Add shift operations to x64 assembler.

src/x64/assembler-x64.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 540 matching lines @@
     immediate_arithmetic_op(0x1, dst, src);
   }
 
   void or_(const Operand& dst, Immediate src) {
     immediate_arithmetic_op(0x1, dst, src);
   }
 
 
   void rcl(Register dst, uint8_t imm8);
 
-  void sar(Register dst, uint8_t imm8);
-  void sar(Register dst);
-
   void sbb(Register dst, const Operand& src);
 
   void shld(Register dst, const Operand& src);
 
-  void shl(Register dst, uint8_t imm8);
-  void shl(Register dst);
-
   void shrd(Register dst, const Operand& src);
 
-  void shr(Register dst, uint8_t imm8);
-  void shr(Register dst);
-  void shr_cl(Register dst);
+  // Shifts dst right, duplicating sign bit, by shift_amount bits.
+  // Shifting by 1 is handled efficiently.
+  void sar(Register dst, Immediate shift_amount) {
+    shift(dst, shift_amount, 0x7);
+  }
+
+  // Shifts dst right, duplicating sign bit, by cl % 64 bits.
+  void sar(Register dst) {
+    shift(dst, 0x7);
+  }
+
+  void shl(Register dst, Immediate shift_amount) {
+    shift(dst, shift_amount, 0x4);
+  }
+
+  void shl(Register dst) {
+    shift(dst, 0x4);
+  }
+
+  void shr(Register dst, Immediate shift_amount) {
+    shift(dst, shift_amount, 0x5);
+  }
+
+  void shr(Register dst) {
+    shift(dst, 0x5);
+  }
 
   void sub(Register dst, Register src) {
     arithmetic_op(0x2B, dst, src);
   }
 
   void sub(Register dst, const Operand& src) {
     arithmetic_op(0x2B, dst, src);
   }
 
   void sub(const Operand& dst, Register src) {
@@ skipping 291 matching lines @@
   inline void emit_code_relative_offset(Label* label);
 
   // Emit machine code for one of the operations ADD, ADC, SUB, SBC,
   // AND, OR, XOR, or CMP.  The encodings of these operations are all
   // similar, differing just in the opcode or in the reg field of the
   // Mod/RM byte.
   void arithmetic_op(byte opcode, Register dst, Register src);
   void arithmetic_op(byte opcode, Register reg, const Operand& op);
   void immediate_arithmetic_op(byte subcode, Register dst, Immediate src);
   void immediate_arithmetic_op(byte subcode, const Operand& dst, Immediate src);
+  // Emit machine code for a shift operation.
+  void shift(Register dst, Immediate shift_amount, int subcode);
+  // Shift dst by cl % 64 bits.
+  void shift(Register dst, int subcode);
 
   void emit_farith(int b1, int b2, int i);
 
   // labels
   void print(Label* L);
   void bind_to(Label* L, int pos);
   void link_to(Label* L, Label* appendix);
 
   // record reloc info for current pc_
   void RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data = 0);
@@ skipping 48 matching lines @@
  private:
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_ASSEMBLER_X64_H_