[turbofan] Support inlining of unguarded loops.

test/cctest/compiler/test-run-inlining.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "test/cctest/compiler/function-tester.h"
 
 #if V8_TURBOFAN_TARGET
 
@@ skipping 302 matching lines @@
       "  function bar(s,t) { return foo(foo(s,t),t); };"
       "  return bar;"
       "})();",
       kInlineFlags);
 
   InstallAssertInlineCountHelper(CcTest::isolate());
   T.CheckCall(T.Val(0.0), T.Val(11), T.Val(4));
 }
 
 
+TEST(InlineLoopUnguardedEmpty) {
+  FLAG_turbo_deoptimization = true;
+  FunctionTester T(
+      "(function () {"
+      "  function foo(s) { AssertInlineCount(2); while (s); return s; };"
+      "  function bar(s, t) { return foo(s); };"
+      "  return bar;"
+      "})();",
+      kInlineFlags);
+
+  InstallAssertInlineCountHelper(CcTest::isolate());
+  T.CheckCall(T.Val(0.0), T.Val(0.0), T.Val(4));
+}
+
+
+TEST(InlineLoopUnguardedOnce) {
+  FLAG_turbo_deoptimization = true;
+  FunctionTester T(
+      "(function () {"
+      "  function foo(s) { AssertInlineCount(2); while (s) {"
+      "                    s = s - 1; }; return s; };"
+      "  function bar(s, t) { return foo(s); };"
+      "  return bar;"
+      "})();",
+      kInlineFlags);
+
+  InstallAssertInlineCountHelper(CcTest::isolate());
+  T.CheckCall(T.Val(0.0), T.Val(0.0), T.Val(4));
+}
+
+
+TEST(InlineLoopUnguardedTwice) {
+  FLAG_turbo_deoptimization = true;
+  FunctionTester T(
+      "(function () {"
+      "  function foo(s) { AssertInlineCount(2); while (s > 0) {"
+      "                    s = s - 1; }; return s; };"
+      "  function bar(s,t) { return foo(foo(s,t),t); };"
+      "  return bar;"
+      "})();",
+      kInlineFlags);
+
+  InstallAssertInlineCountHelper(CcTest::isolate());
+  T.CheckCall(T.Val(0.0), T.Val(0.0), T.Val(4));
+}
+
+
 TEST(InlineStrictIntoNonStrict) {
   FLAG_turbo_deoptimization = true;
   FunctionTester T(
       "(function () {"
       "  var x = Object.create({}, { y: { value:42, writable:false } });"
       "  function foo(s) { 'use strict';"
       "                     x.y = 9; };"
       "  function bar(s,t) { return foo(s); };"
       "  return bar;"
       "})();",
@@ skipping 98 matching lines @@
       "  function bar() { return foo(13, 14, 15); };"
       "  return bar;"
       "})();",
       kInlineFlags);
 
   InstallAssertInlineCountHelper(CcTest::isolate());
   T.CheckCall(T.true_value(), T.Val(12), T.Val(14));
 }
 
 #endif  // V8_TURBOFAN_TARGET