diff --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -24,7 +24,7 @@
 // RISC-V Target
 class RISCVTargetInfo : public TargetInfo {
 protected:
-  std::string ABI;
+  std::string ABI, CPU;
   bool HasM;
   bool HasA;
   bool HasF;
@@ -44,6 +44,13 @@
     WIntType = UnsignedInt;
   }
 
+  bool setCPU(const std::string &Name) override {
+    if (!isValidCPUName(Name))
+      return false;
+    CPU = Name;
+    return true;
+  }
+
   StringRef getABI() const override { return ABI; }
   void getTargetDefines(const LangOptions &Opts,
                         MacroBuilder &Builder) const override;
@@ -97,6 +104,9 @@
     return false;
   }
 
+  bool isValidCPUName(StringRef Name) const override;
+  void fillValidCPUList(SmallVectorImpl<StringRef> &Values) const override;
+
   void setMaxAtomicWidth() override {
     MaxAtomicPromoteWidth = 128;
 
@@ -121,6 +131,9 @@
     return false;
   }
 
+  bool isValidCPUName(StringRef Name) const override;
+  void fillValidCPUList(SmallVectorImpl<StringRef> &Values) const override;
+
   void setMaxAtomicWidth() override {
     MaxAtomicPromoteWidth = 128;
 
diff --git a/clang/lib/Basic/Targets/RISCV.cpp b/clang/lib/Basic/Targets/RISCV.cpp
--- a/clang/lib/Basic/Targets/RISCV.cpp
+++ b/clang/lib/Basic/Targets/RISCV.cpp
@@ -13,6 +13,7 @@
 #include "RISCV.h"
 #include "clang/Basic/MacroBuilder.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/Support/TargetParser.h"
 
 using namespace clang;
 using namespace clang::targets;
@@ -166,3 +167,23 @@
 
   return true;
 }
+
+bool RISCV32TargetInfo::isValidCPUName(StringRef Name) const {
+  return llvm::RISCV::checkCPUKind(llvm::RISCV::parseCPUKind(Name),
+                                   /*Is64Bit=*/false);
+}
+
+void RISCV32TargetInfo::fillValidCPUList(
+    SmallVectorImpl<StringRef> &Values) const {
+  llvm::RISCV::fillValidCPUArchList(Values, false);
+}
+
+bool RISCV64TargetInfo::isValidCPUName(StringRef Name) const {
+  return llvm::RISCV::checkCPUKind(llvm::RISCV::parseCPUKind(Name),
+                                   /*Is64Bit=*/true);
+}
+
+void RISCV64TargetInfo::fillValidCPUList(
+    SmallVectorImpl<StringRef> &Values) const {
+  llvm::RISCV::fillValidCPUArchList(Values, true);
+}
diff --git a/clang/lib/Driver/ToolChains/Arch/RISCV.h b/clang/lib/Driver/ToolChains/Arch/RISCV.h
--- a/clang/lib/Driver/ToolChains/Arch/RISCV.h
+++ b/clang/lib/Driver/ToolChains/Arch/RISCV.h
@@ -26,6 +26,8 @@
                       const llvm::Triple &Triple);
 StringRef getRISCVArch(const llvm::opt::ArgList &Args,
                        const llvm::Triple &Triple);
+StringRef getMArchFromMabi(StringRef MABI);
+StringRef getMArchFromTriple(const llvm::Triple &Triple);
 } // end namespace riscv
 } // namespace tools
 } // end namespace driver
diff --git a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
--- a/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
@@ -436,6 +436,19 @@
   return true;
 }
 
+// Get features except standard extension feature
+void getRISCFeaturesFromMcpu(const Driver &D, const llvm::Triple &Triple,
+                             const llvm::opt::ArgList &Args,
+                             const llvm::opt::Arg *A, StringRef Mcpu,
+                             std::vector<StringRef> &Features) {
+  bool Is64Bit = (Triple.getArch() == llvm::Triple::riscv64);
+  llvm::RISCV::CPUKind CPUKind = llvm::RISCV::parseCPUKind(Mcpu);
+  if (!llvm::RISCV::checkCPUKind(CPUKind, Is64Bit) ||
+      !llvm::RISCV::getCPUFeaturesExceptStdExt(CPUKind, Features)) {
+    D.Diag(clang::diag::err_drv_clang_unsupported) << A->getAsString(Args);
+  }
+}
+
 void riscv::getRISCVTargetFeatures(const Driver &D, const llvm::Triple &Triple,
                                    const ArgList &Args,
                                    std::vector<StringRef> &Features) {
@@ -444,6 +457,11 @@
   if (!getArchFeatures(D, MArch, Features, Args))
     return;
 
