diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1995,7 +1995,34 @@
       }
     LLVM_FALLTHROUGH;
   }
-  case Intrinsic::vector_reduce_add:
+  case Intrinsic::vector_reduce_add: {
+    if (IID == Intrinsic::vector_reduce_add) {
+      // Convert vector_reduce_add(ZExt(<n x i1>)) to
+      // ZExtOrTrunc(ctpop(bitcast <n x i1> to in)).
+      // Convert vector_reduce_add(SExt(<n x i1>)) to
+      // -ZExtOrTrunc(ctpop(bitcast <n x i1> to in)).
+      // Convert vector_reduce_add(<n x i1>) to
+      // Trunc(ctpop(bitcast <n x i1> to in)).
+      Value *Arg = II->getArgOperand(0);
+      Value *Vect;
+      if (match(Arg, m_ZExtOrSExtOrSelf(m_Value(Vect)))) {
+        if (auto *FTy = dyn_cast<FixedVectorType>(Vect->getType()))
+          if (FTy->getElementType() == Builder.getInt1Ty()) {
+            Value *V = Builder.CreateBitCast(
+                Vect, Builder.getIntNTy(FTy->getNumElements()));
+            Value *Res = Builder.CreateUnaryIntrinsic(Intrinsic::ctpop, V);
+            if (Res->getType() != II->getType())
+              Res = Builder.CreateZExtOrTrunc(Res, II->getType());
+            if (Arg != Vect &&
+                cast<Instruction>(Arg)->getOpcode() == Instruction::SExt)
+              Res = Builder.CreateNeg(Res);
+            replaceInstUsesWith(CI, Res);
+            return eraseInstFromFunction(CI);
+          }
+      }
+    }
+    LLVM_FALLTHROUGH;
+  }
   case Intrinsic::vector_reduce_mul:
   case Intrinsic::vector_reduce_xor:
   case Intrinsic::vector_reduce_umax:
diff --git a/llvm/test/Transforms/InstCombine/reduction-add-sext-zext-i1.ll b/llvm/test/Transforms/InstCombine/reduction-add-sext-zext-i1.ll
--- a/llvm/test/Transforms/InstCombine/reduction-add-sext-zext-i1.ll
+++ b/llvm/test/Transforms/InstCombine/reduction-add-sext-zext-i1.ll
@@ -3,8 +3,11 @@
 
 define i1 @reduce_add_self(<8 x i1> %x) {
 ; CHECK-LABEL: @reduce_add_self(
-; CHECK-NEXT:    [[RES:%.*]] = call i1 @llvm.vector.reduce.add.v8i1(<8 x i1> [[X:%.*]])
-; CHECK-NEXT:    ret i1 [[RES]]
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <8 x i1> [[X:%.*]] to i8
+; CHECK-NEXT:    [[TMP2:%.*]] = call i8 @llvm.ctpop.i8(i8 [[TMP1]]), !range [[RNG0:![0-9]+]]
+; CHECK-NEXT:    [[TMP3:%.*]] = and i8 [[TMP2]], 1
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp ne i8 [[TMP3]], 0
+; CHECK-NEXT:    ret i1 [[TMP4]]
 ;
   %res = call i1 @llvm.vector.reduce.add.v8i32(<8 x i1> %x)
   ret i1 %res
@@ -12,9 +15,11 @@
 
 define i32 @reduce_add_sext(<4 x i1> %x) {
 ; CHECK-LABEL: @reduce_add_sext(
-; CHECK-NEXT:    [[SEXT:%.*]] = sext <4 x i1> [[X:%.*]] to <4 x i32>
-; CHECK-NEXT:    [[RES:%.*]] = call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> [[SEXT]])
-; CHECK-NEXT:    ret i32 [[RES]]
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <4 x i1> [[X:%.*]] to i4
+; CHECK-NEXT:    [[TMP2:%.*]] = call i4 @llvm.ctpop.i4(i4 [[TMP1]]), !range [[RNG1:![0-9]+]]
+; CHECK-NEXT:    [[TMP3:%.*]] = zext i4 [[TMP2]] to i32
+; CHECK-NEXT:    [[TMP4:%.*]] = sub nsw i32 0, [[TMP3]]
+; CHECK-NEXT:    ret i32 [[TMP4]]
 ;
   %sext = sext <4 x i1> %x to <4 x i32>
   %res = call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> %sext)
@@ -23,9 +28,10 @@
 
 define i64 @reduce_add_zext(<8 x i1> %x) {
 ; CHECK-LABEL: @reduce_add_zext(
-; CHECK-NEXT:    [[ZEXT:%.*]] = zext <8 x i1> [[X:%.*]] to <8 x i64>
-; CHECK-NEXT:    [[RES:%.*]] = call i64 @llvm.vector.reduce.add.v8i64(<8 x i64> [[ZEXT]])
-; CHECK-NEXT:    ret i64 [[RES]]
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <8 x i1> [[X:%.*]] to i8
+; CHECK-NEXT:    [[TMP2:%.*]] = call i8 @llvm.ctpop.i8(i8 [[TMP1]]), !range [[RNG0]]
+; CHECK-NEXT:    [[TMP3:%.*]] = zext i8 [[TMP2]] to i64
+; CHECK-NEXT:    ret i64 [[TMP3]]
 ;
   %zext = zext <8 x i1> %x to <8 x i64>
   %res = call i64 @llvm.vector.reduce.add.v8i64(<8 x i64> %zext)
@@ -34,9 +40,10 @@
 
 define i16 @reduce_add_sext_same(<16 x i1> %x) {
 ; CHECK-LABEL: @reduce_add_sext_same(
-; CHECK-NEXT:    [[SEXT:%.*]] = sext <16 x i1> [[X:%.*]] to <16 x i16>
-; CHECK-NEXT:    [[RES:%.*]] = call i16 @llvm.vector.reduce.add.v16i16(<16 x i16> [[SEXT]])
-; CHECK-NEXT:    ret i16 [[RES]]
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <16 x i1> [[X:%.*]] to i16
+; CHECK-NEXT:    [[TMP2:%.*]] = call i16 @llvm.ctpop.i16(i16 [[TMP1]]), !range [[RNG2:![0-9]+]]
+; CHECK-NEXT:    [[TMP3:%.*]] = sub nsw i16 0, [[TMP2]]
+; CHECK-NEXT:    ret i16 [[TMP3]]
 ;
   %sext = sext <16 x i1> %x to <16 x i16>
   %res = call i16 @llvm.vector.reduce.add.v16i16(<16 x i16> %sext)
@@ -45,9 +52,11 @@
 
 define i8 @reduce_add_zext_long(<128 x i1> %x) {
 ; CHECK-LABEL: @reduce_add_zext_long(
-; CHECK-NEXT:    [[SEXT:%.*]] = sext <128 x i1> [[X:%.*]] to <128 x i8>
-; CHECK-NEXT:    [[RES:%.*]] = call i8 @llvm.vector.reduce.add.v128i8(<128 x i8> [[SEXT]])
-; CHECK-NEXT:    ret i8 [[RES]]
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <128 x i1> [[X:%.*]] to i128
+; CHECK-NEXT:    [[TMP2:%.*]] = call i128 @llvm.ctpop.i128(i128 [[TMP1]]), !range [[RNG3:![0-9]+]]
+; CHECK-NEXT:    [[TMP3:%.*]] = trunc i128 [[TMP2]] to i8
+; CHECK-NEXT:    [[TMP4:%.*]] = sub i8 0, [[TMP3]]
+; CHECK-NEXT:    ret i8 [[TMP4]]
 ;
   %sext = sext <128 x i1> %x to <128 x i8>
   %res = call i8 @llvm.vector.reduce.add.v128i8(<128 x i8> %sext)
@@ -57,11 +66,14 @@
 @glob = external global i8, align 1
 define i8 @reduce_add_zext_long_external_use(<128 x i1> %x) {
 ; CHECK-LABEL: @reduce_add_zext_long_external_use(
-; CHECK-NEXT:    [[SEXT:%.*]] = sext <128 x i1> [[X:%.*]] to <128 x i8>
-; CHECK-NEXT:    [[RES:%.*]] = call i8 @llvm.vector.reduce.add.v128i8(<128 x i8> [[SEXT]])
-; CHECK-NEXT:    [[EXT:%.*]] = extractelement <128 x i8> [[SEXT]], i32 0
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <128 x i1> [[X:%.*]] to i128
+; CHECK-NEXT:    [[TMP2:%.*]] = call i128 @llvm.ctpop.i128(i128 [[TMP1]]), !range [[RNG3]]
+; CHECK-NEXT:    [[TMP3:%.*]] = trunc i128 [[TMP2]] to i8
+; CHECK-NEXT:    [[TMP4:%.*]] = sub i8 0, [[TMP3]]
+; CHECK-NEXT:    [[TMP5:%.*]] = extractelement <128 x i1> [[X]], i32 0
+; CHECK-NEXT:    [[EXT:%.*]] = sext i1 [[TMP5]] to i8
 ; CHECK-NEXT:    store i8 [[EXT]], i8* @glob, align 1
-; CHECK-NEXT:    ret i8 [[RES]]
+; CHECK-NEXT:    ret i8 [[TMP4]]
 ;
   %sext = sext <128 x i1> %x to <128 x i8>
   %res = call i8 @llvm.vector.reduce.add.v128i8(<128 x i8> %sext)
@@ -73,11 +85,13 @@
 @glob1 = external global i64, align 8
 define i64 @reduce_add_zext_external_use(<8 x i1> %x) {
 ; CHECK-LABEL: @reduce_add_zext_external_use(
-; CHECK-NEXT:    [[ZEXT:%.*]] = zext <8 x i1> [[X:%.*]] to <8 x i64>
-; CHECK-NEXT:    [[RES:%.*]] = call i64 @llvm.vector.reduce.add.v8i64(<8 x i64> [[ZEXT]])
-; CHECK-NEXT:    [[EXT:%.*]] = extractelement <8 x i64> [[ZEXT]], i32 0
+; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <8 x i1> [[X:%.*]] to i8
+; CHECK-NEXT:    [[TMP2:%.*]] = call i8 @llvm.ctpop.i8(i8 [[TMP1]]), !range [[RNG0]]
+; CHECK-NEXT:    [[TMP3:%.*]] = zext i8 [[TMP2]] to i64
+; CHECK-NEXT:    [[TMP4:%.*]] = extractelement <8 x i1> [[X]], i32 0
+; CHECK-NEXT:    [[EXT:%.*]] = zext i1 [[TMP4]] to i64
 ; CHECK-NEXT:    store i64 [[EXT]], i64* @glob1, align 8
-; CHECK-NEXT:    ret i64 [[RES]]
+; CHECK-NEXT:    ret i64 [[TMP3]]
 ;
   %zext = zext <8 x i1> %x to <8 x i64>
   %res = call i64 @llvm.vector.reduce.add.v8i64(<8 x i64> %zext)