diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -12,6 +12,7 @@
 #include "ToolChains/AMDGPUOpenMP.h"
 #include "ToolChains/AVR.h"
 #include "ToolChains/Ananas.h"
+#include "ToolChains/Arch/RISCV.h"
 #include "ToolChains/BareMetal.h"
 #include "ToolChains/CSKYToolChain.h"
 #include "ToolChains/Clang.h"
@@ -689,8 +690,9 @@
   // If target is RISC-V adjust the target triple according to
   // provided architecture name
   if (Target.isRISCV()) {
-    if ((A = Args.getLastArg(options::OPT_march_EQ))) {
-      StringRef ArchName = A->getValue();
+    if (Args.hasArg(options::OPT_march_EQ) ||
+        Args.hasArg(options::OPT_mcpu_EQ)) {
+      StringRef ArchName = tools::riscv::getRISCVArch(Args, Target);
       if (ArchName.startswith_insensitive("rv32"))
         Target.setArch(llvm::Triple::riscv32);
       else if (ArchName.startswith_insensitive("rv64"))
diff --git a/clang/test/Driver/riscv-arch.c b/clang/test/Driver/riscv-arch.c
--- a/clang/test/Driver/riscv-arch.c
+++ b/clang/test/Driver/riscv-arch.c
@@ -355,12 +355,20 @@
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-TARGET %s
 // RUN: %clang --target=riscv64-unknown-elf -march=rv32i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-TARGET %s
+// RUN: %clang --target=riscv32-unknown-elf -mcpu=generic-rv32 -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-TARGET %s
+// RUN: %clang --target=riscv64-unknown-elf -mcpu=generic-rv32 -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-TARGET %s
 // RV32-TARGET: "-triple" "riscv32-unknown-unknown-elf"
 
 // RUN: %clang --target=riscv32-unknown-elf -march=rv64i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
 // RUN: %clang --target=riscv64-unknown-elf -march=rv64i -### %s \
 // RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
+// RUN: %clang --target=riscv32-unknown-elf -mcpu=generic-rv64 -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
+// RUN: %clang --target=riscv64-unknown-elf -mcpu=generic-rv64 -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
 // RV64-TARGET: "-triple" "riscv64-unknown-unknown-elf"
 
 // RUN: %clang --target=riscv32-unknown-elf -march=rv32ifzfh01p0 -### %s \
diff --git a/clang/test/Driver/riscv-cpus.c b/clang/test/Driver/riscv-cpus.c
--- a/clang/test/Driver/riscv-cpus.c
+++ b/clang/test/Driver/riscv-cpus.c
@@ -174,6 +174,3 @@
 
 // RUN: %clang --target=riscv32 -### -c %s 2>&1 -mcpu=generic-rv32 -march=rv64i | FileCheck -check-prefix=MISMATCH-ARCH %s
 // MISMATCH-ARCH: cpu 'generic-rv32' does not support rv64
-
-// RUN: %clang --target=riscv32 -### -c %s 2>&1 -mcpu=generic-rv64 | FileCheck -check-prefix=MISMATCH-MCPU %s
-// MISMATCH-MCPU: error: cpu 'generic-rv64' does not support rv32