Split the AST LoopStatement type into separate types for do/while,...

src/x64/codegen-x64.cc

Index: src/x64/codegen-x64.cc
===================================================================
--- src/x64/codegen-x64.cc	(revision 3045)
+++ src/x64/codegen-x64.cc	(working copy)
@@ -1292,288 +1292,335 @@
 }
 
 
-void CodeGenerator::VisitLoopStatement(LoopStatement* node) {
+void CodeGenerator::VisitDoWhileStatement(DoWhileStatement* node) {
   ASSERT(!in_spilled_code());
-  Comment cmnt(masm_, "[ LoopStatement");
+  Comment cmnt(masm_, "[ DoWhileStatement");
   CodeForStatementPosition(node);
   node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
+  JumpTarget body(JumpTarget::BIDIRECTIONAL);
+  IncrementLoopNesting();
 
-  // Simple condition analysis.  ALWAYS_TRUE and ALWAYS_FALSE represent a
-  // known result for the test expression, with no side effects.
-  enum { ALWAYS_TRUE, ALWAYS_FALSE, DONT_KNOW } info = DONT_KNOW;
-  if (node->cond() == NULL) {
-    ASSERT(node->type() == LoopStatement::FOR_LOOP);
-    info = ALWAYS_TRUE;
-  } else {
-    Literal* lit = node->cond()->AsLiteral();
-    if (lit != NULL) {
-      if (lit->IsTrue()) {
-        info = ALWAYS_TRUE;
-      } else if (lit->IsFalse()) {
-        info = ALWAYS_FALSE;
+  ConditionAnalysis info = AnalyzeCondition(node->cond());
+  // Label the top of the loop for the backward jump if necessary.
+  switch (info) {
+    case ALWAYS_TRUE:
+      // Use the continue target.
+      node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
+      node->continue_target()->Bind();
+      break;
+    case ALWAYS_FALSE:
+      // No need to label it.
+      node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
+      break;
+    case DONT_KNOW:
+      // Continue is the test, so use the backward body target.
+      node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
+      body.Bind();
+      break;
+  }
+
+  CheckStack();  // TODO(1222600): ignore if body contains calls.
+  Visit(node->body());
+
+  // Compile the test.
+  switch (info) {
+    case ALWAYS_TRUE:
+      // If control flow can fall off the end of the body, jump back
+      // to the top and bind the break target at the exit.
+      if (has_valid_frame()) {
+        node->continue_target()->Jump();
       }
-    }
+      if (node->break_target()->is_linked()) {
+        node->break_target()->Bind();
+      }
+      break;
+    case ALWAYS_FALSE:
+      // We may have had continues or breaks in the body.
+      if (node->continue_target()->is_linked()) {
+        node->continue_target()->Bind();
+      }
+      if (node->break_target()->is_linked()) {
+        node->break_target()->Bind();
+      }
+      break;
+    case DONT_KNOW:
+      // We have to compile the test expression if it can be reached by
+      // control flow falling out of the body or via continue.
+      if (node->continue_target()->is_linked()) {
+        node->continue_target()->Bind();
+      }
+      if (has_valid_frame()) {
+        ControlDestination dest(&body, node->break_target(), false);
+        LoadCondition(node->cond(), NOT_INSIDE_TYPEOF, &dest, true);
+      }
+      if (node->break_target()->is_linked()) {
+        node->break_target()->Bind();
+      }
+      break;
   }
 
-  switch (node->type()) {
-    case LoopStatement::DO_LOOP: {
-      JumpTarget body(JumpTarget::BIDIRECTIONAL);
-      IncrementLoopNesting();
+  DecrementLoopNesting();
+  node->continue_target()->Unuse();
+  node->break_target()->Unuse();
+}
 
