diff options
Diffstat (limited to 'subx/018jump_disp16.cc')
-rw-r--r-- | subx/018jump_disp16.cc | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/subx/018jump_disp16.cc b/subx/018jump_disp16.cc new file mode 100644 index 00000000..1cbb50a4 --- /dev/null +++ b/subx/018jump_disp16.cc @@ -0,0 +1,293 @@ +//: jump to 16-bit offset + +//:: jump + +:(before "End Initialize Op Names(name)") +put(name, "e9", "jump disp16 bytes away"); + +:(scenario jump_rel16) +== 0x1 +# 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(90, "run") << "jump " << offset << end(); + EIP += offset; + break; +} +:(code) +int16_t imm16() { + int16_t result = next(); + result |= (next()<<8); + return result; +} + +//:: jump if equal/zero + +:(before "End Initialize Op Names(name)") +put(name_0f, "84", "jump disp16 bytes away if ZF is set"); + +:(scenario je_rel16_success) +% ZF = true; +== 0x1 +# 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(90, "run") << "jump " << NUM(offset) << end(); + EIP += offset; + } + break; +} + +:(scenario je_rel16_fail) +% ZF = false; +== 0x1 +# 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 + +:(before "End Initialize Op Names(name)") +put(name_0f, "85", "jump disp16 bytes away if ZF is not set"); + +:(scenario jne_rel16_success) +% ZF = false; +== 0x1 +# 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(90, "run") << "jump " << NUM(offset) << end(); + EIP += offset; + } + break; +} + +:(scenario jne_rel16_fail) +% ZF = true; +== 0x1 +# 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 + +:(before "End Initialize Op Names(name)") +put(name_0f, "8f", "jump disp16 bytes away if greater (ZF is unset, SF == OF)"); + +:(scenario jg_rel16_success) +% ZF = false; +% SF = false; +% OF = false; +== 0x1 +# 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(90, "run") << "jump " << NUM(offset) << end(); + EIP += offset; + } + break; +} + +:(scenario jg_rel16_fail) +% ZF = false; +% SF = true; +% OF = false; +== 0x1 +# 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 + +:(before "End Initialize Op Names(name)") +put(name_0f, "8d", "jump disp16 bytes away if greater or equal (SF == OF)"); + +:(scenario jge_rel16_success) +% SF = false; +% OF = false; +== 0x1 +# 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(90, "run") << "jump " << NUM(offset) << end(); + EIP += offset; + } + break; +} + +:(scenario jge_rel16_fail) +% SF = true; +% OF = false; +== 0x1 +# 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 + +:(before "End Initialize Op Names(name)") +put(name_0f, "8c", "jump disp16 bytes away if lesser (SF != OF)"); + +:(scenario jl_rel16_success) +% ZF = false; +% SF = true; +% OF = false; +== 0x1 +# 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(90, "run") << "jump " << NUM(offset) << end(); + EIP += offset; + } + break; +} + +:(scenario jl_rel16_fail) +% ZF = false; +% SF = false; +% OF = false; +== 0x1 +# 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 + +:(before "End Initialize Op Names(name)") +put(name_0f, "8e", "jump disp16 bytes away if lesser or equal (ZF is set or SF != OF)"); + +:(scenario jle_rel16_equal) +% ZF = true; +% SF = false; +% OF = false; +== 0x1 +# 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; +== 0x1 +# 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(90, "run") << "jump " << NUM(offset) << end(); + EIP += offset; + } + break; +} + +:(scenario jle_rel16_greater) +% ZF = false; +% SF = false; +% OF = false; +== 0x1 +# 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 |