[LLVMdev] Inneffiecient code produced by reg2mem?

Owen Anderson resistor at mac.com
Wed Jul 25 14:03:38 PDT 2012


Why are you running reg2mem if you want efficient code?

--Owen 

On Jul 25, 2012, at 1:28 PM, ryan baird <ryanrbaird at gmail.com> wrote:

> Is there a pass I can use after reg2mem to get rid of occurances like this?:
> 
>   store i32 %cond, i32* %cond.reg2mem
>   %cond.reload = load i32* %cond.reg2mem
>   store i32 %cond.reload, i32* %cond4.reg2mem
> 
> Essentially, in this case, reg2mem creates an extra memory space to store and load a value from just here, and never uses the value again; since this isn't efficient code, I'm wondering if there's another pass I can use to fix the innefficient code reg2mem produces, or if my translator should do it's own PHI elimination?
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev




More information about the llvm-dev mailing list