[llvm] r214550 - MS inline asm: Use memory constraints for functions instead of registers

[Duncan P. N. Exon Smith]

> On 2014 Aug 1, at 13:21, Reid Kleckner <reid at kleckner.net> wrote:
> 
> Author: rnk
> Date: Fri Aug  1 15:21:24 2014
> New Revision: 214550
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=214550&view=rev
> Log:
> MS inline asm: Use memory constraints for functions instead of registers
> 
> This is consistent with how we parse them in a standalone .s file, and
> inline assembly shouldn't differ.
> 
> This fixes errors about requiring more registers than available in
> cases like this:
>  void f();
>  void __declspec(naked) g() {
>    __asm pusha
>    __asm call f
>    __asm popa
>    __asm ret
>  }
> 
> There are no registers available to pass the address of 'f' into the asm
> blob.  The asm should now directly call 'f'.
> 
> Tests will land in Clang shortly.
> 
> Modified:
>    llvm/trunk/lib/Target/X86/AsmParser/X86AsmParser.cpp
>    llvm/trunk/test/CodeGen/X86/ms-inline-asm.ll

This testcase is failing locally for me on Darwin:

> error: inline assembly requires more registers than available
> FileCheck error: '-' is empty.

Let me know if you need help reproducing.