[wasm] Remove renumbering of local variables from asm->wasm.

src/wasm/wasm-macro-gen.h

 // 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.
 
 #ifndef V8_WASM_MACRO_GEN_H_
 #define V8_WASM_MACRO_GEN_H_
 
 #include "src/wasm/wasm-opcodes.h"
 
+#include "src/zone-containers.h"
+
 #define U32_LE(v)                                    \
   static_cast<byte>(v), static_cast<byte>((v) >> 8), \
       static_cast<byte>((v) >> 16), static_cast<byte>((v) >> 24)
 
 #define U16_LE(v) static_cast<byte>(v), static_cast<byte>((v) >> 8)
 
 #define WASM_MODULE_HEADER U32_LE(kWasmMagic), U32_LE(kWasmVersion)
 
 #define SIG_INDEX(v) U16_LE(v)
 // TODO(binji): make SIG_INDEX match this.
@@ skipping 103 matching lines @@
   DCHECK(length == 5 || I32V_IN_RANGE(value, length));
 }
 
 inline void CheckI64v(int64_t value, int length) {
   DCHECK(length >= 1 && length <= 10);
   DCHECK(length == 10 || I64V_IN_RANGE(value, length));
 }
 
 // A helper for encoding local declarations prepended to the body of a
 // function.
+// TODO(titzer): move this to an appropriate header.
 class LocalDeclEncoder {
  public:
+  explicit LocalDeclEncoder(Zone* zone, FunctionSig* s = nullptr)
+      : sig(s), local_decls(zone), total(0) {}
+
   // Prepend local declarations by creating a new buffer and copying data
   // over. The new buffer must be delete[]'d by the caller.
   void Prepend(const byte** start, const byte** end) const {
     size_t size = (*end - *start);
     byte* buffer = new byte[Size() + size];
     size_t pos = Emit(buffer);
     memcpy(buffer + pos, *start, size);
     pos += size;
     *start = buffer;
     *end = buffer + pos;
   }
 
   size_t Emit(byte* buffer) const {
     size_t pos = 0;
     pos = WriteUint32v(buffer, pos, static_cast<uint32_t>(local_decls.size()));
     for (size_t i = 0; i < local_decls.size(); i++) {
       pos = WriteUint32v(buffer, pos, local_decls[i].first);
       buffer[pos++] = WasmOpcodes::LocalTypeCodeFor(local_decls[i].second);
     }
     DCHECK_EQ(Size(), pos);
     return pos;
   }
 
   // Add locals declarations to this helper. Return the index of the newly added
   // local(s), with an optional adjustment for the parameters.
-  uint32_t AddLocals(uint32_t count, LocalType type,
-                     FunctionSig* sig = nullptr) {
-    if (count == 0) {
-      return static_cast<uint32_t>((sig ? sig->parameter_count() : 0) +
-                                   local_decls.size());
-    }
-    size_t pos = local_decls.size();
+  uint32_t AddLocals(uint32_t count, LocalType type) {
+    uint32_t result =
+        static_cast<uint32_t>(total + (sig ? sig->parameter_count() : 0));
+    total += count;
     if (local_decls.size() > 0 && local_decls.back().second == type) {
       count += local_decls.back().first;
       local_decls.pop_back();
     }
     local_decls.push_back(std::pair<uint32_t, LocalType>(count, type));
-    return static_cast<uint32_t>(pos + (sig ? sig->parameter_count() : 0));
+    return result;
   }
 
   size_t Size() const {
     size_t size = SizeofUint32v(static_cast<uint32_t>(local_decls.size()));
     for (auto p : local_decls) size += 1 + SizeofUint32v(p.first);
     return size;
   }
 
+  bool has_sig() const { return sig != nullptr; }
+  FunctionSig* get_sig() const { return sig; }
+  void set_sig(FunctionSig* s) { sig = s; }
+
  private:
-  std::vector<std::pair<uint32_t, LocalType>> local_decls;
+  FunctionSig* sig;
+  ZoneVector<std::pair<uint32_t, LocalType>> local_decls;
+  size_t total;
 
   size_t SizeofUint32v(uint32_t val) const {
     size_t size = 1;
     while (true) {
       byte b = val & MASK_7;
       if (b == val) return size;
       size++;
       val = val >> 7;
     }
   }
@@ skipping 381 matching lines @@
 #define SIG_ENTRY_x(r) kWasmFunctionTypeForm, 0, 1, r
 #define SIG_ENTRY_x_x(r, a) kWasmFunctionTypeForm, 1, a, 1, r
 #define SIG_ENTRY_x_xx(r, a, b) kWasmFunctionTypeForm, 2, a, b, 1, r
 #define SIG_ENTRY_x_xxx(r, a, b, c) kWasmFunctionTypeForm, 3, a, b, c, 1, r
 #define SIZEOF_SIG_ENTRY_x 4
 #define SIZEOF_SIG_ENTRY_x_x 5
 #define SIZEOF_SIG_ENTRY_x_xx 6
 #define SIZEOF_SIG_ENTRY_x_xxx 7
 
 #endif  // V8_WASM_MACRO_GEN_H_