diff --git a/compiler-rt/test/lit.common.cfg.py b/compiler-rt/test/lit.common.cfg.py
--- a/compiler-rt/test/lit.common.cfg.py
+++ b/compiler-rt/test/lit.common.cfg.py
@@ -55,7 +55,9 @@
 
   # Try using `-print-runtime-dir`. This is only supported by very new versions of Clang.
   # so allow failure here.
-  runtime_dir, clang_cmd = get_path_from_clang(['-print-runtime-dir'], allow_failure=True)
+  runtime_dir, clang_cmd = get_path_from_clang(shlex.split(config.target_cflags)
+                                               + ['-print-runtime-dir'],
+                                               allow_failure=True)
   if runtime_dir:
     if os.path.exists(runtime_dir):
       return os.path.realpath(runtime_dir)
@@ -123,6 +125,16 @@
 # Add compiler ID to the list of available features.
 config.available_features.add(compiler_id)
 
+# When LLVM_ENABLE_PER_TARGET_RUNTIME_DIR=on, the initial value of
+# config.compiler_rt_libdir (COMPILER_RT_RESOLVED_LIBRARY_OUTPUT_DIR) has the
+# triple as the trailing path component. The value is incorrect for -m32/-m64.
+# Adjust config.compiler_rt accordingly.
+if config.enable_per_target_runtime_dir:
+    if '-m32' in shlex.split(config.target_cflags):
+        config.compiler_rt_libdir = re.sub(r'/x86_64(?=-[^/]+$)', '/i386', config.compiler_rt_libdir)
+    elif '-m64' in shlex.split(config.target_cflags):
+        config.compiler_rt_libdir = re.sub(r'/i386(?=-[^/]+$)', '/x86_64', config.compiler_rt_libdir)
+
 # Ask the compiler for the path to libraries it is going to use. If this
 # doesn't match config.compiler_rt_libdir then it means we might be testing the
 # compiler's own runtime libraries rather than the ones we just built.