diff --git a/part1/build.bat b/part1/build.bat index d2fdc1a..1e5861c 100644 --- a/part1/build.bat +++ b/part1/build.bat @@ -12,6 +12,7 @@ copy /Y %script_dir%\listing_0038_many_register_mov %build_dir% 1>NUL copy /Y %script_dir%\listing_0039_more_movs %build_dir% 1>NUL copy /Y %script_dir%\listing_0040_challenge_movs %build_dir% 1>NUL copy /Y %script_dir%\listing_0041_add_sub_cmp_jnz %build_dir% 1>NUL +copy /Y %script_dir%\listing_0042_completionist_decode %build_dir% 1>NUL REM Build REM =========================================================================== @@ -45,3 +46,8 @@ set listing_0041=%build_dir%\listing_0041_add_sub_cmp_jnz %build_dir%\sim8086.exe %listing_0041% > %listing_0041%_disassembled.asm nasm %listing_0041%_disassembled.asm fc /B %listing_0041% %listing_0041%_disassembled || exit /b 1 + +set listing_0042=%build_dir%\listing_0042_completionist_decode +%build_dir%\sim8086.exe %listing_0042% > %listing_0042%_disassembled.asm +nasm %listing_0042%_disassembled.asm +fc /B %listing_0042% %listing_0042%_disassembled || exit /b 1 diff --git a/part1/sim8086.c b/part1/sim8086.c index 052ea30..2613c82 100644 --- a/part1/sim8086.c +++ b/part1/sim8086.c @@ -77,6 +77,14 @@ typedef enum S86_InstructionType { S86_InstructionType_MOVRegOrMemToSegReg, S86_InstructionType_MOVSegRegToRegOrMem, + S86_InstructionType_PUSHRegOrMem, + S86_InstructionType_PUSHReg, + S86_InstructionType_PUSHSegReg, + + S86_InstructionType_POPRegOrMem, + S86_InstructionType_POPReg, + S86_InstructionType_POPSegReg, + S86_InstructionType_ADDRegOrMemToOrFromReg, S86_InstructionType_ADDImmediateToRegOrMem, S86_InstructionType_ADDImmediateToAccum, @@ -265,12 +273,6 @@ void S86_Print(S86_Str8 string) } } -void S86_PrintLn(S86_Str8 string) -{ - S86_Print(string); - S86_Print(S86_STR8("\n")); -} - void S86_PrintFmt(char const *fmt, ...) { va_list args, args_copy; @@ -291,6 +293,12 @@ void S86_PrintFmt(char const *fmt, ...) va_end(args); } +void S86_PrintLn(S86_Str8 string) +{ + S86_Print(string); + S86_Print(S86_STR8("\n")); +} + void S86_PrintLnFmt(char const *fmt, ...) { va_list args, args_copy; @@ -410,81 +418,103 @@ int main(int argc, char **argv) REGISTER_FIELD_ENCODING[0b1][6] = S86_STR8("si"); REGISTER_FIELD_ENCODING[0b1][7] = S86_STR8("di"); -S86_Instruction const S86_INSTRUCTIONS[S86_InstructionType_Count] = { - [S86_InstructionType_MOVRegOrMemToOrFromReg] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b1000'1000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, - [S86_InstructionType_MOVImmediateToRegOrMem] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0011'1000, - .op_bits0 = 0b1100'0110, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, - [S86_InstructionType_MOVImmediateToReg] = {.op_mask0 = 0b1111'0000, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b1011'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, - [S86_InstructionType_MOVMemToAccum] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b1010'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, - [S86_InstructionType_MOVAccumToMem] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b1010'0010, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, - [S86_InstructionType_MOVRegOrMemToSegReg] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0010'0000, - .op_bits0 = 0b1000'1110, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, - [S86_InstructionType_MOVSegRegToRegOrMem] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0010'0000, - .op_bits0 = 0b1000'1100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, - [S86_InstructionType_ADDRegOrMemToOrFromReg] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0000'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("add")}, - [S86_InstructionType_ADDImmediateToRegOrMem] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0011'1000, - .op_bits0 = 0b1000'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("add")}, - [S86_InstructionType_ADDImmediateToAccum] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0000'0100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("add")}, - [S86_InstructionType_SUBRegOrMemToOrFromReg] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0010'1000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("sub")}, - [S86_InstructionType_SUBImmediateFromRegOrMem] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0011'1000, - .op_bits0 = 0b1000'0000, .op_bits1 = 0b0010'1000, .mnemonic = S86_STR8("sub")}, - [S86_InstructionType_SUBImmediateFromAccum] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0010'1100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("sub")}, - [S86_InstructionType_CMPRegOrMemAndReg] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0011'1000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("cmp")}, - [S86_InstructionType_CMPImmediateWithRegOrMem] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0011'1000, - .op_bits0 = 0b1000'0000, .op_bits1 = 0b0011'1000, .mnemonic = S86_STR8("cmp")}, - [S86_InstructionType_CMPImmediateWithAccum] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0011'1100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("cmp")}, - [S86_InstructionType_JE_JZ] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'0100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("je")}, - [S86_InstructionType_JL_JNGE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'1100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jl")}, - [S86_InstructionType_JLE_JNG] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'1110, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jle")}, - [S86_InstructionType_JB_JNAE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'0010, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jb")}, - [S86_InstructionType_JBE_JNA] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'0110, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jbe")}, - [S86_InstructionType_JP_JPE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'1010, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jp")}, - [S86_InstructionType_JO] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jo")}, - [S86_InstructionType_JS] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'1000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("js")}, - [S86_InstructionType_JNE_JNZ] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'0101, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jnz")}, - [S86_InstructionType_JNL_JGE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'1101, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jnl")}, - [S86_InstructionType_JNLE_JG] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'1111, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jg")}, - [S86_InstructionType_JNB_JAE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'0011, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jnb")}, - [S86_InstructionType_JNBE_JA] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'0111, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("ja")}, - [S86_InstructionType_JNP_JO] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'1011, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jnp")}, - [S86_InstructionType_JNO] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'0001, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jno")}, - [S86_InstructionType_JNS] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b0111'1001, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jns")}, - [S86_InstructionType_LOOP] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b1110'0010, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("loop")}, - [S86_InstructionType_LOOPZ_LOOPE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b1110'0001, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("loopz")}, - [S86_InstructionType_LOOPNZ_LOOPNE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b1110'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("loopnz")}, - [S86_InstructionType_JCXZ] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, - .op_bits0 = 0b1110'0011, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jcxz")}, -}; + S86_Instruction const S86_INSTRUCTIONS[S86_InstructionType_Count] = { + [S86_InstructionType_MOVRegOrMemToOrFromReg] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b1000'1000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, + [S86_InstructionType_MOVImmediateToRegOrMem] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0011'1000, + .op_bits0 = 0b1100'0110, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, + [S86_InstructionType_MOVImmediateToReg] = {.op_mask0 = 0b1111'0000, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b1011'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, + [S86_InstructionType_MOVMemToAccum] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b1010'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, + [S86_InstructionType_MOVAccumToMem] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b1010'0010, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, + [S86_InstructionType_MOVRegOrMemToSegReg] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0010'0000, + .op_bits0 = 0b1000'1110, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, + [S86_InstructionType_MOVSegRegToRegOrMem] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0010'0000, + .op_bits0 = 0b1000'1100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("mov")}, + [S86_InstructionType_PUSHRegOrMem] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0011'1000, + .op_bits0 = 0b1111'1111, .op_bits1 = 0b0011'0000, .mnemonic = S86_STR8("push")}, + [S86_InstructionType_PUSHReg] = {.op_mask0 = 0b1111'1000, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0101'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("push")}, + [S86_InstructionType_PUSHSegReg] = {.op_mask0 = 0b1110'0111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0000'0110, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("push")}, + + [S86_InstructionType_POPRegOrMem] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0011'1000, + .op_bits0 = 0b1000'1111, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("pop")}, + [S86_InstructionType_POPReg] = {.op_mask0 = 0b1111'1000, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0101'1000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("pop")}, + [S86_InstructionType_POPSegReg] = {.op_mask0 = 0b1110'0111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0000'0111, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("pop")}, + + + [S86_InstructionType_ADDRegOrMemToOrFromReg] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0000'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("add")}, + [S86_InstructionType_ADDImmediateToRegOrMem] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0011'1000, + .op_bits0 = 0b1000'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("add")}, + [S86_InstructionType_ADDImmediateToAccum] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0000'0100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("add")}, + [S86_InstructionType_SUBRegOrMemToOrFromReg] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0010'1000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("sub")}, + [S86_InstructionType_SUBImmediateFromRegOrMem] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0011'1000, + .op_bits0 = 0b1000'0000, .op_bits1 = 0b0010'1000, .mnemonic = S86_STR8("sub")}, + [S86_InstructionType_SUBImmediateFromAccum] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0010'1100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("sub")}, + [S86_InstructionType_CMPRegOrMemAndReg] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0011'1000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("cmp")}, + [S86_InstructionType_CMPImmediateWithRegOrMem] = {.op_mask0 = 0b1111'1100, .op_mask1 = 0b0011'1000, + .op_bits0 = 0b1000'0000, .op_bits1 = 0b0011'1000, .mnemonic = S86_STR8("cmp")}, + [S86_InstructionType_CMPImmediateWithAccum] = {.op_mask0 = 0b1111'1110, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0011'1100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("cmp")}, + [S86_InstructionType_JE_JZ] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'0100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("je")}, + [S86_InstructionType_JL_JNGE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'1100, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jl")}, + [S86_InstructionType_JLE_JNG] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'1110, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jle")}, + [S86_InstructionType_JB_JNAE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'0010, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jb")}, + [S86_InstructionType_JBE_JNA] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'0110, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jbe")}, + [S86_InstructionType_JP_JPE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'1010, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jp")}, + [S86_InstructionType_JO] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jo")}, + [S86_InstructionType_JS] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'1000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("js")}, + [S86_InstructionType_JNE_JNZ] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'0101, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jnz")}, + [S86_InstructionType_JNL_JGE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'1101, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jnl")}, + [S86_InstructionType_JNLE_JG] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'1111, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jg")}, + [S86_InstructionType_JNB_JAE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'0011, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jnb")}, + [S86_InstructionType_JNBE_JA] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'0111, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("ja")}, + [S86_InstructionType_JNP_JO] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'1011, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jnp")}, + [S86_InstructionType_JNO] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'0001, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jno")}, + [S86_InstructionType_JNS] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b0111'1001, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jns")}, + [S86_InstructionType_LOOP] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b1110'0010, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("loop")}, + [S86_InstructionType_LOOPZ_LOOPE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b1110'0001, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("loopz")}, + [S86_InstructionType_LOOPNZ_LOOPNE] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b1110'0000, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("loopnz")}, + [S86_InstructionType_JCXZ] = {.op_mask0 = 0b1111'1111, .op_mask1 = 0b0000'0000, + .op_bits0 = 0b1110'0011, .op_bits1 = 0b0000'0000, .mnemonic = S86_STR8("jcxz")}, + }; + + S86_Str8 SEGMENT_REGISTER_NAME[] = { + [0b00] = S86_STR8("es"), + [0b01] = S86_STR8("cs"), + [0b10] = S86_STR8("ss"), + [0b11] = S86_STR8("ds"), + }; // NOTE: Decode assembly // ========================================================================= @@ -539,6 +569,35 @@ S86_Instruction const S86_INSTRUCTIONS[S86_InstructionType_Count] = { switch (instruction_type) { + case S86_InstructionType_POPRegOrMem: /*FALLTHRU*/ + case S86_InstructionType_PUSHRegOrMem: { + S86_ASSERT(op_code_size == 2); + uint8_t mod = (op_code_bytes[1] & 0b1100'0000) >> 6; + uint8_t rm = (op_code_bytes[1] & 0b0000'0111) >> 0; + S86_ASSERT(mod < 4); S86_ASSERT(rm < 8); + S86_EffectiveAddressStr8 effective_address = S86_EffectiveAddressCalc(&buffer_it, rm, mod, 0 /*w*/); + S86_PrintLnFmt("%.*s word %.*s", S86_STR8_FMT(instruction->mnemonic), S86_STR8_FMT(effective_address)); + } break; + + case S86_InstructionType_PUSHReg: /*FALLTHRU*/ + case S86_InstructionType_POPReg: /*FALLTHRU*/ + case S86_InstructionType_PUSHSegReg: /*FALLTHRU*/ + case S86_InstructionType_POPSegReg: { + S86_ASSERT(op_code_size == 1); + S86_Str8 reg_name = {0}; + if (instruction_type == S86_InstructionType_PUSHReg || + instruction_type == S86_InstructionType_POPReg) { + uint8_t reg = (op_code_bytes[0] & 0b0000'0111) >> 0; + reg_name = REGISTER_FIELD_ENCODING[/*w*/1][reg]; + } else { + S86_ASSERT(instruction_type == S86_InstructionType_PUSHSegReg || + instruction_type == S86_InstructionType_POPSegReg); + uint8_t sr = (op_code_bytes[0] & 0b0001'1000) >> 3; + reg_name = SEGMENT_REGISTER_NAME[sr]; + } + S86_PrintLnFmt("%.*s %.*s", S86_STR8_FMT(instruction->mnemonic), S86_STR8_FMT(reg_name)); + } break; + case S86_InstructionType_CMPRegOrMemAndReg: /*FALLTHRU*/ case S86_InstructionType_SUBRegOrMemToOrFromReg: /*FALLTHRU*/ case S86_InstructionType_ADDRegOrMemToOrFromReg: /*FALLTHRU*/