-      // Label the top of the loop for the backward jump if necessary.
-      if (info == ALWAYS_TRUE) {
-        // Use the continue target.
+
+void CodeGenerator::VisitWhileStatement(WhileStatement* node) {
+  ASSERT(!in_spilled_code());
+  Comment cmnt(masm_, "[ WhileStatement");
+  CodeForStatementPosition(node);
+
+  // If the condition is always false and has no side effects, we do not
+  // need to compile anything.
+  ConditionAnalysis info = AnalyzeCondition(node->cond());
+  if (info == ALWAYS_FALSE) return;
+
+  // Do not duplicate conditions that may have function literal
+  // subexpressions.  This can cause us to compile the function literal
+  // twice.
+  bool test_at_bottom = !node->may_have_function_literal();
+  node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
+  IncrementLoopNesting();
+  JumpTarget body;
+  if (test_at_bottom) {
+    body.set_direction(JumpTarget::BIDIRECTIONAL);
+  }
+
+  // Based on the condition analysis, compile the test as necessary.
+  switch (info) {
+    case ALWAYS_TRUE:
+      // We will not compile the test expression.  Label the top of the
+      // loop with the continue target.
+      node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
+      node->continue_target()->Bind();
+      break;
+    case DONT_KNOW: {
+      if (test_at_bottom) {
+        // Continue is the test at the bottom, no need to label the test
+        // at the top.  The body is a backward target.
+        node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
+      } else {
+        // Label the test at the top as the continue target.  The body
+        // is a forward-only target.
         node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
         node->continue_target()->Bind();
-      } else if (info == ALWAYS_FALSE) {
-        // No need to label it.
-        node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
-      } else {
-        // Continue is the test, so use the backward body target.
-        ASSERT(info == DONT_KNOW);
-        node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
-        body.Bind();
       }
+      // Compile the test with the body as the true target and preferred
+      // fall-through and with the break target as the false target.
+      ControlDestination dest(&body, node->break_target(), true);
+      LoadCondition(node->cond(), NOT_INSIDE_TYPEOF, &dest, true);
 
-      CheckStack();  // TODO(1222600): ignore if body contains calls.
-      Visit(node->body());
-
-      // Compile the test.
-      if (info == ALWAYS_TRUE) {
-        // If control flow can fall off the end of the body, jump back
-        // to the top and bind the break target at the exit.
-        if (has_valid_frame()) {
-          node->continue_target()->Jump();
+      if (dest.false_was_fall_through()) {
+        // If we got the break target as fall-through, the test may have
+        // been unconditionally false (if there are no jumps to the
+        // body).
+        if (!body.is_linked()) {
+          DecrementLoopNesting();
+          return;
         }
-        if (node->break_target()->is_linked()) {
-          node->break_target()->Bind();
-        }
 
-      } else if (info == ALWAYS_FALSE) {
-        // We may have had continues or breaks in the body.
-        if (node->continue_target()->is_linked()) {
-          node->continue_target()->Bind();
-        }
-        if (node->break_target()->is_linked()) {
-          node->break_target()->Bind();
-        }
+        // Otherwise, jump around the body on the fall through and then
+        // bind the body target.
+        node->break_target()->Unuse();
+        node->break_target()->Jump();
+        body.Bind();
+      }
+      break;
+    }
+    case ALWAYS_FALSE:
+      UNREACHABLE();
+      break;
+  }
 
-      } else {
-        ASSERT(info == DONT_KNOW);
-        // We have to compile the test expression if it can be reached by
-        // control flow falling out of the body or via continue.
+  CheckStack();  // TODO(1222600): ignore if body contains calls.
+  Visit(node->body());
+
+  // Based on the condition analysis, compile the backward jump as
+  // necessary.
+  switch (info) {
+    case ALWAYS_TRUE:
+      // The loop body has been labeled with the continue target.
+      if (has_valid_frame()) {
+        node->continue_target()->Jump();
+      }
+      break;
+    case DONT_KNOW:
+      if (test_at_bottom) {
+        // If we have chosen to recompile the test at the bottom,
+        // then it is the continue target.
         if (node->continue_target()->is_linked()) {
           node->continue_target()->Bind();
         }
         if (has_valid_frame()) {
+          // The break target is the fall-through (body is a backward
+          // jump from here and thus an invalid fall-through).
           ControlDestination dest(&body, node->break_target(), false);
           LoadCondition(node->cond(), NOT_INSIDE_TYPEOF, &dest, true);
         }
-        if (node->break_target()->is_linked()) {
-          node->break_target()->Bind();
+      } else {
+        // If we have chosen not to recompile the test at the
+        // bottom, jump back to the one at the top.
+        if (has_valid_frame()) {
+          node->continue_target()->Jump();
         }
       }
       break;
-    }
+    case ALWAYS_FALSE:
+      UNREACHABLE();
+      break;
+  }
 
-    case LoopStatement::WHILE_LOOP: {
-      // Do not duplicate conditions that may have function literal
-      // subexpressions.  This can cause us to compile the function
-      // literal twice.
-      bool test_at_bottom = !node->may_have_function_literal();
+  // The break target may be already bound (by the condition), or there
+  // may not be a valid frame.  Bind it only if needed.
+  if (node->break_target()->is_linked()) {
+    node->break_target()->Bind();
+  }
+  DecrementLoopNesting();
+}
 
