VM: New calling convention for generated code.

runtime/vm/code_patcher_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/assembler.h"
 #include "vm/code_patcher.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/instructions.h"
 #include "vm/object.h"
 #include "vm/raw_object.h"
 
 namespace dart {
 
 // The expected pattern of a Dart unoptimized call (static and instance):
 //  mov ECX, ic-data
+//  mov EDI, target-code-object
 //  call target_address (stub)
 //  <- return address
 class UnoptimizedCall : public ValueObject {
  public:
   explicit UnoptimizedCall(uword return_address)
-      : start_(return_address - (kNumInstructions * kInstructionSize)) {
-    ASSERT(IsValid(return_address));
-    ASSERT(kInstructionSize == Assembler::kCallExternalLabelSize);
-  }
-
-  static bool IsValid(uword return_address) {
-    uint8_t* code_bytes =
-        reinterpret_cast<uint8_t*>(
-            return_address - (kNumInstructions * kInstructionSize));
-    return (code_bytes[0] == 0xB9) &&
-           (code_bytes[1 * kInstructionSize] == 0xE8);
-  }
-
-  uword target() const {
-    const uword offset = *reinterpret_cast<uword*>(call_address() + 1);
-    return return_address() + offset;
-  }
-
-  void set_target(uword target) const {
-    uword* target_addr = reinterpret_cast<uword*>(call_address() + 1);
-    uword offset = target - return_address();
-    WritableInstructionsScope writable(reinterpret_cast<uword>(target_addr),
-                                       sizeof(offset));
-    *target_addr = offset;
-    CPU::FlushICache(call_address(), kInstructionSize);
+      : start_(return_address - kPatternSize) {
+    ASSERT(IsValid());
   }
 
   RawObject* ic_data() const {
     return *reinterpret_cast<RawObject**>(start_ + 1);
   }
 
-  static const int kNumInstructions = 2;
-  static const int kInstructionSize = 5;  // All instructions have same length.
+  static const int kMovInstructionSize = 5;
+  static const int kCallInstructionSize = 3;
+  static const int kPatternSize =
+      2 * kMovInstructionSize + kCallInstructionSize;
 
  private:
+  bool IsValid() {
+    uint8_t* code_bytes = reinterpret_cast<uint8_t*>(start_);
+    return (code_bytes[0] == 0xB9) &&
+           (code_bytes[2 * kMovInstructionSize] == 0xFF);
+  }
+
   uword return_address() const {
-    return start_ + kNumInstructions * kInstructionSize;
+    return start_ + kPatternSize;
   }
 
   uword call_address() const {
-    return start_ + 1 * kInstructionSize;
+    return start_ + 2 * kMovInstructionSize;
   }
 
  protected:
   uword start_;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(UnoptimizedCall);
 };
 
 
@@ skipping 43 matching lines @@
 #endif  // DEBUG
   }
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(UnoptimizedStaticCall);
 };
 
 
 // The expected pattern of a dart static call:
 //  mov EDX, arguments_descriptor_array (optional in polymorphic calls)
-//  call target_address
+//  mov EDI, Immediate(code_object)
+//  call [EDI + entry_point_offset]
 //  <- return address
 class StaticCall : public ValueObject {
  public:
   explicit StaticCall(uword return_address)
-      : start_(return_address - (kNumInstructions * kInstructionSize)) {
-    ASSERT(IsValid(return_address));
-    ASSERT(kInstructionSize == Assembler::kCallExternalLabelSize);
+      : start_(return_address - (kMovInstructionSize + kCallInstructionSize)) {
+    ASSERT(IsValid());
   }
 
-  static bool IsValid(uword return_address) {
-    uint8_t* code_bytes =
-        reinterpret_cast<uint8_t*>(
-            return_address - (kNumInstructions * kInstructionSize));
-    return (code_bytes[0] == 0xE8);
+  bool IsValid() {
+    uint8_t* code_bytes = reinterpret_cast<uint8_t*>(start_);
+    return (code_bytes[0] == 0xBF) && (code_bytes[5] == 0xFF);
   }
 
-  uword target() const {
-    const uword offset = *reinterpret_cast<uword*>(call_address() + 1);
-    return return_address() + offset;
+  RawCode* target() const {
+    const uword imm = *reinterpret_cast<uword*>(start_ + 1);
+    return reinterpret_cast<RawCode*>(imm);
   }
 
-  void set_target(uword target) const {
-    uword* target_addr = reinterpret_cast<uword*>(call_address() + 1);
-    uword offset = target - return_address();
-    *target_addr = offset;
-    CPU::FlushICache(call_address(), kInstructionSize);
+  void set_target(const Code& target) const {
+    uword* target_addr = reinterpret_cast<uword*>(start_ + 1);
+    uword imm = reinterpret_cast<uword>(target.raw());
+    *target_addr = imm;
+    CPU::FlushICache(start_ + 1, sizeof(imm));
   }
 
