Revert "Reduce copying, redundancy & repetition for codegen of comparison instructions"

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
diff --git a/runtime/vm/intermediate_language_x64.cc b/runtime/vm/intermediate_language_x64.cc
index b947742092ea4131014fc362e4f07c3fb82019ec..e9c8f208bd53f20c50df4774d02553c538e7f99b 100644
--- a/runtime/vm/intermediate_language_x64.cc
+++ b/runtime/vm/intermediate_language_x64.cc
@@ -165,11 +165,8 @@ void IfThenElseInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   __ xorq(RDX, RDX);
 
   // Emit comparison code. This must not overwrite the result register.
-  // IfThenElseInstr::Supports() should prevent EmitComparisonCode from using
-  // the labels or returning an invalid condition.
   BranchLabels labels = {NULL, NULL, NULL};
   Condition true_condition = comparison()->EmitComparisonCode(compiler, labels);
-  ASSERT(true_condition != INVALID_CONDITION);
 
   const bool is_power_of_two_kind = IsPowerOfTwoKind(if_true_, if_false_);
 
@@ -576,13 +573,13 @@ Condition EqualityCompareInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
 }
 
 
-void ComparisonInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+void EqualityCompareInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  ASSERT((kind() == Token::kEQ) || (kind() == Token::kNE));
+
   Label is_true, is_false;
   BranchLabels labels = {&is_true, &is_false, &is_false};
   Condition true_condition = EmitComparisonCode(compiler, labels);
-  if (true_condition != INVALID_CONDITION) {
-    EmitBranchOnCondition(compiler, true_condition, labels);
-  }
+  EmitBranchOnCondition(compiler, true_condition, labels);
 
   Register result = locs()->out(0).reg();
   Label done;
@@ -595,13 +592,13 @@ void ComparisonInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
 }
 
 
-void ComparisonInstr::EmitBranchCode(FlowGraphCompiler* compiler,
-                                     BranchInstr* branch) {
+void EqualityCompareInstr::EmitBranchCode(FlowGraphCompiler* compiler,
+                                          BranchInstr* branch) {
+  ASSERT((kind() == Token::kNE) || (kind() == Token::kEQ));
+
   BranchLabels labels = compiler->CreateBranchLabels(branch);
   Condition true_condition = EmitComparisonCode(compiler, labels);
-  if (true_condition != INVALID_CONDITION) {
-    EmitBranchOnCondition(compiler, true_condition, labels);
-  }
+  EmitBranchOnCondition(compiler, true_condition, labels);
 }
 
 
@@ -634,6 +631,20 @@ Condition TestSmiInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
 }
 
 
+void TestSmiInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  // Never emitted outside of the BranchInstr.
+  UNREACHABLE();
+}
+
+
+void TestSmiInstr::EmitBranchCode(FlowGraphCompiler* compiler,
+                                  BranchInstr* branch) {
+  BranchLabels labels = compiler->CreateBranchLabels(branch);
+  Condition true_condition = EmitComparisonCode(compiler, labels);
+  EmitBranchOnCondition(compiler, true_condition, labels);
+}
+
+
 LocationSummary* TestCidsInstr::MakeLocationSummary(Zone* zone,
                                                     bool opt) const {
   const intptr_t kNumInputs = 1;
@@ -685,9 +696,30 @@ Condition TestCidsInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
   } else {
     __ jmp(deopt);
   }
-  // Dummy result as this method already did the jump, there's no need
-  // for the caller to branch on a condition.
-  return INVALID_CONDITION;
+  // Dummy result as the last instruction is a jump, any conditional
+  // branch using the result will therefore be skipped.
+  return ZERO;
+}
+
+
+void TestCidsInstr::EmitBranchCode(FlowGraphCompiler* compiler,
+                                   BranchInstr* branch) {
+  BranchLabels labels = compiler->CreateBranchLabels(branch);
+  EmitComparisonCode(compiler, labels);
+}
+
+
+void TestCidsInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Register result_reg = locs()->out(0).reg();
+  Label is_true, is_false, done;
+  BranchLabels labels = {&is_true, &is_false, &is_false};
+  EmitComparisonCode(compiler, labels);
+  __ Bind(&is_false);
+  __ LoadObject(result_reg, Bool::False());
+  __ jmp(&done, Assembler::kNearJump);
+  __ Bind(&is_true);
+  __ LoadObject(result_reg, Bool::True());
+  __ Bind(&done);
 }
 
 
@@ -735,6 +767,31 @@ Condition RelationalOpInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
 }
 
