[llvm] [Analysis][ValueTracking] Unify most of the tracking between AssumptionCache and DomConditionCache (PR #83161)

[Yingwei Zheng via llvm-commits]

================
@@ -7,75 +7,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/DomConditionCache.h"
-#include "llvm/IR/PatternMatch.h"
-
+#include "llvm/Analysis/ValueTracking.h"
 using namespace llvm;
-using namespace llvm::PatternMatch;
 
-// TODO: This code is very similar to findAffectedValues() in
-// AssumptionCache, but currently specialized to just the patterns that
-// computeKnownBits() supports, and without the notion of result elem indices
-// that are AC specific. Deduplicate this code once we have a clearer picture
-// of how much they can be shared.
 static void findAffectedValues(Value *Cond,
                                SmallVectorImpl<Value *> &Affected) {
-  auto AddAffected = [&Affected](Value *V) {
-    if (isa<Argument>(V) || isa<GlobalValue>(V)) {
-      Affected.push_back(V);
-    } else if (auto *I = dyn_cast<Instruction>(V)) {
-      Affected.push_back(I);
-
-      // Peek through unary operators to find the source of the condition.
-      Value *Op;
-      if (match(I, m_PtrToInt(m_Value(Op)))) {
-        if (isa<Instruction>(Op) || isa<Argument>(Op))
-          Affected.push_back(Op);
-      }
-    }
-  };
-
-  SmallVector<Value *, 8> Worklist;
-  SmallPtrSet<Value *, 8> Visited;
-  Worklist.push_back(Cond);
-  while (!Worklist.empty()) {
-    Value *V = Worklist.pop_back_val();
-    if (!Visited.insert(V).second)
-      continue;
-
-    CmpInst::Predicate Pred;
-    Value *A, *B;
-    if (match(V, m_LogicalOp(m_Value(A), m_Value(B)))) {
-      Worklist.push_back(A);
-      Worklist.push_back(B);
-    } else if (match(V, m_ICmp(Pred, m_Value(A), m_Constant()))) {
-      AddAffected(A);
-
-      if (ICmpInst::isEquality(Pred)) {
-        Value *X;
-        // (X & C) or (X | C) or (X ^ C).
-        // (X << C) or (X >>_s C) or (X >>_u C).
-        if (match(A, m_BitwiseLogic(m_Value(X), m_ConstantInt())) ||
-            match(A, m_Shift(m_Value(X), m_ConstantInt())))
-          AddAffected(X);
-      } else {
-        Value *X;
-        // Handle (A + C1) u< C2, which is the canonical form of
-        // A > C3 && A < C4.
-        if (match(A, m_Add(m_Value(X), m_ConstantInt())))
-          AddAffected(X);
-        // Handle icmp slt/sgt (bitcast X to int), 0/-1, which is supported by
-        // computeKnownFPClass().
-        if ((Pred == ICmpInst::ICMP_SLT || Pred == ICmpInst::ICMP_SGT) &&
-            match(A, m_ElementWiseBitCast(m_Value(X))))
-          Affected.push_back(X);
-      }
-    } else if (match(Cond, m_CombineOr(m_FCmp(Pred, m_Value(A), m_Constant()),
-                                       m_Intrinsic<Intrinsic::is_fpclass>(
-                                           m_Value(A), m_Constant())))) {
-      // Handle patterns that computeKnownFPClass() support.
-      AddAffected(A);
-    }
-  }
+  auto InsertAffected = [&Affected](Value *V) { Affected.push_back(V); };
+  llvm::findValuesAffectedByCondition(Cond, /*IsAssume*/ false, InsertAffected);
----------------
dtcxzyw wrote:

```suggestion
  llvm::findValuesAffectedByCondition(Cond, /*IsAssume=*/ false, InsertAffected);
```

https://github.com/llvm/llvm-project/pull/83161