From 93ce419991444b6406e5eb752b46b6eaa7c4b6e9 Mon Sep 17 00:00:00 2001
From: Gert Wollny <gert.wollny@collabora.com>
Date: Fri, 19 Apr 2024 21:47:02 +0200
Subject: [PATCH] r600/sfn: Use dependecies to order barriers and LDS/RAT
 instructions

This gives more freedom to schedule the group barrier and removes
the need to add blocks around a barrier to keep the scheduler in
check. This should avoid emitting some CF instructions.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/11002

Fixes: fe881bf0976cf5799afba52911cdf6df45e8641f
    r600/sfn: move kill handling fully to scheduling

v2: grammar fixes (lorn10)

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28840>
(cherry picked from commit bf44ce61bb4f19a8d921a119a949468a08e2c0b3)
---
 .pick_status.json                           |  2 +-
 src/gallium/drivers/r600/sfn/sfn_shader.cpp | 23 +++++++++++++++++----
 src/gallium/drivers/r600/sfn/sfn_shader.h   |  2 ++
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/.pick_status.json b/.pick_status.json
index bfb6ce9bc3f..03da6829c7a 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -34,7 +34,7 @@
         "description": "r600/sfn: Use dependecies to order barriers and LDS/RAT instructions",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "fe881bf0976cf5799afba52911cdf6df45e8641f",
         "notes": null
diff --git a/src/gallium/drivers/r600/sfn/sfn_shader.cpp b/src/gallium/drivers/r600/sfn/sfn_shader.cpp
index 7af0000f45b..495df1f73b6 100644
--- a/src/gallium/drivers/r600/sfn/sfn_shader.cpp
+++ b/src/gallium/drivers/r600/sfn/sfn_shader.cpp
@@ -1364,6 +1364,22 @@ void Shader::InstructionChain::visit(AluInstr *instr)
          }
       }
    }
+
+   if (instr->has_lds_access()) {
+      last_lds_access = instr;
+      if (last_group_barrier)
+         instr->add_required_instr(last_group_barrier);
+   }
+
+   if (!instr->has_alu_flag(alu_is_lds) &&
+       instr->opcode() == op0_group_barrier) {
+      last_group_barrier = instr;
+      if (last_lds_access)
+         instr->add_required_instr(last_group_barrier);
+      if (last_ssbo_instr)
+         instr->add_required_instr(last_ssbo_instr);
+   }
+
 }
 
 void
@@ -1402,6 +1418,9 @@ Shader::InstructionChain::visit(RatInstr *instr)
 
    if (last_kill_instr)
       instr->add_required_instr(last_kill_instr);
+
+   if (last_group_barrier)
+      instr->add_required_instr(last_group_barrier);
 }
 
 void
@@ -1464,13 +1483,9 @@ Shader::emit_group_barrier(nir_intrinsic_instr *intr)
 {
    assert(m_control_flow_depth == 0);
    (void)intr;
-   /* Put barrier into it's own block, so that optimizers and the
-    * scheduler don't move code */
-   start_new_block(0);
    auto op = new AluInstr(op0_group_barrier, 0);
    op->set_alu_flag(alu_last_instr);
    emit_instruction(op);
-   start_new_block(0);
    return true;
 }
 
diff --git a/src/gallium/drivers/r600/sfn/sfn_shader.h b/src/gallium/drivers/r600/sfn/sfn_shader.h
index 9b442bdab04..8b340ca2649 100644
--- a/src/gallium/drivers/r600/sfn/sfn_shader.h
+++ b/src/gallium/drivers/r600/sfn/sfn_shader.h
@@ -413,6 +413,8 @@ private:
       Instr *last_gds_instr{nullptr};
       Instr *last_ssbo_instr{nullptr};
       Instr *last_kill_instr{nullptr};
+      Instr *last_lds_access{nullptr};
+      Instr *last_group_barrier{nullptr};
       std::unordered_map<int, Instr * > last_alu_with_indirect_reg;
       bool prepare_mem_barrier{false};
    };