[wasm] Introduce EmitVarInt and EmitWithVarInt

src/asmjs/asm-wasm-builder.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/v8.h"
 
 // Required to get M_E etc. in MSVC.
 #if defined(_WIN32)
 #define _USE_MATH_DEFINES
 #endif
@@ skipping 665 matching lines @@
     if (!(value->IsNumber() || expr->raw_value()->IsTrue() ||
           expr->raw_value()->IsFalse()) ||
         (scope_ != kFuncScope && scope_ != kInitScope)) {
       return;
     }
     AsmType* type = typer_->TypeOf(expr);
     DCHECK_NE(type, AsmType::None());
 
     if (type->IsA(AsmType::Signed())) {
       int32_t i = 0;
-      if (!value->ToInt32(&i)) {
-        UNREACHABLE();
-      }
-      byte code[] = {WASM_I32V(i)};
-      current_function_builder_->EmitCode(code, sizeof(code));
+      CHECK(value->ToInt32(&i));
+      current_function_builder_->EmitI32Const(i);
     } else if (type->IsA(AsmType::Unsigned()) || type->IsA(AsmType::FixNum())) {
       uint32_t u = 0;
-      if (!value->ToUint32(&u)) {
-        UNREACHABLE();
-      }
-      int32_t i = static_cast<int32_t>(u);
-      byte code[] = {WASM_I32V(i)};
-      current_function_builder_->EmitCode(code, sizeof(code));
+      CHECK(value->ToUint32(&u));
+      current_function_builder_->EmitI32Const(bit_cast<int32_t>(u));
     } else if (type->IsA(AsmType::Int())) {
       // The parser can collapse !0, !1 etc to true / false.
       // Allow these as int literals.
       if (expr->raw_value()->IsTrue()) {
-        byte code[] = {WASM_I32V(1)};
+        byte code[] = {WASM_ONE};
         current_function_builder_->EmitCode(code, sizeof(code));
       } else if (expr->raw_value()->IsFalse()) {
-        byte code[] = {WASM_I32V(0)};
+        byte code[] = {WASM_ZERO};
         current_function_builder_->EmitCode(code, sizeof(code));
       } else if (expr->raw_value()->IsNumber()) {
         // This can happen when -x becomes x * -1 (due to the parser).
         int32_t i = 0;
-        if (!value->ToInt32(&i) || i != -1) {
-          UNREACHABLE();
-        }
-        byte code[] = {WASM_I32V(i)};
+        CHECK(value->ToInt32(&i) && i == -1);
+        byte code[] = {WASM_I32V_1(-1)};
         current_function_builder_->EmitCode(code, sizeof(code));
       } else {
         UNREACHABLE();
       }
     } else if (type->IsA(AsmType::Double())) {
       // TODO(bradnelson): Pattern match the case where negation occurs and
       // emit f64.neg instead.
       double val = expr->raw_value()->AsNumber();
       byte code[] = {WASM_F64(val)};
       current_function_builder_->EmitCode(code, sizeof(code));
@@ skipping 1290 matching lines @@
   impl.builder_->WriteAsmJsOffsetTable(*asm_offsets_buffer);
   return {module_buffer, asm_offsets_buffer, success};
 }
 
 const char* AsmWasmBuilder::foreign_init_name = "__foreign_init__";
 const char* AsmWasmBuilder::single_function_name = "__single_function__";
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8