Revert "[ValueTracking] Let isGuaranteedNotToBeUndefOrPoison look into branch conditions of dominating blocks' terminators"

That commit causes SIGSEGV on some simple tests.
This reverts commit 952ad4701cf0d8da79789f6b83ddaa386c60d535.

1 files changed, 1 insertions, 26 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 34f8abd..e11f5e2 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -4525,9 +4525,7 @@ bool llvm::isOverflowIntrinsicNoWrap(const WithOverflowInst *WO,
   return llvm::any_of(GuardingBranches, AllUsesGuardedByBranch);
 }
 
-bool llvm::isGuaranteedNotToBeUndefOrPoison(const Value *V,
-                                            const Instruction *CtxI,
-                                            const DominatorTree *DT) {
+bool llvm::isGuaranteedNotToBeUndefOrPoison(const Value *V) {
   // If the value is a freeze instruction, then it can never
   // be undef or poison.
   if (isa<FreezeInst>(V))
@@ -4560,29 +4558,6 @@ bool llvm::isGuaranteedNotToBeUndefOrPoison(const Value *V,
       return true;
   }
 
-  if (!CtxI || !DT)
-    return false;
-
-  // If V is used as a branch condition before reaching CtxI, V cannot be
-  // undef or poison.
-  //   br V, BB1, BB2
-  // BB1:
-  //   CtxI ; V cannot be undef or poison here
-  auto Dominator = DT->getNode(CtxI->getParent())->getIDom();
-  while (Dominator) {
-    auto *TI = Dominator->getBlock()->getTerminator();
-
-    if (auto BI = dyn_cast<BranchInst>(TI)) {
-      if (BI->isConditional() && BI->getCondition() == V)
-        return true;
-    } else if (auto SI = dyn_cast<SwitchInst>(TI)) {
-      if (SI->getCondition() == V)
-        return true;
-    }
-
-    Dominator = Dominator->getIDom();
-  }
-
   return false;
 }