-  static const int kNumInstructions = 1;
-  static const int kInstructionSize = 5;  // All instructions have same length.
+  static const int kNumInstructions = 2;
+  static const int kMovInstructionSize = 5;
+  static const int kCallInstructionSize = 3;
 
  private:
   uword return_address() const {
-    return start_ + kNumInstructions * kInstructionSize;
+    return start_ + kMovInstructionSize +  kCallInstructionSize;
   }
 
   uword call_address() const {
-    return start_;
+    return start_ + kMovInstructionSize;
   }
 
   uword start_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(StaticCall);
 };
 
 
-uword CodePatcher::GetStaticCallTargetAt(uword return_address,
-                                         const Code& code) {
+RawCode* CodePatcher::GetStaticCallTargetAt(uword return_address,
+                                            const Code& code) {
   ASSERT(code.ContainsInstructionAt(return_address));
   StaticCall call(return_address);
   return call.target();
 }
 
 
 void CodePatcher::PatchStaticCallAt(uword return_address,
                                     const Code& code,
-                                    uword new_target) {
+                                    const Code& new_target) {
   ASSERT(code.ContainsInstructionAt(return_address));
   StaticCall call(return_address);
   call.set_target(new_target);
 }
 
 
-void CodePatcher::PatchInstanceCallAt(uword return_address,
-                                      const Code& code,
-                                      uword new_target) {
-  ASSERT(code.ContainsInstructionAt(return_address));
-  InstanceCall call(return_address);
-  call.set_target(new_target);
-}
-
-
-void CodePatcher::InsertCallAt(uword start, uword target) {
+void CodePatcher::InsertDeoptimizationCallAt(uword start, uword target) {
   // The inserted call should not overlap the lazy deopt jump code.
   ASSERT(start + CallPattern::pattern_length_in_bytes() <= target);
   *reinterpret_cast<uint8_t*>(start) = 0xE8;
   CallPattern call(start);
   call.SetTargetAddress(target);
   CPU::FlushICache(start, CallPattern::pattern_length_in_bytes());
 }
 
 
-uword CodePatcher::GetInstanceCallAt(
+RawCode* CodePatcher::GetInstanceCallAt(
     uword return_address, const Code& code, ICData* ic_data) {
   ASSERT(code.ContainsInstructionAt(return_address));
   InstanceCall call(return_address);
   if (ic_data != NULL) {
     *ic_data ^= call.ic_data();
   }
-  return call.target();
+  return Code::null();
 }
 
 
 RawFunction* CodePatcher::GetUnoptimizedStaticCallAt(
     uword return_address, const Code& code, ICData* ic_data_result) {
   ASSERT(code.ContainsInstructionAt(return_address));
   UnoptimizedStaticCall static_call(return_address);
   ICData& ic_data = ICData::Handle();
   ic_data ^= static_call.ic_data();
   if (ic_data_result != NULL) {
     *ic_data_result = ic_data.raw();
   }
   return ic_data.GetTargetAt(0);
 }
 
 
 void CodePatcher::PatchNativeCallAt(uword return_address,
                                     const Code& code,
                                     NativeFunction target,
                                     const Code& trampoline) {
-  ASSERT(code.ContainsInstructionAt(return_address));
-  NativeCall call(return_address);
-  call.set_target(trampoline.EntryPoint());
-  call.set_native_function(target);
+  UNREACHABLE();
 }
 
 
-uword CodePatcher::GetNativeCallAt(uword return_address,
-                                   const Code& code,
-                                   NativeFunction* target) {
-  ASSERT(code.ContainsInstructionAt(return_address));
-  NativeCall call(return_address);
-  *target = call.native_function();
-  return call.target();
+RawCode* CodePatcher::GetNativeCallAt(uword return_address,
+                                      const Code& code,
+                                      NativeFunction* target) {
+  UNREACHABLE();
+  return NULL;
 }
 
 
 
 intptr_t CodePatcher::InstanceCallSizeInBytes() {
-  return InstanceCall::kNumInstructions * InstanceCall::kInstructionSize;
+  return InstanceCall::kPatternSize;
 }
 
 
 // The expected code pattern of an edge counter in unoptimized code:
 //  b8 imm32    mov EAX, immediate
 class EdgeCounter : public ValueObject {
  public:
   EdgeCounter(uword pc, const Code& ignored)
       : end_(pc - FlowGraphCompiler::EdgeCounterIncrementSizeInBytes()) {
     ASSERT(IsValid(end_));
@@ skipping 14 matching lines @@
 
 RawObject* CodePatcher::GetEdgeCounterAt(uword pc, const Code& code) {
   ASSERT(code.ContainsInstructionAt(pc));
   EdgeCounter counter(pc, code);
   return counter.edge_counter();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32