From aded548e6600b5684e7d278799e9aa8d44779f39 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Daniel=20Sch=C3=BCrmann?= <daniel@schuermann.dev>
Date: Wed, 30 Oct 2019 14:42:00 +0100
Subject: [PATCH] aco: ensure that spilled VGPR reloads are done after
 p_logical_start

Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
---
 src/amd/compiler/aco_spill.cpp | 77 +++++++++++++++++++---------------
 1 file changed, 43 insertions(+), 34 deletions(-)

diff --git a/src/amd/compiler/aco_spill.cpp b/src/amd/compiler/aco_spill.cpp
index b684d560abf..0d6ea9271e4 100644
--- a/src/amd/compiler/aco_spill.cpp
+++ b/src/amd/compiler/aco_spill.cpp
@@ -656,11 +656,45 @@ void add_coupling_code(spill_ctx& ctx, Block* block, unsigned block_idx)
    /* branch block: TODO take other branch into consideration */
    if (block->linear_preds.size() == 1 && !(block->kind & block_kind_loop_exit)) {
       assert(ctx.processed[block->linear_preds[0]]);
+      assert(ctx.register_demand[block_idx].size() == block->instructions.size());
+      std::vector<RegisterDemand> reg_demand;
+      unsigned insert_idx = 0;
+      unsigned pred_idx = block->linear_preds[0];
+
+      for (std::pair<Temp, std::pair<uint32_t, uint32_t>> live : ctx.next_use_distances_start[block_idx]) {
+         if (!live.first.is_linear())
+            continue;
+         /* still spilled */
+         if (ctx.spills_entry[block_idx].find(live.first) != ctx.spills_entry[block_idx].end())
+            continue;
+
+         /* in register at end of predecessor */
+         if (ctx.spills_exit[pred_idx].find(live.first) == ctx.spills_exit[pred_idx].end()) {
+            std::map<Temp, Temp>::iterator it = ctx.renames[pred_idx].find(live.first);
+            if (it != ctx.renames[pred_idx].end())
+               ctx.renames[block_idx].insert(*it);
+            continue;
+         }
+
+         /* variable is spilled at predecessor and live at current block: create reload instruction */
+         Temp new_name = {ctx.program->allocateId(), live.first.regClass()};
+         aco_ptr<Instruction> reload = do_reload(ctx, live.first, new_name, ctx.spills_exit[pred_idx][live.first]);
+         instructions.emplace_back(std::move(reload));
+         reg_demand.push_back(RegisterDemand());
+         ctx.renames[block_idx][live.first] = new_name;
+      }
 
       if (block->logical_preds.size() == 1) {
+         do {
+            assert(insert_idx < block->instructions.size());
+            instructions.emplace_back(std::move(block->instructions[insert_idx]));
+            reg_demand.push_back(ctx.register_demand[block_idx][insert_idx]);
+            insert_idx++;
+         } while (instructions.back()->opcode != aco_opcode::p_logical_start);
+
          unsigned pred_idx = block->logical_preds[0];
          for (std::pair<Temp, std::pair<uint32_t, uint32_t>> live : ctx.next_use_distances_start[block_idx]) {
-            if (live.first.type() == RegType::sgpr)
+            if (live.first.is_linear())
                continue;
             /* still spilled */
             if (ctx.spills_entry[block_idx].find(live.first) != ctx.spills_entry[block_idx].end())
@@ -678,45 +712,20 @@ void add_coupling_code(spill_ctx& ctx, Block* block, unsigned block_idx)
             Temp new_name = {ctx.program->allocateId(), live.first.regClass()};
             aco_ptr<Instruction> reload = do_reload(ctx, live.first, new_name, ctx.spills_exit[pred_idx][live.first]);
             instructions.emplace_back(std::move(reload));
+            reg_demand.emplace_back(reg_demand.back());
             ctx.renames[block_idx][live.first] = new_name;
          }
       }
 
-      unsigned pred_idx = block->linear_preds[0];
-      for (std::pair<Temp, std::pair<uint32_t, uint32_t>> live : ctx.next_use_distances_start[block_idx]) {
-         if (live.first.type() == RegType::vgpr)
-            continue;
-         /* still spilled */
-         if (ctx.spills_entry[block_idx].find(live.first) != ctx.spills_entry[block_idx].end())
-            continue;
-
-         /* in register at end of predecessor */
-         if (ctx.spills_exit[pred_idx].find(live.first) == ctx.spills_exit[pred_idx].end()) {
-            std::map<Temp, Temp>::iterator it = ctx.renames[pred_idx].find(live.first);
-            if (it != ctx.renames[pred_idx].end())
-               ctx.renames[block_idx].insert(*it);
-            continue;
-         }
-
-         /* variable is spilled at predecessor and live at current block: create reload instruction */
-         Temp new_name = {ctx.program->allocateId(), live.first.regClass()};
-         aco_ptr<Instruction> reload = do_reload(ctx, live.first, new_name, ctx.spills_exit[pred_idx][live.first]);
-         instructions.emplace_back(std::move(reload));
-         ctx.renames[block_idx][live.first] = new_name;
-      }
-
       /* combine new reload instructions with original block */
       if (!instructions.empty()) {
-         unsigned insert_idx = 0;
-         while (block->instructions[insert_idx]->opcode == aco_opcode::p_phi ||
-                block->instructions[insert_idx]->opcode == aco_opcode::p_linear_phi) {
-            insert_idx++;
-         }
-         ctx.register_demand[block->index].insert(std::next(ctx.register_demand[block->index].begin(), insert_idx),
-                                                  instructions.size(), RegisterDemand());
-         block->instructions.insert(std::next(block->instructions.begin(), insert_idx),
-                                    std::move_iterator<std::vector<aco_ptr<Instruction>>::iterator>(instructions.begin()),
-                                    std::move_iterator<std::vector<aco_ptr<Instruction>>::iterator>(instructions.end()));
+         reg_demand.insert(reg_demand.end(), std::next(ctx.register_demand[block->index].begin(), insert_idx),
+                           ctx.register_demand[block->index].end());
+         ctx.register_demand[block_idx] = std::move(reg_demand);
+         instructions.insert(instructions.end(),
+                             std::move_iterator<std::vector<aco_ptr<Instruction>>::iterator>(std::next(block->instructions.begin(), insert_idx)),
+                             std::move_iterator<std::vector<aco_ptr<Instruction>>::iterator>(block->instructions.end()));
+         block->instructions = std::move(instructions);
       }
       return;
    }
-- 
2.30.2