assembler-x64.h in mustang-0.1.0

- old
+ new

@@ -28,11 +28,11 @@
 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // The original source code covered by the above license above has been
 // modified significantly by Google Inc.
-// Copyright 2010 the V8 project authors. All rights reserved.
+// Copyright 2011 the V8 project authors. All rights reserved.
 
 // A lightweight X64 Assembler.
 
 #ifndef V8_X64_ASSEMBLER_X64_H_
 #define V8_X64_ASSEMBLER_X64_H_
@@ -91,12 +91,12 @@
   // The non-allocatable registers are:
   //  rsp - stack pointer
   //  rbp - frame pointer
   //  rsi - context register
   //  r10 - fixed scratch register
+  //  r12 - smi constant register
   //  r13 - root register
-  //  r15 - smi constant register
   static const int kNumRegisters = 16;
   static const int kNumAllocatableRegisters = 10;
 
   static int ToAllocationIndex(Register reg) {
     return kAllocationIndexByRegisterCode[reg.code()];
@@ -118,11 +118,11 @@
       "rdi",
       "r8",
       "r9",
       "r11",
       "r14",
-      "r12"
+      "r15"
     };
     return names[index];
   }
 
   static Register toRegister(int code) {
@@ -393,10 +393,17 @@
 
   // Checks whether either base or index register is the given register.
   // Does not check the "reg" part of the Operand.
   bool AddressUsesRegister(Register reg) const;
 
+  // Queries related to the size of the generated instruction.
+  // Whether the generated instruction will have a REX prefix.
+  bool requires_rex() const { return rex_ != 0; }
+  // Size of the ModR/M, SIB and displacement parts of the generated
+  // instruction.
+  int operand_size() const { return len_; }
+
  private:
   byte rex_;
   byte buf_[6];
   // The number of bytes of buf_ in use.
   byte len_;
@@ -429,54 +436,87 @@
 //   }
 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(bool portable);
+  static void Probe();
+
   // Check whether a feature is supported by the target CPU.
   static bool IsSupported(CpuFeature f) {
+    ASSERT(initialized_);
     if (f == SSE2 && !FLAG_enable_sse2) return false;
     if (f == SSE3 && !FLAG_enable_sse3) return false;
     if (f == CMOV && !FLAG_enable_cmov) return false;
     if (f == RDTSC && !FLAG_enable_rdtsc) return false;
     if (f == SAHF && !FLAG_enable_sahf) return false;
     return (supported_ & (V8_UINT64_C(1) << f)) != 0;
   }
+
+#ifdef DEBUG
   // Check whether a feature is currently enabled.
   static bool IsEnabled(CpuFeature f) {
-    return (enabled_ & (V8_UINT64_C(1) << f)) != 0;
+    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 & (V8_UINT64_C(1) << f)) != 0;
   }
+#endif
+
   // Enable a specified feature within a scope.
   class Scope BASE_EMBEDDED {
 #ifdef DEBUG
    public:
     explicit Scope(CpuFeature f) {
-      uint64_t mask = (V8_UINT64_C(1) << f);
+      uint64_t mask = V8_UINT64_C(1) << f;
       ASSERT(CpuFeatures::IsSupported(f));
-      ASSERT(!Serializer::enabled() || (found_by_runtime_probing_ & mask) == 0);
-      old_enabled_ = CpuFeatures::enabled_;
-      CpuFeatures::enabled_ |= mask;
+      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);
+      }
     }
-    ~Scope() { CpuFeatures::enabled_ = old_enabled_; }
+    ~Scope() {
+      ASSERT_EQ(Isolate::UncheckedCurrent(), isolate_);
+      if (isolate_ != NULL) {
+        isolate_->set_enabled_cpu_features(old_enabled_);
+      }
+    }
    private:
+    Isolate* isolate_;
     uint64_t old_enabled_;
 #else
    public:
     explicit Scope(CpuFeature f) {}
 #endif
   };
+
  private:
   // Safe defaults include SSE2 and CMOV for X64. It is always available, if
   // anyone checks, but they shouldn't need to check.
+  // The required user mode extensions in X64 are (from AMD64 ABI Table A.1):
+  //   fpu, tsc, cx8, cmov, mmx, sse, sse2, fxsr, syscall
   static const uint64_t kDefaultCpuFeatures = (1 << SSE2 | 1 << CMOV);
+
+#ifdef DEBUG
+  static bool initialized_;
+#endif
   static uint64_t supported_;
-  static uint64_t enabled_;
   static uint64_t found_by_runtime_probing_;
+
+  DISALLOW_COPY_AND_ASSIGN(CpuFeatures);
 };
 
