Reland "[wasm] [cleanup] Only pass information really needed"

This is a reland of fa18e78d.

Mips compile error is fixed.

Original change's description:
> [wasm] [cleanup] Only pass information really needed
>
> Instead of always passing the MachineType, we can often just pass the
> accessed memory size or the MachineRepresentation, which is less
> information to pass and will simplify the upcoming refactoring for
> memory operations in Liftoff.
>
> R=titzer@chromium.org
>
> Bug: v8:6600
> Change-Id: I8748f8e00dcfdbc4082893143fe88bdafde99053
> Reviewed-on: https://chromium-review.googlesource.com/822194
> Reviewed-by: Ben Titzer <titzer@chromium.org>
> Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#50041}

TBR=titzer@chromium.org

Bug: v8:6600
Change-Id: Ia2c47464277a7c7a70099e7f7d6e32003e34d87e
Reviewed-on: https://chromium-review.googlesource.com/822342Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50047}

src/compiler/wasm-compiler.h

@@ -353,7 +353,7 @@ class WasmGraphBuilder {
   Node* LoadMem(wasm::ValueType type, MachineType memtype, Node* index,
                 uint32_t offset, uint32_t alignment,
                 wasm::WasmCodePosition position);
-  Node* StoreMem(MachineType memtype, Node* index, uint32_t offset,
+  Node* StoreMem(MachineRepresentation mem_rep, Node* index, uint32_t offset,
                  uint32_t alignment, Node* val, wasm::WasmCodePosition position,
                  wasm::ValueType type);
   static void PrintDebugName(Node* node);
@@ -457,11 +457,11 @@ class WasmGraphBuilder {
 
   Node* String(const char* string);
   Node* MemBuffer(uint32_t offset);
-  void BoundsCheckMem(MachineType memtype, Node* index, uint32_t offset,
+  void BoundsCheckMem(uint8_t access_size, Node* index, uint32_t offset,
                       wasm::WasmCodePosition position);
   const Operator* GetSafeLoadOperator(int offset, wasm::ValueType type);
   const Operator* GetSafeStoreOperator(int offset, wasm::ValueType type);
-  Node* BuildChangeEndiannessStore(Node* node, MachineType type,
+  Node* BuildChangeEndiannessStore(Node* node, MachineRepresentation rep,
                                    wasm::ValueType wasmtype = wasm::kWasmStmt);
   Node* BuildChangeEndiannessLoad(Node* node, MachineType type,
                                   wasm::ValueType wasmtype = wasm::kWasmStmt);

src/wasm/baseline/liftoff-compiler.cc

@@ -528,7 +528,7 @@ class LiftoffCompiler {
                Value* result) {
     unsupported(decoder, "memory load");
   }
-  void StoreMem(Decoder* decoder, ValueType type, MachineType mem_type,
+  void StoreMem(Decoder* decoder, ValueType type, MachineRepresentation mem_rep,
                 const MemoryAccessOperand<validate>& operand,
                 const Value& index, const Value& value) {
     unsupported(decoder, "memory store");

src/wasm/function-body-decoder-impl.h

@@ -581,7 +581,7 @@ struct ControlWithNamedConstructors : public ControlBase<Value> {
   F(LoadMem, ValueType type, MachineType mem_type,                             \
     const MemoryAccessOperand<validate>& operand, const Value& index,          \
     Value* result)                                                             \
-  F(StoreMem, ValueType type, MachineType mem_type,                            \
+  F(StoreMem, ValueType type, MachineRepresentation mem_rep,                   \
     const MemoryAccessOperand<validate>& operand, const Value& index,          \
     const Value& value)                                                        \
   F(CurrentMemoryPages, Value* result)                                         \
@@ -1997,8 +1997,8 @@ class WasmFullDecoder : public WasmDecoder<validate> {
         ElementSizeLog2Of(mem_type.representation()));
     auto value = Pop(1, type);
     auto index = Pop(0, kWasmI32);
-    CALL_INTERFACE_IF_REACHABLE(StoreMem, type, mem_type, operand, index,
-                                value);
+    CALL_INTERFACE_IF_REACHABLE(StoreMem, type, mem_type.representation(),
+                                operand, index, value);
     return operand.length;
   }
 

src/wasm/function-body-decoder.cc

@@ -347,10 +347,10 @@ class WasmGraphBuildingInterface {
                          operand.alignment, decoder->position());
   }
 
-  void StoreMem(Decoder* decoder, ValueType type, MachineType mem_type,
+  void StoreMem(Decoder* decoder, ValueType type, MachineRepresentation mem_rep,
                 const MemoryAccessOperand<validate>& operand,
                 const Value& index, const Value& value) {
-    BUILD(StoreMem, mem_type, index.node, operand.offset, operand.alignment,
+    BUILD(StoreMem, mem_rep, index.node, operand.offset, operand.alignment,
           value.node, decoder->position(), type);
   }
 

src/wasm/wasm-opcodes.h

@@ -551,7 +551,7 @@ class V8_EXPORT_PRIVATE WasmOpcodes {
   static const char* TrapReasonMessage(TrapReason reason);
 
   static byte MemSize(MachineType type) {
-    return 1 << ElementSizeLog2Of(type.representation());
+    return MemSize(type.representation());
   }
 
   static byte MemSize(ValueType type) { return 1 << ElementSizeLog2Of(type); }