[llvm-dev] Bug or incorrect use of inline asm?

[Johan Engelen via llvm-dev]

Hi all,
  I stumbled upon either a bug, or we are emitting wrong inline asm code.

The testcase is:
```
source_filename = "testcase.d"
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx"

define void @_D7asanasm3fooFZv() {
  %a = alloca [4 x i32], align 32
  call void asm sideeffect "movl %ebx, 4+$0", "=*m,~{memory}"([4 x i32]* %a)
  ret void
}
```

When I try to compile this to assembly code with llc, llc errors.
> llc testcase.ll -o testcase.s -O0
<inline asm>:1:16: error: unknown token in expression
        movl %ebx, 4+(%rsp)
                      ^

The explicit `-O0` is required for the error to arise.

The error is gone after removing (or reducing) the alignment of `%a`. This
makes me believe that our inline asm syntax is correct to add an offset to
a pointer: " 4+$0 ".

Is this a bug in the asm parser?

Thanks,
  Johan
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