 
-class Assembler : public Malloced {
+class Assembler : public AssemblerBase {
  private:
   // We check before assembling an instruction that there is sufficient
   // space to write an instruction and its relocation information.
   // The relocation writer's position must be kGap bytes above the end of
   // the generated instructions. This leaves enough space for the
@@ -499,13 +539,16 @@
   //
   // If the provided buffer is not NULL, the assembler uses the provided buffer
   // 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.
-  Assembler(void* buffer, int buffer_size);
+  Assembler(Isolate* isolate, void* buffer, int buffer_size);
   ~Assembler();
 
+  // Overrides the default provided by FLAG_debug_code.
+  void set_emit_debug_code(bool value) { emit_debug_code_ = value; }
+
   // GetCode emits any pending (non-emitted) code and fills the descriptor
   // desc. GetCode() is idempotent; it returns the same result if no other
   // Assembler functions are invoked in between GetCode() calls.
   void GetCode(CodeDesc* desc);
 
@@ -647,11 +690,11 @@
   // position (after the move) to the destination.
   void movl(const Operand& dst, Label* src);
 
   // Move sign extended immediate to memory location.
   void movq(const Operand& dst, Immediate value);
-  // New x64 instructions to load a 64-bit immediate into a register.
+  // Instructions to load a 64-bit immediate into a register.
   // All 64-bit immediates must have a relocation mode.
   void movq(Register dst, void* ptr, RelocInfo::Mode rmode);
   void movq(Register dst, int64_t value, RelocInfo::Mode rmode);
   void movq(Register dst, const char* s, RelocInfo::Mode rmode);
   // Moves the address of the external reference into the register.
@@ -672,11 +715,11 @@
   void repmovsb();
   void repmovsw();
   void repmovsl();
   void repmovsq();
 
-  // New x64 instruction to load from an immediate 64-bit pointer into RAX.
+  // Instruction to load from an immediate 64-bit pointer into RAX.
   void load_rax(void* ptr, RelocInfo::Mode rmode);
   void load_rax(ExternalReference ext);
 
   // Conditional moves.
   void cmovq(Condition cc, Register dst, Register src);
@@ -1107,10 +1150,11 @@
   void bt(const Operand& dst, Register src);
   void bts(const Operand& dst, Register src);
 
   // Miscellaneous
   void clc();
+  void cld();
   void cpuid();
   void hlt();
   void int3();
   void nop();
   void nop(int n);
@@ -1282,10 +1326,12 @@
   void addsd(XMMRegister dst, XMMRegister src);
   void subsd(XMMRegister dst, XMMRegister src);
   void mulsd(XMMRegister dst, XMMRegister src);
   void divsd(XMMRegister dst, XMMRegister src);
 
+  void andpd(XMMRegister dst, XMMRegister src);
+  void orpd(XMMRegister dst, XMMRegister src);
   void xorpd(XMMRegister dst, XMMRegister src);
   void sqrtsd(XMMRegister dst, XMMRegister src);
 
   void ucomisd(XMMRegister dst, XMMRegister src);
   void ucomisd(XMMRegister dst, const Operand& src);
@@ -1339,10 +1385,13 @@
 
   // Avoid overflows for displacements etc.
   static const int kMaximalBufferSize = 512*MB;
   static const int kMinimalBufferSize = 4*KB;
 
+ protected:
+  bool emit_debug_code() const { return emit_debug_code_; }
+
  private:
   byte* addr_at(int pos)  { return buffer_ + pos; }
   byte byte_at(int pos)  { return buffer_[pos]; }
   void set_byte_at(int pos, byte value) { buffer_[pos] = value; }
   uint32_t long_at(int pos)  {
@@ -1532,21 +1581,22 @@
   // The buffer into which code and relocation info are generated.
   byte* buffer_;
   int buffer_size_;
   // True if the assembler owns the buffer, false if buffer is external.
   bool own_buffer_;
-  // A previously allocated buffer of kMinimalBufferSize bytes, or NULL.
-  static byte* spare_buffer_;
 
   // code generation
   byte* pc_;  // the program counter; moves forward
   RelocInfoWriter reloc_info_writer;
 
   List< Handle<Code> > code_targets_;
   // push-pop elimination
   byte* last_pc_;
 
   PositionsRecorder positions_recorder_;
+
+  bool emit_debug_code_;
+
   friend class PositionsRecorder;
 };
 
 
 // Helper class that ensures that there is enough space for generating