[LLVMdev] RegAllocSimple doesn't work

[Evan Cheng]

I am not surprised. Since no one has been using it, it has bit rotted. Notice it has been removed from top of tree.

Why not use RegAllocLocal?

Evan

On Oct 26, 2009, at 1:35 PM, Susan Horwitz wrote:

> I tried both the most recent version of "simple" register allocation and the one from last August, and neither seems to work correctly (they run, but produce bad output).  I used them to compile an old version of the Unix "replace" utility (source code attached).  Here's how I created the executable:
> 
>  llvm-gcc -emit-llvm -O0 -c replace.c -o replace.bc
>  opt -mem2reg replace.bc > replace.ssa
>  mv replace.ssa replace.bc
>  llc -f -regalloc=simple replace.bc
>  gcc replace.s
> 
> Then I ran it like this (file "input" also attached):
> 
>  a.out This XXXX < input
> 
> I get a Segmentation fault with the current version of LLVM.  With the old version it runs, but I get garbage output.
> 
> If I create the ".s" file using just
>  llc -f replace.bc
> everything is fine.
> 
> 
> Does anyone know how to fix either version of RegAllocSimple?
> 
> Susan Horwitz
> <replace.c><input.txt>_______________________________________________
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