Index: clang/lib/Driver/ToolChains/CommonArgs.cpp
===================================================================
--- clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -676,6 +676,9 @@
   else if (IsThinLTO && IsOSAIX)
     CmdArgs.push_back(Args.MakeArgString(Twine("-bdbg:thinlto")));
 
+  // Matrix intrinsic lowering happens at link time with ThinLTO.
+  if (IsThinLTO && Args.hasArg(options::OPT_fenable_matrix))
+    CmdArgs.push_back(Args.MakeArgString(Twine(PluginOptPrefix) + "-enable-matrix"));
 
   StringRef Parallelism = getLTOParallelism(Args, D);
   if (!Parallelism.empty())
Index: clang/test/Driver/matrix.c
===================================================================
--- /dev/null
+++ clang/test/Driver/matrix.c
@@ -0,0 +1,8 @@
+// RUN: touch %t.o
+// RUN: %clang -flto=thin -fenable-matrix %t.o -### --target=powerpc64-ibm-aix-xcoff 2>&1 \
+// RUN:     | FileCheck %s -check-prefix=CHECK-THINLTO-MATRIX-AIX
+// CHECK-THINLTO-MATRIX-AIX: "-bplugin_opt:-enable-matrix"
+//
+// RUN: %clang -flto=thin -fenable-matrix %t.o -### --target=x86_64-unknown-linux 2>&1 \
+// RUN:     | FileCheck %s -check-prefix=CHECK-THINLTO-MATRIX
+// CHECK-THINLTO-MATRIX: "-plugin-opt=-enable-matrix"