commit 2a32cdda6d0e3da8f370bed159543590f7702b89
author Stevie Strickland <sstrickl@google.com> Fri May 10 09:31:19 2019 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> Fri May 10 09:31:19 2019 +0000
tree b1fc9a108fe0f8e4abae7665522fb150ab286c56
parent 0db620a2a538eb58cfbfbe2399dfc2385995b44c

[vm/compiler] Replace LoadClassId for known cids.

Change-Id: I4c5b31cd83882892657d0cfff1e75aab494fd20b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/101661
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>

runtime/vm/compiler/backend/constant_propagator.cc

diff --git a/runtime/vm/compiler/backend/constant_propagator.cc b/runtime/vm/compiler/backend/constant_propagator.cc
index acf4f9c..931ffa3 100644
--- a/runtime/vm/compiler/backend/constant_propagator.cc
+++ b/runtime/vm/compiler/backend/constant_propagator.cc
@@ -844,15 +844,9 @@
 }
 
 void ConstantPropagator::VisitLoadClassId(LoadClassIdInstr* instr) {
-  intptr_t cid = instr->object()->Type()->ToCid();
-  if (cid != kDynamicCid) {
-    SetValue(instr, Smi::ZoneHandle(Z, Smi::New(cid)));
-    return;
-  }
-
   const Object& object = instr->object()->definition()->constant_value();
   if (IsConstant(object)) {
-    cid = object.GetClassId();
+    const intptr_t cid = object.GetClassId();
     SetValue(instr, Smi::ZoneHandle(Z, Smi::New(cid)));
     return;
   }

runtime/vm/compiler/backend/il.cc

diff --git a/runtime/vm/compiler/backend/il.cc b/runtime/vm/compiler/backend/il.cc
index 635c4be..cbffc1a 100644
--- a/runtime/vm/compiler/backend/il.cc
+++ b/runtime/vm/compiler/backend/il.cc
@@ -3414,6 +3414,15 @@
   return cids().HasClassId(value_cid) ? NULL : this;
 }
 
+Definition* LoadClassIdInstr::Canonicalize(FlowGraph* flow_graph) {
+  const intptr_t cid = object()->Type()->ToCid();
+  if (cid != kDynamicCid) {
+    const auto& smi = Smi::ZoneHandle(flow_graph->zone(), Smi::New(cid));
+    return flow_graph->GetConstant(smi);
+  }
+  return this;
+}
+
 Instruction* CheckClassIdInstr::Canonicalize(FlowGraph* flow_graph) {
   if (value()->BindsToConstant()) {
     const Object& constant_value = value()->BoundConstant();

runtime/vm/compiler/backend/il.h

diff --git a/runtime/vm/compiler/backend/il.h b/runtime/vm/compiler/backend/il.h
index 370136a..cf93aaa 100644
--- a/runtime/vm/compiler/backend/il.h
+++ b/runtime/vm/compiler/backend/il.h
@@ -5246,6 +5246,8 @@
   DECLARE_INSTRUCTION(LoadClassId)
   virtual CompileType ComputeType() const;
 
+  virtual Definition* Canonicalize(FlowGraph* flow_graph);
+
   Value* object() const { return inputs_[0]; }
 
   virtual bool ComputeCanDeoptimize() const { return false; }