-      IncrementLoopNesting();
 
-      // If the condition is always false and has no side effects, we
-      // do not need to compile anything.
-      if (info == ALWAYS_FALSE) break;
+void CodeGenerator::VisitForStatement(ForStatement* node) {
+  ASSERT(!in_spilled_code());
+  Comment cmnt(masm_, "[ ForStatement");
+  CodeForStatementPosition(node);
 
-      JumpTarget body;
-      if (test_at_bottom) {
-        body.set_direction(JumpTarget::BIDIRECTIONAL);
-      }
+  // Compile the init expression if present.
+  if (node->init() != NULL) {
+    Visit(node->init());
+  }
 
-      // Based on the condition analysis, compile the test as necessary.
-      if (info == ALWAYS_TRUE) {
-        // We will not compile the test expression.  Label the top of
-        // the loop with the continue target.
+  // If the condition is always false and has no side effects, we do not
+  // need to compile anything else.
+  ConditionAnalysis info = AnalyzeCondition(node->cond());
+  if (info == ALWAYS_FALSE) return;
+
+  // Do not duplicate conditions that may have function literal
+  // subexpressions.  This can cause us to compile the function literal
+  // twice.
+  bool test_at_bottom = !node->may_have_function_literal();
+  node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
+  IncrementLoopNesting();
+
+  // Target for backward edge if no test at the bottom, otherwise
+  // unused.
+  JumpTarget loop(JumpTarget::BIDIRECTIONAL);
+
+  // Target for backward edge if there is a test at the bottom,
+  // otherwise used as target for test at the top.
+  JumpTarget body;
+  if (test_at_bottom) {
+    body.set_direction(JumpTarget::BIDIRECTIONAL);
+  }
+
+  // Based on the condition analysis, compile the test as necessary.
+  switch (info) {
+    case ALWAYS_TRUE:
+      // We will not compile the test expression.  Label the top of the
+      // loop.
+      if (node->next() == NULL) {
+        // Use the continue target if there is no update expression.
         node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
         node->continue_target()->Bind();
       } else {
-        ASSERT(info == DONT_KNOW);  // ALWAYS_FALSE cannot reach here.
-        if (test_at_bottom) {
-          // Continue is the test at the bottom, no need to label the
-          // test at the top.  The body is a backward target.
-          node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
-        } else {
-          // Label the test at the top as the continue target.  The
-          // body is a forward-only target.
-          node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
-          node->continue_target()->Bind();
-        }
-        // Compile the test with the body as the true target and
-        // preferred fall-through and with the break target as the
-        // false target.
-        ControlDestination dest(&body, node->break_target(), true);
-        LoadCondition(node->cond(), NOT_INSIDE_TYPEOF, &dest, true);
-
-        if (dest.false_was_fall_through()) {
-          // If we got the break target as fall-through, the test may
-          // have been unconditionally false (if there are no jumps to
-          // the body).
-          if (!body.is_linked()) break;
-
-          // Otherwise, jump around the body on the fall through and
-          // then bind the body target.
-          node->break_target()->Unuse();
-          node->break_target()->Jump();
-          body.Bind();
-        }
+        // Otherwise use the backward loop target.
+        node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
+        loop.Bind();
       }
+      break;
+    case DONT_KNOW: {
+      if (test_at_bottom) {
+        // Continue is either the update expression or the test at the
+        // bottom, no need to label the test at the top.
+        node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
+      } else if (node->next() == NULL) {
+        // We are not recompiling the test at the bottom and there is no
+        // update expression.
+        node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
+        node->continue_target()->Bind();
+      } else {
+        // We are not recompiling the test at the bottom and there is an
+        // update expression.
+        node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
+        loop.Bind();
+      }
 
-      CheckStack();  // TODO(1222600): ignore if body contains calls.
-      Visit(node->body());
+      // Compile the test with the body as the true target and preferred
+      // fall-through and with the break target as the false target.
+      ControlDestination dest(&body, node->break_target(), true);
+      LoadCondition(node->cond(), NOT_INSIDE_TYPEOF, &dest, true);
 
