x86_64: Clean-up after cmp-long fix
The patch adresses the coments from review done by Ian Rogers.
Clean-up of assembler.
Change-Id: I9dbb350dfc6645f8a63d624b2b785233529459a9
Signed-off-by: Serguei Katkov <serguei.i.katkov@intel.com>
diff --git a/disassembler/disassembler_x86.cc b/disassembler/disassembler_x86.cc
index e6cbf05..61d5c81 100644
--- a/disassembler/disassembler_x86.cc
+++ b/disassembler/disassembler_x86.cc
@@ -201,7 +201,8 @@
std::ostringstream opcode;
bool store = false; // stores to memory (ie rm is on the left)
bool load = false; // loads from memory (ie rm is on the right)
- bool byte_operand = false;
+ bool byte_operand = false; // true when the opcode is dealing with byte operands
+ bool byte_second_operand = false; // true when the source operand is a byte register but the target register isn't (ie movsxb/movzxb).
bool target_specific = false; // register name depends on target (64 vs 32 bits).
bool ax = false; // implicit use of ax
bool cx = false; // implicit use of cx
@@ -732,9 +733,9 @@
break;
case 0xAF: opcode << "imul"; has_modrm = true; load = true; break;
case 0xB1: opcode << "cmpxchg"; has_modrm = true; store = true; break;
- case 0xB6: opcode << "movzxb"; has_modrm = true; load = true; break;
+ case 0xB6: opcode << "movzxb"; has_modrm = true; load = true; byte_second_operand = true; break;
case 0xB7: opcode << "movzxw"; has_modrm = true; load = true; break;
- case 0xBE: opcode << "movsxb"; has_modrm = true; load = true; break;
+ case 0xBE: opcode << "movsxb"; has_modrm = true; load = true; byte_second_operand = true; rex |= (rex == 0 ? 0 : 0b1000); break;
case 0xBF: opcode << "movsxw"; has_modrm = true; load = true; break;
case 0xC5:
if (prefix[2] == 0x66) {
@@ -1124,7 +1125,8 @@
} else {
if (mod == 3) {
if (!no_ops) {
- DumpRmReg(address, rex_w, rm, byte_operand, prefix[2], load ? src_reg_file : dst_reg_file);
+ DumpRmReg(address, rex_w, rm, byte_operand || byte_second_operand,
+ prefix[2], load ? src_reg_file : dst_reg_file);
}
} else {
address << "[";