Index: llvm/lib/Analysis/ValueTracking.cpp
===================================================================
--- llvm/lib/Analysis/ValueTracking.cpp
+++ llvm/lib/Analysis/ValueTracking.cpp
@@ -2450,21 +2450,19 @@
   else if (const PHINode *PN = dyn_cast<PHINode>(V)) {
     // Try and detect a recurrence that monotonically increases from a
     // starting value, as these are common as induction variables.
-    if (PN->getNumIncomingValues() == 2) {
-      Value *Start = PN->getIncomingValue(0);
-      Value *Induction = PN->getIncomingValue(1);
-      if (isa<ConstantInt>(Induction) && !isa<ConstantInt>(Start))
-        std::swap(Start, Induction);
-      if (ConstantInt *C = dyn_cast<ConstantInt>(Start)) {
-        if (!C->isZero() && !C->isNegative()) {
-          ConstantInt *X;
-          if (Q.IIQ.UseInstrInfo &&
-              (match(Induction, m_NSWAdd(m_Specific(PN), m_ConstantInt(X))) ||
-               match(Induction, m_NUWAdd(m_Specific(PN), m_ConstantInt(X)))) &&
-              !X->isNegative())
-            return true;
-        }
-      }
+    BinaryOperator *BO = nullptr;
+    Value *Start = nullptr, *Step = nullptr;
+    const APInt *StartC, *StepC;
+    if (Q.IIQ.UseInstrInfo && matchSimpleRecurrence(PN, BO, Start, Step) &&
+        match(Start, m_APInt(StartC)) && match(Step, m_APInt(StepC))) {
+      if (BO->getOpcode() == Instruction::Add &&
+          (BO->hasNoUnsignedWrap() || BO->hasNoSignedWrap()) &&
+          StartC->isStrictlyPositive() && !StepC->isNegative())
+        return true;
+      if (BO->getOpcode() == Instruction::Mul &&
+          (BO->hasNoUnsignedWrap() || BO->hasNoSignedWrap()) &&
+          !StartC->isNullValue() && StepC->isStrictlyPositive())
+        return true;
     }
     // Check if all incoming values are non-zero using recursion.
     Query RecQ = Q;
Index: llvm/test/Analysis/ValueTracking/monotonic-phi.ll
===================================================================
--- llvm/test/Analysis/ValueTracking/monotonic-phi.ll
+++ llvm/test/Analysis/ValueTracking/monotonic-phi.ll
@@ -77,3 +77,204 @@
   %cmp = icmp eq i8 %add, 0
   ret i1 %cmp
 }
+
+define i1 @test4(i8 %p, i8* %pq, i8 %n, i8 %r) {
+; CHECK-LABEL: @test4(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[A:%.*]] = phi i8 [ 0, [[ENTRY:%.*]] ], [ [[NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[NEXT]] = add nuw i8 [[A]], 1
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i8 [[A]], [[N:%.*]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[ADD:%.*]] = or i8 [[A]], [[R:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[ADD]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+entry:
+  br label %loop
+loop:
+  %A = phi i8 [ 0, %entry ], [ %next, %loop ]
+  %next = add nuw i8 %A, 1
+  %cmp1 = icmp eq i8 %A, %n
+  br i1 %cmp1, label %exit, label %loop
+exit:
+  %add = or i8 %A, %r
+  %cmp = icmp eq i8 %add, 0
+  ret i1 %cmp
+}
+
+define i1 @test5(i8 %p, i8* %pq, i8 %n, i8 %r) {
+; CHECK-LABEL: @test5(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[A:%.*]] = phi i8 [ -2, [[ENTRY:%.*]] ], [ [[NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[NEXT]] = add nuw i8 [[A]], 1
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i8 [[A]], [[N:%.*]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[ADD:%.*]] = or i8 [[A]], [[R:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[ADD]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+entry:
+  br label %loop
+loop:
+  %A = phi i8 [ -2, %entry ], [ %next, %loop ]
+  %next = add nuw i8 %A, 1
+  %cmp1 = icmp eq i8 %A, %n
+  br i1 %cmp1, label %exit, label %loop
+exit:
+  %add = or i8 %A, %r
+  %cmp = icmp eq i8 %add, 0
+  ret i1 %cmp
+}
+
+define i1 @test6(i8 %p, i8* %pq, i8 %n, i8 %r) {
