LGTM on algorithm of local analysis.
juzhe.zh...@rivai.ai
From: Lehua Ding
Date: 2023-10-17 19:34
To: gcc-patches
CC: juzhe.zhong; kito.cheng; rdapp.gcc; palmer; jeffreyalaw; lehua.ding
Subject: [PATCH V2 05/14] RISC-V: P5: combine phase 1 and 2
This sub-patch combine phase 1 and 2 to use the new demand system and
delay the insert of vsetvl insn into phase 4.
gcc/ChangeLog:
* config/riscv/riscv-vsetvl.cc (pre_vsetvl::fuse_local_vsetvl_info): New.
(pass_vsetvl::compute_local_backward_infos): Removed.
(pass_vsetvl::need_vsetvl): Removed.
(pass_vsetvl::transfer_before): Removed.
(pass_vsetvl::transfer_after): Removed.
(pass_vsetvl::emit_local_forward_vsetvls): Removed.
---
gcc/config/riscv/riscv-vsetvl.cc | 269 ++++++++++++++-----------------
1 file changed, 123 insertions(+), 146 deletions(-)
diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index 3f07fde782f..33bdcec04d8 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -2669,6 +2669,129 @@ public:
}
};
+void
+pre_vsetvl::fuse_local_vsetvl_info ()
+{
+ reg_def_loc
+ = sbitmap_vector_alloc (last_basic_block_for_fn (cfun), GP_REG_LAST + 1);
+ bitmap_vector_clear (reg_def_loc, last_basic_block_for_fn (cfun));
+ bitmap_ones (reg_def_loc[ENTRY_BLOCK_PTR_FOR_FN (cfun)->index]);
+
+ for (bb_info *bb : crtl->ssa->bbs ())
+ {
+ auto &block_info = get_block_info (bb);
+ block_info.m_bb = bb;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " Try fuse basic block %d\n", bb->index ());
+ }
+ auto_vec<vsetvl_info> infos;
+ for (insn_info *insn : bb->real_nondebug_insns ())
+ {
+ vsetvl_info curr_info = vsetvl_info (insn);
+ if (curr_info.valid_p () || curr_info.unknown_p ())
+ infos.safe_push (curr_info);
+
+ /* Collecting GP registers modified by the current bb. */
+ if (insn->is_real ())
+ for (def_info *def : insn->defs ())
+ if (def->is_reg () && GP_REG_P (def->regno ()))
+ bitmap_set_bit (reg_def_loc[bb->index ()], def->regno ());
+ }
+
+ vsetvl_info prev_info = vsetvl_info ();
+ prev_info.set_empty ();
+ for (auto &curr_info : infos)
+ {
+ if (prev_info.empty_p ())
+ prev_info = curr_info;
+ else if ((curr_info.unknown_p () && prev_info.valid_p ())
+ || (curr_info.valid_p () && prev_info.unknown_p ()))
+ {
+ block_info.infos.safe_push (prev_info);
+ prev_info = curr_info;
+ }
+ else if (curr_info.valid_p () && prev_info.valid_p ())
+ {
+ if (dem.available_with (prev_info, curr_info))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file,
+ " Ignore curr info since prev info "
+ "available with it:\n");
+ fprintf (dump_file, " prev_info: ");
+ prev_info.dump (dump_file, " ");
+ fprintf (dump_file, " curr_info: ");
+ curr_info.dump (dump_file, " ");
+ fprintf (dump_file, "\n");
+ }
+ if (!curr_info.use_by_non_rvv_insn_p ()
+ && vsetvl_insn_p (curr_info.get_insn ()->rtl ()))
+ delete_list.safe_push (curr_info);
+
+ if (curr_info.get_read_vl_insn ())
+ prev_info.set_read_vl_insn (curr_info.get_read_vl_insn ());
+ }
+ else if (dem.compatible_with (prev_info, curr_info))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " Fuse curr info since prev info "
+ "compatible with it:\n");
+ fprintf (dump_file, " prev_info: ");
+ prev_info.dump (dump_file, " ");
+ fprintf (dump_file, " curr_info: ");
+ curr_info.dump (dump_file, " ");
+ }
+ dem.merge_with (prev_info, curr_info);
+ if (curr_info.get_read_vl_insn ())
+ prev_info.set_read_vl_insn (curr_info.get_read_vl_insn ());
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " prev_info after fused: ");
+ prev_info.dump (dump_file, " ");
+ fprintf (dump_file, "\n");
+ }
+ }
+ else
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file,
+ " Cannot fuse uncompatible infos:\n");
+ fprintf (dump_file, " prev_info: ");
+ prev_info.dump (dump_file, " ");
+ fprintf (dump_file, " curr_info: ");
+ curr_info.dump (dump_file, " ");
+ }
+ block_info.infos.safe_push (prev_info);
+ prev_info = curr_info;
+ }
+ }
+ }
+
+ if (prev_info.valid_p () || prev_info.unknown_p ())
+ block_info.infos.safe_push (prev_info);
+ }
+
+ avl_regs = sbitmap_alloc (GP_REG_LAST + 1);
+ bitmap_clear (avl_regs);
+ for (const bb_info *bb : crtl->ssa->bbs ())
+ {
+ vsetvl_block_info &block_info = get_block_info (bb);
+ if (block_info.empty_p ())
+ continue;
+
+ vsetvl_info &header_info = block_info.get_header_info ();
+ if (header_info.valid_p () && header_info.has_reg_avl ())
+ {
+ gcc_assert (GP_REG_P (REGNO (header_info.get_avl ())));
+ bitmap_set_bit (avl_regs, REGNO (header_info.get_avl ()));
+ }
+ }
+}
+
const pass_data pass_data_vsetvl = {
