From 5b1faade55d22a3b29171512b562d7a5f299cd19 Mon Sep 17 00:00:00 2001
From: "lrn@chromium.org"
 <lrn@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Mon, 9 Nov 2009 13:22:38 +0000
Subject: [PATCH] Fast-compiler: Added trivial implementations of while and
 do/while.

Review URL: http://codereview.chromium.org/372055


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3250 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/compiler.cc     | 12 ++++++++++--
 src/fast-codegen.cc | 45 +++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/src/compiler.cc b/src/compiler.cc
index 22384bf8d1..75060b0a7b 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -708,12 +708,20 @@ void CodeGenSelector::VisitSwitchStatement(SwitchStatement* stmt) {
 
 
 void CodeGenSelector::VisitDoWhileStatement(DoWhileStatement* stmt) {
-  BAILOUT("DoWhileStatement");
+  // We do not handle loops with breaks or continue statements in their
+  // body.  We will bailout when we hit those statements in the body.
+  ProcessExpression(stmt->cond(), Expression::kTest);
+  CHECK_BAILOUT;
+  Visit(stmt->body());
 }
 
 
 void CodeGenSelector::VisitWhileStatement(WhileStatement* stmt) {
-  BAILOUT("WhileStatement");
+  // We do not handle loops with breaks or continue statements in their
+  // body.  We will bailout when we hit those statements in the body.
+  ProcessExpression(stmt->cond(), Expression::kTest);
+  CHECK_BAILOUT;
+  Visit(stmt->body());
 }
 
 
diff --git a/src/fast-codegen.cc b/src/fast-codegen.cc
index f5a6157de9..bb5ed8ab08 100644
--- a/src/fast-codegen.cc
+++ b/src/fast-codegen.cc
@@ -304,12 +304,53 @@ void FastCodeGenerator::VisitSwitchStatement(SwitchStatement* stmt) {
 
 
 void FastCodeGenerator::VisitDoWhileStatement(DoWhileStatement* stmt) {
-  UNREACHABLE();
+  Comment cmnt(masm_, "[ DoWhileStatement");
+  increment_loop_depth();
+  Label body, exit;
+
+  // Emit the test at the bottom of the loop.
+  __ bind(&body);
+  Visit(stmt->body());
+
+  // 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());
+
+  __ bind(&exit);
+
+  decrement_loop_depth();
 }
 
 
 void FastCodeGenerator::VisitWhileStatement(WhileStatement* stmt) {
-  UNREACHABLE();
+  Comment cmnt(masm_, "[ WhileStatement");
+  increment_loop_depth();
+  Label test, body, exit;
+
+  // Emit the test at the bottom of the loop.
+  __ jmp(&test);
+
+  __ bind(&body);
+  Visit(stmt->body());
+
+  __ bind(&test);
+  // 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());
+
+  __ bind(&exit);
+
+  decrement_loop_depth();
 }