+  // If users give march and mcpu, get std extension feature from MArch
+  // and other features (ex. mirco architecture feature) from mcpu
+  if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
+    getRISCFeaturesFromMcpu(D, Triple, Args, A, A->getValue(), Features);
+
   // Handle features corresponding to "-ffixed-X" options
   if (Args.hasArg(options::OPT_ffixed_x1))
     Features.push_back("+reserve-x1");
@@ -533,11 +551,9 @@
 
   // GCC's logic around choosing a default `-mabi=` is complex. If GCC is not
   // configured using `--with-abi=`, then the logic for the default choice is
-  // defined in config.gcc. This function is based on the logic in GCC 9.2.0. We
-  // deviate from GCC's default only on baremetal targets (UnknownOS) where
-  // neither `-march` nor `-mabi` is specified.
+  // defined in config.gcc. This function is based on the logic in GCC 9.2.0.
   //
-  // The logic uses the following, in order:
+  // The logic uses in GCC 9.2.0 as the following, in order:
   // 1. Explicit choices using `--with-abi=`
   // 2. A default based on `--with-arch=`, if provided
   // 3. A default based on the target triple's arch
@@ -546,55 +562,40 @@
   //
   // Clang does not have `--with-arch=` or `--with-abi=`, so we use `-march=`
   // and `-mabi=` respectively instead.
+  //
+  // In order to make chosing logic more clear, clang uses the following logic,
+  // in order:
+  // 1. Explicit choices using `-mabi=`
+  // 2. A default based on clang's choosing arch logic. The order of default
+  // arch login is `-march`, `-mcpu` and target triples`.
 
   // 1. If `-mabi=` is specified, use it.
   if (const Arg *A = Args.getLastArg(options::OPT_mabi_EQ))
     return A->getValue();
 
-  // 2. Choose a default based on `-march=`
+  // 2. Choose a default based on clang's choosing arch logic.
   //
   // rv32g | rv32*d -> ilp32d
   // rv32e -> ilp32e
   // rv32* -> ilp32
   // rv64g | rv64*d -> lp64d
   // rv64* -> lp64
-  if (const Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
-    StringRef MArch = A->getValue();
-
-    if (MArch.startswith_lower("rv32")) {
-      // FIXME: parse `March` to find `D` extension properly
-      if (MArch.substr(4).contains_lower("d") ||
-          MArch.startswith_lower("rv32g"))
-        return "ilp32d";
-      else if (MArch.startswith_lower("rv32e"))
-        return "ilp32e";
-      else
-        return "ilp32";
-    } else if (MArch.startswith_lower("rv64")) {
-      // FIXME: parse `March` to find `D` extension properly
-      if (MArch.substr(4).contains_lower("d") ||
-          MArch.startswith_lower("rv64g"))
-        return "lp64d";
-      else
-        return "lp64";
-    }
-  }
+  StringRef MArch = getRISCVArch(Args, Triple);
 
-  // 3. Choose a default based on the triple
-  //
-  // We deviate from GCC's defaults here:
-  // - On `riscv{XLEN}-unknown-elf` we use the integer calling convention only.
-  // - On all other OSs we use the double floating point calling convention.
-  if (Triple.getArch() == llvm::Triple::riscv32) {
-    if (Triple.getOS() == llvm::Triple::UnknownOS)
-      return "ilp32";
-    else
+  if (MArch.startswith_lower("rv32")) {
+    // FIXME: parse `March` to find `D` extension properly
+    if (MArch.substr(4).contains_lower("d") || MArch.startswith_lower("rv32g"))
       return "ilp32d";
-  } else {
-    if (Triple.getOS() == llvm::Triple::UnknownOS)
-      return "lp64";
+    else if (MArch.startswith_lower("rv32e"))
+      return "ilp32e";
     else
+      return "ilp32";
+  } else if (MArch.startswith_lower("rv64")) {
+    // FIXME: parse `March` to find `D` extension properly
+    if (MArch.substr(4).contains_lower("d") || MArch.startswith_lower("rv64g"))
       return "lp64d";
+    else
+      return "lp64";
   }
 }
 
