D Source:
import core.stdc.stdio;
void main() {
ulong stuff;
asm {
xor RDI, RDI;
mov DIL, 1;
mov stuff, RDI;
}
printf("%lld\n", stuff);
}
Output: 0
obj2asm disassembly of main():
push RBP
mov RBP,RSP
sub RSP,010h
mov qword ptr -8[RBP],0
xor RDI,RDI
mov BH,1
mov -8[RBP],RDI
mov RSI,-8[RBP]
mov RDI,offset FLAT:.rodata@64
xor EAX,EAX
call printf@PC32
xor EAX,EAX
mov RSP,RBP
pop RBP
ret
The opcode for BH is being generated when the assembly language code says DIL.
Similarly, DH is generated when SIL is in the source code.