[llvm-commits] [llvm] r117267 - /llvm/trunk/docs/LangRef.html

[Michael Spencer]

On Mon, Oct 25, 2010 at 12:29 PM, Charles Davis <cdavis at mines.edu> wrote:
> Author: cdavis
> Date: Mon Oct 25 11:29:03 2010
> New Revision: 117267
>
> URL: http://llvm.org/viewvc/llvm-project?rev=117267&view=rev
> Log:
> Make hotpatch attribute description a little less Wintel-specific.
>
> Modified:
>    llvm/trunk/docs/LangRef.html
>
> Modified: llvm/trunk/docs/LangRef.html
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/LangRef.html?rev=117267&r1=117266&r2=117267&view=diff
> ==============================================================================
> --- llvm/trunk/docs/LangRef.html (original)
> +++ llvm/trunk/docs/LangRef.html Mon Oct 25 11:29:03 2010
> @@ -1132,9 +1132,11 @@
>       threshold for this caller.</dd>
>
>   <dt><tt><b>hotpatch</b></tt></dt>
> -  <dd>This attribute indicates that the prologue should contain a 'hotpatch'
> -      sequence at the beginning. This is the same sequence used in the
> -      system DLLs in Microsoft Windows XP Service Pack 2 and higher.</dd>
> +  <dd>This attribute indicates that the function should be 'hotpatchable',
> +      meaning the function can be patched even while it is loaded into memory.
> +      On x86, the function prologue will contain a two-byte no-op sequence;
> +      this is the same sequence used in the system DLLs in Microsoft Windows
> +      XP Service Pack 2 and higher.</dd>
>
>   <dt><tt><b>inlinehint</b></tt></dt>
>   <dd>This attribute indicates that the source code contained a hint that inlining

The constraint is not a two byte no-op. The constraint is actually
that there be an instruction that is 2 bytes or larger. See
http://blogs.msdn.com/b/freik/archive/2006/03/07/x64-hotpatchability.aspx

- Michael Spencer