@@ -607,10 +608,11 @@
   // GCC's logic around choosing a default `-march=` is complex. If GCC is not
   // configured using `--with-arch=`, then the logic for the default choice is
   // defined in config.gcc. This function is based on the logic in GCC 9.2.0. We
-  // deviate from GCC's default only on baremetal targets (UnknownOS) where
-  // neither `-march` nor `-mabi` is specified.
+  // deviate from GCC's default on additional `-mcpu` option (GCC does not
+  // support `-mcpu`) and baremetal targets (UnknownOS) where neither `-march`
+  // nor `-mabi` is specified.
   //
-  // The logic uses the following, in order:
+  // The logic uses in GCC 9.2.0 as the following, in order:
   // 1. Explicit choices using `--with-arch=`
   // 2. A default based on `--with-abi=`, if provided
   // 3. A default based on the target triple's arch
@@ -620,6 +622,12 @@
   // Clang does not have `--with-arch=` or `--with-abi=`, so we use `-march=`
   // and `-mabi=` respectively instead.
   //
+  // Clang uses the following logic, in order:
+  // 1. Explicit choices using `-march=`
+  // 2. Based on `-mcpu` if target cpu has default isa extension feature
+  // 3. A default based on `-mabi`, if provided
+  // 4. A default based on the target triple's arch
+  //
   // Clang does not yet support MULTILIB_REUSE, so we use `rv{XLEN}imafdc`
   // instead of `rv{XLEN}gc` though they are (currently) equivalent.
 
@@ -627,7 +635,15 @@
   if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))
     return A->getValue();
 
-  // 2. Choose a default based on `-mabi=`
+  // 2. Get march (isa string) based on `-mcpu=`
+  if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ)) {
+    StringRef MArch = llvm::RISCV::getMArchFromMcpu(A->getValue());
+    // Bypass if target cpu's default march is empty.
+    if (MArch != "")
+      return MArch;
+  }
+
+  // 3. Choose a default based on `-mabi=`
   //
   // ilp32e -> rv32e
   // ilp32 | ilp32f | ilp32d -> rv32imafdc
@@ -643,7 +659,7 @@
       return "rv64imafdc";
   }
 
-  // 3. Choose a default based on the triple
+  // 4. Choose a default based on the triple
   //
   // We deviate from GCC's defaults here:
   // - On `riscv{XLEN}-unknown-elf` we default to `rv{XLEN}imac`
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -333,6 +333,11 @@
 
     return TargetCPUName;
   }
+  case llvm::Triple::riscv32:
+  case llvm::Triple::riscv64:
+    if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
+      return A->getValue();
+    return "";
 
