InstSimplify: Require instruction be parented

Unlike every other analysis and transform, simplifyInstruction
permitted operating on instructions which are not inserted
into a function. This created an edge case no other code needs
to really worry about, and limited transforms in cases that
can make use of the context function. Only the inliner and a handful
of other utilities were making use of this, so just fix up these
edge cases. Results in some IR ordering differences since
cloned blocks are inserted eagerly now. Plus some additional
simplifications trigger (e.g. some add 0s now folded out that
previously didn't).

1 files changed, 6 insertions, 9 deletions

diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index 272970e..d552086 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -470,9 +470,8 @@ void PruningFunctionCloner::CloneBlock(
 
   // Nope, clone it now.
   BasicBlock *NewBB;
-  BBEntry = NewBB = BasicBlock::Create(BB->getContext());
-  if (BB->hasName())
-    NewBB->setName(BB->getName() + NameSuffix);
+  Twine NewName(BB->hasName() ? Twine(BB->getName()) + NameSuffix : "");
+  BBEntry = NewBB = BasicBlock::Create(BB->getContext(), NewName, NewFunc);
 
   // It is only legal to clone a function if a block address within that
   // function is never referenced outside of the function.  Given that, we
@@ -498,6 +497,7 @@ void PruningFunctionCloner::CloneBlock(
        ++II) {
 
     Instruction *NewInst = cloneInstruction(II);
+    NewInst->insertInto(NewBB, NewBB->end());
 
     if (HostFuncIsStrictFP) {
       // All function calls in the inlined function must get 'strictfp'
@@ -516,8 +516,6 @@ void PruningFunctionCloner::CloneBlock(
       // If we can simplify this instruction to some other value, simply add
       // a mapping to that value rather than inserting a new instruction into
       // the basic block.
-      //
-      // FIXME: simplifyInstruction should know the context of the new function.
       if (Value *V =
               simplifyInstruction(NewInst, BB->getModule()->getDataLayout())) {
         // On the off-chance that this simplifies to an instruction in the old
@@ -528,7 +526,7 @@ void PruningFunctionCloner::CloneBlock(
 
         if (!NewInst->mayHaveSideEffects()) {
           VMap[&*II] = V;
-          NewInst->deleteValue();
+          NewInst->eraseFromParent();
           continue;
         }
       }
@@ -537,7 +535,6 @@ void PruningFunctionCloner::CloneBlock(
     if (II->hasName())
       NewInst->setName(II->getName() + NameSuffix);
     VMap[&*II] = NewInst; // Add instruction map to value.
-    NewInst->insertInto(NewBB, NewBB->end());
     if (isa<CallInst>(II) && !II->isDebugOrPseudoInst()) {
       hasCalls = true;
       hasMemProfMetadata |= II->hasMetadata(LLVMContext::MD_memprof);
@@ -685,8 +682,8 @@ void llvm::CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc,
     if (!NewBB)
       continue; // Dead block.
 
-    // Add the new block to the new function.
-    NewFunc->insert(NewFunc->end(), NewBB);
+    // Move the new block to preserve the order in the original function.
+    NewBB->moveBefore(NewFunc->end());
 
     // Handle PHI nodes specially, as we have to remove references to dead
     // blocks.