Add a mjsunit test to cover more paths in the ia32 code generator.

test/mjsunit/codegen_coverage.js

Index: test/mjsunit/codegen_coverage.js
===================================================================
--- test/mjsunit/codegen_coverage.js	(revision 0)
+++ test/mjsunit/codegen_coverage.js	(revision 0)
@@ -0,0 +1,91 @@
+// 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 the paths in the code generator where values in specific
+// registers get moved around so that the shift operation can use
+// register ECX on ia32 for the shift amount.  Other codegen coverage
+// tests should go here too.
+
+
+
+function identity(x) {
+  return x;
+}
+
+function cover_codegen_paths() {
+  var x = 1;
+  var a;  // Register EAX
+  var b;  // Register EBX
+  var c;  // Register ECX
+  var d;  // Register EDX
+  // Register ESI is already used.
+  var di;  // Register EDI
+
+  while (x == 1) {
+    x = identity(1);
+    a = x + 1;
+    c = x + 1;
+    d = x + 1;
+    b = x + 1;
+    di = x + 1;
+    // Locals are in the corresponding registers here.
+    assertEquals(c << a, 8);
+
+    x = identity(1);
+    a = x + 1;
+    c = x + 1;
+    d = x + 1;
+    b = x + 1;
+    di = x + 1;
+    // Locals are in the corresponding registers here.
+    assertEquals(a << c, 8);
+
+    x = identity(1);
+    a = x + 1;
+    c = x + 1;
+    d = x + 1;
+    b = x + 1;
+    di = x + 1;
+    // Locals are in the corresponding registers here.
+    c = 0; // Free register ecx.
+    assertEquals(a << d, 8);
+
+    x = identity(1);
+    a = x + 1;
+    c = x + 1;
+    d = x + 1;
+    b = x + 1;
+    di = x + 1;
+    // Locals are in the corresponding registers here.
+    b = 0; // Free register ebx.
+    assertEquals(a << d, 8);
+
+    x = 3;
+  }
+}
+
+cover_codegen_paths();