Implement UnalignedLoad and UnalignedStore in WASM using LoadByte/Shift/Or and StoreByte/Shift/And.

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

Index: test/cctest/wasm/test-run-wasm.cc
diff --git a/test/cctest/wasm/test-run-wasm.cc b/test/cctest/wasm/test-run-wasm.cc
index 3b7af54ca0901fe4d56823acb5321d171c4c961f..690bf023b5a11561142cd3457d69fdd328e15caa 100644
--- a/test/cctest/wasm/test-run-wasm.cc
+++ b/test/cctest/wasm/test-run-wasm.cc
@@ -1304,6 +1304,26 @@ TEST(Run_Wasm_LoadMemI32) {
   CHECK_EQ(77777777, r.Call(0));
 }
 
+TEST(Run_Wasm_LoadMemI32_alignment) {

[titzer, 2016/05/11 15:22:35]

Can you move this into test-run-load-store.cc?

[ivica.bogosavljevic, 2016/05/12 12:09:55]

This test cannot be moved to test-run-load-store.cc, because tests in those
files test turbofan operators, whereas Unaligned access is generated by
wasm-compiler.cc, so it needs to be tested in this test suite.

We could copy code for unaligned access from wasm-compiler to a separate test in
test-run-load-store.cc and test it, but I don't like that approach. If somebody
breaks something in wasm-compiler related to unaligned access, the test will
pass, but wasm-compiler will be broken

[titzer, 2016/05/17 11:57:39]

Acknowledged.

+  TestingModule module;
+  int32_t* memory = module.AddMemoryElems<int32_t>(8);
+  for (byte alignment = 0; alignment <= 2; alignment++) {
+    WasmRunner<int32_t> r(&module, MachineType::Int32());
+    module.RandomizeMemory(1111);
+
+    BUILD(r,
+          WASM_LOAD_MEM_ALIGNMENT(MachineType::Int32(), WASM_I8(0), alignment));
+
+    memory[0] = 0x1a2b3c4d;
+    CHECK_EQ(0x1a2b3c4d, r.Call(0));
+
+    memory[0] = 0x5e6f7a8b;
+    CHECK_EQ(0x5e6f7a8b, r.Call(0));
+
+    memory[0] = 0x9ca0b1c2;
+    CHECK_EQ(0x9ca0b1c2, r.Call(0));
+  }
+}
 
 TEST(Run_Wasm_LoadMemI32_oob) {
   TestingModule module;
@@ -1400,8 +1420,6 @@ TEST(Run_Wasm_LoadMemI32_offset) {
 }
 
 
-#if !V8_TARGET_ARCH_MIPS && !V8_TARGET_ARCH_MIPS64
-
 TEST(Run_Wasm_LoadMemI32_const_oob_misaligned) {
   const int kMemSize = 12;
   // TODO(titzer): Fix misaligned accesses on MIPS and re-enable.
@@ -1425,8 +1443,6 @@ TEST(Run_Wasm_LoadMemI32_const_oob_misaligned) {
   }
 }
 
-#endif
-
 
 TEST(Run_Wasm_LoadMemI32_const_oob) {
   const int kMemSize = 24;
@@ -1450,6 +1466,22 @@ TEST(Run_Wasm_LoadMemI32_const_oob) {
   }
 }
 
+TEST(Run_Wasm_StoreMemI32_alignment) {
+  TestingModule module;
+  int32_t* memory = module.AddMemoryElems<int32_t>(4);
+  const int32_t kWritten = 0x12345678;
+
+  for (byte i = 0; i <= 2; i++) {
+    WasmRunner<int32_t> r(&module, MachineType::Int32());
+    BUILD(r, WASM_STORE_MEM_ALIGNMENT(MachineType::Int32(), WASM_ZERO, i,
+                                      WASM_GET_LOCAL(0)));
+    module.RandomizeMemory(1111);
+    memory[0] = 0;
+
+    CHECK_EQ(kWritten, r.Call(kWritten));
+    CHECK_EQ(kWritten, memory[0]);
+  }
+}
 
 TEST(Run_Wasm_StoreMemI32_offset) {
   TestingModule module;