[llvm-commits] [llvm] r133108 - in /llvm/trunk: include/llvm/ include/llvm/Analysis/ include/llvm/Support/ include/llvm/Transforms/ lib/CodeGen/ lib/Transforms/Scalar/ test/Transforms/ObjCARC/

[Chris Lattner]

On Jun 15, 2011, at 4:37 PM, John McCall wrote:

> Author: rjmccall
> Date: Wed Jun 15 18:37:01 2011
> New Revision: 133108
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=133108&view=rev
> Log:
> The ARC language-specific optimizer.  Credit to Dan Gohman.


Hi Dan,

> +++ llvm/trunk/include/llvm/Support/PassManagerBuilder.h Wed Jun 15 18:37:01 2011
> @@ -188,6 +188,7 @@
>       MPM.add(createArgumentPromotionPass());   // Scalarize uninlined fn args
> 
>     // Start of function pass.
> +    MPM.add(createObjCARCExpandPass());         // Canonicalize ObjC ARC code.
>     // Break up aggregate allocas, using SSAUpdater.
>     MPM.add(createScalarReplAggregatesPass(-1, false));
>     MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
> @@ -223,6 +224,7 @@
>     MPM.add(createJumpThreadingPass());         // Thread jumps
>     MPM.add(createCorrelatedValuePropagationPass());
>     MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
> +    MPM.add(createObjCARCOptPass());            // Objective-C ARC optimizations.
>     MPM.add(createAggressiveDCEPass());         // Delete dead instructions
>     MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
>     MPM.add(createInstructionCombiningPass());  // Clean up after everything.

I don't think that it makes sense to add this pass unconditionally to the pass manager.  Non-ObjC languages shouldn't have to link in the pass etc.  Can you change clang to use PassManagerBuilder::addExtension (adding extension points as needed)?

This way only clang will have to link in the pass, not everything that uses the standard sequence.  Likewise for the codegen passmgr.

-Chris