when merging, use the attribute from the declaration

Author: DenisBakhvalov

clang/lib/Sema/SemaDeclAttr.cpp

@@ -5137,9 +5137,12 @@ Sema::MergeSYCLIntelESimdVectorizeAttr(Decl *D,
         if (DeclExpr->getResultAsAPSInt() != MergeExpr->getResultAsAPSInt()) {
           Diag(DeclAttr->getLoc(), diag::warn_duplicate_attribute) << &A;
           Diag(A.getLoc(), diag::note_previous_attribute);
+          // Drop the attribute from the current declaration
+          D->dropAttr<SYCLIntelESimdVectorizeAttr>();
+        } else {
+          // Do not add a duplicate attribute.
+          return nullptr;
         }
-        // Do not add a duplicate attribute.
-        return nullptr;
       }
     }
   }

clang/test/CodeGenSYCL/esimd-vectorize-md.cpp

@@ -11,8 +11,7 @@
 
 [[intel::sycl_esimd_vectorize(8)]] __attribute__((sycl_device)) void foo3();
 [[intel::sycl_esimd_vectorize(16)]] __attribute__((sycl_device)) void foo3() {}
-// CHECK: @_Z4foo3v() #[[ATTR3:[0-9]+]]
+// CHECK: @_Z4foo3v() #[[ATTR2]]
 
 // CHECK: attributes #[[ATTR1]] = { {{.*}} "CMGenxSIMT"="32" {{.*}}}
 // CHECK: attributes #[[ATTR2]] = { {{.*}} "CMGenxSIMT"="8" {{.*}}}
-// CHECK: attributes #[[ATTR3]] = { {{.*}} "CMGenxSIMT"="16" {{.*}}}