Relax requirement from VFP3 to VFP2 where possible.

src/arm/assembler-arm.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 492 matching lines @@
 class CpuFeatures : public AllStatic {
  public:
   // Detect features of the target CPU. Set safe defaults if the serializer
   // is enabled (snapshots must be portable).
   static void Probe();
 
   // Check whether a feature is supported by the target CPU.
   static bool IsSupported(CpuFeature f) {
     ASSERT(initialized_);
     if (f == VFP3 && !FLAG_enable_vfp3) return false;
+    if (f == VFP2 && !FLAG_enable_vfp3) return false;

[Sven Panne, 2012/07/25 07:49:06]

This is confusing, I think we should add a new flag for VFP2 or rename the
existing one. In any case our build bots have to be changed accordingly.

     return (supported_ & (1u << 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);
     }
     unsigned enabled = static_cast<unsigned>(isolate->enabled_cpu_features());
     return (enabled & (1u << f)) != 0;
   }
 #endif
 
   // Enable a specified feature within a scope.
   class Scope BASE_EMBEDDED {
 #ifdef DEBUG
 
    public:
     explicit Scope(CpuFeature f) {
       unsigned mask = 1u << f;
+      // VFP2 and ARMv2 are implied by VFP3.

[Sven Panne, 2012/07/25 07:49:06]

ARMv7?

+      if (f == VFP3) mask |= 1u << VFP2 | 1u << ARMv7;
       ASSERT(CpuFeatures::IsSupported(f));
       ASSERT(!Serializer::enabled() ||
              (CpuFeatures::found_by_runtime_probing_ & mask) == 0);
       isolate_ = Isolate::UncheckedCurrent();
       old_enabled_ = 0;
       if (isolate_ != NULL) {
         old_enabled_ = static_cast<unsigned>(isolate_->enabled_cpu_features());
         isolate_->set_enabled_cpu_features(old_enabled_ | mask);
       }
     }
@@ skipping 906 matching lines @@
  public:
   explicit EnsureSpace(Assembler* assembler) {
     assembler->CheckBuffer();
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_H_