-      // Based on the condition analysis, compile the backward jump as
-      // necessary.
-      if (info == ALWAYS_TRUE) {
-        // The loop body has been labeled with the continue target.
-        if (has_valid_frame()) {
-          node->continue_target()->Jump();
+      if (dest.false_was_fall_through()) {
+        // If we got the break target as fall-through, the test may have
+        // been unconditionally false (if there are no jumps to the
+        // body).
+        if (!body.is_linked()) {
+          DecrementLoopNesting();
+          return;
         }
-      } else {
-        ASSERT(info == DONT_KNOW);  // ALWAYS_FALSE cannot reach here.
-        if (test_at_bottom) {
-          // If we have chosen to recompile the test at the bottom,
-          // then it is the continue target.
-          if (node->continue_target()->is_linked()) {
-            node->continue_target()->Bind();
-          }
-          if (has_valid_frame()) {
-            // The break target is the fall-through (body is a backward
-            // jump from here and thus an invalid fall-through).
-            ControlDestination dest(&body, node->break_target(), false);
-            LoadCondition(node->cond(), NOT_INSIDE_TYPEOF, &dest, true);
-          }
-        } else {
-          // If we have chosen not to recompile the test at the
-          // bottom, jump back to the one at the top.
-          if (has_valid_frame()) {
-            node->continue_target()->Jump();
-          }
-        }
-      }
 
-      // The break target may be already bound (by the condition), or
-      // there may not be a valid frame.  Bind it only if needed.
-      if (node->break_target()->is_linked()) {
-        node->break_target()->Bind();
+        // Otherwise, jump around the body on the fall through and then
+        // bind the body target.
+        node->break_target()->Unuse();
+        node->break_target()->Jump();
+        body.Bind();
       }
       break;
     }
+    case ALWAYS_FALSE:
+      UNREACHABLE();
+      break;
+  }
 
-    case LoopStatement::FOR_LOOP: {
-      // Do not duplicate conditions that may have function literal
-      // subexpressions.  This can cause us to compile the function
-      // literal twice.
-      bool test_at_bottom = !node->may_have_function_literal();
+  CheckStack();  // TODO(1222600): ignore if body contains calls.
+  Visit(node->body());
 
-      // Compile the init expression if present.
-      if (node->init() != NULL) {
-        Visit(node->init());
-      }
+  // If there is an update expression, compile it if necessary.
+  if (node->next() != NULL) {
+    if (node->continue_target()->is_linked()) {
+      node->continue_target()->Bind();
+    }
 
-      IncrementLoopNesting();
+    // Control can reach the update by falling out of the body or by a
+    // continue.
+    if (has_valid_frame()) {
+      // Record the source position of the statement as this code which
+      // is after the code for the body actually belongs to the loop
+      // statement and not the body.
+      CodeForStatementPosition(node);
+      Visit(node->next());
+    }
+  }
 
