diff options
Diffstat (limited to 'subx/012direct_addressing.cc')
| -rw-r--r-- | subx/012direct_addressing.cc | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/subx/012direct_addressing.cc b/subx/012direct_addressing.cc index 43b1137b..aefe3214 100644 --- a/subx/012direct_addressing.cc +++ b/subx/012direct_addressing.cc @@ -87,6 +87,32 @@ case 0x29: { // subtract r32 from r/m32 break; } +//:: multiply + +:(before "End Initialize Op Names(name)") +put(name_0f, "af", "multiply r32 into rm32"); + +:(scenario multiply_r32_into_r32) +% Reg[EAX].i = 4; +% Reg[EBX].i = 2; +== 0x1 +# op ModR/M SIB displacement immediate + 0f af d8 # subtract EBX into EAX +# ModR/M in binary: 11 (direct mode) 011 (src EBX) 000 (dest EAX) ++run: multiply EBX into r/m32 ++run: r/m32 is EAX ++run: storing 0x00000008 + +:(before "End Two-Byte Opcodes Starting With 0f") +case 0xaf: { // multiply r32 into r/m32 + uint8_t modrm = next(); + uint8_t arg2 = (modrm>>3)&0x7; + trace(90, "run") << "multiply " << rname(arg2) << " into r/m32" << end(); + int32_t* arg1 = effective_address(modrm); + BINARY_ARITHMETIC_OP(*, *arg1, Reg[arg2].i); + break; +} + //:: and :(before "End Initialize Op Names(name)") |