   case llvm::Triple::bpfel:
   case llvm::Triple::bpfeb:
diff --git a/clang/test/Driver/riscv-cpus.c b/clang/test/Driver/riscv-cpus.c
new file mode 100644
--- /dev/null
+++ b/clang/test/Driver/riscv-cpus.c
@@ -0,0 +1,38 @@
+// Check target CPUs are correctly passed.
+
+// RUN: %clang -target riscv32 -### -c %s 2>&1 -mcpu=rocket-rv32 | FileCheck -check-prefix=MCPU-ROCKETCHIP32 %s
+// MCPU-ROCKETCHIP32: "-nostdsysteminc" "-target-cpu" "rocket-rv32"
+
+// RUN: %clang -target riscv64 -### -c %s 2>&1 -mcpu=rocket-rv64 | FileCheck -check-prefix=MCPU-ROCKETCHIP64 %s
+// MCPU-ROCKETCHIP64: "-nostdsysteminc" "-target-cpu" "rocket-rv64"
+// MCPU-ROCKETCHIP64: "-target-feature" "+64bit"
+
+// mcpu with default march
+// RUN: %clang -target riscv64 -### -c %s 2>&1 -mcpu=sifive-u54 | FileCheck -check-prefix=MCPU-SIFIVE-U54 %s
+// MCPU-SIFIVE-U54: "-nostdsysteminc" "-target-cpu" "sifive-u54"
+// MCPU-SIFIVE-U54: "-target-feature" "+m" "-target-feature" "+a" "-target-feature" "+f" "-target-feature" "+d"
+// MCPU-SIFIVE-U54: "-target-feature" "+c" "-target-feature" "+64bit"
+// MCPU-SIFIVE-U54: "-target-abi" "lp64d"
+
+// mcpu with mabi option
+// RUN: %clang -target riscv64 -### -c %s 2>&1 -mcpu=sifive-u54 -mabi=lp64 | FileCheck -check-prefix=MCPU-ABI-SIFIVE-U54 %s
+// MCPU-ABI-SIFIVE-U54: "-nostdsysteminc" "-target-cpu" "sifive-u54"
+// MCPU-ABI-SIFIVE-U54: "-target-feature" "+m" "-target-feature" "+a" "-target-feature" "+f" "-target-feature" "+d"
+// MCPU-ABI-SIFIVE-U54: "-target-feature" "+c" "-target-feature" "+64bit"
+// MCPU-ABI-SIFIVE-U54: "-target-abi" "lp64"
+
+// march overwirte mcpu's default march
+// RUN: %clang -target riscv32 -### -c %s 2>&1 -mcpu=sifive-e31 -march=rv32imc | FileCheck -check-prefix=MCPU-MARCH %s
+// MCPU-MARCH: "-nostdsysteminc" "-target-cpu" "sifive-e31" "-target-feature" "+m" "-target-feature" "+c"
+// MCPU-MARCH: "-target-abi" "ilp32"
+
+// Check failed cases
+
+// RUN: %clang -target riscv32 -### -c %s 2>&1 -mcpu=generic-rv321 | FileCheck -check-prefix=FAIL-MCPU-NAME %s
+// FAIL-MCPU-NAME: clang-11: error: the clang compiler does not support '-mcpu=generic-rv321'
+
+// RUN: %clang -target riscv32 -### -c %s 2>&1 -mcpu=generic-rv32 -march=rv64i | FileCheck -check-prefix=MISMATCH-ARCH %s
+// MISMATCH-ARCH: clang-11: error: the clang compiler does not support '-mcpu=generic-rv32'
+
+// RUN: %clang -target riscv32 -### -c %s 2>&1 -mcpu=generic-rv64 | FileCheck -check-prefix=MISMATCH-MCPU %s
+// MISMATCH-MCPU: clang-11: error: the clang compiler does not support '-mcpu=generic-rv64'
diff --git a/llvm/include/llvm/Support/RISCVTargetParser.def b/llvm/include/llvm/Support/RISCVTargetParser.def
new file mode 100644
--- /dev/null
+++ b/llvm/include/llvm/Support/RISCVTargetParser.def
@@ -0,0 +1,13 @@
+#ifndef PROC
+#define PROC(ENUM, NAME, FEATURES, DEFAULT_MARCH)
+#endif
+
+PROC(INVALID, {"invalid"}, FK_INVALID, {""})
+PROC(GENERIC_RV32, {"generic-rv32"}, FK_NONE, {""})
+PROC(GENERIC_RV64, {"generic-rv64"}, FK_64BIT, {""})
+PROC(ROCKET_RV32, {"rocket-rv32"}, FK_NONE, {""})
+PROC(ROCKET_RV64, {"rocket-rv64"}, FK_64BIT, {""})
+PROC(SIFIVE_E31, {"sifive-e31"}, FK_NONE, {"rv32imac"})
+PROC(SIFIVE_U54, {"sifive-u54"}, FK_64BIT, {"rv64gc"})
+
+#undef PROC
diff --git a/llvm/include/llvm/Support/TargetParser.h b/llvm/include/llvm/Support/TargetParser.h
--- a/llvm/include/llvm/Support/TargetParser.h
+++ b/llvm/include/llvm/Support/TargetParser.h
@@ -130,6 +130,32 @@
 
 } // namespace AMDGPU
 
+namespace RISCV {
+
+enum CPUKind : unsigned {
+#define PROC(ENUM, NAME, FEATURES, DEFAULT_MARCH) CK_##ENUM,
+#include "RISCVTargetParser.def"
+};
+
+enum FeatureKind : unsigned {
+  FK_INVALID = 0,
+  FK_NONE = 1,
+  FK_STDEXTM = 1 << 2,
+  FK_STDEXTA = 1 << 3,
+  FK_STDEXTF = 1 << 4,
+  FK_STDEXTD = 1 << 5,
+  FK_STDEXTC = 1 << 6,
+  FK_64BIT = 1 << 7,
+};
+
+bool checkCPUKind(CPUKind kind, bool IsRV64);
+CPUKind parseCPUKind(StringRef CPU);
+StringRef getMArchFromMcpu(StringRef CPU);
+void fillValidCPUArchList(SmallVectorImpl<StringRef> &Values, bool IsRV64);
+bool getCPUFeaturesExceptStdExt(CPUKind kind, std::vector<StringRef> &Features);
+
+} // namespace RISCV
+
 } // namespace llvm
 
