1 //: jump to 8-bit offset
  2 
  3 //:: jump
  4 
  5 :(before "End Initialize Op Names")
  6 put_new(Name, "eb", "jump disp8 bytes away (jmp)");
  7 
  8 :(code)
  9 void test_jump_disp8() {
 10   run(
 11       "== code 0x1\n"
 12       // op     ModR/M  SIB   displacement  immediate
 13       "  eb                   05                        \n"  // skip 1 instruction
 14       "  05                                 00 00 00 01 \n"
 15       "  05                                 00 00 00 02 \n"
 16   );
 17   CHECK_TRACE_CONTENTS(
 18       "run: 0x00000001 opcode: eb\n"
 19       "run: jump 5\n"
 20       "run: 0x00000008 opcode: 05\n"
 21   );
 22   CHECK_TRACE_DOESNT_CONTAIN("run: 0x00000003 opcode: 05");
 23 }
 24 
 25 :(before "End Single-Byte Opcodes")
 26 case 0xeb: {  // jump disp8
 27   int8_t offset = static_cast<int>(next());
 28   trace(Callstack_depth+1, "run") << "jump " << NUM(offset) << end();
 29   EIP += offset;
 30   break;
 31 }
 32 
 33 //:: jump if equal/zero
 34 
 35 :(before "End Initialize Op Names")
 36 put_new(Name, "74", "jump disp8 bytes away if equal, if ZF is set (jcc/jz/je)");
 37 
 38 :(code)
 39 void test_je_disp8_success() {
 40   ZF = true;
 41   run(
 42       "== code 0x1\n"
 43       // op     ModR/M  SIB   displacement  immediate
 44       "  74                   05                        \n"  // skip 1 instruction
 45       "  05                                 00 00 00 01 \n"
 46       "  05                                 00 00 00 02 \n"
 47   );
 48   CHECK_TRACE_CONTENTS(
 49       "run: 0x00000001 opcode: 74\n"
 50       "run: jump 5\n"
 51       "run: 0x00000008 opcode: 05\n"
 52   );
 53   CHECK_TRACE_DOESNT_CONTAIN("run: 0x00000003 opcode: 05");
 54 }
 55 
 56 :(before "End Single-Byte Opcodes")
 57 case 0x74: {  // jump disp8 if ZF
 58   const int8_t offset = static_cast<int>(next());
 59   if (ZF) {
 60     trace(Callstack_depth+1, "run") << "jump " << NUM(offset) << end();
 61     EIP += offset;
 62   }
 63   break;
 64 }
 65 
 66 :(code)
 67 void test_je_disp8_fail() {
 68   ZF = false;
 69   run(
 70       "== code 0x1\n"
 71       // op     ModR/M  SIB   displacement  immediate
 72       "  74                   05                        \n"  // skip 1 instruction
 73       "  05                                 00 00 00 01 \n"
 74       "  05                                 00 00 00 02 \n"
 75   );
 76   CHECK_TRACE_CONTENTS(
 77       "run: 0x00000001 opcode: 74\n"
 78       "run: 0x00000003 opcode: 05\n"
 79       "run: 0x00000008 opcode: 05\n"
 80   );
 81   CHECK_TRACE_DOESNT_CONTAIN("run: jump 5");
 82 }
 83 
 84 //:: jump if not equal/not zero
 85 
 86 :(before "End Initialize Op Names")
 87 put_new(Name, "75", "jump disp8 bytes away if not equal, if ZF is not set (jcc/jnz/jne)");
 88 
 89 :(code)
 90 void test_jne_disp8_success() {
 91   ZF = false;
 92   run(
 93       "== code 0x1\n"
 94       // op     ModR/M  SIB   displacement  immediate
 95       "  75                   05                        \n"  // skip 1 instruction
 96       "  05                                 00 00 00 01 \n"
 97       "  05                                 00 00 00 02 \n"
 98   );
 99   CHECK_TRACE_CONTENTS(
100       "run: 0x00000001 opcode: 75\n"
101       "run: jump 5\n"
102       "run: 0x00000008 opcode: 05\n"
103   );
104   CHECK_TRACE_DOESNT_CONTAIN("run: 0x00000003 opcode: 05");
105 }
106 
107 :(before "End Single-Byte Opcodes")
108 case 0x75: {  // jump disp8 if !ZF
109   const int8_t offset = static_cast<int>(next());
110   if (!ZF) {
111     trace(Callstack_depth+1, "run") << "jump " << NUM