[wasm] Add native x64 implementations for I32x4Splat, I32x4ExtractLane

test/cctest/wasm/test-run-wasm-simd.cc

+// 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.
+
+#include "src/wasm/wasm-macro-gen.h"
+
+#include "test/cctest/cctest.h"
+#include "test/cctest/compiler/value-helper.h"
+#include "test/cctest/wasm/wasm-run-utils.h"
+
+using namespace v8::base;
+using namespace v8::internal;
+using namespace v8::internal::compiler;
+using namespace v8::internal::wasm;
+
+// Store SIMD value in a local variable, use extract lane to check lane values
+//
+// SetLocal(1, I32x4Splat(Local(0)));
+// For each lane index
+// if(Local(0) != I32x4ExtractLane(Local(1), index)
+//   return 0
+//
+// return 1
+
+WASM_EXEC_TEST(SplatExtract) {
+  FLAG_wasm_simd_prototype = true;
+
+  WasmRunner<int32_t> r(kExecuteCompiled, MachineType::Int32());
+  r.AllocateLocal(kAstS128);
+  BUILD(r,
+        WASM_BLOCK(WASM_SET_LOCAL(1, WASM_SIMD_I32x4_SPLAT(WASM_GET_LOCAL(0))),

[bbudge, 2016/08/22 19:09:52]

Using splat, it's not really possible to write a good test of ExtractLane, since
all lane values are equal. So I would look at this as a temporary test, until we
have a way to generate more interesting SIMD values. Given that, you should
probably just test a single lane, and leave a comment so no one thinks these are
the tests for extract.

[gdeepti, 2016/08/22 23:26:11]

Agree that it is not possible to have a good test for ExtractLane with just
Splat, changed test name to be Splat, added a comment as well. I was mostly
experimenting with testing lane values in Wasm code and put the test in for
feedback and as a comprehensive test for splat with a range of int values. 

As we won't have meaningful SIMD values till shuffle/swizzle are added, would it
be a bad idea to expose Simd.Create as a (debug/regular) opcode? 

[bbudge, 2016/08/23 13:57:13]

If it's not too hard, implementing ReplaceLane would allow you to test
everything. Of course, Create does too.

[gdeepti, 2016/08/23 19:53:34]

Did not think of replace lane, I'll add replace lane + extract lane test with
replace lane in a follow up CL. 

+                   WASM_IF(WASM_I32_NE(WASM_GET_LOCAL(0),
+                                       WASM_SIMD_I32x4_EXTRACT_LANE(
+                                           WASM_GET_LOCAL(1), WASM_I8(0))),
+                           WASM_RETURN1(WASM_ZERO)),
+                   WASM_IF(WASM_I32_NE(WASM_GET_LOCAL(0),
+                                       WASM_SIMD_I32x4_EXTRACT_LANE(
+                                           WASM_GET_LOCAL(1), WASM_I8(1))),
+                           WASM_RETURN1(WASM_ZERO)),
+                   WASM_IF(WASM_I32_NE(WASM_GET_LOCAL(0),
+                                       WASM_SIMD_I32x4_EXTRACT_LANE(
+                                           WASM_GET_LOCAL(1), WASM_I8(2))),
+                           WASM_RETURN1(WASM_ZERO)),
+                   WASM_IF(WASM_I32_NE(WASM_GET_LOCAL(0),
+                                       WASM_SIMD_I32x4_EXTRACT_LANE(
+                                           WASM_GET_LOCAL(1), WASM_I8(3))),
+                           WASM_RETURN1(WASM_ZERO)),
+                   WASM_RETURN1(WASM_ONE)));
+
+  FOR_INT32_INPUTS(i) { CHECK_EQ(1, r.Call(*i)); }
+}