ARM: Make use of d16-d31 when available.

src/arm/deoptimizer-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 860 matching lines @@
 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
   // Set the register values. The values are not important as there are no
   // callee saved registers in JavaScript frames, so all registers are
   // spilled. Registers fp and sp are set to the correct values though.
 
   for (int i = 0; i < Register::kNumRegisters; i++) {
     input_->SetRegister(i, i * 4);
   }
   input_->SetRegister(sp.code(), reinterpret_cast<intptr_t>(frame->sp()));
   input_->SetRegister(fp.code(), reinterpret_cast<intptr_t>(frame->fp()));
-  for (int i = 0; i < DoubleRegister::kNumAllocatableRegisters; i++) {
+  for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); i++) {
     input_->SetDoubleRegister(i, 0.0);
   }
 
   // Fill the frame content from the actual data on the frame.
   for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
     input_->SetFrameSlot(i, Memory::uint32_at(tos + i));
   }
 }
 
 
 #define __ masm()->
 
 // This code tries to be close to ia32 code so that any changes can be
 // easily ported.
 void Deoptimizer::EntryGenerator::Generate() {
   GeneratePrologue();
 
   Isolate* isolate = masm()->isolate();
 
   CpuFeatures::Scope scope(VFP3);
   // Save all general purpose registers before messing with them.
   const int kNumberOfRegisters = Register::kNumRegisters;
 
   // Everything but pc, lr and ip which will be saved but not restored.
   RegList restored_regs = kJSCallerSaved | kCalleeSaved | ip.bit();
 
   const int kDoubleRegsSize =
-      kDoubleSize * DwVfpRegister::kNumAllocatableRegisters;
+      kDoubleSize * DwVfpRegister::NumAllocatableRegisters();
 
   // Save all VFP registers before messing with them.
   DwVfpRegister first = DwVfpRegister::FromAllocationIndex(0);
-  DwVfpRegister last =
-      DwVfpRegister::FromAllocationIndex(
-          DwVfpRegister::kNumAllocatableRegisters - 1);
+  DwVfpRegister last = DwVfpRegister::FromAllocationIndex(
+      DwVfpRegister::NumAllocatableRegisters() - 1);
   ASSERT(last.code() > first.code());
-  ASSERT((last.code() - first.code()) ==
-      (DwVfpRegister::kNumAllocatableRegisters - 1));
 #ifdef DEBUG
-  for (int i = 0; i <= (DwVfpRegister::kNumAllocatableRegisters - 1); i++) {
+  for (int i = 0; i <= (DwVfpRegister::NumAllocatableRegisters() - 1); i++) {
     ASSERT((DwVfpRegister::FromAllocationIndex(i).code() <= last.code()) &&
            (DwVfpRegister::FromAllocationIndex(i).code() >= first.code()));
   }
 #endif
-  __ vstm(db_w, sp, first, last);
+  if (last.code() > DwVfpRegister::ScratchReg().code()) {
+    // This happens when we also have d16-d31 available.
+    // Store the registers < ZeroReg and > ScratchReg separately.
+    ASSERT(DwVfpRegister::ScratchReg().code() ==
+           DwVfpRegister::ZeroReg().code() + 1);
+    __ vstm(db_w, sp, DwVfpRegister::from_code(
+        DwVfpRegister::ScratchReg().code() + 1), last);
+    __ vstm(db_w, sp, first, DwVfpRegister::from_code(
+        DwVfpRegister::ZeroReg().code() - 1));
+  } else {
+    ASSERT(last.code() - first.code() ==
+           DwVfpRegister::NumAllocatableRegisters() - 1);
+    __ vstm(db_w, sp, first, last);
+  }
 
   // Push all 16 registers (needed to populate FrameDescription::registers_).
   // TODO(1588) Note that using pc with stm is deprecated, so we should perhaps
   // handle this a bit differently.
   __ stm(db_w, sp, restored_regs  | sp.bit() | lr.bit() | pc.bit());
 
   const int kSavedRegistersAreaSize =
       (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
 
   // Get the bailout id from the stack.
@@ skipping 41 matching lines @@
   ASSERT(Register::kNumRegisters == kNumberOfRegisters);
   for (int i = 0; i < kNumberOfRegisters; i++) {
     int offset = (i * kPointerSize) + FrameDescription::registers_offset();
     __ ldr(r2, MemOperand(sp, i * kPointerSize));
     __ str(r2, MemOperand(r1, offset));
   }
 
