//: jump to 16-bit offset //:: jump :(scenario jump_rel16) # op ModR/M SIB displacement immediate e9 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: jump 5 +run: inst: 0x00000009 -run: inst: 0x00000003 :(before "End Single-Byte Opcodes") case 0xe9: { // jump rel8 int16_t offset = imm16(); trace(2, "run") << "jump " << offset << end(); EIP += offset; break; } :(code) int16_t imm16() { int16_t result = next(); result |= (next()<<8); return result; } //:: jump if equal/zero :(scenario je_rel16_success) % ZF = true; # op ModR/M SIB displacement immediate 0f 84 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: jump 5 +run: inst: 0x0000000a -run: inst: 0x00000005 :(before "End Two-Byte Opcodes Starting With 0f") case 0x84: { // jump rel16 if ZF int8_t offset = imm16(); if (ZF) { trace(2, "run") << "jump " << NUM(offset) << end(); EIP += offset; } break; } :(scenario je_rel16_fail) % ZF = false; # op ModR/M SIB displacement immediate 0f 84 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: inst: 0x00000005 +run: inst: 0x0000000a -run: jump 5 //:: jump if not equal/not zero :(scenario jne_rel16_success) % ZF = false; # op ModR/M SIB displacement immediate 0f 85 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: jump 5 +run: inst: 0x0000000a -run: inst: 0x00000005 :(before "End Two-Byte Opcodes Starting With 0f") case 0x85: { // jump rel16 unless ZF int8_t offset = imm16(); if (!ZF) { trace(2, "run") << "jump " << NUM(offset) << end(); EIP += offset; } break; } :(scenario jne_rel16_fail) % ZF = true; # op ModR/M SIB displacement immediate 0f 85 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: inst: 0x00000005 +run: inst: 0x0000000a -run: jump 5 //:: jump if greater :(scenario jg_rel16_success) % ZF = false; % SF = false; % OF = false; # op ModR/M SIB displacement immediate 0f 8f 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: jump 5 +run: inst: 0x0000000a -run: inst: 0x00000005 :(before "End Two-Byte Opcodes Starting With 0f") case 0x8f: { // jump rel16 if !SF and !ZF int8_t offset = imm16(); if (!ZF && SF == OF) { trace(2, "run") << "jump " << NUM(offset) << end(); EIP += offset; } break; } :(scenario jg_rel16_fail) % ZF = false; % SF = true; % OF = false; # op ModR/M SIB displacement immediate 0f 8f 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: inst: 0x00000005 +run: inst: 0x0000000a -run: jump 5 //:: jump if greater or equal :(scenario jge_rel16_success) % SF = false; % OF = false; # op ModR/M SIB displacement immediate 0f 8d 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: jump 5 +run: inst: 0x0000000a -run: inst: 0x00000005 :(before "End Two-Byte Opcodes Starting With 0f") case 0x8d: { // jump rel16 if !SF int8_t offset = imm16(); if (SF == OF) { trace(2, "run") << "jump " << NUM(offset) << end(); EIP += offset; } break; } :(scenario jge_rel16_fail) % SF = true; % OF = false; # op ModR/M SIB displacement immediate 0f 8d 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: inst: 0x00000005 +run: inst: 0x0000000a -run: jump 5 //:: jump if lesser :(scenario jl_rel16_success) % ZF = false; % SF = true; % OF = false; # op ModR/M SIB displacement immediate 0f 8c 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: jump 5 +run: inst: 0x0000000a -run: inst: 0x00000005 :(before "End Two-Byte Opcodes Starting With 0f") case 0x8c: { // jump rel16 if SF and !ZF int8_t offset = imm16(); if (SF != OF) { trace(2, "run") << "jump " << NUM(offset) << end(); EIP += offset; } break; } :(scenario jl_rel16_fail) % ZF = false; % SF = false; % OF = false; # op ModR/M SIB displacement immediate 0f 8c 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: inst: 0x00000005 +run: inst: 0x0000000a -run: jump 5 //:: jump if lesser or equal :(scenario jle_rel16_equal) % ZF = true; % SF = false; % OF = false; # op ModR/M SIB displacement immediate 0f 8e 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: jump 5 +run: inst: 0x0000000a -run: inst: 0x00000005 :(scenario jle_rel16_lesser) % ZF = false; % SF = true; % OF = false; # op ModR/M SIB displacement immediate 0f 8e 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: jump 5 +run: inst: 0x0000000a -run: inst: 0x00000005 :(before "End Two-Byte Opcodes Starting With 0f") case 0x8e: { // jump rel16 if SF or ZF int8_t offset = imm16(); if (ZF || SF != OF) { trace(2, "run") << "jump " << NUM(offset) << end(); EIP += offset; } break; } :(scenario jle_rel16_greater) % ZF = false; % SF = false; % OF = false; # op ModR/M SIB displacement immediate 0f 8e 05 00 # skip 1 instruction 05 00 00 00 01 05 00 00 00 02 +run: inst: 0x00000001 +run: inst: 0x00000005 +run: inst: 0x0000000a -run: jump 5