[Liftoff] Adapt to ptrsize memory mask

Since https://crrev.com/c/1112003, the memory size is stored as size_t
instead of uint32_t in order to support 4GB memories.
This CL fixes Liftoff to load and handle that field as ptrsized field
instead of 32 bit integer.
Drive-by: Fix wrong machine type on Phi in TF wasm compiler.

R=titzer@chromium.org

Bug: v8:8130
Change-Id: I40a92a2c24f6311e05b5e2608a0902674a2ce411
Reviewed-on: https://chromium-review.googlesource.com/1206008
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55702}

src/compiler/wasm-compiler.cc

@@ -2818,9 +2818,9 @@ void WasmGraphBuilder::PrepareInstanceCacheForLoop(
                                            instance_cache->field, control);
 
   INTRODUCE_PHI(mem_start, MachineType::PointerRepresentation());
-  INTRODUCE_PHI(mem_size, MachineRepresentation::kWord32);
+  INTRODUCE_PHI(mem_size, MachineType::PointerRepresentation());
   if (untrusted_code_mitigations_) {
-    INTRODUCE_PHI(mem_mask, MachineRepresentation::kWord32);
+    INTRODUCE_PHI(mem_mask, MachineType::PointerRepresentation());
   }
 
 #undef INTRODUCE_PHI

src/wasm/baseline/liftoff-assembler.h

@@ -455,6 +455,14 @@ class LiftoffAssembler : public TurboAssembler {
       emit_i32_sub(dst, lhs, rhs);
     }
   }
+  inline void emit_ptrsize_and(Register dst, Register lhs, Register rhs) {
+    if (kPointerSize == 8) {
+      emit_i64_and(LiftoffRegister(dst), LiftoffRegister(lhs),
+                   LiftoffRegister(rhs));
+    } else {
+      emit_i32_and(dst, lhs, rhs);
+    }
+  }
   inline void emit_ptrsize_shr(Register dst, Register src, int amount) {
     if (kPointerSize == 8) {
       emit_i64_shr(LiftoffRegister(dst), LiftoffRegister(src), amount);

src/wasm/baseline/liftoff-compiler.cc

@@ -1477,12 +1477,9 @@ class LiftoffCompiler {
     }
     LiftoffRegister tmp = __ GetUnusedRegister(kGpReg, pinned);
     __ LoadConstant(tmp, WasmValue(*offset));
-    __ emit_i32_add(index.gp(), index.gp(), tmp.gp());
-    // TODO(clemensh): Use LOAD_INSTANCE_FIELD once the type is fixed.
-    // LOAD_INSTANCE_FIELD(tmp, MemoryMask, kUInt32Size);
-    __ LoadFromInstance(tmp.gp(), WASM_INSTANCE_OBJECT_OFFSET(MemoryMask),
-                        kUInt32Size);
-    __ emit_i32_and(index.gp(), index.gp(), tmp.gp());
+    __ emit_ptrsize_add(index.gp(), index.gp(), tmp.gp());
+    LOAD_INSTANCE_FIELD(tmp, MemoryMask, kPointerSize);
+    __ emit_ptrsize_and(index.gp(), index.gp(), tmp.gp());
     *offset = 0;
     return index;
   }