Revert "[InstCombine] Fix PR35618: Instcombine hangs on single minmax load bitcast."

This reverts commit r320510 - again sanitizers bbots.

llvm-svn: 320513

1 files changed, 11 insertions, 29 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index 5e4d32d6880..01fc1528681 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -1339,39 +1339,25 @@ static bool equivalentAddressValues(Value *A, Value *B) {
 /// Converts store (bitcast (load (bitcast (select ...)))) to
 /// store (load (select ...)), where select is minmax:
 /// select ((cmp load V1, load V2), V1, V2).
-static Instruction *removeBitcastsFromLoadStoreOnMinMax(InstCombiner &IC,
-                                                        StoreInst &SI) {
+bool removeBitcastsFromLoadStoreOnMinMax(InstCombiner &IC, StoreInst &SI) {
   // bitcast?
-  if (!match(SI.getPointerOperand(), m_BitCast(m_Value())))
-    return nullptr;
+  Value *StoreAddr;
+  if (!match(SI.getPointerOperand(), m_BitCast(m_Value(StoreAddr))))
+    return false;
   // load? integer?
   Value *LoadAddr;
   if (!match(SI.getValueOperand(), m_Load(m_BitCast(m_Value(LoadAddr)))))
-    return nullptr;
+    return false;
   auto *LI = cast<LoadInst>(SI.getValueOperand());
   if (!LI->getType()->isIntegerTy())
-    return nullptr;
+    return false;
   if (!isMinMaxWithLoads(LoadAddr))
-    return nullptr;
-
-  if (!all_of(LI->users(), [LI, LoadAddr](User *U) {
-        auto *SI = dyn_cast<StoreInst>(U);
-        return SI && SI->getPointerOperand() != LI &&
-               peekThroughBitcast(SI->getPointerOperand()) != LoadAddr &&
-               !SI->getPointerOperand()->isSwiftError();
-      }))
-    return nullptr;
+    return false;
 
-  IC.Builder.SetInsertPoint(LI);
   LoadInst *NewLI = combineLoadToNewType(
       IC, *LI, LoadAddr->getType()->getPointerElementType());
-  // Replace all the stores with stores of the newly loaded value.
-  for (auto *UI : LI->users()) {
-    auto *USI = cast<StoreInst>(UI);
-    IC.Builder.SetInsertPoint(USI);
-    combineStoreToNewValue(IC, *USI, NewLI);
-  }
-  return LI;
+  combineStoreToNewValue(IC, SI, NewLI);
+  return true;
 }
 
 Instruction *InstCombiner::visitStoreInst(StoreInst &SI) {
@@ -1398,12 +1384,8 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) {
   if (unpackStoreToAggregate(*this, SI))
     return eraseInstFromFunction(SI);
 
-  if (Instruction *I = removeBitcastsFromLoadStoreOnMinMax(*this, SI)) {
-    for (auto *UI : I->users())
-      eraseInstFromFunction(*cast<Instruction>(UI));
-    eraseInstFromFunction(*I);
-    return nullptr;
-  }
+  if (removeBitcastsFromLoadStoreOnMinMax(*this, SI))
+    return eraseInstFromFunction(SI);
 
   // Replace GEP indices if possible.
   if (Instruction *NewGEPI = replaceGEPIdxWithZero(*this, Ptr, SI)) {