvl.cc
> (vector_infos_manager::vector_infos_manager): Add probability.
> (vector_infos_manager::dump): Ditto.
> (pass_vsetvl::compute_probabilities): Ditto.
> * config/riscv/riscv-vsetvl.h (struct vector_block_info): Ditto.
>
> ---
> gcc/config/riscv/riscv-vsetvl.cc | 39
> gcc/config/riscv/riscv-vsetvl.h | 3 +++
> 2 files changed, 42 insertions(+)
>
> diff --git a/gcc/config/riscv/riscv-vsetvl.cc
> b/gcc/config/riscv/riscv-vsetvl.cc
> index 0f12d4ddb23..7d8c3a32aaa 100644
> --- a/gcc/config/riscv/riscv-vsetvl.cc
> +++ b/gcc/config/riscv/riscv-vsetvl.cc
> @@ -1465,6 +1465,7 @@ vector_infos_manager::vector_infos_manager ()
> vector_block_infos[bb->index ()].reaching_out = vector_insn_info
> ();
> for (insn_info *insn : bb->real_insns ())
> vector_insn_infos[insn->uid ()].parse_insn (insn);
> + vector_block_infos[bb->index ()].probability =
> profile_probability ();
> }
> }
> }
> @@ -1642,6 +1643,8 @@ vector_infos_manager::dump (FILE *file) const
> }
>fprintf (file, "=");
>vector_block_infos[cfg_bb->index].reaching_out.dump (file);
> + fprintf (file, "=");
> + vector_block_infos[cfg_bb->index].probability.dump (file);
>fprintf (file, "\n\n");
> }
>
> @@ -1764,6 +1767,7 @@ private:
>
>void init (void);
>void done (void);
> + void compute_probabilities (void);
>
> public:
>pass_vsetvl (gcc::context *ctxt) : rtl_opt_pass (pass_data_vsetvl,
> ctxt) {}
> @@ -2629,6 +2633,41 @@ pass_vsetvl::done (void)
>m_vector_manager = nullptr;
> }
>
> +/* Compute probability for each block. */
> +void
> +pass_vsetvl::compute_probabilities (void)
> +{
> + /* Don't compute it in -O0 since we don't need it. */
> + if (!optimize)
> +return;
> + edge e;
> + edge_iterator ei;
> +
> + for (const bb_info *bb : crtl->ssa->bbs ())
> +{
> + basic_block cfg_bb = bb->cfg_bb ();
> + auto &curr_prob
> + = m_vector_manager->vector_block_infos[cfg_bb->index].probability;
> + if (ENTRY_BLOCK_PTR_FOR_FN (cfun) == cfg_bb)
> + curr_prob = profile_probability::always ();
> + gcc_assert (curr_prob.initialized_p ());
> + FOR_EACH_EDGE (e, ei, cfg_bb->succs)
> + {
> + auto &new_prob
> + =
> m_vector_manager->vector_block_infos[e->dest->index].probability;
> + if (!new_prob.initialized_p ())
> + new_prob = curr_prob * e->probability;
> + else if (new_prob == profile_probability::always ())
> + continue;
> + else
> + new_prob += curr_prob * e->probability;
> + }
> +}
> + auto &exit_block
> += m_vector_manager->vector_block_infos[EXIT_BLOCK_PTR_FOR_FN
> (cfun)->index];
> + exit_block.probability = profile_probability::always ();
> +}
> +
> /* Lazy vsetvl insertion for optimize > 0. */
> void
> pass_vsetvl::lazy_vsetvl (void)
> diff --git a/gcc/config/riscv/riscv-vsetvl.h
> b/gcc/config/riscv/riscv-vsetvl.h
> index 563ad3084ed..fb3ebb9db79 100644
> --- a/gcc/config/riscv/riscv-vsetvl.h
> +++ b/gcc/config/riscv/riscv-vsetvl.h
> @@ -291,6 +291,9 @@ struct vector_block_info
>/* The reaching_out vector insn_info of the block. */
>vector_insn_info reaching_out;
>
> + /* The static execute probability of the demand info. */
> + profile_probability probability;
> +
>vector_block_info () = default;
> };
>
> --
> 2.36.1
>
>
[PATCH] RISC-V: Add probability model of each block to prevent endless loop of Phase 3
From: Ju-Zhe Zhong
Notice that the PASS is just simpily pick the probability >= 50%
to do the backward fusion which will create endless loop on Phase 3.
