commit cd6dffedf1bd8e6dfb3fb0c933551f9a90f7de3f
author Calin Juravle <calin@google.com> Thu Jan 08 17:35:35 2015 +0000
committer Calin Juravle <calin@google.com> Fri Jan 16 17:27:03 2015 +0000
tree 0d83e9fdf65bded684d6e836078f253e63b7e11f
parent 12c03ac7575db242a6f35739bb459e8277115da4

Add implicit null checks for the optimizing compiler

- for backends: arm, arm64, x86, x86_64
- fixed parameter passing for CodeGenerator
- 003-omnibus-opcodes test verifies that NullPointerExceptions work as
expected

Change-Id: I1b302acd353342504716c9169a80706cf3aba2c8

compiler/optimizing/code_generator_x86.cc

diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 1a0df44..22b2aa0 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -373,8 +373,9 @@
   return kX86WordSize;
 }
 
-CodeGeneratorX86::CodeGeneratorX86(HGraph* graph)
-    : CodeGenerator(graph, kNumberOfCpuRegisters, kNumberOfXmmRegisters, kNumberOfRegisterPairs),
+CodeGeneratorX86::CodeGeneratorX86(HGraph* graph, const CompilerOptions& compiler_options)
+    : CodeGenerator(graph, kNumberOfCpuRegisters, kNumberOfXmmRegisters,
+                    kNumberOfRegisterPairs, compiler_options),
       block_labels_(graph->GetArena(), 0),
       location_builder_(graph, this),
       instruction_visitor_(graph, this),
@@ -2924,13 +2925,23 @@
 void LocationsBuilderX86::VisitNullCheck(HNullCheck* instruction) {
   LocationSummary* locations =
       new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);
-  locations->SetInAt(0, Location::Any());
+  Location loc = codegen_->GetCompilerOptions().GetImplicitNullChecks()
+      ? Location::RequiresRegister()
+      : Location::Any();
+  locations->SetInAt(0, loc);
   if (instruction->HasUses()) {
     locations->SetOut(Location::SameAsFirstInput());
   }
 }
 
-void InstructionCodeGeneratorX86::VisitNullCheck(HNullCheck* instruction) {
+void InstructionCodeGeneratorX86::GenerateImplicitNullCheck(HNullCheck* instruction) {
+  LocationSummary* locations = instruction->GetLocations();
+  Location obj = locations->InAt(0);
+  __ testl(EAX, Address(obj.AsRegister<Register>(), 0));
+  codegen_->RecordPcInfo(instruction, instruction->GetDexPc());
+}
+
+void InstructionCodeGeneratorX86::GenerateExplicitNullCheck(HNullCheck* instruction) {
   SlowPathCodeX86* slow_path = new (GetGraph()->GetArena()) NullCheckSlowPathX86(instruction);
   codegen_->AddSlowPath(slow_path);
 
@@ -2950,6 +2961,14 @@
   __ j(kEqual, slow_path->GetEntryLabel());
 }
 
+void InstructionCodeGeneratorX86::VisitNullCheck(HNullCheck* instruction) {
+  if (codegen_->GetCompilerOptions().GetImplicitNullChecks()) {
+    GenerateImplicitNullCheck(instruction);
+  } else {
+    GenerateExplicitNullCheck(instruction);
+  }
+}
+
 void LocationsBuilderX86::VisitArrayGet(HArrayGet* instruction) {
   LocationSummary* locations =
       new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);