diff options
Diffstat (limited to 'subx')
| -rw-r--r-- | subx/014indirect_addressing.cc | 64 | ||||
| -rw-r--r-- | subx/021byte_addressing.cc | 63 |
2 files changed, 63 insertions, 64 deletions
diff --git a/subx/014indirect_addressing.cc b/subx/014indirect_addressing.cc index c6bedace..1e20cff5 100644 --- a/subx/014indirect_addressing.cc +++ b/subx/014indirect_addressing.cc @@ -382,70 +382,6 @@ case 0x8b: { // copy r32 to r/m32 break; } -//: - -:(before "End Initialize Op Names(name)") -put(name, "88", "copy r8 (lowermost byte of r32) to r8/m8-at-r32"); - -:(scenario copy_r8_to_mem_at_r32) -% Reg[EBX].i = 0x224488ab; -% Reg[EAX].i = 0x2000; -== 0x1 -# op ModR/M SIB displacement immediate - 88 18 # copy just the lowermost byte of EBX to the byte at *EAX -# ModR/M in binary: 00 (indirect mode) 011 (src EBX) 000 (dest EAX) -== 0x2000 -f0 cc bb aa # 0xf0 with more data in following bytes -+run: copy lowermost byte of EBX to r8/m8-at-r32 -+run: effective address is 0x2000 (EAX) -+run: storing 0xab -% CHECK_EQ(0xaabbccab, read_mem_u32(0x2000)); - -:(before "End Single-Byte Opcodes") -case 0x88: { // copy r8 to r/m8 - const uint8_t modrm = next(); - const uint8_t rsrc = (modrm>>3)&0x7; - trace(90, "run") << "copy lowermost byte of " << rname(rsrc) << " to r8/m8-at-r32" << end(); - // use unsigned to zero-extend 8-bit value to 32 bits - uint8_t* dest = reinterpret_cast<uint8_t*>(effective_address(modrm)); - *dest = Reg[rsrc].u; - trace(90, "run") << "storing 0x" << HEXBYTE << NUM(*dest) << end(); - break; -} - -//: - -:(before "End Initialize Op Names(name)") -put(name, "8a", "copy r8/m8-at-r32 to r8 (lowermost byte of r32)"); - -:(scenario copy_mem_at_r32_to_r8) -% Reg[EBX].i = 0xaabbcc0f; // one nibble each of lowest byte set to all 0s and all 1s, to maximize value of this test -% Reg[EAX].i = 0x2000; -== 0x1 -# op ModR/M SIB displacement immediate - 8a 18 # copy just the byte at *EAX to lowermost byte of EBX (clearing remaining bytes) -# ModR/M in binary: 00 (indirect mode) 011 (dest EBX) 000 (src EAX) -== 0x2000 # data segment -ab ff ff ff # 0xab with more data in following bytes -+run: copy r8/m8-at-r32 to lowermost byte of EBX -+run: effective address is 0x2000 (EAX) -+run: storing 0xab -# remaining bytes of EBX are *not* cleared -+run: EBX now contains 0xaabbccab - -:(before "End Single-Byte Opcodes") -case 0x8a: { // copy r/m8 to r8 - const uint8_t modrm = next(); - const uint8_t rdest = (modrm>>3)&0x7; - trace(90, "run") << "copy r8/m8-at-r32 to lowermost byte of " << rname(rdest) << end(); - // use unsigned to zero-extend 8-bit value to 32 bits - const uint8_t* src = reinterpret_cast<uint8_t*>(effective_address(modrm)); - trace(90, "run") << "storing 0x" << HEXBYTE << NUM(*src) << end(); - *reinterpret_cast<uint8_t*>(&Reg[rdest].u) = *src; // assumes host is little-endian - trace(90, "run") << rname(rdest) << " now contains 0x" << HEXWORD << Reg[rdest].u << end(); - break; -} - //:: jump :(scenario jump_mem_at_r32) diff --git a/subx/021byte_addressing.cc b/subx/021byte_addressing.cc new file mode 100644 index 00000000..84a51779 --- /dev/null +++ b/subx/021byte_addressing.cc @@ -0,0 +1,63 @@ +//: + +:(before "End Initialize Op Names(name)") +put(name, "88", "copy r8 (lowermost byte of r32) to r8/m8-at-r32"); + +:(scenario copy_r8_to_mem_at_r32) +% Reg[EBX].i = 0x224488ab; +% Reg[EAX].i = 0x2000; +== 0x1 +# op ModR/M SIB displacement immediate + 88 18 # copy just the lowermost byte of EBX to the byte at *EAX +# ModR/M in binary: 00 (indirect mode) 011 (src EBX) 000 (dest EAX) +== 0x2000 +f0 cc bb aa # 0xf0 with more data in following bytes ++run: copy lowermost byte of EBX to r8/m8-at-r32 ++run: effective address is 0x2000 (EAX) ++run: storing 0xab +% CHECK_EQ(0xaabbccab, read_mem_u32(0x2000)); + +:(before "End Single-Byte Opcodes") +case 0x88: { // copy r8 to r/m8 + const uint8_t modrm = next(); + const uint8_t rsrc = (modrm>>3)&0x7; + trace(90, "run") << "copy lowermost byte of " << rname(rsrc) << " to r8/m8-at-r32" << end(); + // use unsigned to zero-extend 8-bit value to 32 bits + uint8_t* dest = reinterpret_cast<uint8_t*>(effective_address(modrm)); + *dest = Reg[rsrc].u; + trace(90, "run") << "storing 0x" << HEXBYTE << NUM(*dest) << end(); + break; +} + +//: + +:(before "End Initialize Op Names(name)") +put(name, "8a", "copy r8/m8-at-r32 to r8 (lowermost byte of r32)"); + +:(scenario copy_mem_at_r32_to_r8) +% Reg[EBX].i = 0xaabbcc0f; // one nibble each of lowest byte set to all 0s and all 1s, to maximize value of this test +% Reg[EAX].i = 0x2000; +== 0x1 +# op ModR/M SIB displacement immediate + 8a 18 # copy just the byte at *EAX to lowermost byte of EBX (clearing remaining bytes) +# ModR/M in binary: 00 (indirect mode) 011 (dest EBX) 000 (src EAX) +== 0x2000 # data segment +ab ff ff ff # 0xab with more data in following bytes ++run: copy r8/m8-at-r32 to lowermost byte of EBX ++run: effective address is 0x2000 (EAX) ++run: storing 0xab +# remaining bytes of EBX are *not* cleared ++run: EBX now contains 0xaabbccab + +:(before "End Single-Byte Opcodes") +case 0x8a: { // copy r/m8 to r8 + const uint8_t modrm = next(); + const uint8_t rdest = (modrm>>3)&0x7; + trace(90, "run") << "copy r8/m8-at-r32 to lowermost byte of " << rname(rdest) << end(); + // use unsigned to zero-extend 8-bit value to 32 bits + const uint8_t* src = reinterpret_cast<uint8_t*>(effective_address(modrm)); + trace(90, "run") << "storing 0x" << HEXBYTE << NUM(*src) << end(); + *reinterpret_cast<uint8_t*>(&Reg[rdest].u) = *src; // assumes host is little-endian + trace(90, "run") << rname(rdest) << " now contains 0x" << HEXWORD << Reg[rdest].u << end(); + break; +} |