Inline assembly disappears from output

[uzytkownik]

It seems like bug in LLVM generator. Code

let rip: u64;
asm!("movq %rip, %rax" : "={rax}"(rip) ::: "volatile");

Produces correct LLVM IR:

  %46 = call i64 asm sideeffect "movq %rip, %rax", "={rax},~{dirflag},~{fpsr},~{flags}"(), !dbg !4561, !srcloc !4562

But the output sometimes does not contain the instruction and the value of rip is 0x1d1d1d1d1d1d1d1d.

[eefriedman]

Umm, I think you meant to write "leaq (%rip), %rax"? You can't MOV out of RIP.

It's probably a bug that LLVM doesn't reject it, though.

[uzytkownik]

It looks like this is issue 22892 after all.

Umm, I think you meant to write "leaq (%rip), %rax"? You can't MOV out of RIP.

Yes, I just didn't remembered that I cannot.

[jethrogb]

Referencing #22892

[jethrogb]

This issue can be closed, fixed in nightly: https://is.gd/Q3RvxB