src/hotspot/cpu/x86/nativeInst_x86.hpp

rev 48154 : 8193009: compiler/c2/Test7029152.java crashes with SIGILL in java.lang.StringLatin1.indexOf with -XX:+UseJVMCICompiler
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*** 704,721 ****
  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);
--- 704,718 ----
  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()) {
      const bool has_rex_prefix = ubyte_at(0) == NativeTstRegMem::instruction_rex_b_prefix;
!     const int test_offset = has_rex_prefix ? 1 : 0;
!     const bool is_test_opcode = ubyte_at(test_offset) == NativeTstRegMem::instruction_code_memXregl;
!     const bool is_rax_target = (ubyte_at(test_offset + 1) & NativeTstRegMem::modrm_mask) == NativeTstRegMem::modrm_reg;
!     return is_test_opcode && is_rax_target;
    }
    // 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);