diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1876,6 +1876,19 @@
   if (Instruction *Z = narrowMaskedBinOp(I))
     return Z;
 
+  if (I.getType()->isIntOrIntVectorTy(1)) {
+    if (auto *SI0 = dyn_cast<SelectInst>(Op0)) {
+      if (auto *I =
+              foldAndOrOfSelectUsingImpliedCond(Op1, *SI0, /* IsAnd */ true))
+        return I;
+    }
+    if (auto *SI1 = dyn_cast<SelectInst>(Op1)) {
+      if (auto *I =
+              foldAndOrOfSelectUsingImpliedCond(Op0, *SI1, /* IsAnd */ true))
+        return I;
+    }
+  }
+
   if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
     return FoldedLogic;
 
@@ -2553,6 +2566,20 @@
   if (Value *V = SimplifyBSwap(I, Builder))
     return replaceInstUsesWith(I, V);
 
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
+  if (I.getType()->isIntOrIntVectorTy(1)) {
+    if (auto *SI0 = dyn_cast<SelectInst>(Op0)) {
+      if (auto *I =
+              foldAndOrOfSelectUsingImpliedCond(Op1, *SI0, /* IsAnd */ false))
+        return I;
+    }
+    if (auto *SI1 = dyn_cast<SelectInst>(Op1)) {
+      if (auto *I =
+              foldAndOrOfSelectUsingImpliedCond(Op0, *SI1, /* IsAnd */ false))
+        return I;
+    }
+  }
+
   if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
     return FoldedLogic;
 
@@ -2577,7 +2604,6 @@
   }
 
   // (A & C)|(B & D)
-  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   Value *A, *B, *C, *D;
   if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
       match(Op1, m_And(m_Value(B), m_Value(D)))) {
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
--- a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
+++ b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
@@ -357,6 +357,13 @@
   Instruction *foldIntrinsicWithOverflowCommon(IntrinsicInst *II);
   Instruction *foldFPSignBitOps(BinaryOperator &I);
 
+  // Optimize one of these forms:
+  //   and i1 Op, SI / select i1 Op, i1 SI, i1 false (if IsAnd = true)
+  //   or i1 Op, SI  / select i1 Op, i1 true, i1 SI  (if IsAnd = false)
+  // into simplier select instruction using isImpliedCondition.
+  Instruction *foldAndOrOfSelectUsingImpliedCond(Value *Op, SelectInst &SI,
+                                                 bool IsAnd);
+
 public:
   /// Inserts an instruction \p New before instruction \p Old
   ///
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -2586,6 +2586,48 @@
   return nullptr;
 }
 
+Instruction *InstCombinerImpl::foldAndOrOfSelectUsingImpliedCond(Value *Op,
+                                                                 SelectInst &SI,
+                                                                 bool IsAnd) {
+  Value *CondVal = SI.getCondition();
+  Value *A = SI.getTrueValue();
+  Value *B = SI.getFalseValue();
+
+  assert(Op->getType()->isIntOrIntVectorTy(1) &&
+         "Op must be either i1 or vector of i1.");
+
+  Optional<bool> Res = isImpliedCondition(Op, CondVal, DL, IsAnd);
+  if (!Res)
+    return nullptr;
+
+  Value *Zero = Constant::getNullValue(A->getType());
+  Value *One = Constant::getAllOnesValue(A->getType());
+
+  if (*Res == true) {
+    if (IsAnd)
+      // select op, (select cond, A, B), false => select op, A, false
+      // and    op, (select cond, A, B)        => select op, A, false
+      //   if op = true implies condval = true.
+      return SelectInst::Create(Op, A, Zero);
+    else
+      // select op, true, (select cond, A, B) => select op, true, A
+      // or     op, (select cond, A, B)       => select op, true, A
+      //   if op = false implies condval = true.
+      return SelectInst::Create(Op, One, A);
+  } else {
+    if (IsAnd)
+      // select op, (select cond, A, B), false => select op, B, false
+      // and    op, (select cond, A, B)        => select op, B, false
+      //   if op = true implies condval = false.
+      return SelectInst::Create(Op, B, Zero);
+    else
+      // select op, true, (select cond, A, B) => select op, true, B
+      // or     op, (select cond, A, B)       => select op, true, B
+      //   if op = false implies condval = false.
+      return SelectInst::Create(Op, One, B);
+  }
+}
+
 Instruction *InstCombinerImpl::visitSelectInst(SelectInst &SI) {
   Value *CondVal = SI.getCondition();
   Value *TrueVal = SI.getTrueValue();
@@ -2709,6 +2751,11 @@
         replaceUse(*Y, FI);
         return replaceInstUsesWith(SI, Op1);
       }
+
+      if (auto *Op1SI = dyn_cast<SelectInst>(Op1))
+        if (auto *I = foldAndOrOfSelectUsingImpliedCond(CondVal, *Op1SI,
+                                                        /* IsAnd */ IsAnd))
+          return I;
     }
 
