[ValueTracking] Tracking or disjoint conditions as add in Assumption/DomCondition Cache

We can definitionally treat `or disjoint` as `add` anywhere.

Author: goldsteinn

llvm/lib/Analysis/ValueTracking.cpp

@@ -699,7 +699,7 @@ static void computeKnownBitsFromCmp(const Value *V, CmpInst::Predicate Pred,
   }
   default:
     const APInt *Offset = nullptr;
-    if (match(LHS, m_CombineOr(m_V, m_Add(m_V, m_APInt(Offset)))) &&
+    if (match(LHS, m_CombineOr(m_V, m_AddLike(m_V, m_APInt(Offset)))) &&
         match(RHS, m_APInt(C))) {
       ConstantRange LHSRange = ConstantRange::makeAllowedICmpRegion(Pred, *C);
       if (Offset)
@@ -9285,7 +9285,7 @@ void llvm::findValuesAffectedByCondition(
       } else {
         // 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())) &&
+        if (match(A, m_AddLike(m_Value(X), m_ConstantInt())) &&
             match(B, m_ConstantInt()))
           AddAffected(X);
 

llvm/test/Transforms/InstCombine/known-bits.ll

@@ -490,8 +490,7 @@ define i1 @test_icmp_or_distjoint(i8 %n, i1 %other) {
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i8 [[N_OR]], -111
 ; CHECK-NEXT:    br i1 [[CMP]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
 ; CHECK:       if.then:
-; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[N]], 0
-; CHECK-NEXT:    ret i1 [[R]]
+; CHECK-NEXT:    ret i1 true
 ; CHECK:       if.else:
 ; CHECK-NEXT:    ret i1 [[OTHER:%.*]]
 ;