ARM: Make use of d16-d31 when available.

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
index dc1dc1da9b68de5ce5753500fe4155ca951a00fb..37a4e0e8b1cc73dd412d37b8b0ac09e20df9dc76 100644
--- a/src/arm/macro-assembler-arm.cc
+++ b/src/arm/macro-assembler-arm.cc
@@ -642,20 +642,24 @@ void MacroAssembler::PopSafepointRegisters() {
 
 
 void MacroAssembler::PushSafepointRegistersAndDoubles() {
+  // Number of d-regs not known at snapshot time.
+  ASSERT(!Serializer::enabled());
   PushSafepointRegisters();
-  sub(sp, sp, Operand(DwVfpRegister::kNumAllocatableRegisters *
+  sub(sp, sp, Operand(DwVfpRegister::NumAllocatableRegisters() *
                       kDoubleSize));
-  for (int i = 0; i < DwVfpRegister::kNumAllocatableRegisters; i++) {
+  for (int i = 0; i < DwVfpRegister::NumAllocatableRegisters(); i++) {
     vstr(DwVfpRegister::FromAllocationIndex(i), sp, i * kDoubleSize);
   }
 }
 
 
 void MacroAssembler::PopSafepointRegistersAndDoubles() {
-  for (int i = 0; i < DwVfpRegister::kNumAllocatableRegisters; i++) {
+  // Number of d-regs not known at snapshot time.
+  ASSERT(!Serializer::enabled());
+  for (int i = 0; i < DwVfpRegister::NumAllocatableRegisters(); i++) {
     vldr(DwVfpRegister::FromAllocationIndex(i), sp, i * kDoubleSize);
   }
-  add(sp, sp, Operand(DwVfpRegister::kNumAllocatableRegisters *
+  add(sp, sp, Operand(DwVfpRegister::NumAllocatableRegisters() *
                       kDoubleSize));
   PopSafepointRegisters();
 }
@@ -690,8 +694,10 @@ MemOperand MacroAssembler::SafepointRegisterSlot(Register reg) {
 
 
 MemOperand MacroAssembler::SafepointRegistersAndDoublesSlot(Register reg) {
+  // Number of d-regs not known at snapshot time.
+  ASSERT(!Serializer::enabled());
   // General purpose registers are pushed last on the stack.
-  int doubles_size = DwVfpRegister::kNumAllocatableRegisters * kDoubleSize;
+  int doubles_size = DwVfpRegister::NumAllocatableRegisters() * kDoubleSize;
   int register_offset = SafepointRegisterStackIndex(reg.code()) * kPointerSize;
   return MemOperand(sp, doubles_size + register_offset);
 }
@@ -831,6 +837,50 @@ void MacroAssembler::Vmov(const DwVfpRegister dst,
 }
 
 
+void MacroAssembler::Vpop(Register base,
+                          const DwVfpRegister first,
+                          const DwVfpRegister last,
+                          Condition cond) {
+  ASSERT(CpuFeatures::IsEnabled(VFP2));
+  ASSERT_LE(first.code(), last.code());
+
+  const int first_code = first.code();
+  const int last_code = last.code();
+  const int count = last_code - first_code + 1;
+
+  if (count <= 16) {
+    vldm(ia_w, base, first, last, cond);
+  } else {
+    // Since we are increasing the address, load the first registers first.
+    ASSERT(first_code < 16 && last_code >= 16);
+    vldm(ia_w, base, first, d15, cond);
+    vldm(ia_w, base, d16, last, cond);
+  }
+}
+
+
+void MacroAssembler::Vpush(Register base,
+                           const DwVfpRegister first,
+                           const DwVfpRegister last,
+                           Condition cond) {
+  ASSERT(CpuFeatures::IsEnabled(VFP2));
+  ASSERT_LE(first.code(), last.code());
+
+  const int first_code = first.code();
+  const int last_code = last.code();
+  const int count = last_code - first_code + 1;
+
+  if (count <= 16) {
+    vstm(db_w, base, first, last, cond);
+  } else {
+    // Since we are decreasing the address, write the last registers first.
+    ASSERT(first_code < 16 && last_code >= 16);
+    vstm(db_w, base, d16, last, cond);
+    vstm(db_w, base, first, d15, cond);
+  }
+}
+
+
 void MacroAssembler::EnterFrame(StackFrame::Type type) {
   // r0-r3: preserved
   stm(db_w, sp, cp.bit() | fp.bit() | lr.bit());
@@ -878,12 +928,15 @@ void MacroAssembler::EnterExitFrame(bool save_doubles, int stack_space) {
 
   // Optionally save all double registers.
   if (save_doubles) {
+    // Number of d-regs not known at snapshot time.
+    ASSERT(!Serializer::enabled());
     DwVfpRegister first = d0;
     DwVfpRegister last =
-        DwVfpRegister::from_code(DwVfpRegister::kNumRegisters - 1);
-    vstm(db_w, sp, first, last);
+        DwVfpRegister::from_code(DwVfpRegister::NumAvailableRegisters() - 1);
+    Vpush(sp, first, last);
     // Note that d0 will be accessible at
-    //   fp - 2 * kPointerSize - DwVfpRegister::kNumRegisters * kDoubleSize,
+    //   fp - 2 * kPointerSize -
+    //   DwVfpRegister::NumAvailableRegisters() * kDoubleSize,
     // since the sp slot and code slot were pushed after the fp.
   }
 
@@ -938,13 +991,16 @@ void MacroAssembler::LeaveExitFrame(bool save_doubles,
                                     Register argument_count) {
   // Optionally restore all double registers.
   if (save_doubles) {
+    // Number of d-regs not known at snapshot time.
+    ASSERT(!Serializer::enabled());
     // Calculate the stack location of the saved doubles and restore them.
     const int offset = 2 * kPointerSize;
-    sub(r3, fp, Operand(offset + DwVfpRegister::kNumRegisters * kDoubleSize));
+    sub(r3, fp, Operand(offset + DwVfpRegister::NumAvailableRegisters() *
+                        kDoubleSize));
     DwVfpRegister first = d0;
     DwVfpRegister last =
-        DwVfpRegister::from_code(DwVfpRegister::kNumRegisters - 1);
-    vldm(ia, r3, first, last);
+        DwVfpRegister::from_code(DwVfpRegister::NumAvailableRegisters() - 1);
+    Vpop(r3, first, last);
   }
 
   // Clear top frame.