[LLVMdev] [PATCH] Fix nondeterministic behaviour in the CodeExtractor

[Julien Lerouge]

On Fri, Jan 08, 2010 at 05:04:17PM -0800, Chris Lattner wrote:

> On Jan 8, 2010, at 5:01 PM, Julien Lerouge wrote:

> >Hello,
> >
> >The CodeExtractor contains a std::set<BasicBlock*> to keep track
> >of the
> >blocks to extract. Iterators on this set are not deterministic, and so
> >the functions that are generated are not (the order of the
> >inputs/outputs can change).
> >
> >The attached patch uses a SetVector instead. Ok to apply ?

> Nice catch, please apply,

> -Chris

Thanks for the quick review. There is actually more, is it ok to apply
this one as well (avoid std:vector<Value*> being sorted) ? 

Thanks,
Julien

-- 
Julien Lerouge
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-------------- next part --------------
Index: lib/Transforms/Utils/CodeExtractor.cpp
===================================================================
--- lib/Transforms/Utils/CodeExtractor.cpp	(revision 93080)
+++ lib/Transforms/Utils/CodeExtractor.cpp	(working copy)
@@ -%ld,%ld +%ld,%ld @@
 
 namespace {
   class CodeExtractor {
-    typedef std::vector<Value*> Values;
+    typedef SetVector<Value*> Values;
     SetVector<BasicBlock*> BlocksToExtract;
     DominatorTree* DT;
     bool AggregateArgs;
@@ -%ld,%ld +%ld,%ld @@
       // instruction is used outside the region, it's an output.
       for (User::op_iterator O = I->op_begin(), E = I->op_end(); O != E; ++O)
         if (definedInCaller(*O))
-          inputs.push_back(*O);
+          inputs.insert(*O);
 
       // Consider uses of this instruction (outputs).
       for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
            UI != E; ++UI)
         if (!definedInRegion(*UI)) {
-          outputs.push_back(I);
+          outputs.insert(I);
           break;
         }
     } // for: insts
@@ -%ld,%ld +%ld,%ld @@
   } // for: basic blocks
 
   NumExitBlocks = ExitBlocks.size();
-
-  // Eliminate duplicates.
-  std::sort(inputs.begin(), inputs.end());
-  inputs.erase(std::unique(inputs.begin(), inputs.end()), inputs.end());
-  std::sort(outputs.begin(), outputs.end());
-  outputs.erase(std::unique(outputs.begin(), outputs.end()), outputs.end());
 }
 
 /// constructFunction - make a function based on inputs and outputs, as follows: