MIPS: Fix int64->int32 lowering in wasm-to-interpeter entry on big-endian archs.

src/compiler/wasm-compiler.cc

 // Copyright 2015 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/compiler/wasm-compiler.h"
 
 #include <memory>
 
 #include "src/assembler-inl.h"
 #include "src/base/platform/elapsed-timer.h"
@@ skipping 2957 matching lines @@
                          : graph()->NewNode(jsgraph()->machine()->StackSlot(
                                std::max(args_size_bytes, return_size_bytes)));
 
   // Now store all our arguments to the buffer.
   int param_index = 0;
   int offset = 0;
   for (int i = 0; i < wasm_count; i++) {
     Node* param = Param(param_index++);
     bool is_i64_as_two_params =
         jsgraph()->machine()->Is32() && sig->GetParam(i) == wasm::kWasmI64;
-    MachineRepresentation param_rep =
-        is_i64_as_two_params ? wasm::kWasmI32 : sig->GetParam(i);
-    StoreRepresentation store_rep(param_rep, WriteBarrierKind::kNoWriteBarrier);
-    *effect_ =
-        graph()->NewNode(jsgraph()->machine()->Store(store_rep), arg_buffer,
-                         Int32Constant(offset), param, *effect_, *control_);
 
     if (is_i64_as_two_params) {
-      offset += 1 << ElementSizeLog2Of(wasm::kWasmI32);
-    } else {
-      offset += RoundUpToMultipleOfPowOf2(1 << ElementSizeLog2Of(param_rep), 8);
-    }
-
-    // TODO(clemensh): Respect endianess here. Might need to swap upper and
-    // lower word.
-    if (is_i64_as_two_params) {
-      // Also store the upper half.
-      param = Param(param_index++);
       StoreRepresentation store_rep(wasm::kWasmI32,
                                     WriteBarrierKind::kNoWriteBarrier);
       *effect_ =
           graph()->NewNode(jsgraph()->machine()->Store(store_rep), arg_buffer,
+                           Int32Constant(offset + kInt64LowerHalfMemoryOffset),
+                           param, *effect_, *control_);
+
+      param = Param(param_index++);
+      *effect_ =
+          graph()->NewNode(jsgraph()->machine()->Store(store_rep), arg_buffer,
+                           Int32Constant(offset + kInt64UpperHalfMemoryOffset),
+                           param, *effect_, *control_);
+      offset += 8;
+
+    } else {
+      MachineRepresentation param_rep = sig->GetParam(i);
+      StoreRepresentation store_rep(param_rep,
+                                    WriteBarrierKind::kNoWriteBarrier);
+      *effect_ =
+          graph()->NewNode(jsgraph()->machine()->Store(store_rep), arg_buffer,
                            Int32Constant(offset), param, *effect_, *control_);
-      offset += 1 << ElementSizeLog2Of(wasm::kWasmI32);
+      offset += RoundUpToMultipleOfPowOf2(1 << ElementSizeLog2Of(param_rep), 8);
     }
 
     DCHECK(IsAligned(offset, 8));
   }
   DCHECK_EQ(param_count, param_index);
   DCHECK_EQ(args_size_bytes, offset);
 
   // We are passing the raw arg_buffer here. To the GC and other parts, it looks
   // like a Smi (lowest bit not set). In the runtime function however, don't
   // call Smi::value on it, but just cast it to a byte pointer.
@@ skipping 1151 matching lines @@
            function_->code_end_offset - function_->code_start_offset,
            codegen_ms);
   }
 
   return code;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8