diff --git a/clang/lib/Basic/Targets/AMDGPU.h b/clang/lib/Basic/Targets/AMDGPU.h
--- a/clang/lib/Basic/Targets/AMDGPU.h
+++ b/clang/lib/Basic/Targets/AMDGPU.h
@@ -131,6 +131,11 @@
     });
 
     StringRef S(Name);
+    if (S == "A") {
+      Info.setRequiresImmediate();
+      return true;
+    }
+
     bool HasLeftParen = false;
     if (S.front() == '{') {
       HasLeftParen = true;
diff --git a/clang/test/Sema/inline-asm-validate-amdgpu.cl b/clang/test/Sema/inline-asm-validate-amdgpu.cl
--- a/clang/test/Sema/inline-asm-validate-amdgpu.cl
+++ b/clang/test/Sema/inline-asm-validate-amdgpu.cl
@@ -17,6 +17,10 @@
 
   // vgpr constraints
   __asm__ ("v_mov_b32 %0, %1" : "=v" (vgpr) : "v" (imm) : );
+
+  // 'A' constraint
+  __asm__ ("s_mov_b32 %0, %1" : "=s" (sgpr) : "A" (imm) : );
+
 }
 
 __kernel void