Add support for for loops to the toplevel code generator.

Review URL: http://codereview.chromium.org/340059

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3199 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler.cc

@@ -587,7 +587,21 @@ void CodeGenSelector::VisitWhileStatement(WhileStatement* stmt) {
 
 
 void CodeGenSelector::VisitForStatement(ForStatement* stmt) {
-  BAILOUT("ForStatement");
+  // We do not handle loops with breaks or continue statements in their
+  // body.  We will bailout when we hit those statements in the body.
+  if (stmt->init() != NULL) {
+    Visit(stmt->init());
+    CHECK_BAILOUT;
+  }
+  if (stmt->cond() != NULL) {
+    ProcessExpression(stmt->cond(), Expression::kTest);
+    CHECK_BAILOUT;
+  }
+  Visit(stmt->body());
+  if (stmt->next() != NULL) {
+    CHECK_BAILOUT;
+    Visit(stmt->next());
+  }
 }
 
 

src/fast-codegen.cc

@@ -298,6 +298,7 @@ void FastCodeGenerator::VisitIfStatement(IfStatement* stmt) {
   // Do not worry about optimizing for empty then or else bodies.
   true_label_ = &then_part;
   false_label_ = &else_part;
+  ASSERT(stmt->condition()->context() == Expression::kTest);
   Visit(stmt->condition());
   true_label_ = NULL;
   false_label_ = NULL;
@@ -349,7 +350,33 @@ void FastCodeGenerator::VisitWhileStatement(WhileStatement* stmt) {
 
 
 void FastCodeGenerator::VisitForStatement(ForStatement* stmt) {
-  UNREACHABLE();
+  Label test, body, exit;
+  if (stmt->init() != NULL) Visit(stmt->init());
+
+  // Emit the test at the bottom of the loop (even if empty).
+  __ jmp(&test);
+  __ bind(&body);
+  Visit(stmt->body());
+  if (stmt->next() != NULL) Visit(stmt->next());
+
+  __ bind(&test);
+  if (stmt->cond() == NULL) {
+    // For an empty test jump to the top of the loop.
+    __ jmp(&body);
+  } else {
+    // We are not in an expression context because we have been compiling
+    // statements.  Set up a test expression context for the condition.
+    ASSERT_EQ(NULL, true_label_);
+    ASSERT_EQ(NULL, false_label_);
+    true_label_ = &body;
+    false_label_ = &exit;
+    ASSERT(stmt->cond()->context() == Expression::kTest);
+    Visit(stmt->cond());
+    true_label_ = NULL;
+    false_label_ = NULL;
+  }
+
+  __ bind(&exit);
 }
 
 

test/mjsunit/compiler/loops.js

+// Copyright 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Test compilation of loops.
+
+var n = 1;
+for (var i = 1; (6 - i); i++) {
+  // Factorial!
+  n = n * i;
+}
+assertEquals(120, n);