From e4f5b74dd1ce0d87fb0237f96d0aca5dc7f043c4 Mon Sep 17 00:00:00 2001
From: "whesse@chromium.org"
 <whesse@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Mon, 2 Nov 2009 08:44:19 +0000
Subject: [PATCH] Add conditional expressions (ternary choice operator) to fast
 compiler. Review URL: http://codereview.chromium.org/340058

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3192 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/compiler.cc     |  6 +++++-
 src/fast-codegen.cc | 31 ++++++++++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/compiler.cc b/src/compiler.cc
index 63824f566f..4ff6bc65d8 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -625,7 +625,11 @@ void CodeGenSelector::VisitFunctionBoilerplateLiteral(
 
 
 void CodeGenSelector::VisitConditional(Conditional* expr) {
-  BAILOUT("Conditional");
+  ProcessExpression(expr->condition(), Expression::kTest);
+  CHECK_BAILOUT;
+  ProcessExpression(expr->then_expression(), context_);
+  CHECK_BAILOUT;
+  ProcessExpression(expr->else_expression(), context_);
 }
 
 
diff --git a/src/fast-codegen.cc b/src/fast-codegen.cc
index 411ae0c484..7d7b21fdc5 100644
--- a/src/fast-codegen.cc
+++ b/src/fast-codegen.cc
@@ -380,7 +380,36 @@ void FastCodeGenerator::VisitFunctionBoilerplateLiteral(
 
 
 void FastCodeGenerator::VisitConditional(Conditional* expr) {
-  UNREACHABLE();
+  ASSERT_EQ(Expression::kTest, expr->condition()->context());
+  ASSERT_EQ(expr->context(), expr->then_expression()->context());
+  ASSERT_EQ(expr->context(), expr->else_expression()->context());
+
+
+  Label true_case, false_case, done;
+  Label* saved_true = true_label_;
+  Label* saved_false = false_label_;
+
+  true_label_ = &true_case;
+  false_label_ = &false_case;
+  Visit(expr->condition());
+  true_label_ = saved_true;
+  false_label_ = saved_false;
+
+  __ bind(&true_case);
+  Visit(expr->then_expression());
+  // If control flow falls through Visit, jump to done.
+  if (expr->context() == Expression::kEffect ||
+      expr->context() == Expression::kValue) {
+    __ jmp(&done);
+  }
+
+  __ bind(&false_case);
+  Visit(expr->else_expression());
+  // If control flow falls through Visit, merge it with true case here.
+  if (expr->context() == Expression::kEffect ||
+      expr->context() == Expression::kValue) {
+    __ bind(&done);
+  }
 }