[llvm-commits] [llvm] r48909 - /llvm/trunk/lib/Transforms/Scalar/GVN.cpp

[Duncan Sands]

Hi Chris,

> > is this counting bytes stored, or store instructions?
> 
> This is checking # stores.  I'm open to suggestions, this is certainly  
> work in progress.  The idea is that merging just a few stores could be  
> done by the code generator, turning them into a larger scalar store.

it just doesn't seem canonical, while counting the number of bytes is.
By the way, how about turning 4 i8 stores into an i32 store here if you
think it's not worth doing a memset?  (Watch out for creating unaligned
stores!).

> What I want the optimizer to get is to turn huge sequences of stores  
> into memset.  For example, the testcase I'm working from looks like:

... snip example with a tiny number of stores :) ...

Also, are you planning to synthesize memset out of loops?  (Please say yes!)

Ciao,

Duncan.