Simplify StringCharCodeAt in non-crankshaft codegen.

test/mjsunit/string-slices.js

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-// Flags: --string-slices --expose-externalize-string
+// Flags: --string-slices --expose-externalize-string --allow-natives-syntax

[Lasse Reichstein, 2011/11/09 12:48:11]

If string-slices is on by default now, we should remove the flag here.

 
 var s = 'abcdefghijklmn';
 assertEquals(s, s.substr());
 assertEquals(s, s.substr(0));
 assertEquals(s, s.substr('0'));
 assertEquals(s, s.substr(void 0));
 assertEquals(s, s.substr(null));
 assertEquals(s, s.substr(false));
 assertEquals(s, s.substr(0.9));
 assertEquals(s, s.substr({ valueOf: function() { return 0; } }));
@@ skipping 54 matching lines @@
     var w = Math.random() * 42;  // Allocate something new in new-space.
     assertEquals(j, z.length);
     for (var k = 0; k < j; k++) {
       assertEquals(x.charAt(i+k), z.charAt(k));
     }
   }
 }
 
 // Keep creating strings to to force allocation failure on substring creation.
 var x = "0123456789ABCDEF";
-x += x;  // 2^5
-x += x;
-x += x;
-x += x;
-x += x;
-x += x;  // 2^10
-x += x;
-x += x;
+for (var i = 0; i < 8; i++) x += x;
 var xl = x.length;
 var cache = [];
 for (var i = 0; i < 1000; i++) {
   var z = x.substring(i % xl);
   assertEquals(xl - (i % xl), z.length);
   cache.push(z);
 }
 
 
 // Same with two-byte strings
 var x = "\u2028123456789ABCDEF";
-x += x;  // 2^5
-x += x;
-x += x;
-x += x;
-x += x;
-x += x;  // 2^10
-x += x;
-x += x;
+for (var i = 0; i < 8; i++) x += x;
 var xl = x.length;
 var cache = [];
 for (var i = 0; i < 1000; i++) {
   var z = x.substring(i % xl);
   assertEquals(xl - (i % xl), z.length);
   cache.push(z);
 }
 
 // Substring of substring.
 var cache = [];
@@ skipping 55 matching lines @@
 assertEquals(a.slice(1,-1), b);
 
 assertTrue(isAsciiString(a));
 externalizeString(a, true);
 assertFalse(isAsciiString(a));
 
 assertEquals(a.slice(1,-1), b);
 assertTrue(/3456789qwe/.test(a));
 assertEquals(5, a.indexOf("678"));
 assertEquals("12345", a.split("6")[0]);
+
+// Create a slice with an external string as parent string.
+var c = a.slice(1,-1);
+
+function test_crankshaft() {
+  for (var i = 0; i < 20; i++) {
+    assertEquals(b.charAt(i), a.charAt(i + 1));
+    assertEquals(b.charAt(i), c.charAt(i));
+    assertEquals(b.charAt(4), c.charAt(4));
+    assertTrue(/3456789qwe/.test(c));
+    assertEquals(4, c.indexOf("678"));
+    assertEquals("2345", c.split("6")[0]);
+  }
+}
+
+test_crankshaft();
+%OptimizeFunctionOnNextCall(test_crankshaft);
+test_crankshaft();