 
+void RelationalOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Label is_true, is_false;
+  BranchLabels labels = {&is_true, &is_false, &is_false};
+  Condition true_condition = EmitComparisonCode(compiler, labels);
+  EmitBranchOnCondition(compiler, true_condition, labels);
+
+  Register result = locs()->out(0).reg();
+  Label done;
+  __ Bind(&is_false);
+  __ LoadObject(result, Bool::False());
+  __ jmp(&done);
+  __ Bind(&is_true);
+  __ LoadObject(result, Bool::True());
+  __ Bind(&done);
+}
+
+
+void RelationalOpInstr::EmitBranchCode(FlowGraphCompiler* compiler,
+                                       BranchInstr* branch) {
+  BranchLabels labels = compiler->CreateBranchLabels(branch);
+  Condition true_condition = EmitComparisonCode(compiler, labels);
+  EmitBranchOnCondition(compiler, true_condition, labels);
+}
+
+
 LocationSummary* NativeCallInstr::MakeLocationSummary(Zone* zone,
                                                       bool opt) const {
   return MakeCallSummary(zone);
@@ -3052,7 +3109,6 @@ void CheckedSmiComparisonInstr::EmitBranchCode(FlowGraphCompiler* compiler,
   compiler->AddSlowPathCode(slow_path);
   EMIT_SMI_CHECK;
   Condition true_condition = EmitComparisonCode(compiler, labels);
-  ASSERT(true_condition != INVALID_CONDITION);
   EmitBranchOnCondition(compiler, true_condition, labels);
   __ Bind(slow_path->exit_label());
 }
@@ -3067,7 +3123,6 @@ void CheckedSmiComparisonInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   compiler->AddSlowPathCode(slow_path);
   EMIT_SMI_CHECK;
   Condition true_condition = EmitComparisonCode(compiler, labels);
-  ASSERT(true_condition != INVALID_CONDITION);
   EmitBranchOnCondition(compiler, true_condition, labels);
   Register result = locs()->out(0).reg();
   __ Bind(&false_label);
@@ -3896,6 +3951,32 @@ Condition DoubleTestOpInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
 }
 
 
+void DoubleTestOpInstr::EmitBranchCode(FlowGraphCompiler* compiler,
+                                       BranchInstr* branch) {
+  ASSERT(compiler->is_optimizing());
+  BranchLabels labels = compiler->CreateBranchLabels(branch);
+  Condition true_condition = EmitComparisonCode(compiler, labels);
+  EmitBranchOnCondition(compiler, true_condition, labels);
+}
+
+
+void DoubleTestOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Label is_true, is_false;
+  BranchLabels labels = {&is_true, &is_false, &is_false};
+  Condition true_condition = EmitComparisonCode(compiler, labels);
+  EmitBranchOnCondition(compiler, true_condition, labels);
+
+  Register result = locs()->out(0).reg();
+  Label done;
+  __ Bind(&is_false);
+  __ LoadObject(result, Bool::False());
+  __ jmp(&done);
+  __ Bind(&is_true);
+  __ LoadObject(result, Bool::True());
+  __ Bind(&done);
+}
+
+
 LocationSummary* BinaryFloat32x4OpInstr::MakeLocationSummary(Zone* zone,
                                                              bool opt) const {
   const intptr_t kNumInputs = 2;
@@ -6557,6 +6638,36 @@ Condition StrictCompareInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
 }
 
 
+void StrictCompareInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  ASSERT(kind() == Token::kEQ_STRICT || kind() == Token::kNE_STRICT);
+
+  Label is_true, is_false;
+  BranchLabels labels = {&is_true, &is_false, &is_false};
+
+  Condition true_condition = EmitComparisonCode(compiler, labels);
+  EmitBranchOnCondition(compiler, true_condition, labels);
+
+  Register result = locs()->out(0).reg();
+  Label done;
+  __ Bind(&is_false);
+  __ LoadObject(result, Bool::False());
+  __ jmp(&done);
+  __ Bind(&is_true);
+  __ LoadObject(result, Bool::True());
+  __ Bind(&done);
+}
+
+
+void StrictCompareInstr::EmitBranchCode(FlowGraphCompiler* compiler,
+                                        BranchInstr* branch) {
+  ASSERT(kind() == Token::kEQ_STRICT || kind() == Token::kNE_STRICT);
+
+  BranchLabels labels = compiler->CreateBranchLabels(branch);
+  Condition true_condition = EmitComparisonCode(compiler, labels);
+  EmitBranchOnCondition(compiler, true_condition, labels);
+}
+
+
 LocationSummary* ClosureCallInstr::MakeLocationSummary(Zone* zone,
                                                        bool opt) const {
   const intptr_t kNumInputs = 1;