   // Copy VFP registers to
   // double_registers_[DoubleRegister::kNumAllocatableRegisters]
   int double_regs_offset = FrameDescription::double_registers_offset();
-  for (int i = 0; i < DwVfpRegister::kNumAllocatableRegisters; ++i) {
+  for (int i = 0; i < DwVfpRegister::NumAllocatableRegisters(); ++i) {
     int dst_offset = i * kDoubleSize + double_regs_offset;
     int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
     __ vldr(d0, sp, src_offset);
     __ vstr(d0, r1, dst_offset);
   }
 
   // Remove the bailout id, eventually return address, and the saved registers
   // from the stack.
   if (type() == EAGER || type() == OSR) {
     __ add(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
@@ skipping 22 matching lines @@
   __ push(r0);  // Preserve deoptimizer object across call.
   // r0: deoptimizer object; r1: scratch.
   __ PrepareCallCFunction(1, r1);
   // Call Deoptimizer::ComputeOutputFrames().
   {
     AllowExternalCallThatCantCauseGC scope(masm());
     __ CallCFunction(
         ExternalReference::compute_output_frames_function(isolate), 1);
   }
   __ pop(r0);  // Restore deoptimizer object (class Deoptimizer).
+  __ mov(r4, r0);

[Rodolph Perfetta, 2012/12/12 14:29:15]

minor tweak: the code below could be rewritten not to corrupt r0, removing the
need for this mov.

[hans, 2012/12/12 17:58:47]

Is it OK if I note this in a TODO instead, so as to keep the diff small? This
will be easy to fix in a separate patch.

 
   // Replace the current (input) frame with the output frames.
   Label outer_push_loop, inner_push_loop;
   // Outer loop state: r0 = current "FrameDescription** output_",
   // r1 = one past the last FrameDescription**.
   __ ldr(r1, MemOperand(r0, Deoptimizer::output_count_offset()));
   __ ldr(r0, MemOperand(r0, Deoptimizer::output_offset()));  // r0 is output_.
   __ add(r1, r0, Operand(r1, LSL, 2));
   __ bind(&outer_push_loop);
   // Inner loop state: r2 = current FrameDescription*, r3 = loop index.
   __ ldr(r2, MemOperand(r0, 0));  // output_[ix]
   __ ldr(r3, MemOperand(r2, FrameDescription::frame_size_offset()));
   __ bind(&inner_push_loop);
   __ sub(r3, r3, Operand(sizeof(uint32_t)));
   __ add(r6, r2, Operand(r3));
   __ ldr(r7, MemOperand(r6, FrameDescription::frame_content_offset()));
   __ push(r7);
   __ cmp(r3, Operand(0));
   __ b(ne, &inner_push_loop);  // test for gt?
   __ add(r0, r0, Operand(kPointerSize));
   __ cmp(r0, r1);
   __ b(lt, &outer_push_loop);
 
+  // In case of OSR, we have to restore the d registers.
+  if (type() == OSR) {
+    __ ldr(r1, MemOperand(r4, Deoptimizer::input_offset()));
+    for (int i = 0; i < DwVfpRegister::NumAllocatableRegisters(); ++i) {
+      DwVfpRegister reg = DwVfpRegister::FromAllocationIndex(i);
+      int src_offset = double_regs_offset + i * kDoubleSize;
+      __ vldr(reg, r1, src_offset);
+    }
+  }
+
   // Push state, pc, and continuation from the last output frame.
   if (type() != OSR) {
     __ ldr(r6, MemOperand(r2, FrameDescription::state_offset()));
     __ push(r6);
   }
 
   __ ldr(r6, MemOperand(r2, FrameDescription::pc_offset()));
   __ push(r6);
   __ ldr(r6, MemOperand(r2, FrameDescription::continuation_offset()));
   __ push(r6);
@@ skipping 37 matching lines @@
     __ push(ip);
     __ b(&done);
     ASSERT(masm()->pc_offset() - start == table_entry_size_);
   }
   __ bind(&done);
 }
 
 #undef __
 
 } }  // namespace v8::internal