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
@@ -82,6 +82,11 @@
 
   const char *getClobbers() const override { return ""; }
 
+  StringRef getConstraintRegister(StringRef Constraint,
+                                  StringRef Expression) const override {
+    return Expression;
+  }
+
   ArrayRef<const char *> getGCCRegNames() const override;
 
   int getEHDataRegisterNumber(unsigned RegNo) const override {
diff --git a/clang/test/Sema/inline-asm-validate-riscv.c b/clang/test/Sema/inline-asm-validate-riscv.c
--- a/clang/test/Sema/inline-asm-validate-riscv.c
+++ b/clang/test/Sema/inline-asm-validate-riscv.c
@@ -21,3 +21,11 @@
   asm volatile ("" :: "K"(BelowMin)); // expected-error{{value '-1' out of range for constraint 'K'}}
   asm volatile ("" :: "K"(AboveMax)); // expected-error{{value '32' out of range for constraint 'K'}}
 }
+
+void test_clobber_conflict(void) {
+  register long x10 asm("x10");
+  asm volatile("" :: "r"(x10) : "x10"); // expected-error {{conflicts with asm clobber list}}
+  asm volatile("" :: "r"(x10) : "a0"); // expected-error {{conflicts with asm clobber list}}
+  asm volatile("" : "=r"(x10) :: "x10"); // expected-error {{conflicts with asm clobber list}}
+  asm volatile("" : "=r"(x10) :: "a0"); // expected-error {{conflicts with asm clobber list}}
+}