src/hotspot/cpu/x86/nativeInst_x86.hpp

rev 47415 : Add Thread Local handshakes and thread local polling

*** 27,36 ****
--- 27,37 ----
  
  #include "asm/assembler.hpp"
  #include "memory/allocation.hpp"
  #include "runtime/icache.hpp"
  #include "runtime/os.hpp"
+ #include "runtime/safepointMechanism.hpp"
  
  // We have interfaces for the following instructions:
  // - NativeInstruction
  // - - NativeCall
  // - - NativeMovConstReg
*** 676,685 ****
--- 677,687 ----
  class NativeTstRegMem: public NativeInstruction {
   public:
    enum Intel_specific_constants {
      instruction_rex_prefix_mask = 0xF0,
      instruction_rex_prefix      = Assembler::REX,
+     instruction_rex_b_prefix    = Assembler::REX_B,
      instruction_code_memXregl   = 0x85,
      modrm_mask                  = 0x38, // select reg from the ModRM byte
      modrm_reg                   = 0x00  // rax
    };
  };
*** 701,710 ****
--- 703,722 ----
  inline bool NativeInstruction::is_far_jump()     { return is_mov_literal64(); }
  inline bool NativeInstruction::is_cond_jump()    { return (int_at(0) & 0xF0FF) == 0x800F /* long jump */ ||
                                                            (ubyte_at(0) & 0xF0) == 0x70;  /* short jump */ }
  inline bool NativeInstruction::is_safepoint_poll() {
  #ifdef AMD64
+   if (SafepointMechanism::uses_thread_local_poll()) {
+     // We know that the poll must have a REX_B prefix since we enforce its source to be
+     // a rex-register and the destination to be rax.
+     const bool has_rex_prefix = ubyte_at(0) == NativeTstRegMem::instruction_rex_b_prefix;
+     const bool is_test_opcode = ubyte_at(1) == NativeTstRegMem::instruction_code_memXregl;
+     const bool is_rax_target = (ubyte_at(2) & NativeTstRegMem::modrm_mask) == NativeTstRegMem::modrm_reg;
+     if (has_rex_prefix && is_test_opcode && is_rax_target) {
+       return true;
+     }
+   }
    // Try decoding a near safepoint first:
    if (ubyte_at(0) == NativeTstRegMem::instruction_code_memXregl &&
        ubyte_at(1) == 0x05) { // 00 rax 101
      address fault = addr_at(6) + int_at(2);
      NOT_JVMCI(assert(!Assembler::is_polling_page_far(), "unexpected poll encoding");)