Revert "InstSimplify: Require instruction be parented"

This reverts commit 1536e299e63d7788f38117b0212ca50eb76d7a3b.

Reason: causes a regression in the inliner (see https://crbug.com/1454531 and https://reviews.llvm.org/rG1536e299e63d7788f38117b0212ca50eb76d7a3b#1217141)

1 files changed, 3 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp b/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
index d81db56..1a9eaf24 100644
--- a/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
+++ b/llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
@@ -435,8 +435,6 @@ bool LoopRotate::rotateLoop(Loop *L, bool SimplifiedLatch) {
 
       // Otherwise, create a duplicate of the instruction.
       Instruction *C = Inst->clone();
-      C->insertBefore(LoopEntryBranch);
-
       ++NumInstrsDuplicated;
 
       // Eagerly remap the operands of the instruction.
@@ -446,7 +444,7 @@ bool LoopRotate::rotateLoop(Loop *L, bool SimplifiedLatch) {
       // Avoid inserting the same intrinsic twice.
       if (auto *DII = dyn_cast<DbgVariableIntrinsic>(C))
         if (DbgIntrinsics.count(makeHash(DII))) {
-          C->eraseFromParent();
+          C->deleteValue();
           continue;
         }
 
@@ -459,7 +457,7 @@ bool LoopRotate::rotateLoop(Loop *L, bool SimplifiedLatch) {
         // in the map.
         InsertNewValueIntoMap(ValueMap, Inst, V);
         if (!C->mayHaveSideEffects()) {
-          C->eraseFromParent();
+          C->deleteValue();
           C = nullptr;
         }
       } else {
@@ -468,6 +466,7 @@ bool LoopRotate::rotateLoop(Loop *L, bool SimplifiedLatch) {
       if (C) {
         // Otherwise, stick the new instruction into the new block!
         C->setName(Inst->getName());
+        C->insertBefore(LoopEntryBranch);
 
         if (auto *II = dyn_cast<AssumeInst>(C))
           AC->registerAssumption(II);