Index: clang/lib/Driver/Driver.cpp
===================================================================
--- clang/lib/Driver/Driver.cpp
+++ clang/lib/Driver/Driver.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Driver/Driver.h"
+#include "ToolChains/Arch/RISCV.h"
 #include "ToolChains/AIX.h"
 #include "ToolChains/AMDGPU.h"
 #include "ToolChains/AMDGPUOpenMP.h"
@@ -650,13 +651,16 @@
   }
 
   // If target is RISC-V adjust the target triple according to
-  // provided architecture name
-  A = Args.getLastArg(options::OPT_march_EQ);
-  if (A && Target.isRISCV()) {
-    StringRef ArchName = A->getValue();
-    if (ArchName.startswith_insensitive("rv32"))
+  // provided architecture relative info such as -march/-mcpu/-mabi.
+  if (Target.isRISCV()) {
+    StringRef ArchName = tools::riscv::getRISCVArch(Args, Target);
+    llvm::Triple::ArchType RVArch = Target.getArch();
+
+    if (RVArch == llvm::Triple::riscv64 &&
+        ArchName.startswith_insensitive("rv32"))
       Target.setArch(llvm::Triple::riscv32);
-    else if (ArchName.startswith_insensitive("rv64"))
+    else if (RVArch == llvm::Triple::riscv32 &&
+             ArchName.startswith_insensitive("rv64"))
       Target.setArch(llvm::Triple::riscv64);
   }
 
Index: clang/test/Driver/riscv-abi.c
===================================================================
--- clang/test/Driver/riscv-abi.c
+++ clang/test/Driver/riscv-abi.c
@@ -40,11 +40,6 @@
 
 // CHECK-ILP32D: "-target-abi" "ilp32d"
 
-// RUN: not %clang --target=riscv32-unknown-elf %s -o %t.o -mabi=lp64 2>&1 \
-// RUN:   | FileCheck -check-prefix=CHECK-RV32-LP64 %s
-
-// CHECK-RV32-LP64: error: unknown target ABI 'lp64'
-
 // RUN: %clang --target=riscv64-unknown-elf %s -### 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-LP64 %s
 // RUN: %clang --target=riscv64-unknown-elf %s -### -mabi=lp64 2>&1 \
@@ -77,8 +72,3 @@
 // RUN:   | FileCheck -check-prefix=CHECK-LP64D  %s
 
 // CHECK-LP64D: "-target-abi" "lp64d"
-
-// RUN: not %clang --target=riscv64-unknown-elf %s -o %t.o -mabi=ilp32 2>&1 \
-// RUN:   | FileCheck -check-prefix=CHECK-RV64-ILP32 %s
-
-// CHECK-RV64-ILP32: error: unknown target ABI 'ilp32'
Index: clang/test/Driver/riscv-arch.c
===================================================================
--- clang/test/Driver/riscv-arch.c
+++ clang/test/Driver/riscv-arch.c
@@ -392,12 +392,29 @@
 // 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=sifive-e20 -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-TARGET %s
+// RUN: %clang --target=riscv64-unknown-elf -mcpu=sifive-e20 -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-TARGET %s
+// RUN: %clang --target=riscv32-unknown-elf -mabi=ilp32 -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV32-TARGET %s
+// RUN: %clang --target=riscv64-unknown-elf -mabi=ilp32 -### %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=sifive-s21 -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
+// RUN: %clang --target=riscv64-unknown-elf -mcpu=sifive-s21 -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
+// RUN: %clang --target=riscv32-unknown-elf -mabi=lp64 -### %s \
+// RUN: -fsyntax-only 2>&1 | FileCheck -check-prefix=RV64-TARGET %s
+// RUN: %clang --target=riscv64-unknown-elf -mabi=lp64 -### %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 \