RTL_PASS, /* type */
"vsetvl", /* name */
@@ -2801,152 +2924,6 @@ make_pass_vsetvl (gcc::context *ctxt)
return new pass_vsetvl (ctxt);
}
-/* Compute demanded information by backward data-flow analysis. */
-void
-pass_vsetvl::compute_local_backward_infos (const bb_info *bb)
-{
- vector_insn_info change;
- change.set_empty ();
-
- auto &block_info = m_vector_manager->vector_block_infos[bb->index ()];
- block_info.reaching_out = change;
-
- for (insn_info *insn : bb->reverse_real_nondebug_insns ())
- {
- auto &info = get_vector_info (insn);
-
- if (info.uninit_p ())
- /* If it is uninitialized, propagate it directly. */
- update_vector_info (insn, change);
- else if (info.unknown_p ())
- change = info;
- else
- {
- gcc_assert (info.valid_p () && "Unexpected Invalid demanded info");
- if (change.valid_p ())
- {
- if (!(propagate_avl_across_demands_p (change, info)
- && !reg_available_p (insn, change))
- && change.compatible_p (info))
- {
- update_vector_info (insn, change.local_merge (info));
- /* Fix PR109399, we should update user vsetvl instruction
- if there is a change in demand fusion. */
- if (vsetvl_insn_p (insn->rtl ()))
- change_vsetvl_insn (insn, info);
- }
- }
- change = info;
- }
- }
-
- block_info.local_dem = change;
- if (block_info.local_dem.empty_p ())
- block_info.reaching_out = block_info.local_dem;
-}
-
-/* Return true if a dem_info is required to transition from curr_info to
- require before INSN. */
-bool
-pass_vsetvl::need_vsetvl (const vector_insn_info &require,
- const vector_insn_info &curr_info) const
-{
- if (!curr_info.valid_p () || curr_info.unknown_p () || curr_info.uninit_p ())
- return true;
-
- if (require.compatible_p (static_cast<const vl_vtype_info &> (curr_info)))
- return false;
-
- return true;
-}
-
-/* Given an incoming state reaching INSN, modifies that state so that it is
- minimally compatible with INSN. The resulting state is guaranteed to be
- semantically legal for INSN, but may not be the state requested by INSN. */
-void
-pass_vsetvl::transfer_before (vector_insn_info &info, insn_info *insn) const
-{
- if (!has_vtype_op (insn->rtl ()))
- return;
-
- const vector_insn_info require = get_vector_info (insn);
- if (info.valid_p () && !need_vsetvl (require, info))
- return;
- info = require;
-}
-
-/* Given a state with which we evaluated insn (see transfer_before above for
why
- this might be different that the state insn requested), modify the state to
- reflect the changes insn might make. */
-void
-pass_vsetvl::transfer_after (vector_insn_info &info, insn_info *insn) const
-{
- if (vector_config_insn_p (insn->rtl ()))
- {
- info = get_vector_info (insn);
- return;
- }
-
- if (fault_first_load_p (insn->rtl ())
- && info.update_fault_first_load_avl (insn))
- return;
-
- /* If this is something that updates VL/VTYPE that we don't know about, set
- the state to unknown. */
- if (insn->is_call () || insn->is_asm ()
- || find_access (insn->defs (), VL_REGNUM)
- || find_access (insn->defs (), VTYPE_REGNUM))
- info = vector_insn_info::get_unknown ();
-}
-
-/* Emit vsetvl within each block by forward data-flow analysis. */
-void
-pass_vsetvl::emit_local_forward_vsetvls (const bb_info *bb)
-{
- auto &block_info = m_vector_manager->vector_block_infos[bb->index ()];
- if (block_info.local_dem.empty_p ())
- return;
-
- vector_insn_info curr_info;
- for (insn_info *insn : bb->real_nondebug_insns ())
- {
- const vector_insn_info prev_info = curr_info;
- enum vsetvl_type type = NUM_VSETVL_TYPE;
- transfer_before (curr_info, insn);
-
- if (has_vtype_op (insn->rtl ()))
- {
- if (static_cast<const vl_vtype_info &> (prev_info)
- != static_cast<const vl_vtype_info &> (curr_info))
- {
- const auto require = get_vector_info (insn);
- if (!require.compatible_p (
- static_cast<const vl_vtype_info &> (prev_info)))
- type = insert_vsetvl (EMIT_BEFORE, insn->rtl (), require,
- prev_info);
- }
- }
-
- /* Fix the issue of following sequence:
- vsetivli zero, 5
- ....
- vsetvli zero, zero
- vmv.x.s (demand AVL = 8).
- ....
- incorrect: vsetvli zero, zero ===> Since the curr_info is AVL = 8.
- correct: vsetivli zero, 8
- vadd (demand AVL = 8). */
- if (type == VSETVL_VTYPE_CHANGE_ONLY)
- {
- /* Update the curr_info to be real correct AVL. */
- curr_info.set_avl_info (prev_info.get_avl_info ());
- }
- transfer_after (curr_info, insn);
- }
-
- block_info.reaching_out = curr_info;
-}
-
/* Assemble the candidates expressions for LCM. */
void
pass_vsetvl::prune_expressions (void)
--
2.36.3