Adding this probability to fix this bug.
gcc/ChangeLog:
* config/riscv/riscv-vsetvl.cc
(vector_infos_manager::vector_infos_manager): Add probability.
(vector_infos_manager::dump): Ditto.
(pass_vsetvl::compute_probabilities): Ditto.
* config/riscv/riscv-vsetvl.h (struct vector_block_info): Ditto.
---
gcc/config/riscv/riscv-vsetvl.cc | 39
gcc/config/riscv/riscv-vsetvl.h | 3 +++
2 files changed, 42 insertions(+)
diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index 0f12d4ddb23..7d8c3a32aaa 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -1465,6 +1465,7 @@ vector_infos_manager::vector_infos_manager ()
vector_block_infos[bb->index ()].reaching_out = vector_insn_info ();
for (insn_info *insn : bb->real_insns ())
vector_insn_infos[insn->uid ()].parse_insn (insn);
+ vector_block_infos[bb->index ()].probability = profile_probability ();
}
}
}
@@ -1642,6 +1643,8 @@ vector_infos_manager::dump (FILE *file) const
}
fprintf (file, "=");
vector_block_infos[cfg_bb->index].reaching_out.dump (file);
+ fprintf (file, "=");
+ vector_block_infos[cfg_bb->index].probability.dump (file);
fprintf (file, "\n\n");
}
@@ -1764,6 +1767,7 @@ private:
void init (void);
void done (void);
+ void compute_probabilities (void);
public:
pass_vsetvl (gcc::context *ctxt) : rtl_opt_pass (pass_data_vsetvl, ctxt) {}
@@ -2629,6 +2633,41 @@ pass_vsetvl::done (void)
m_vector_manager = nullptr;
}
+/* Compute probability for each block. */
+void
+pass_vsetvl::compute_probabilities (void)
+{
+ /* Don't compute it in -O0 since we don't need it. */
+ if (!optimize)
+return;
+ edge e;
+ edge_iterator ei;
+
+ for (const bb_info *bb : crtl->ssa->bbs ())
+{
+ basic_block cfg_bb = bb->cfg_bb ();
+ auto &curr_prob
+ = m_vector_manager->vector_block_infos[cfg_bb->index].probability;
+ if (ENTRY_BLOCK_PTR_FOR_FN (cfun) == cfg_bb)
+ curr_prob = profile_probability::always ();
+ gcc_assert (curr_prob.initialized_p ());
+ FOR_EACH_EDGE (e, ei, cfg_bb->succs)
+ {
+ auto &new_prob
+ = m_vector_manager->vector_block_infos[e->dest->index].probability;
+ if (!new_prob.initialized_p ())
+ new_prob = curr_prob * e->probability;
+ else if (new_prob == profile_probability::always ())
+ continue;
+ else
+ new_prob += curr_prob * e->probability;
+ }
+}
+ auto &exit_block
+= m_vector_manager->vector_block_infos[EXIT_BLOCK_PTR_FOR_FN
(cfun)->index];
+ exit_block.probability = profile_probability::always ();
+}
+
/* Lazy vsetvl insertion for optimize > 0. */
void
pass_vsetvl::lazy_vsetvl (void)
diff --git a/gcc/config/riscv/riscv-vsetvl.h b/gcc/config/riscv/riscv-vsetvl.h
index 563ad3084ed..fb3ebb9db79 100644
--- a/gcc/config/riscv/riscv-vsetvl.h
+++ b/gcc/config/riscv/riscv-vsetvl.h
@@ -291,6 +291,9 @@ struct vector_block_info
/* The reaching_out vector insn_info of the block. */
vector_insn_info reaching_out;
+ /* The static execute probability of the demand info. */
+ profile_probability probability;
+
vector_block_info () = default;
};
--
2.36.1
