asm.js. Adds support for clz32 in asm.js.

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 1067 matching lines @@
         VisitCallArgs(call);
         if (call_type == kAstF32) {
           current_function_builder_->Emit(kExprF32Sqrt);
         } else if (call_type == kAstF64) {
           current_function_builder_->Emit(kExprF64Sqrt);
         } else {
           UNREACHABLE();
         }
         break;
       }
+      case AsmTyper::kMathClz32: {
+        VisitCallArgs(call);
+        DCHECK(call_type == kAstI32);
+        current_function_builder_->Emit(kExprI32Clz);
+        break;
+      }
       case AsmTyper::kMathAbs: {
         if (call_type == kAstI32) {
           uint32_t tmp = current_function_builder_->AddLocal(kAstI32);
 
           // if set_local(tmp, x) < 0
           Visit(call->arguments()->at(0));
           current_function_builder_->EmitSetLocal(tmp);
           byte code[] = {WASM_I8(0)};
           current_function_builder_->EmitCode(code, sizeof(code));
           current_function_builder_->Emit(kExprI32LtS);
@@ skipping 678 matching lines @@
   AsmWasmBuilderImpl impl(isolate_, zone_, literal_, typer_);
   impl.Build();
   *foreign_args = impl.GetForeignArgs();
   ZoneBuffer* buffer = new (zone_) ZoneBuffer(zone_);
   impl.builder_->WriteTo(*buffer);
   return buffer;
 }
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8