[llvm-commits] [llvm] r91104 - in /llvm/trunk/lib/Target/X86: X86InstrInfo.cpp X86InstrInfo.h

[Dan Gohman]

On Dec 10, 2009, at 10:01 PM, Evan Cheng wrote:

> Author: evancheng
> Date: Fri Dec 11 00:01:48 2009
> New Revision: 91104
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=91104&view=rev
> Log:
> Add support to 3-addressify 16-bit instructions.
> 
> Modified:
>    llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
>    llvm/trunk/lib/Target/X86/X86InstrInfo.h
> 
> Modified: llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrInfo.cpp?rev=91104&r1=91103&r2=91104&view=diff
> 
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/X86InstrInfo.cpp (original)
> +++ llvm/trunk/lib/Target/X86/X86InstrInfo.cpp Fri Dec 11 00:01:48 2009
> @@ -1058,6 +1058,107 @@
>   return false;
> }
> 
> +/// convertToThreeAddressWithLEA - Helper for convertToThreeAddress when 16-bit
> +/// 16-bit LEA is disabled, use 32-bit LEA to form 3-address code by promoting

Typo: "16-bit 16-bit".

> +/// to a 32-bit superregister and then truncating back down to a 16-bit
> +/// subregister.

This change introduces a partial register stall condition; are you
sure this is worthwhile? If so, please note this in a comment.

Also, do you have a testcase?

Dan