[llvm-commits] [poolalloc] r159572 - /poolalloc/trunk/lib/AssistDS/DSNodeEquivs.cpp

[John Criswell]

On 7/2/12 2:51 PM, Matthew Wala wrote:
> Author: wala1
> Date: Mon Jul  2 14:51:52 2012
> New Revision: 159572
>
> URL: http://llvm.org/viewvc/llvm-project?rev=159572&view=rev
> Log:
> Fix DSNodeEquivs to handle constant expressions; find some DSGraph an
> expression belongs to by looking through its uses.
>
> Modified:
>      poolalloc/trunk/lib/AssistDS/DSNodeEquivs.cpp
>
> Modified: poolalloc/trunk/lib/AssistDS/DSNodeEquivs.cpp
> URL: http://llvm.org/viewvc/llvm-project/poolalloc/trunk/lib/AssistDS/DSNodeEquivs.cpp?rev=159572&r1=159571&r2=159572&view=diff
> ==============================================================================
> --- poolalloc/trunk/lib/AssistDS/DSNodeEquivs.cpp (original)
> +++ poolalloc/trunk/lib/AssistDS/DSNodeEquivs.cpp Mon Jul  2 14:51:52 2012
> @@ -17,6 +17,9 @@
>   #include "llvm/Constants.h"
>   #include "llvm/Module.h"
>   #include "llvm/Support/InstIterator.h"
> +#include "llvm/ADT/SmallSet.h"
> +
> +#include <deque>
>   
>   namespace llvm {
>   
> @@ -233,6 +236,46 @@
>     } else if (isa<Argument>(V)) {
>       const Function *Parent = cast<Argument>(V)->getParent();
>       NHForV = &TDDS.getDSGraph(*Parent)->getNodeForValue(V);
> +  } else {
> +    //
> +    // Iterate over the users to attempt to discover a DSNode that the value
> +    // maps to.
> +    //
> +    std::deque<const User *> WL;
> +    SmallSet<const User *, 8> Visited;
> +
> +    WL.insert(WL.end(), V->use_begin(), V->use_end());
> +    do {
> +      const User *TheUser = WL.front();
> +      WL.pop_front();
> +
> +      if (Visited.count(TheUser))
> +        continue;
> +      else
> +        Visited.insert(TheUser);

You should check and see if the insert method can tell you whether the 
insert succeeded because the element was not in the set or whether the 
insert failed because the element was already in the set.  This feature 
allows you to do a single operation on the set and should speed up the 
analysis.

> +
> +      //
> +      // If the use is a global variable or instruction, then the value should
> +      // be in the corresponding DSGraph.
> +      //
> +      // TODO: Is it possible for a value to belong to some DSGraph and never
> +      // be relied upon by a GlobalValue or Instruction?
> +      //
> +      if (isa<Instruction>(TheUser)) {

Why not use dyn_cast<Instruction> here?  That would avoid the 
cast<Instruction> in the line below.

> +        const Function *Parent =
> +          cast<Instruction>(TheUser)->getParent()->getParent();
> +        NHForV = &TDDS.getDSGraph(*Parent)->getNodeForValue(V);
> +        break;
> +      } else if (isa<GlobalValue>(TheUser)) {
> +        NHForV = &TDDS.getGlobalsGraph()->getNodeForValue(V);
> +        break;
> +      } else {
> +        //
> +        // If this use is of some other nature, look at the users of this use.
> +        //
> +        WL.insert(WL.end(), TheUser->use_begin(), TheUser->use_end());
> +      }
> +    } while (!WL.empty());
>     }

You should have an assertion somewhere that ensures that you find a 
DSNode for the constant expression.

-- John T.