llvm dev - Jul 2007 - [LLVMdev] Question about Constant Expressions

Hi!

Is there a pass that will remove constant expressions from appearing
within other expressions?  For instance it would convert the call:
  %tmp20 = tail call i32 (i8*, ...)* @printf( i8* getelementptr ([4 x
i8]* @.str, i32 0, i32 0), i32 %tmp18 )   ; <i32> [#uses=0]

Into:
  %tmpFresh = getelementptr [4 x i8]* @.str, i32 0, i32 0 ; <i8*> [#uses =
1]
  %tmp20 = tail call i32 (i8*, ...)* @printf( i8* %tmpFresh, i32
%tmp18 )   ; <i32> [#uses=0]

(Ideally it would do this as an .s -> .s transformation and be
accessible through a tool like opt).

Thanks,
Ben Chambers

On Tue, 3 Jul 2007, Ben Chambers wrote:
> Is there a pass that will remove constant expressions from appearing
> within other expressions?  For instance it would convert the call:
>  %tmp20 = tail call i32 (i8*, ...)* @printf( i8* getelementptr ([4 x
> i8]* @.str, i32 0, i32 0), i32 %tmp18 )   ; <i32> [#uses=0]
>
> Into:
>  %tmpFresh = getelementptr [4 x i8]* @.str, i32 0, i32 0 ; <i8*>
[#uses = 1]
>  %tmp20 = tail call i32 (i8*, ...)* @printf( i8* %tmpFresh, i32
> %tmp18 )   ; <i32> [#uses=0]
>
> (Ideally it would do this as an .s -> .s transformation and be
> accessible through a tool like opt).
We used to have a 'lowerconstantexpr' pass in transforms/scalar.  I
don't
know how to see deleted files in svn though.

-Chris

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