Move stack check into AllocateStackSlots so the load delay can be...

src/arm/codegen-arm.cc

 // Copyright 2006-2009 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 158 matching lines @@
     frame_->Enter();
     // tos: code slot
 #ifdef DEBUG
     if (strlen(FLAG_stop_at) > 0 &&
         fun->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
       frame_->SpillAll();
       __ stop("stop-at");
     }
 #endif
 
-    // Allocate space for locals and initialize them.
+    // Allocate space for locals and initialize them.  This also checks
+    // for stack overflow.
     frame_->AllocateStackSlots();
     // Initialize the function return target after the locals are set
     // up, because it needs the expected frame height from the frame.
     function_return_.set_direction(JumpTarget::BIDIRECTIONAL);
     function_return_is_shadowed_ = false;
 
     VirtualFrame::SpilledScope spilled_scope;
     if (scope_->num_heap_slots() > 0) {
       // Allocate local context.
       // Get outer context and create a new context based on it.
@@ skipping 81 matching lines @@
       ProcessDeclarations(scope_->declarations());
       // Bail out if a stack-overflow exception occurred when processing
       // declarations.
       if (HasStackOverflow()) return;
     }
 
     if (FLAG_trace) {
       frame_->CallRuntime(Runtime::kTraceEnter, 0);
       // Ignore the return value.
     }
-    CheckStack();
 
     // Compile the body of the function in a vanilla state. Don't
     // bother compiling all the code if the scope has an illegal
     // redeclaration.
     if (!scope_->HasIllegalRedeclaration()) {
       Comment cmnt(masm_, "[ function body");
 #ifdef DEBUG
       bool is_builtin = Bootstrapper::IsActive();
       bool should_trace =
           is_builtin ? FLAG_trace_builtin_calls : FLAG_trace_calls;
@@ skipping 812 matching lines @@
   target->Branch(cc);
   cc_reg_ = al;
 }
 
 
 void CodeGenerator::CheckStack() {
   VirtualFrame::SpilledScope spilled_scope;
   if (FLAG_check_stack) {
     Comment cmnt(masm_, "[ check stack");
     __ LoadRoot(ip, Heap::kStackLimitRootIndex);
-    __ cmp(sp, Operand(ip));
+    // Put the lr setup insn in the delay slot.  The '4' is added to the

[Mads Ager (chromium), 2009/08/31 09:33:10]

insn -> instruction

+    // implicit 8 that always apples to operations with pc and gives a return

[Mads Ager (chromium), 2009/08/31 09:33:10]

applies?

+    // address 12 bytes down.
+    masm_->add(lr, pc, Operand(4));

[Mads Ager (chromium), 2009/08/31 09:33:10]

Is this just 4 bytes or is it really kPointerSize?

[Erik Corry, 2009/08/31 11:07:57]

Fixed to be sizeof(Instr).  If we move to thumb2 we shall have to revisit this
since thumb2 has variable length instructions.

+    masm_->cmp(sp, Operand(ip));
     StackCheckStub stub;
-    __ CallStub(&stub, lo);  // Call the stub if lower.
+    // Call the stub if lower.
+    masm_->mov(pc,
+               Operand(reinterpret_cast<intptr_t>(stub.GetCode().location()),
+                       RelocInfo::CODE_TARGET),
+               LeaveCC,
+               lo);
   }
 }
 
 
 void CodeGenerator::VisitStatements(ZoneList<Statement*>* statements) {
 #ifdef DEBUG
   int original_height = frame_->height();
 #endif
   VirtualFrame::SpilledScope spilled_scope;
   for (int i = 0; frame_ != NULL && i < statements->length(); i++) {
@@ skipping 5130 matching lines @@
 int CompareStub::MinorKey() {
   // Encode the two parameters in a unique 16 bit value.
   ASSERT(static_cast<unsigned>(cc_) >> 28 < (1 << 15));
   return (static_cast<unsigned>(cc_) >> 27) | (strict_ ? 1 : 0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal