diff --git a/llvm/include/llvm/Support/RISCVISAInfo.h b/llvm/include/llvm/Support/RISCVISAInfo.h
--- a/llvm/include/llvm/Support/RISCVISAInfo.h
+++ b/llvm/include/llvm/Support/RISCVISAInfo.h
@@ -90,6 +90,7 @@
   Error checkDependency();
 
   void updateImplication();
+  void updateCombination();
   void updateFLen();
   void updateMinVLen();
   void updateMaxELen();
diff --git a/llvm/lib/Support/RISCVISAInfo.cpp b/llvm/lib/Support/RISCVISAInfo.cpp
--- a/llvm/lib/Support/RISCVISAInfo.cpp
+++ b/llvm/lib/Support/RISCVISAInfo.cpp
@@ -828,6 +828,38 @@
   }
 }
 
+struct CombinedExtsEntry {
+  StringLiteral CombineExt;
+  ArrayRef<const char *> RequiredExts;
+};
+
+static constexpr CombinedExtsEntry CombineIntoExts[] = {
+    {{"zk"}, {ImpliedExtsZk}},
+    {{"zkn"}, {ImpliedExtsZkn}},
+    {{"zks"}, {ImpliedExtsZks}},
+};
+
+void RISCVISAInfo::updateCombination() {
+  bool IsNewCombine = false;
+  do {
+    IsNewCombine = false;
+    for (CombinedExtsEntry CombineIntoExt : CombineIntoExts) {
+      auto CombineExt = CombineIntoExt.CombineExt;
+      auto RequiredExts = CombineIntoExt.RequiredExts;
+      if (hasExtension(CombineExt))
+        continue;
+      bool IsAllRequiredFeatureExist = true;
+      for (const char *Ext : RequiredExts)
+        IsAllRequiredFeatureExist &= hasExtension(Ext);
+      if (IsAllRequiredFeatureExist) {
+        auto Version = findDefaultVersion(CombineExt);
+        addExtension(CombineExt, Version->Major, Version->Minor);
+        IsNewCombine = true;
+      }
+    }
+  } while (IsNewCombine);
+}
+
 void RISCVISAInfo::updateFLen() {
   FLen = 0;
   // TODO: Handle q extension.
@@ -906,6 +938,7 @@
 llvm::Expected<std::unique_ptr<RISCVISAInfo>>
 RISCVISAInfo::postProcessAndChecking(std::unique_ptr<RISCVISAInfo> &&ISAInfo) {
   ISAInfo->updateImplication();
+  ISAInfo->updateCombination();
   ISAInfo->updateFLen();
   ISAInfo->updateMinVLen();
   ISAInfo->updateMaxELen();
diff --git a/llvm/test/CodeGen/RISCV/attributes.ll b/llvm/test/CodeGen/RISCV/attributes.ll
--- a/llvm/test/CodeGen/RISCV/attributes.ll
+++ b/llvm/test/CodeGen/RISCV/attributes.ll
@@ -33,6 +33,9 @@
 ; RUN: llc -mtriple=riscv32 -mattr=+zks %s -o - | FileCheck --check-prefix=RV32ZKS %s
 ; RUN: llc -mtriple=riscv32 -mattr=+zkt %s -o - | FileCheck --check-prefix=RV32ZKT %s
 ; RUN: llc -mtriple=riscv32 -mattr=+zk %s -o - | FileCheck --check-prefix=RV32ZK %s
+; RUN: llc -mtriple=riscv32 -mattr=+zkn,+zkr,+zkt %s -o - | FileCheck --check-prefix=RV32COMBINEINTOZK %s
+; RUN: llc -mtriple=riscv32 -mattr=+zbkb,+zbkc,+zbkx,+zkne,+zknd,+zknh %s -o - | FileCheck --check-prefix=RV32COMBINEINTOZKN %s
+; RUN: llc -mtriple=riscv32 -mattr=+zbkb,+zbkc,+zbkx,+zksed,+zksh %s -o - | FileCheck --check-prefix=RV32COMBINEINTOZKS %s
 ; RUN: llc -mtriple=riscv64 -mattr=+m %s -o - | FileCheck --check-prefix=RV64M %s
 ; RUN: llc -mtriple=riscv64 -mattr=+a %s -o - | FileCheck --check-prefix=RV64A %s
 ; RUN: llc -mtriple=riscv64 -mattr=+f %s -o - | FileCheck --check-prefix=RV64F %s
@@ -66,6 +69,9 @@
 ; RUN: llc -mtriple=riscv64 -mattr=+zks %s -o - | FileCheck --check-prefix=RV64ZKS %s
 ; RUN: llc -mtriple=riscv64 -mattr=+zkt %s -o - | FileCheck --check-prefix=RV64ZKT %s
 ; RUN: llc -mtriple=riscv64 -mattr=+zk %s -o - | FileCheck --check-prefix=RV64ZK %s
+; RUN: llc -mtriple=riscv64 -mattr=+zkn,+zkr,+zkt %s -o - | FileCheck --check-prefix=RV64COMBINEINTOZK %s
+; RUN: llc -mtriple=riscv64 -mattr=+zbkb,+zbkc,+zbkx,+zkne,+zknd,+zknh %s -o - | FileCheck --check-prefix=RV64COMBINEINTOZKN %s
+; RUN: llc -mtriple=riscv64 -mattr=+zbkb,+zbkc,+zbkx,+zksed,+zksh %s -o - | FileCheck --check-prefix=RV64COMBINEINTOZKS %s
 
