diff --git a/llvm/utils/gn/secondary/compiler-rt/test/BUILD.gn b/llvm/utils/gn/secondary/compiler-rt/test/BUILD.gn
--- a/llvm/utils/gn/secondary/compiler-rt/test/BUILD.gn
+++ b/llvm/utils/gn/secondary/compiler-rt/test/BUILD.gn
@@ -76,6 +76,8 @@
 
   if (host_cpu == "x64") {
     values += [ "HOST_ARCH=x86_64" ]
+  } else if (host_cpu == "arm64") {
+    values += [ "HOST_ARCH=aarch64" ]
   } else {
     assert(false, "unimplemented host_cpu " + host_cpu)
   }
diff --git a/llvm/utils/gn/secondary/llvm/triples.gni b/llvm/utils/gn/secondary/llvm/triples.gni
--- a/llvm/utils/gn/secondary/llvm/triples.gni
+++ b/llvm/utils/gn/secondary/llvm/triples.gni
@@ -23,6 +23,8 @@
     llvm_current_triple = "aarch64-linux-android29"
   } else if (current_os == "ios" || current_os == "mac") {
     llvm_current_triple = "arm64-apple-darwin"
+  } else if (current_os == "linux") {
+    llvm_current_triple = "aarch64-unknown-linux-gnu"
   }
 } else if (current_cpu == "ppc64") {
   if (current_os == "linux") {