Skeleton of a linear scan register allocator.

runtime/vm/flow_graph_compiler_ia32.cc

 // Copyright (c) 2012, 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_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "lib/error.h"
@@ skipping 10 matching lines @@
 DECLARE_FLAG(bool, print_ast);
 DECLARE_FLAG(bool, print_scopes);
 DECLARE_FLAG(bool, trace_functions);
 
 
 void DeoptimizationStub::GenerateCode(FlowGraphCompiler* compiler) {
   Assembler* assem = compiler->assembler();
 #define __ assem->
   __ Comment("Deopt stub for id %d", deopt_id_);
   __ Bind(entry_label());
-  for (intptr_t i = 0; i < registers_.length(); i++) {
-    if (registers_[i] != kNoRegister) {
-      __ pushl(registers_[i]);
+
+  if (deoptimization_env_ == NULL) {

[srdjan, 2012/07/11 17:22:32]

ASSERT in ia32 that deoptimization_env_ == NULL (since else not implemented)

+    for (intptr_t i = 0; i < registers_.length(); i++) {
+      if (registers_[i] != kNoRegister) {
+        __ pushl(registers_[i]);
+      }
+    }
+  } else {
+    // We have a deoptimization environment, we have to tear down optimized
+    // frame and recreate non-optimized one.
+    __ leal(ESP,
+            Address(EBP, ParsedFunction::kFirstLocalSlotIndex * kWordSize));
+
+    const ZoneGrowableArray<Value*>& values = deoptimization_env_->values();
+    const GrowableArray<Location>* locations = deoptimization_env_->locations();
+
+    for (intptr_t i = 0; i < values.length(); i++) {
+      Location loc = (*locations)[i];
+      if (loc.IsInvalid()) {
+        ASSERT(values[i]->IsConstant());
+        __ PushObject(values[i]->AsConstant()->value());
+      } else {
+        ASSERT(loc.IsRegister());
+        __ pushl(loc.reg());
+      }
     }
   }
+
   if (compiler->IsLeaf()) {
     Label L;
     __ call(&L);
     const intptr_t offset = assem->CodeSize();
     __ Bind(&L);
     __ popl(EAX);
     __ subl(EAX,
         Immediate(offset - AssemblerMacros::kOffsetOfSavedPCfromEntrypoint));
     __ movl(Address(EBP, -kWordSize), EAX);
   }
@@ skipping 1024 matching lines @@
   __ jmp(&done);
   __ Bind(&is_smi);
   __ movl(temp, reg);
   __ SmiUntag(temp);
   __ cvtsi2sd(result, temp);
   __ Bind(&done);
 }
 
 
 #undef __
+#define __ compiler_->assembler()->
+
+
+void ParallelMoveResolver::EmitMove(int index) {
+  Location source = moves_[index].src();
+  Location destination = moves_[index].dest();
+
+  ASSERT(destination.IsRegister());
+  if (source.IsRegister()) {
+    __ movl(destination.reg(), source.reg());
+  } else {
+    ASSERT(source.IsConstant());
+    __ LoadObject(destination.reg(), source.constant());
+  }
+  moves_[index].Eliminate();
+}
+
+
+void ParallelMoveResolver::EmitSwap(int index) {
+  Location source = moves_[index].src();
+  Location destination = moves_[index].dest();
+
+  ASSERT(source.IsRegister() && destination.IsRegister());
+  __ xchgl(destination.reg(), source.reg());
+
+  // The swap of source and destination has executed a move from source to
+  // destination.
+  moves_[index].Eliminate();
+
+  // Any unperformed (including pending) move with a source of either
+  // this move's source or destination needs to have their source
+  // changed to reflect the state of affairs after the swap.
+  for (int i = 0; i < moves_.length(); ++i) {
+    MoveOperands other_move = moves_[i];
+    if (other_move.Blocks(source)) {
+      moves_[i].set_src(destination);
+    } else if (other_move.Blocks(destination)) {
+      moves_[i].set_src(source);
+    }
+  }
+}
+
+
+#undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32