Revert "[Arguments] Merge (7442,7496] from bleeding_edge."

src/ia32/assembler-ia32.h

Index: src/ia32/assembler-ia32.h
diff --git a/src/ia32/assembler-ia32.h b/src/ia32/assembler-ia32.h
index 079dca757734cc9f71eea92d1c4b86c26ab3e8ee..8e0c762a477a01615197df590390e2a0021d6d2b 100644
--- a/src/ia32/assembler-ia32.h
+++ b/src/ia32/assembler-ia32.h
@@ -446,15 +446,16 @@ class Displacement BASE_EMBEDDED {
 //   } else {
 //     // Generate standard x87 floating point code.
 //   }
-class CpuFeatures : public AllStatic {
+class CpuFeatures {
  public:
-  // Detect features of the target CPU. Set safe defaults if the serializer
-  // is enabled (snapshots must be portable).
-  static void Probe();
+  // Detect features of the target CPU. If the portable flag is set,
+  // the method sets safe defaults if the serializer is enabled
+  // (snapshots must be portable).
+  void Probe(bool portable);
+  void Clear() { supported_ = 0; }
 
   // Check whether a feature is supported by the target CPU.
-  static bool IsSupported(CpuFeature f) {
-    ASSERT(initialized_);
+  bool IsSupported(CpuFeature f) const {
     if (f == SSE2 && !FLAG_enable_sse2) return false;
     if (f == SSE3 && !FLAG_enable_sse3) return false;
     if (f == SSE4_1 && !FLAG_enable_sse4_1) return false;
@@ -462,85 +463,46 @@ class CpuFeatures : public AllStatic {
     if (f == RDTSC && !FLAG_enable_rdtsc) return false;
     return (supported_ & (static_cast<uint64_t>(1) << f)) != 0;
   }
-
-#ifdef DEBUG
   // Check whether a feature is currently enabled.
-  static bool IsEnabled(CpuFeature f) {
-    ASSERT(initialized_);
-    Isolate* isolate = Isolate::UncheckedCurrent();
-    if (isolate == NULL) {
-      // When no isolate is available, work as if we're running in
-      // release mode.
-      return IsSupported(f);
-    }
-    uint64_t enabled = isolate->enabled_cpu_features();
-    return (enabled & (static_cast<uint64_t>(1) << f)) != 0;
+  bool IsEnabled(CpuFeature f) const {
+    return (enabled_ & (static_cast<uint64_t>(1) << f)) != 0;
   }
-#endif
-
   // Enable a specified feature within a scope.
   class Scope BASE_EMBEDDED {
 #ifdef DEBUG
    public:
-    explicit Scope(CpuFeature f) {
+    explicit Scope(CpuFeature f)
+        : cpu_features_(Isolate::Current()->cpu_features()),
+          isolate_(Isolate::Current()) {
       uint64_t mask = static_cast<uint64_t>(1) << f;
-      ASSERT(CpuFeatures::IsSupported(f));
+      ASSERT(cpu_features_->IsSupported(f));
       ASSERT(!Serializer::enabled() ||
-             (CpuFeatures::found_by_runtime_probing_ & mask) == 0);
-      isolate_ = Isolate::UncheckedCurrent();
-      old_enabled_ = 0;
-      if (isolate_ != NULL) {
-        old_enabled_ = isolate_->enabled_cpu_features();
-        isolate_->set_enabled_cpu_features(old_enabled_ | mask);
-      }
+          (cpu_features_->found_by_runtime_probing_ & mask) == 0);
+      old_enabled_ = cpu_features_->enabled_;
+      cpu_features_->enabled_ |= mask;
     }
     ~Scope() {
-      ASSERT_EQ(Isolate::UncheckedCurrent(), isolate_);
-      if (isolate_ != NULL) {
-        isolate_->set_enabled_cpu_features(old_enabled_);
-      }
+      ASSERT_EQ(Isolate::Current(), isolate_);
+      cpu_features_->enabled_ = old_enabled_;
     }
    private:
-    Isolate* isolate_;
     uint64_t old_enabled_;
+    CpuFeatures* cpu_features_;
+    Isolate* isolate_;
 #else
    public:
     explicit Scope(CpuFeature f) {}
 #endif
   };
 
-  class TryForceFeatureScope BASE_EMBEDDED {
-   public:
-    explicit TryForceFeatureScope(CpuFeature f)
-        : old_supported_(CpuFeatures::supported_) {
-      if (CanForce()) {
-        CpuFeatures::supported_ |= (static_cast<uint64_t>(1) << f);
-      }
-    }
-
-    ~TryForceFeatureScope() {
-      if (CanForce()) {
-        CpuFeatures::supported_ = old_supported_;
-      }
-    }
+ private:
+  CpuFeatures();
 
-   private:
-    static bool CanForce() {
-      // It's only safe to temporarily force support of CPU features
-      // when there's only a single isolate, which is guaranteed when
-      // the serializer is enabled.
-      return Serializer::enabled();
-    }
+  uint64_t supported_;
+  uint64_t enabled_;
+  uint64_t found_by_runtime_probing_;
 
-    const uint64_t old_supported_;
-  };
-
- private:
-#ifdef DEBUG
-  static bool initialized_;
-#endif
-  static uint64_t supported_;
-  static uint64_t found_by_runtime_probing_;
+  friend class Isolate;
 
   DISALLOW_COPY_AND_ASSIGN(CpuFeatures);
 };
@@ -573,8 +535,7 @@ class Assembler : public AssemblerBase {
   // for code generation and assumes its size to be buffer_size. If the buffer
   // is too small, a fatal error occurs. No deallocation of the buffer is done
   // upon destruction of the assembler.
-  // TODO(vitalyr): the assembler does not need an isolate.
-  Assembler(Isolate* isolate, void* buffer, int buffer_size);
+  Assembler(void* buffer, int buffer_size);
   ~Assembler();
 
   // Overrides the default provided by FLAG_debug_code.