[wasm] Binary 11: AST changes.

src/wasm/encoder.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/signature.h"
 
 #include "src/handles.h"
 #include "src/v8.h"
 #include "src/zone-containers.h"
 
@@ skipping 172 matching lines @@
 
 void WasmFunctionBuilder::EmitWithVarInt(WasmOpcode opcode,
                                          uint32_t immediate) {
   body_.push_back(static_cast<byte>(opcode));
   size_t immediate_size = SizeOfVarInt(immediate);
   body_.insert(body_.end(), immediate_size, 0);
   byte* p = &body_[body_.size() - immediate_size];
   EmitVarInt(&p, immediate);
 }
 
+void WasmFunctionBuilder::EmitI32Const(int32_t value) {
+  // TODO(titzer): variable-length signed and unsigned i32 constants.
+  if (-128 <= value && value <= 127) {
+    EmitWithU8(kExprI8Const, static_cast<byte>(value));
+  } else {
+    byte code[] = {WASM_I32V_5(value)};
+    EmitCode(code, sizeof(code));
+  }
+}
+
 uint32_t WasmFunctionBuilder::EmitEditableVarIntImmediate() {
   // Guess that the immediate will be 1 byte. If it is more, we'll have to
   // shift everything down.
   body_.push_back(0);
   return static_cast<uint32_t>(body_.size()) - 1;
 }
 
 void WasmFunctionBuilder::EditVarIntImmediate(uint32_t offset,
                                               const uint32_t immediate) {
   uint32_t immediate_size = static_cast<uint32_t>(SizeOfVarInt(immediate));
@@ skipping 527 matching lines @@
       next = next | 0x80;
     }
     output.push_back(next);
     shift += 7;
   } while ((next & 0x80) != 0);
   return output;
 }
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8