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| author | Kartik K. Agaram <vc@akkartik.com> | 2017-10-12 17:57:59 -0700 |
|---|---|---|
| committer | Kartik K. Agaram <vc@akkartik.com> | 2017-10-12 17:57:59 -0700 |
| commit | 7c0f7d69ae75ac06b5a17ee4d1e84ae05ac3a1c3 (patch) | |
| tree | 939e86bca328bd794a370b5dfd6cd4cb54b2472b | |
| parent | bcafd01fdfda38c7ea49ab3f9683dbd03282241f (diff) | |
| download | mu-7c0f7d69ae75ac06b5a17ee4d1e84ae05ac3a1c3.tar.gz | |
4036
| -rw-r--r-- | subx/011add.cc | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/subx/011add.cc b/subx/011add.cc index b84797d1..4f504be6 100644 --- a/subx/011add.cc +++ b/subx/011add.cc @@ -4,16 +4,16 @@ # word in addresses 0x60-0x63 has value 1 % Mem[0x60] = 1; # op ModR/M SIB displacement immediate - 01 18 # add EBX to *EAX -+run: add register 3 to effective address -+run: effective address is memory at address 0x60 (register 0) + 01 18 # add EBX (reg 3) to *EAX (reg 0) ++run: add reg 3 to effective address ++run: effective address is mem at address 0x60 (reg 0) +run: storing 0x11 :(before "End Single-Byte Opcodes") case 0x01: { // add r32 to r/m32 uint8_t modrm = next(); uint8_t arg2 = (modrm>>3)&0x7; - trace(2, "run") << "add register " << static_cast<int>(arg2) << " to effective address" << end(); + trace(2, "run") << "add reg " << static_cast<int>(arg2) << " to effective address" << end(); int32_t* arg1 = effective_address(modrm); BINARY_ARITHMETIC_OP(+, *arg1, Reg[arg2].i); break; @@ -25,7 +25,7 @@ case 0x01: { // add r32 to r/m32 // 'Mem' at once. int32_t* effective_address(uint8_t modrm) { uint8_t mod = (modrm>>6); - // ignore middle 3 'register opcode' bits + // ignore middle 3 'reg opcode' bits uint8_t rm = modrm & 0x7; int32_t* result = 0; switch (mod) { @@ -33,7 +33,7 @@ int32_t* effective_address(uint8_t modrm) { // mod 0 is usually indirect addressing switch (rm) { default: - trace(99, "run") << "effective address is memory at address 0x" << std::hex << Reg[rm].u << " (register " << static_cast<int>(rm) << ")" << end(); + trace(99, "run") << "effective address is mem at address 0x" << std::hex << Reg[rm].u << " (reg " << static_cast<int>(rm) << ")" << end(); assert(Reg[rm].u + sizeof(int32_t) <= Mem.size()); result = reinterpret_cast<int32_t*>(&Mem.at(Reg[rm].u)); // rely on the host itself being in little-endian order break; |