[wasm][bulk-memory] Adjust memory.fill to recent spec changes

R=binji@chromium.org

Change-Id: I01721c708b1e40cdef4bd48a1f9ca68b31c8f49d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1708470Reviewed-by: Ben Smith <binji@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62814}

src/compiler/wasm-compiler.cc

@@ -4842,6 +4842,18 @@ Node* WasmGraphBuilder::MemoryCopy(Node* dst, Node* src, Node* size,
 
 Node* WasmGraphBuilder::MemoryFill(Node* dst, Node* value, Node* size,
                                    wasm::WasmCodePosition position) {
+  auto machine = mcgraph()->machine();
+  auto common = mcgraph()->common();
+  // If size == 0, then memory.copy is a no-op.
+  Node* size_null_check = graph()->NewNode(machine->Word32Equal(), size,
+                                           mcgraph()->Int32Constant(0));
+  Node* size_null_branch = graph()->NewNode(common->Branch(BranchHint::kFalse),
+                                            size_null_check, Control());
+
+  Node* size_null_etrue = Effect();
+  Node* size_null_if_false =
+      graph()->NewNode(common->IfFalse(), size_null_branch);
+  SetControl(size_null_if_false);
   Node* fail = BoundsCheckMemRange(&dst, &size, position);
   Node* function = graph()->NewNode(mcgraph()->common()->ExternalConstant(
       ExternalReference::wasm_memory_fill()));
@@ -4849,7 +4861,15 @@ Node* WasmGraphBuilder::MemoryFill(Node* dst, Node* value, Node* size,
                              MachineType::Uint32()};
   MachineSignature sig(0, 3, sig_types);
   BuildCCall(&sig, function, dst, value, size);
-  return TrapIfTrue(wasm::kTrapMemOutOfBounds, fail, position);
+  TrapIfTrue(wasm::kTrapMemOutOfBounds, fail, position);
+  Node* size_null_if_true =
+      graph()->NewNode(common->IfTrue(), size_null_branch);
+
+  Node* merge = SetControl(
+      graph()->NewNode(common->Merge(2), size_null_if_true, Control()));
+  SetEffect(
+      graph()->NewNode(common->EffectPhi(2), size_null_etrue, Effect(), merge));
+  return merge;
 }
 
 Node* WasmGraphBuilder::CheckElemSegmentIsPassiveAndNotDropped(

src/wasm/wasm-interpreter.cc

@@ -1841,14 +1841,17 @@ class ThreadImpl {
       case kExprMemoryFill: {
         MemoryIndexImmediate<Decoder::kNoValidate> imm(decoder,
                                                        code->at(pc + 1));
+        *len += imm.length;
         auto size = Pop().to<uint32_t>();
         auto value = Pop().to<uint32_t>();
         auto dst = Pop().to<uint32_t>();
+        if (size == 0) {
+          return true;
+        }
         Address dst_addr;
         bool ok = BoundsCheckMemRange(dst, &size, &dst_addr);
         memory_fill_wrapper(dst_addr, value, size);
         if (!ok) DoTrap(kTrapMemOutOfBounds, pc);
-        *len += imm.length;
         return ok;
       }
       case kExprTableInit: {

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

@@ -323,8 +323,8 @@ WASM_EXEC_TEST(MemoryFillOutOfBounds) {
   CHECK_EQ(0xDEADBEEF, r.Call(1000, v, kWasmPageSize));
   CHECK_EQ(0xDEADBEEF, r.Call(kWasmPageSize, v, 1));
 
-  // Fill 0 out-of-bounds fails.
-  CHECK_EQ(0xDEADBEEF, r.Call(kWasmPageSize + 1, v, 0));
+  // Fill 0 out-of-bounds succeeds.
+  CHECK_EQ(0, r.Call(kWasmPageSize + 1, v, 0));
 
   // Make sure bounds aren't checked with 32-bit wrapping.
   CHECK_EQ(0xDEADBEEF, r.Call(1, v, 0xFFFFFFFF));

test/wasm-spec-tests/wasm-spec-tests.status

@@ -17,8 +17,6 @@
   # TODO(ahaas): Incorporate recent changes to the bulk-memory-operations
   # proposal.
   'tests/proposals/bulk-memory-operations/elem': [FAIL],
-  'tests/proposals/bulk-memory-operations/memory_fill': [FAIL],
-  'tests/proposals/bulk-memory-operations/bulk': [FAIL],
   'tests/proposals/bulk-memory-operations/data': [FAIL],
 }],  # ALWAYS