+; CHECK-LABEL: @test6(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[A:%.*]] = phi i8 [ 2, [[ENTRY:%.*]] ], [ [[NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[NEXT]] = mul nsw i8 [[A]], 2
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i8 [[A]], [[N:%.*]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i1 false
+;
+entry:
+  br label %loop
+loop:
+  %A = phi i8 [ 2, %entry ], [ %next, %loop ]
+  %next = mul nsw i8 %A, 2
+  %cmp1 = icmp eq i8 %A, %n
+  br i1 %cmp1, label %exit, label %loop
+exit:
+  %cmp = icmp eq i8 %A, 0
+  ret i1 %cmp
+}
+
+define i1 @test7(i8 %p, i8* %pq, i8 %n, i8 %r) {
+; CHECK-LABEL: @test7(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[A:%.*]] = phi i8 [ 2, [[ENTRY:%.*]] ], [ [[NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[NEXT]] = mul i8 [[A]], 2
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i8 [[A]], [[N:%.*]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[A]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+entry:
+  br label %loop
+loop:
+  %A = phi i8 [ 2, %entry ], [ %next, %loop ]
+  %next = mul i8 %A, 2
+  %cmp1 = icmp eq i8 %A, %n
+  br i1 %cmp1, label %exit, label %loop
+exit:
+  %cmp = icmp eq i8 %A, 0
+  ret i1 %cmp
+}
+
+define i1 @test8(i8 %p, i8* %pq, i8 %n, i8 %r) {
+; CHECK-LABEL: @test8(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[A:%.*]] = phi i8 [ 2, [[ENTRY:%.*]] ], [ [[NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[NEXT]] = mul nuw i8 [[A]], 2
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i8 [[A]], [[N:%.*]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i1 false
+;
+entry:
+  br label %loop
+loop:
+  %A = phi i8 [ 2, %entry ], [ %next, %loop ]
+  %next = mul nuw i8 %A, 2
+  %cmp1 = icmp eq i8 %A, %n
+  br i1 %cmp1, label %exit, label %loop
+exit:
+  %cmp = icmp eq i8 %A, 0
+  ret i1 %cmp
+}
+
+define i1 @test9(i8 %p, i8* %pq, i8 %n, i8 %r) {
+; CHECK-LABEL: @test9(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[A:%.*]] = phi i8 [ 0, [[ENTRY:%.*]] ], [ [[NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[NEXT]] = mul nuw i8 [[A]], 2
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i8 [[A]], [[N:%.*]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[A]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+entry:
+  br label %loop
+loop:
+  %A = phi i8 [ 0, %entry ], [ %next, %loop ]
+  %next = mul nuw i8 %A, 2
+  %cmp1 = icmp eq i8 %A, %n
+  br i1 %cmp1, label %exit, label %loop
+exit:
+  %cmp = icmp eq i8 %A, 0
+  ret i1 %cmp
+}
+
+define i1 @test10(i8 %p, i8* %pq, i8 %n, i8 %r) {
+; CHECK-LABEL: @test10(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[A:%.*]] = phi i8 [ 2, [[ENTRY:%.*]] ], [ [[NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[NEXT]] = mul nuw i8 [[A]], -2
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i8 [[A]], [[N:%.*]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[A]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+entry:
+  br label %loop
+loop:
+  %A = phi i8 [ 2, %entry ], [ %next, %loop ]
+  %next = mul nuw i8 %A, -2
+  %cmp1 = icmp eq i8 %A, %n
+  br i1 %cmp1, label %exit, label %loop
+exit:
+  %cmp = icmp eq i8 %A, 0
+  ret i1 %cmp
+}
+
+define i1 @test11(i8 %p, i8* %pq, i8 %n, i8 %r) {
+; CHECK-LABEL: @test11(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK-NEXT:    [[A:%.*]] = phi i8 [ -2, [[ENTRY:%.*]] ], [ [[NEXT:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[NEXT]] = mul nuw i8 [[A]], 2
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i8 [[A]], [[N:%.*]]
+; CHECK-NEXT:    br i1 [[CMP1]], label [[EXIT:%.*]], label [[LOOP]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret i1 false
+;
+entry:
+  br label %loop
+loop:
+  %A = phi i8 [ -2, %entry ], [ %next, %loop ]
+  %next = mul nuw i8 %A, 2
+  %cmp1 = icmp eq i8 %A, %n
+  br i1 %cmp1, label %exit, label %loop
+exit:
+  %cmp = icmp eq i8 %A, 0
+  ret i1 %cmp
+}