 #endif
diff --git a/llvm/lib/Support/TargetParser.cpp b/llvm/lib/Support/TargetParser.cpp
--- a/llvm/lib/Support/TargetParser.cpp
+++ b/llvm/lib/Support/TargetParser.cpp
@@ -13,6 +13,7 @@
 
 #include "llvm/Support/ARMBuildAttributes.h"
 #include "llvm/Support/TargetParser.h"
+#include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Twine.h"
@@ -208,3 +209,64 @@
   default:         return {0, 0, 0};
   }
 }
+
+namespace llvm {
+namespace RISCV {
+
+struct CPUInfo {
+  StringLiteral Name;
+  CPUKind Kind;
+  unsigned Features;
+  StringLiteral DefaultMarch;
+  bool Is64Bit() const { return (Features & FK_64BIT); }
+};
+
+constexpr CPUInfo RISCVCPUInfo[] = {
+#define PROC(ENUM, NAME, FEATURES, DEFAULT_MARCH)                              \
+  {NAME, CK_##ENUM, FEATURES, DEFAULT_MARCH},
+#include "llvm/Support/RISCVTargetParser.def"
+};
+
+bool checkCPUKind(CPUKind Kind, bool IsRV64) {
+  if (Kind == CK_INVALID)
+    return false;
+  return RISCVCPUInfo[static_cast<unsigned>(Kind)].Is64Bit() == IsRV64;
+}
+
+CPUKind parseCPUKind(StringRef CPU) {
+  return llvm::StringSwitch<CPUKind>(CPU)
+#define PROC(ENUM, NAME, FEATURES, DEFAULT_MARCH) .Case(NAME, CK_##ENUM)
+#include "llvm/Support/RISCVTargetParser.def"
+      .Default(CK_INVALID);
+}
+
+StringRef getMArchFromMcpu(StringRef CPU) {
+  CPUKind Kind = parseCPUKind(CPU);
+  return RISCVCPUInfo[static_cast<unsigned>(Kind)].DefaultMarch;
+}
+
+void fillValidCPUArchList(SmallVectorImpl<StringRef> &Values, bool IsRV64) {
+  for (const auto &C : RISCVCPUInfo) {
+    if (IsRV64 == C.Is64Bit())
+      Values.emplace_back(C.Name);
+  }
+}
+
+// Get all features except standard extension feature
+bool getCPUFeaturesExceptStdExt(CPUKind Kind,
+                                std::vector<StringRef> &Features) {
+  unsigned features = RISCVCPUInfo[static_cast<unsigned>(Kind)].Features;
+
+  if (features == FK_INVALID)
+    return false;
+
+  if (features & FK_64BIT)
+    Features.push_back("+64bit");
+  else
+    Features.push_back("-64bit");
+
+  return true;
+}
+
+} // namespace RISCV
+} // namespace llvm
diff --git a/llvm/lib/Target/RISCV/RISCV.td b/llvm/lib/Target/RISCV/RISCV.td
--- a/llvm/lib/Target/RISCV/RISCV.td
+++ b/llvm/lib/Target/RISCV/RISCV.td
@@ -215,6 +215,16 @@
 
 def : ProcessorModel<"rocket-rv64", Rocket64Model, [Feature64Bit]>;
 
+def : ProcessorModel<"sifive-e31", Rocket32Model, [FeatureStdExtM,
+                                                   FeatureStdExtA,
+                                                   FeatureStdExtC]>;
+
+def : ProcessorModel<"sifive-u54", Rocket64Model, [Feature64Bit,
+                                                   FeatureStdExtM,
+                                                   FeatureStdExtA,
+                                                   FeatureStdExtF,
+                                                   FeatureStdExtD,
+                                                   FeatureStdExtC]>;
 
 //===----------------------------------------------------------------------===//
 // Define the RISC-V target.