X64: Change strategy for spilling to match ia32. It's just better.

Align deferred code blocks to 16-byte address boundaries.

Review URL: http://codereview.chromium.org/2855018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4914 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/assembler-arm.cc

@@ -394,6 +394,11 @@ void Assembler::Align(int m) {
 }
 
 
+void Assembler::CodeTargetAlign() {
+  Align(16);  // Tentative value.
+}
+
+
 bool Assembler::IsNop(Instr instr, int type) {
   // Check for mov rx, rx.
   ASSERT(0 <= type && type <= 14);  // mov pc, pc is not a nop.

src/arm/assembler-arm.h

@@ -703,6 +703,8 @@ class Assembler : public Malloced {
   // possible to align the pc offset to a multiple
   // of m. m must be a power of 2 (>= 4).
   void Align(int m);
+  // Aligns code to something that's optimal for a jump target for the platform.
+  void CodeTargetAlign();
 
   // Branch instructions
   void b(int branch_offset, Condition cond = al);

src/codegen.cc

@@ -69,6 +69,7 @@ void CodeGenerator::ProcessDeferred() {
   while (!deferred_.is_empty()) {
     DeferredCode* code = deferred_.RemoveLast();
     ASSERT(masm_ == code->masm());
+    masm_->CodeTargetAlign();
     // Record position of deferred code stub.
     masm_->RecordStatementPosition(code->statement_position());
     if (code->position() != RelocInfo::kNoPosition) {

src/ia32/assembler-ia32.cc

@@ -378,6 +378,11 @@ void Assembler::Align(int m) {
 }
 
 
+void Assembler::CodeTargetAlign() {
+  Align(16);  // Preferred alignment of jump targets on ia32.
+}
+
+
 void Assembler::cpuid() {
   ASSERT(CpuFeatures::IsEnabled(CPUID));
   EnsureSpace ensure_space(this);

src/ia32/assembler-ia32.h

@@ -507,6 +507,8 @@ class Assembler : public Malloced {
   // possible to align the pc offset to a multiple
   // of m. m must be a power of 2.
   void Align(int m);
+  // Aligns code to something that's optimal for a jump target for the platform.
+  void CodeTargetAlign();
 
   // Stack
   void pushad();

src/x64/assembler-x64.cc

@@ -382,6 +382,11 @@ void Assembler::Align(int m) {
 }
 
 
+void Assembler::CodeTargetAlign() {
+  Align(16);  // Preferred alignment of jump targets on x64.
+}
+
+
 void Assembler::bind_to(Label* L, int pos) {
   ASSERT(!L->is_bound());  // Label may only be bound once.
   last_pc_ = NULL;

src/x64/assembler-x64.h

@@ -499,6 +499,8 @@ class Assembler : public Malloced {
   // possible to align the pc offset to a multiple
   // of m. m must be a power of 2.
   void Align(int m);
+  // Aligns code to something that's optimal for a jump target for the platform.
+  void CodeTargetAlign();
 
   // Stack
   void pushfq();

src/x64/macro-assembler-x64.cc

@@ -456,13 +456,8 @@ void MacroAssembler::Set(Register dst, int64_t x) {
 
 
 void MacroAssembler::Set(const Operand& dst, int64_t x) {
-  if (x == 0) {
-    xor_(kScratchRegister, kScratchRegister);
-    movq(dst, kScratchRegister);
-  } else if (is_int32(x)) {
+  if (is_int32(x)) {
     movq(dst, Immediate(static_cast<int32_t>(x)));
-  } else if (is_uint32(x)) {
-    movl(dst, Immediate(static_cast<uint32_t>(x)));
   } else {
     movq(kScratchRegister, x, RelocInfo::NONE);
     movq(dst, kScratchRegister);

src/x64/virtual-frame-x64.cc

@@ -961,16 +961,18 @@ void VirtualFrame::SyncRange(int begin, int end) {
   // Sync elements below the range if they have not been materialized
   // on the stack.
   int start = Min(begin, stack_pointer_ + 1);
+  int end_or_stack_pointer = Min(stack_pointer_, end);
+  // Emit normal push instructions for elements above stack pointer
+  // and use mov instructions if we are below stack pointer.
+  int i = start;
 
-  // If positive we have to adjust the stack pointer.
-  int delta = end - stack_pointer_;
-  if (delta > 0) {
-    stack_pointer_ = end;
-    __ subq(rsp, Immediate(delta * kPointerSize));
-  }
-
-  for (int i = start; i <= end; i++) {
+  while (i <= end_or_stack_pointer) {
     if (!elements_[i].is_synced()) SyncElementBelowStackPointer(i);
+    i++;
+  }
+  while (i <= end) {
+    SyncElementByPushing(i);
+    i++;
   }
 }