Commit 19cad46f authored by Bill Wendling's avatar Bill Wendling
Browse files

Approved by Chris: 

$ svn merge -c 113820 https://llvm.org/svn/llvm-project/llvm/trunk
--- Merging r113820 into '.':
U    test/Transforms/LICM/crash.ll
U    lib/Transforms/Scalar/LICM.cpp

Log:
fix PR8102, a case where we'd copyValue from a value that we already
deleted.  Fix this by doing the copyValue's before we delete stuff!

llvm-svn: 113823
parent 078d13e7

llvm/lib/Transforms/Scalar/LICM.cpp

+11 −11
Original line number Diff line number Diff line
@@ -852,6 +852,17 @@ void LICM::PromoteAliasSet(AliasSet &AS) { 
    ReplacedLoads[ALoad] = NewVal;

  }

  

  // If the preheader load is itself a pointer, we need to tell alias analysis

  // about the new pointer we created in the preheader block and about any PHI

  // nodes that just got inserted.

  if (PreheaderLoad->getType()->isPointerTy()) {

    // Copy any value stored to or loaded from a must-alias of the pointer.

    CurAST->copyValue(SomeValue, PreheaderLoad);

    

    for (unsigned i = 0, e = NewPHIs.size(); i != e; ++i)

      CurAST->copyValue(SomeValue, NewPHIs[i]);

  }

  

  // Now that everything is rewritten, delete the old instructions from the body

  // of the loop.  They should all be dead now.

  for (unsigned i = 0, e = LoopUses.size(); i != e; ++i) {
@@ -882,17 +893,6 @@ void LICM::PromoteAliasSet(AliasSet &AS) { 
    User->eraseFromParent();

  }

  

  // If the preheader load is itself a pointer, we need to tell alias analysis

  // about the new pointer we created in the preheader block and about any PHI

  // nodes that just got inserted.

  if (PreheaderLoad->getType()->isPointerTy()) {

    // Copy any value stored to or loaded from a must-alias of the pointer.

    CurAST->copyValue(SomeValue, PreheaderLoad);



    for (unsigned i = 0, e = NewPHIs.size(); i != e; ++i)

      CurAST->copyValue(SomeValue, NewPHIs[i]);

  }

  

  // fwew, we're done!

}

llvm/test/Transforms/LICM/crash.ll

+20 −0
Original line number Diff line number Diff line
@@ -39,3 +39,23 @@ for.body: ; preds = %for.body, %entry 
  store i32 undef, i32* @g_8, align 4

  br label %for.body

}



; PR8102

define void @test3() {

entry:

  %__first = alloca { i32* }

  br i1 undef, label %for.cond, label %for.end



for.cond:                                         ; preds = %for.cond, %entry

  %tmp1 = getelementptr { i32*}* %__first, i32 0, i32 0

  %tmp2 = load i32** %tmp1, align 4

  %call = tail call i32* @test3helper(i32* %tmp2)

  %tmp3 = getelementptr { i32*}* %__first, i32 0, i32 0

  store i32* %call, i32** %tmp3, align 4

  br i1 false, label %for.cond, label %for.end



for.end:                                          ; preds = %for.cond, %entry

  ret void

}



declare i32* @test3helper(i32*)