From 6f8e2c9913b24f746a154dda700f609cee3095f9 Mon Sep 17 00:00:00 2001
From: Nicolas Geoffray <ngeoffray@google.com>
Date: Thu, 23 Mar 2017 14:37:26 +0000
Subject: Make data dependency around HDeoptimize correct.

We use HDeoptimize in a few places, but when it comes to data
dependency we either:
- don't have any (BCE, CHA), in which case we should make sure no
  code that the deoptimzation guards moves before the HDeoptimize
- have one on the receiver (inline cache), in which case we can
  update the dominated users with the HDeoptimize to get the data
  dependency correct.

bug:35661819
bug:36371709
test: 644-checker-deopt
Change-Id: I4820c6710b06939e7f5a59606971693e995fb958
---
 compiler/optimizing/nodes.cc | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

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

diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 020e4463d4..48152ce08e 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -1088,6 +1088,19 @@ void HInstruction::ReplaceWith(HInstruction* other) {
   DCHECK(env_uses_.empty());
 }
 
+void HInstruction::ReplaceUsesDominatedBy(HInstruction* dominator, HInstruction* replacement) {
+  const HUseList<HInstruction*>& uses = GetUses();
+  for (auto it = uses.begin(), end = uses.end(); it != end; /* ++it below */) {
+    HInstruction* user = it->GetUser();
+    size_t index = it->GetIndex();
+    // Increment `it` now because `*it` may disappear thanks to user->ReplaceInput().
+    ++it;
+    if (dominator->StrictlyDominates(user)) {
+      user->ReplaceInput(replacement, index);
+    }
+  }
+}
+
 void HInstruction::ReplaceInput(HInstruction* replacement, size_t index) {
   HUserRecord<HInstruction*> input_use = InputRecordAt(index);
   if (input_use.GetInstruction() == replacement) {
@@ -1323,6 +1336,18 @@ std::ostream& operator<<(std::ostream& os, const ComparisonBias& rhs) {
   }
 }
 
+std::ostream& operator<<(std::ostream& os, const HDeoptimize::Kind& rhs) {
+  switch (rhs) {
+    case HDeoptimize::Kind::kBCE:
+      return os << "bce";
+    case HDeoptimize::Kind::kInline:
+      return os << "inline";
+    default:
+      LOG(FATAL) << "Unknown Deoptimization kind: " << static_cast<int>(rhs);
+      UNREACHABLE();
+  }
+}
+
 bool HCondition::IsBeforeWhenDisregardMoves(HInstruction* instruction) const {
   return this == instruction->GetPreviousDisregardingMoves();
 }
-- 
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