-      // If the condition is always false and has no side effects, we
-      // do not need to compile anything else.
-      if (info == ALWAYS_FALSE) break;
-
-      // Target for backward edge if no test at the bottom, otherwise
-      // unused.
-      JumpTarget loop(JumpTarget::BIDIRECTIONAL);
-
-      // Target for backward edge if there is a test at the bottom,
-      // otherwise used as target for test at the top.
-      JumpTarget body;
-      if (test_at_bottom) {
-        body.set_direction(JumpTarget::BIDIRECTIONAL);
-      }
-
-      // Based on the condition analysis, compile the test as necessary.
-      if (info == ALWAYS_TRUE) {
-        // We will not compile the test expression.  Label the top of
-        // the loop.
+  // Based on the condition analysis, compile the backward jump as
+  // necessary.
+  switch (info) {
+    case ALWAYS_TRUE:
+      if (has_valid_frame()) {
         if (node->next() == NULL) {
-          // Use the continue target if there is no update expression.
-          node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
-          node->continue_target()->Bind();
+          node->continue_target()->Jump();
         } else {
-          // Otherwise use the backward loop target.
-          node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
-          loop.Bind();
+          loop.Jump();
         }
-      } else {
-        ASSERT(info == DONT_KNOW);
-        if (test_at_bottom) {
-          // Continue is either the update expression or the test at
-          // the bottom, no need to label the test at the top.
-          node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
-        } else if (node->next() == NULL) {
-          // We are not recompiling the test at the bottom and there
-          // is no update expression.
-          node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
-          node->continue_target()->Bind();
-        } else {
-          // We are not recompiling the test at the bottom and there
-          // is an update expression.
-          node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
-          loop.Bind();
-        }
-
-        // Compile the test with the body as the true target and
-        // preferred fall-through and with the break target as the
-        // false target.
-        ControlDestination dest(&body, node->break_target(), true);
-        LoadCondition(node->cond(), NOT_INSIDE_TYPEOF, &dest, true);
-
-        if (dest.false_was_fall_through()) {
-          // If we got the break target as fall-through, the test may
-          // have been unconditionally false (if there are no jumps to
-          // the body).
-          if (!body.is_linked()) break;
-
-          // Otherwise, jump around the body on the fall through and
-          // then bind the body target.
-          node->break_target()->Unuse();
-          node->break_target()->Jump();
-          body.Bind();
-        }
       }
-
-      CheckStack();  // TODO(1222600): ignore if body contains calls.
-      Visit(node->body());
-
-      // If there is an update expression, compile it if necessary.
-      if (node->next() != NULL) {
+      break;
+    case DONT_KNOW:
+      if (test_at_bottom) {
         if (node->continue_target()->is_linked()) {
+          // We can have dangling jumps to the continue target if there
+          // was no update expression.
           node->continue_target()->Bind();
         }
-
-        // Control can reach the update by falling out of the body or
-        // by a continue.
+        // Control can reach the test at the bottom by falling out of
+        // the body, by a continue in the body, or from the update
+        // expression.
         if (has_valid_frame()) {
-          // Record the source position of the statement as this code
-          // which is after the code for the body actually belongs to
-          // the loop statement and not the body.
-          CodeForStatementPosition(node);
-          Visit(node->next());
+          // The break target is the fall-through (body is a backward
+          // jump from here).
+          ControlDestination dest(&body, node->break_target(), false);
+          LoadCondition(node->cond(), NOT_INSIDE_TYPEOF, &dest, true);
         }
-      }
-
-      // Based on the condition analysis, compile the backward jump as
-      // necessary.
-      if (info == ALWAYS_TRUE) {
+      } else {
+        // Otherwise, jump back to the test at the top.
         if (has_valid_frame()) {
           if (node->next() == NULL) {
             node->continue_target()->Jump();
@@ -1581,47 +1628,19 @@
             loop.Jump();
           }
         }
-      } else {
-        ASSERT(info == DONT_KNOW);  // ALWAYS_FALSE cannot reach here.
-        if (test_at_bottom) {
-          if (node->continue_target()->is_linked()) {
-            // We can have dangling jumps to the continue target if
-            // there was no update expression.
-            node->continue_target()->Bind();
-          }
-          // Control can reach the test at the bottom by falling out
-          // of the body, by a continue in the body, or from the
-          // update expression.
-          if (has_valid_frame()) {
-            // The break target is the fall-through (body is a
-            // backward jump from here).
-            ControlDestination dest(&body, node->break_target(), false);
-            LoadCondition(node->cond(), NOT_INSIDE_TYPEOF, &dest, true);
-          }
-        } else {
-          // Otherwise, jump back to the test at the top.
-          if (has_valid_frame()) {
-            if (node->next() == NULL) {
-              node->continue_target()->Jump();
-            } else {
-              loop.Jump();
-            }
-          }
-        }
       }
-
-      // The break target may be already bound (by the condition), or
-      // there may not be a valid frame.  Bind it only if needed.
-      if (node->break_target()->is_linked()) {
-        node->break_target()->Bind();
-      }
       break;
-    }
+    case ALWAYS_FALSE:
+      UNREACHABLE();
+      break;
   }
 
+  // The break target may be already bound (by the condition), or there
+  // may not be a valid frame.  Bind it only if needed.
+  if (node->break_target()->is_linked()) {
+    node->break_target()->Bind();
+  }
   DecrementLoopNesting();
-  node->continue_target()->Unuse();
-  node->break_target()->Unuse();
 }
 
 
@@ -1813,10 +1832,10 @@
   node->break_target()->Unuse();
 }
 
-void CodeGenerator::VisitTryCatch(TryCatch* node) {
+void CodeGenerator::VisitTryCatchStatement(TryCatchStatement* node) {
   ASSERT(!in_spilled_code());
   VirtualFrame::SpilledScope spilled_scope;
-  Comment cmnt(masm_, "[ TryCatch");
+  Comment cmnt(masm_, "[ TryCatchStatement");
   CodeForStatementPosition(node);
 
   JumpTarget try_block;
@@ -1952,10 +1971,10 @@
 }
 
 
-void CodeGenerator::VisitTryFinally(TryFinally* node) {
+void CodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* node) {
   ASSERT(!in_spilled_code());
   VirtualFrame::SpilledScope spilled_scope;
-  Comment cmnt(masm_, "[ TryFinally");
+  Comment cmnt(masm_, "[ TryFinallyStatement");
   CodeForStatementPosition(node);
 
   // State: Used to keep track of reason for entering the finally