ART: Implement support for instruction inlining

Optimizing HIR contains 'non-materialized' instructions which are
emitted at their use sites rather than their defining sites. This
was not properly handled by the liveness analysis which did not
adjust the use positions of the inputs of such instructions.
Despite the analysis being incorrect, the current use cases never
produce incorrect code.

This patch generalizes the concept of inlined instructions and
updates liveness analysis to set the compute use positions correctly.

Change-Id: Id703c154b20ab861241ae5c715a150385d3ff621

1 files changed, 8 insertions, 8 deletions

diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 41c2f17cd9..922696bb5d 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -1819,6 +1819,7 @@ class HInstruction : public ArenaObject<kArenaAllocInstruction> {
         dex_pc_(dex_pc),
         id_(-1),
         ssa_index_(-1),
+        emitted_at_use_site_(false),
         environment_(nullptr),
         locations_(nullptr),
         live_interval_(nullptr),
@@ -2081,6 +2082,9 @@ class HInstruction : public ArenaObject<kArenaAllocInstruction> {
   // The caller must ensure that this is safe to do.
   void RemoveEnvironmentUsers();
 
+  bool IsEmittedAtUseSite() const { return emitted_at_use_site_; }
+  void MarkEmittedAtUseSite() { emitted_at_use_site_ = true; }
+
  protected:
   virtual const HUserRecord<HInstruction*> InputRecordAt(size_t i) const = 0;
   virtual void SetRawInputRecordAt(size_t index, const HUserRecord<HInstruction*>& input) = 0;
@@ -2102,6 +2106,10 @@ class HInstruction : public ArenaObject<kArenaAllocInstruction> {
   // When doing liveness analysis, instructions that have uses get an SSA index.
   int ssa_index_;
 
+  // If set, the machine code for this instruction is assumed to be generated by
+  // its users. Used by liveness analysis to compute use positions accordingly.
+  bool emitted_at_use_site_;
+
   // List of instructions that have this instruction as input.
   HUseList<HInstruction*> uses_;
 
@@ -2711,12 +2719,8 @@ class HCondition : public HBinaryOperation {
  public:
   HCondition(HInstruction* first, HInstruction* second, uint32_t dex_pc = kNoDexPc)
       : HBinaryOperation(Primitive::kPrimBoolean, first, second, SideEffects::None(), dex_pc),
-        needs_materialization_(true),
         bias_(ComparisonBias::kNoBias) {}
 
-  bool NeedsMaterialization() const { return needs_materialization_; }
-  void ClearNeedsMaterialization() { needs_materialization_ = false; }
-
   // For code generation purposes, returns whether this instruction is just before
   // `instruction`, and disregard moves in between.
   bool IsBeforeWhenDisregardMoves(HInstruction* instruction) const;
@@ -2748,10 +2752,6 @@ class HCondition : public HBinaryOperation {
   }
 
  private:
-  // For register allocation purposes, returns whether this instruction needs to be
-  // materialized (that is, not just be in the processor flags).
-  bool needs_materialization_;
-
   // Needed if we merge a HCompare into a HCondition.
   ComparisonBias bias_;