[llvm-commits] [llvm] r165989 - in /llvm/trunk: lib/Target/X86/X86ISelDAGToDAG.cpp lib/Target/X86/X86ISelLowering.cpp lib/Target/X86/X86ISelLowering.h lib/Target/X86/X86InstrCompiler.td lib/Target/X86/X86InstrInfo.td lib/Target/X86/X86RegisterInf

[Eli Friedman]

On Mon, Oct 15, 2012 at 3:39 PM, Michael Liao <michael.liao at intel.com> wrote:
> Author: hliao
> Date: Mon Oct 15 17:39:43 2012
> New Revision: 165989
>
> URL: http://llvm.org/viewvc/llvm-project?rev=165989&view=rev
> Log:
> Add __builtin_setjmp/_longjmp supprt in X86 backend
>
> - Besides used in SjLj exception handling, __builtin_setjmp/__longjmp is also
>   used as a light-weight replacement of setjmp/longjmp which are used to
>   implementation continuation, user-level threading, and etc. The support added
>   in this patch ONLY addresses this usage and is NOT intended to support SjLj
>   exception handling as zero-cost DWARF exception handling is used by default
>   in X86.

The implementation of __builtin_setjmp causes a link error on x86-64
OSX.  Specifically, you can't take the address of a label in the way
you're doing it (generating an instruction like "movq	$LBB1_12,
8(%rsi)"); the right way to take the address of a label is using
RIP-relative addressing.

-Eli