Index: lib/Basic/Targets/RISCV.h
===================================================================
--- lib/Basic/Targets/RISCV.h
+++ lib/Basic/Targets/RISCV.h
@@ -26,10 +26,16 @@
 class RISCVTargetInfo : public TargetInfo {
 protected:
   std::string ABI;
+  bool HasM;
+  bool HasA;
+  bool HasF;
+  bool HasD;
+  bool HasC;
 
 public:
   RISCVTargetInfo(const llvm::Triple &Triple, const TargetOptions &)
-      : TargetInfo(Triple) {
+      : TargetInfo(Triple), HasM(false), HasA(false), HasF(false),
+        HasD(false), HasC(false) {
     TLSSupported = false;
     LongDoubleWidth = 128;
     LongDoubleAlign = 128;
@@ -59,6 +65,11 @@
                              TargetInfo::ConstraintInfo &Info) const override {
     return false;
   }
+
+  bool hasFeature(StringRef Feature) const override;
+
+  bool handleTargetFeatures(std::vector<std::string> &Features,
+                            DiagnosticsEngine &Diags) override;
 };
 class LLVM_LIBRARY_VISIBILITY RISCV32TargetInfo : public RISCVTargetInfo {
 public:
Index: lib/Basic/Targets/RISCV.cpp
===================================================================
--- lib/Basic/Targets/RISCV.cpp
+++ lib/Basic/Targets/RISCV.cpp
@@ -49,4 +49,49 @@
   // TODO: modify when more code models and ABIs are supported.
   Builder.defineMacro("__riscv_cmodel_medlow");
   Builder.defineMacro("__riscv_float_abi_soft");
+
+  if (HasM) {
+    Builder.defineMacro("__riscv_mul");
+    Builder.defineMacro("__riscv_div");
+    Builder.defineMacro("__riscv_muldiv");
+  }
+
+  if (HasC)
+    Builder.defineMacro("__riscv_compressed");
+
+  // TODO: Define __riscv_flen, __riscv_fdiv and __riscv_fsqrt after
+  // F and D code gen upstream.
+
+  // TODO: Define __riscv_atomic after A code gen upstream.
+}
+
+bool RISCVTargetInfo::hasFeature(StringRef Feature) const {
+  return llvm::StringSwitch<bool>(Feature)
+      .Case("m", HasM)
+      .Case("a", HasA)
+      .Case("f", HasF)
+      .Case("d", HasD)
+      .Case("c", HasC)
+      .Default(false);
+}
+
+/// handleTargetFeatures - Perform initialization based on the user
+/// configured set of features.
+bool RISCVTargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
+                                           DiagnosticsEngine &Diags) {
+  for (const auto &Feature : Features) {
+    if (Feature == "+m") {
+      HasM = true;
+    } else if (Feature == "+a") {
+      HasA = true;
+    } else if (Feature == "+f") {
+      HasF = true;
+    } else if (Feature == "+d") {
+      HasD = true;
+    } else if (Feature == "+c") {
+      HasC = true;
+    }
+  }
+
+  return true;
 }
Index: test/Preprocessor/riscv-target-features.c
===================================================================
--- /dev/null
+++ test/Preprocessor/riscv-target-features.c
@@ -0,0 +1,17 @@
+// RUN: %clang -target riscv32-unknown-linux-gnu -x c -E -dM %s -o - | FileCheck %s
+// RUN: %clang -target riscv64-unknown-linux-gnu -x c -E -dM %s -o - | FileCheck %s
+
+// CHECK-NOT: __riscv_div
+// CHECK-NOT: __riscv_mul
+// CHECK-NOT: __riscv_muldiv
+// CHECK-NOT: __riscv_compressed
+
+// RUN: %clang -target riscv32-unknown-linux-gnu -march=rv32im -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-M-EXT %s
+// RUN: %clang -target riscv64-unknown-linux-gnu -march=rv64im -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-M-EXT %s
+// CHECK-M-EXT: __riscv_div 1
+// CHECK-M-EXT: __riscv_mul 1
+// CHECK-M-EXT: __riscv_muldiv 1
+
+// RUN: %clang -target riscv32-unknown-linux-gnu -march=rv32ic -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-C-EXT %s
+// RUN: %clang -target riscv64-unknown-linux-gnu -march=rv64ic -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-C-EXT %s
+// CHECK-C-EXT: __riscv_compressed 1