     // select (select a, true, b), c, false -> select a, c, false
diff --git a/llvm/test/Transforms/InstCombine/select-safe-bool-transforms.ll b/llvm/test/Transforms/InstCombine/select-safe-bool-transforms.ll
--- a/llvm/test/Transforms/InstCombine/select-safe-bool-transforms.ll
+++ b/llvm/test/Transforms/InstCombine/select-safe-bool-transforms.ll
@@ -49,9 +49,7 @@
 ; (A land B) lor A
 define i1 @land_lor_left1(i1 %A, i1 %B) {
 ; CHECK-LABEL: @land_lor_left1(
-; CHECK-NEXT:    [[C:%.*]] = select i1 [[A:%.*]], i1 [[B:%.*]], i1 false
-; CHECK-NEXT:    [[RES:%.*]] = or i1 [[C]], [[A]]
-; CHECK-NEXT:    ret i1 [[RES]]
+; CHECK-NEXT:    ret i1 [[A:%.*]]
 ;
   %c = select i1 %A, i1 %B, i1 false
   %res = select i1 %c, i1 true, i1 %A
@@ -71,9 +69,7 @@
 ; (A land B) bor A
 define i1 @land_bor_left1(i1 %A, i1 %B) {
 ; CHECK-LABEL: @land_bor_left1(
-; CHECK-NEXT:    [[C:%.*]] = select i1 [[A:%.*]], i1 [[B:%.*]], i1 false
-; CHECK-NEXT:    [[RES:%.*]] = or i1 [[C]], [[A]]
-; CHECK-NEXT:    ret i1 [[RES]]
+; CHECK-NEXT:    ret i1 [[A:%.*]]
 ;
   %c = select i1 %A, i1 %B, i1 false
   %res = or i1 %c, %A
@@ -129,9 +125,7 @@
 ; (A lor B) land A
 define i1 @lor_land_left1(i1 %A, i1 %B) {
 ; CHECK-LABEL: @lor_land_left1(
-; CHECK-NEXT:    [[C:%.*]] = select i1 [[A:%.*]], i1 true, i1 [[B:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = and i1 [[C]], [[A]]
-; CHECK-NEXT:    ret i1 [[RES]]
+; CHECK-NEXT:    ret i1 [[A:%.*]]
 ;
   %c = select i1 %A, i1 true, i1 %B
   %res = select i1 %c, i1 %A, i1 false
@@ -151,9 +145,7 @@
 ; (A lor B) band A
 define i1 @lor_band_left1(i1 %A, i1 %B) {
 ; CHECK-LABEL: @lor_band_left1(
-; CHECK-NEXT:    [[C:%.*]] = select i1 [[A:%.*]], i1 true, i1 [[B:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = and i1 [[C]], [[A]]
-; CHECK-NEXT:    ret i1 [[RES]]
+; CHECK-NEXT:    ret i1 [[A:%.*]]
 ;
   %c = select i1 %A, i1 true, i1 %B
   %res = and i1 %c, %A
@@ -309,9 +301,7 @@
 ; A bor (A land B)
 define i1 @land_bor_right1(i1 %A, i1 %B) {
 ; CHECK-LABEL: @land_bor_right1(
-; CHECK-NEXT:    [[C:%.*]] = select i1 [[A:%.*]], i1 [[B:%.*]], i1 false
-; CHECK-NEXT:    [[RES:%.*]] = or i1 [[C]], [[A]]
-; CHECK-NEXT:    ret i1 [[RES]]
+; CHECK-NEXT:    ret i1 [[A:%.*]]
 ;
   %c = select i1 %A, i1 %B, i1 false
   %res = or i1 %A, %c
@@ -385,9 +375,7 @@
 ; A band (A lor B)
 define i1 @lor_band_right1(i1 %A, i1 %B) {
 ; CHECK-LABEL: @lor_band_right1(
-; CHECK-NEXT:    [[C:%.*]] = select i1 [[A:%.*]], i1 true, i1 [[B:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = and i1 [[C]], [[A]]
-; CHECK-NEXT:    ret i1 [[RES]]
+; CHECK-NEXT:    ret i1 [[A:%.*]]
 ;
   %c = select i1 %A, i1 true, i1 %B
   %res = and i1 %A, %c
diff --git a/llvm/test/Transforms/InstCombine/select-safe-impliedcond-transforms.ll b/llvm/test/Transforms/InstCombine/select-safe-impliedcond-transforms.ll
--- a/llvm/test/Transforms/InstCombine/select-safe-impliedcond-transforms.ll
+++ b/llvm/test/Transforms/InstCombine/select-safe-impliedcond-transforms.ll
@@ -4,9 +4,7 @@
 define i1 @a_true_implies_b_true(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_true_implies_b_true(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 20
-; CHECK-NEXT:    [[B:%.*]] = icmp ugt i8 [[Z]], 10
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 [[SEL]], i1 false
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 [[X:%.*]], i1 false
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 20
@@ -39,9 +37,7 @@
 define i1 @a_true_implies_b_true2(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_true_implies_b_true2(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 20
-; CHECK-NEXT:    [[B:%.*]] = icmp ugt i8 [[Z]], 10
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = and i1 [[A]], [[SEL]]
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 [[X:%.*]], i1 false
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 20
@@ -54,9 +50,7 @@
 define i1 @a_true_implies_b_true2_comm(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_true_implies_b_true2_comm(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 20
-; CHECK-NEXT:    [[B:%.*]] = icmp ugt i8 [[Z]], 10
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = and i1 [[SEL]], [[A]]
