From d76551c7229060a3fe11258b490a11f4ee91e9f8 Mon Sep 17 00:00:00 2001
From: Santiago Aboy Solanes <solanes@google.com>
Date: Thu, 25 Jan 2024 09:56:06 +0000
Subject: Revert^7 "Disable write-barrier elimination pass"

This reverts commit 1ba3516e8c3e2b86c73084893dd297f468469181.

Reason for revert:
PS1 is reland as-is
PS2 has two related fixes (for RISC-V and arm64) taking into
account that when we store zero, we use a special register.

Bug: 301833859
Bug: 310755375
Bug: 260843353
Test: lunch cf_riscv64_wear-trunk_staging-userdebug && m
Test: lunch starnix_wear_yukawa-trunk_staging-userdebug && m
Change-Id: I5e69890fd56404ddde56ebc457179241363d9243
---
 compiler/optimizing/code_generator.cc | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

(limited to 'compiler/optimizing/code_generator.cc')

diff --git a/compiler/optimizing/code_generator.cc b/compiler/optimizing/code_generator.cc
index b00e7e1873..441a93c38f 100644
--- a/compiler/optimizing/code_generator.cc
+++ b/compiler/optimizing/code_generator.cc
@@ -158,6 +158,25 @@ ReadBarrierOption CodeGenerator::GetCompilerReadBarrierOption() const {
   return EmitReadBarrier() ? kWithReadBarrier : kWithoutReadBarrier;
 }
 
+bool CodeGenerator::ShouldCheckGCCard(DataType::Type type,
+                                      HInstruction* value,
+                                      WriteBarrierKind write_barrier_kind) const {
+  const CompilerOptions& options = GetCompilerOptions();
+  const bool result =
+      // Check the GC card in debug mode,
+      options.EmitRunTimeChecksInDebugMode() &&
+      // only for CC GC,
+      options.EmitReadBarrier() &&
+      // and if we eliminated the write barrier in WBE.
+      !StoreNeedsWriteBarrier(type, value, write_barrier_kind) &&
+      CodeGenerator::StoreNeedsWriteBarrier(type, value);
+
+  DCHECK_IMPLIES(result, write_barrier_kind == WriteBarrierKind::kDontEmit);
+  DCHECK_IMPLIES(result, !GetGraph()->IsCompilingBaseline());
+
+  return result;
+}
+
 ScopedArenaAllocator* CodeGenerator::GetScopedAllocator() {
   DCHECK(code_generation_data_ != nullptr);
   return code_generation_data_->GetScopedAllocator();
@@ -1608,6 +1627,17 @@ void CodeGenerator::EmitParallelMoves(Location from1,
   GetMoveResolver()->EmitNativeCode(&parallel_move);
 }
 
+bool CodeGenerator::StoreNeedsWriteBarrier(DataType::Type type,
+                                           HInstruction* value,
+                                           WriteBarrierKind write_barrier_kind) const {
+  // Check that null value is not represented as an integer constant.
+  DCHECK_IMPLIES(type == DataType::Type::kReference, !value->IsIntConstant());
+  // Branch profiling currently doesn't support running optimizations.
+  return GetGraph()->IsCompilingBaseline()
+            ? CodeGenerator::StoreNeedsWriteBarrier(type, value)
+            : write_barrier_kind != WriteBarrierKind::kDontEmit;
+}
+
 void CodeGenerator::ValidateInvokeRuntime(QuickEntrypointEnum entrypoint,
                                           HInstruction* instruction,
                                           SlowPathCode* slow_path) {
-- 
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