Cleanup of code generation for StrictCompare.

runtime/vm/intermediate_language_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 391 matching lines @@
     case BELOW_EQUAL:   return ABOVE_EQUAL;
     case ABOVE:         return BELOW;
     case ABOVE_EQUAL:   return BELOW_EQUAL;
     default:
       UNIMPLEMENTED();
       return EQUAL;
   }
 }
 
 
-static void EmitBranchOnValue(FlowGraphCompiler* compiler,
-                              TargetEntryInstr* true_successor,
-                              TargetEntryInstr* false_successor,
-                              bool value) {
-  if (value && !compiler->CanFallThroughTo(true_successor)) {
-    __ jmp(compiler->GetJumpLabel(true_successor));
-  } else if (!value && !compiler->CanFallThroughTo(false_successor)) {
-    __ jmp(compiler->GetJumpLabel(false_successor));
-  }
-}
-
-
 static void EmitBranchOnCondition(FlowGraphCompiler* compiler,
                                   TargetEntryInstr* true_successor,
                                   TargetEntryInstr* false_successor,
                                   Condition true_condition) {
   if (compiler->CanFallThroughTo(false_successor)) {
     // If the next block is the false successor, fall through to it.
     __ j(true_condition, compiler->GetJumpLabel(true_successor));
   } else {
     // If the next block is not the false successor, branch to it.
     Condition false_condition = NegateCondition(true_condition);
@@ skipping 112 matching lines @@
     EmitDoubleCompareBool(compiler, true_condition,
                           left, right, locs.out().reg());
   }
 }
 
 
 void EqualityCompareInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT((kind() == Token::kEQ) || (kind() == Token::kNE));
   BranchInstr* kNoBranch = NULL;
   if (operation_cid() == kSmiCid) {
-    // Deoptimizes if both arguments not Smi.
     EmitSmiComparisonOp(compiler, *locs(), kind(), kNoBranch);
     return;
   }
   if (operation_cid() == kDoubleCid) {
-    // Deoptimizes if both arguments are Smi, or if none is Double or Smi.
     EmitDoubleComparisonOp(compiler, *locs(), kind(), kNoBranch);
     return;
   }
   UNREACHABLE();
 }
 
 
 void EqualityCompareInstr::EmitBranchCode(FlowGraphCompiler* compiler,
                                           BranchInstr* branch) {
   ASSERT((kind() == Token::kNE) || (kind() == Token::kEQ));
   if (operation_cid() == kSmiCid) {
-    // Deoptimizes if both arguments not Smi.
     EmitSmiComparisonOp(compiler, *locs(), kind(), branch);
     return;
   }
   if (operation_cid() == kDoubleCid) {
-    // Deoptimizes if both arguments are Smi, or if none is Double or Smi.
     EmitDoubleComparisonOp(compiler, *locs(), kind(), branch);
     return;
   }
   UNREACHABLE();
 }
 
 
 LocationSummary* TestSmiInstr::MakeLocationSummary() const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;
@@ skipping 3785 matching lines @@
     LocationSummary* locs =
         new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kCall);
     locs->set_in(0, Location::RegisterLocation(RAX));
     locs->set_in(1, Location::RegisterLocation(RCX));
     locs->set_out(Location::RegisterLocation(RAX));
     return locs;
   }
   LocationSummary* locs =
       new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
   locs->set_in(0, Location::RegisterOrConstant(left()));
-  locs->set_in(1, Location::RegisterOrConstant(right()));
+  // Only one of the inputs can be a constant. Choose register if the first one
+  // is a constant.
+  locs->set_in(1, locs->in(0).IsConstant()
+                      ? Location::RequiresRegister()
+                      : Location::RegisterOrConstant(right()));
   locs->set_out(Location::RequiresRegister());
   return locs;
 }
 
 
 // Special code for numbers (compare values instead of references.)
 void StrictCompareInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT(kind() == Token::kEQ_STRICT || kind() == Token::kNE_STRICT);
   Location left = locs()->in(0);
   Location right = locs()->in(1);
-  if (left.IsConstant() && right.IsConstant()) {
-    // TODO(vegorov): should be eliminated earlier by constant propagation.
-    const bool result = (kind() == Token::kEQ_STRICT) ?
-        left.constant().raw() == right.constant().raw() :
-        left.constant().raw() != right.constant().raw();
-    __ LoadObject(locs()->out().reg(), Bool::Get(result), PP);
-    return;
-  }
+  ASSERT(!left.IsConstant() || !right.IsConstant());
   if (left.IsConstant()) {
     compiler->EmitEqualityRegConstCompare(right.reg(),
                                           left.constant(),
                                           needs_number_check(),
                                           token_pos());
   } else if (right.IsConstant()) {
     compiler->EmitEqualityRegConstCompare(left.reg(),
                                           right.constant(),
                                           needs_number_check(),
                                           token_pos());
@@ skipping 14 matching lines @@
   __ LoadObject(result, Bool::True(), PP);
   __ Bind(&done);
 }
 
 
 void StrictCompareInstr::EmitBranchCode(FlowGraphCompiler* compiler,
                                         BranchInstr* branch) {
   ASSERT(kind() == Token::kEQ_STRICT || kind() == Token::kNE_STRICT);
   Location left = locs()->in(0);
   Location right = locs()->in(1);
-  if (left.IsConstant() && right.IsConstant()) {
-    // TODO(vegorov): should be eliminated earlier by constant propagation.
-    const bool result = (kind() == Token::kEQ_STRICT) ?
-        left.constant().raw() == right.constant().raw() :
-        left.constant().raw() != right.constant().raw();
-    EmitBranchOnValue(compiler,
-                      branch->true_successor(),
-                      branch->false_successor(),
-                      result);
-    return;
-  }
+  ASSERT(!left.IsConstant() || !right.IsConstant());
   if (left.IsConstant()) {
     compiler->EmitEqualityRegConstCompare(right.reg(),
                                           left.constant(),
                                           needs_number_check(),
                                           token_pos());
   } else if (right.IsConstant()) {
     compiler->EmitEqualityRegConstCompare(left.reg(),
                                           right.constant(),
                                           needs_number_check(),
                                           token_pos());
@@ skipping 120 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64