Introduce intrinsics for double values in Javascript.

test/mjsunit/double-intrinsics.js

+// 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.
+
+// Flags: --allow-natives-syntax
+
+function assertDoubleBits(hi, lo, x) {
+  hi = hi | 0;
+  lo = lo | 0;
+  assertEquals(x, %_ConstructDouble(hi, lo));
+  assertEquals(hi, %_DoubleHi(x));
+  assertEquals(lo, %_DoubleLo(x));
+  assertEquals(x, %_ConstructDouble(%_DoubleHi(x), %_DoubleLo(x)));
+}
+
+function test() {
+  assertDoubleBits(0x7ff80000, 0x00000000, NaN);
+  assertDoubleBits(0x7ff00000, 0x00000000, Infinity);
+  assertDoubleBits(0xfff00000, 0x00000000, -Infinity);
+  assertDoubleBits(0x80000000, 0x00000000, -0);
+  assertDoubleBits(0x400921fb, 0x54442d18, Math.PI);
+  assertDoubleBits(0xc00921fb, 0x54442d18, -Math.PI);
+  assertDoubleBits(0x4005bf0a, 0x8b145769, Math.E);
+  assertDoubleBits(0xc005bf0a, 0x8b145769, -Math.E);
+  assertDoubleBits(0xbfe80000, 0x00000000, -0.75);
+}
+
+test();
+test();
+%OptimizeFunctionOnNextCall(test);

[Sven Panne, 2014/03/05 08:00:52]

Hmmm, this relies on inlining heuristics, otherwise we don't test what we think
we test. It's assertDoubleBits which needs to be optimized.

+test();
+assertOptimized(test);