Question

Doing some inline assembly in clang (basically guessing my way through by using various references) and I’m trying to move the contents of %rdi to the address pointed to by %rdx. However none of my syntax works, this:

mov %rdi, ptr %rdx

gives:

error: expected relocatable expression

What’s wrong? What is the syntax in inline assembly in clang to do this? Thanks.

Answer 1

I don’t know what clang’s assembly syntax might be exactly, but the AT&T syntax used by gcc/gas would be:

movq %rdi, (%rdx)

The Intel/Microsoft assembly syntax would be:

mov qword ptr [rdx], rdi