 ; RV32M: .attribute 5, "rv32i2p0_m2p0"
 ; RV32A: .attribute 5, "rv32i2p0_a2p0"
@@ -100,6 +106,9 @@
 ; RV32ZKS: .attribute 5, "rv32i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zks1p0_zksed1p0_zksh1p0"
 ; RV32ZKT: .attribute 5, "rv32i2p0_zkt1p0"
 ; RV32ZK: .attribute 5, "rv32i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zk1p0_zkn1p0_zknd1p0_zkne1p0_zknh1p0_zkr1p0_zkt1p0"
+; RV32COMBINEINTOZK: .attribute 5, "rv32i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zk1p0_zkn1p0_zknd1p0_zkne1p0_zknh1p0_zkr1p0_zkt1p0"
+; RV32COMBINEINTOZKN: .attribute 5, "rv32i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zkn1p0_zknd1p0_zkne1p0_zknh1p0"
+; RV32COMBINEINTOZKS: .attribute 5, "rv32i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zks1p0_zksed1p0_zksh1p0"
 
 ; RV64M: .attribute 5, "rv64i2p0_m2p0"
 ; RV64A: .attribute 5, "rv64i2p0_a2p0"
@@ -134,6 +143,9 @@
 ; RV64ZKS: .attribute 5, "rv64i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zks1p0_zksed1p0_zksh1p0"
 ; RV64ZKT: .attribute 5, "rv64i2p0_zkt1p0"
 ; RV64ZK: .attribute 5, "rv64i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zk1p0_zkn1p0_zknd1p0_zkne1p0_zknh1p0_zkr1p0_zkt1p0"
+; RV64COMBINEINTOZK: .attribute 5, "rv64i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zk1p0_zkn1p0_zknd1p0_zkne1p0_zknh1p0_zkr1p0_zkt1p0"
+; RV64COMBINEINTOZKN: .attribute 5, "rv64i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zkn1p0_zknd1p0_zkne1p0_zknh1p0"
+; RV64COMBINEINTOZKS: .attribute 5, "rv64i2p0_zbkb1p0_zbkc1p0_zbkx1p0_zks1p0_zksed1p0_zksh1p0"
 
 define i32 @addi(i32 %a) {
   %1 = add i32 %a, 1