Add tracking of loop nesting to ARM code.

src/arm/codegen-arm.cc

Index: src/arm/codegen-arm.cc
===================================================================
--- src/arm/codegen-arm.cc	(revision 4427)
+++ src/arm/codegen-arm.cc	(working copy)
@@ -133,6 +133,7 @@
       allocator_(NULL),
       cc_reg_(al),
       state_(NULL),
+      loop_nesting_(0),
       function_return_is_shadowed_(false) {
 }
 
@@ -156,6 +157,10 @@
   ASSERT(frame_ == NULL);
   frame_ = new VirtualFrame();
   cc_reg_ = al;
+
+  // Adjust for function-level loop nesting.
+  loop_nesting_ += info->loop_nesting();
+
   {
     CodeGenState state(this);
 
@@ -380,9 +385,13 @@
               masm_->InstructionsGeneratedSince(&check_exit_codesize));
   }
 
+  // Adjust for function-level loop nesting.
+  loop_nesting_ -= info->loop_nesting();

[Erik Corry, 2010/04/15 12:46:18]

Seems simpler to ASSERT that loop_nesting() == info->loop_nesting and then set
loop_nesting_ to 0.

+
   // Code generation state must be reset.
   ASSERT(!has_cc());
   ASSERT(state_ == NULL);
+  ASSERT(loop_nesting() == 0);
   ASSERT(!function_return_is_shadowed_);
   function_return_.Unuse();
   DeleteFrame();
@@ -1885,6 +1894,7 @@
   CodeForStatementPosition(node);
   node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
   JumpTarget body(JumpTarget::BIDIRECTIONAL);
+  IncrementLoopNesting();
 
   // Label the top of the loop for the backward CFG edge.  If the test
   // is always true we can use the continue target, and if the test is
@@ -1945,6 +1955,7 @@
   if (node->break_target()->is_linked()) {
     node->break_target()->Bind();
   }
+  DecrementLoopNesting();
   ASSERT(!has_valid_frame() || frame_->height() == original_height);
 }
 
@@ -1963,6 +1974,7 @@
   if (info == ALWAYS_FALSE) return;
 
   node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
+  IncrementLoopNesting();
 
   // Label the top of the loop with the continue target for the backward
   // CFG edge.
@@ -1994,6 +2006,7 @@
   if (node->break_target()->is_linked()) {
     node->break_target()->Bind();
   }
+  DecrementLoopNesting();
   ASSERT(!has_valid_frame() || frame_->height() == original_height);
 }
 
@@ -2015,6 +2028,7 @@
   if (info == ALWAYS_FALSE) return;
 
   node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
+  IncrementLoopNesting();
 
   // If there is no update statement, label the top of the loop with the
   // continue target, otherwise with the loop target.
@@ -2069,6 +2083,7 @@
   if (node->break_target()->is_linked()) {
     node->break_target()->Bind();
   }
+  DecrementLoopNesting();
   ASSERT(!has_valid_frame() || frame_->height() == original_height);
 }