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 [[X:%.*]], i1 false
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 20
@@ -69,9 +63,7 @@
 define i1 @a_true_implies_b_false(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_true_implies_b_false(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 20
-; CHECK-NEXT:    [[B:%.*]] = icmp ult i8 [[Z]], 10
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 [[SEL]], i1 false
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 [[Y:%.*]], i1 false
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 20
@@ -84,9 +76,7 @@
 define i1 @a_true_implies_b_false2(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_true_implies_b_false2(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 20
-; CHECK-NEXT:    [[B:%.*]] = icmp eq i8 [[Z]], 10
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = and i1 [[A]], [[SEL]]
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 [[Y:%.*]], i1 false
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 20
@@ -99,9 +89,7 @@
 define i1 @a_true_implies_b_false2_comm(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_true_implies_b_false2_comm(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 20
-; CHECK-NEXT:    [[B:%.*]] = icmp eq i8 [[Z]], 10
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = and i1 [[SEL]], [[A]]
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 [[Y:%.*]], i1 false
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 20
@@ -114,9 +102,7 @@
 define i1 @a_false_implies_b_true(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_false_implies_b_true(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 10
-; CHECK-NEXT:    [[B:%.*]] = icmp ult i8 [[Z]], 20
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[SEL]]
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[X:%.*]]
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 10
@@ -129,9 +115,7 @@
 define i1 @a_false_implies_b_true2(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_false_implies_b_true2(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 10
-; CHECK-NEXT:    [[B:%.*]] = icmp ult i8 [[Z]], 20
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = or i1 [[A]], [[SEL]]
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[X:%.*]]
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 10
@@ -144,9 +128,7 @@
 define i1 @a_false_implies_b_true2_comm(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_false_implies_b_true2_comm(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 10
-; CHECK-NEXT:    [[B:%.*]] = icmp ult i8 [[Z]], 20
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = or i1 [[SEL]], [[A]]
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[X:%.*]]
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 10
@@ -159,9 +141,7 @@
 define i1 @a_false_implies_b_false(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_false_implies_b_false(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 10
-; CHECK-NEXT:    [[B:%.*]] = icmp ugt i8 [[Z]], 20
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[SEL]]
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[Y:%.*]]
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 10
@@ -174,9 +154,7 @@
 define i1 @a_false_implies_b_false2(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_false_implies_b_false2(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 10
-; CHECK-NEXT:    [[B:%.*]] = icmp ugt i8 [[Z]], 20
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = or i1 [[A]], [[SEL]]
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[Y:%.*]]
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 10
@@ -189,9 +167,7 @@
 define i1 @a_false_implies_b_false2_comm(i8 %z, i1 %X, i1 %Y) {
 ; CHECK-LABEL: @a_false_implies_b_false2_comm(
 ; CHECK-NEXT:    [[A:%.*]] = icmp ugt i8 [[Z:%.*]], 10
-; CHECK-NEXT:    [[B:%.*]] = icmp ugt i8 [[Z]], 20
-; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[B]], i1 [[X:%.*]], i1 [[Y:%.*]]
-; CHECK-NEXT:    [[RES:%.*]] = or i1 [[SEL]], [[A]]
+; CHECK-NEXT:    [[RES:%.*]] = select i1 [[A]], i1 true, i1 [[Y:%.*]]
 ; CHECK-NEXT:    ret i1 [[RES]]
 ;
   %a = icmp ugt i8 %z, 10