Convert SIMD wasm ops to runtime function calls

test/mjsunit/wasm/test-wasm-simd-ops.js

+// Copyright 2016 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: --expose-wasm --wasm-num-compilation-tasks=0
+
+load('test/mjsunit/wasm/wasm-constants.js');
+load('test/mjsunit/wasm/wasm-module-builder.js');
+
+// TODO(gdeepti): Currently wasm simd ops are tested using runtime calls to
+// JS runtime functions, as this needs heap allocation sequential compile is
+// triggered here. This is only used for bootstrapping and needs to be removed
+// when we have architectuaral/scalar implementations for wasm simd ops.
+
+(function SimdSplatExtractTest() {
+  print("simd test");
+  var module = new WasmModuleBuilder();
+  module.addFunction("splatextract", kSig_i_ii)
+      .addBody([kExprGetLocal, 0, kExprSimdPrefix, kExprI32x4Splat,
+          kExprGetLocal, 1, kExprSimdPrefix, kExprI32x4ExtractLane])

[bbudge, 2016/07/06 20:18:08]

If this is a parameter, then we can't determine its value at compile time, and
I32x4ExtractLane can't take a non-immediate argument (your runtime function
lowering works because that function can take a non-immediate argument.)

The wasm code should either create a switch and case the legal values, or just
make this kExprI32Const with the value 2.

[gdeepti, 2016/07/07 04:05:34]

Changed to kExprI32Const with the value 2. Added this as a sanity check to make
sure the runtime pass is working, will follow up with more comprehensive tests
to make sure the opcodes are working as intended. 

+      .exportAs("main");
+  var instance = module.instantiate();
+  assertEquals(123, instance.exports.main(123, 2));
+  print("success");
+})();