diff --git a/llvm/test/CMakeLists.txt b/llvm/test/CMakeLists.txt
--- a/llvm/test/CMakeLists.txt
+++ b/llvm/test/CMakeLists.txt
@@ -17,6 +17,7 @@
   LLVM_BYE_LINK_INTO_TOOLS
   LLVM_HAVE_TF_AOT
   LLVM_HAVE_TF_API
+  LLVM_ENABLE_EXPENSIVE_CHECKS
   )
 
 configure_lit_site_cfg(
diff --git a/llvm/test/CodeGen/PowerPC/aix-overflow-toc.py b/llvm/test/CodeGen/PowerPC/aix-overflow-toc.py
--- a/llvm/test/CodeGen/PowerPC/aix-overflow-toc.py
+++ b/llvm/test/CodeGen/PowerPC/aix-overflow-toc.py
@@ -1,4 +1,4 @@
-# REQUIRES: system-aix || system-linux
+# UNSUPPORTED: expensive_checks, debug
 
 # RUN: python %s > %t.ll
 # RUN: llc -mtriple powerpc-ibm-aix-xcoff -code-model=small -mcpu=pwr4 -mattr=-altivec -O0 < %t.ll | \
diff --git a/llvm/test/lit.cfg.py b/llvm/test/lit.cfg.py
--- a/llvm/test/lit.cfg.py
+++ b/llvm/test/lit.cfg.py
@@ -330,7 +330,8 @@
 
 # Ask llvm-config about asserts
 llvm_config.feature_config(
-    [('--assertion-mode', {'ON': 'asserts'})])
+    [('--assertion-mode', {'ON': 'asserts'}),
+     ('--build-mode', {'[Dd][Ee][Bb][Uu][Gg]': 'debug'})])
 
 if 'darwin' == sys.platform:
     cmd = ['sysctl', 'hw.optional.fma']
@@ -361,3 +362,6 @@
 
 if config.have_opt_viewer_modules:
     config.available_features.add('have_opt_viewer_modules')
+
+if config.expensive_checks:
+    config.available_features.add('expensive_checks')
diff --git a/llvm/test/lit.site.cfg.py.in b/llvm/test/lit.site.cfg.py.in
--- a/llvm/test/lit.site.cfg.py.in
+++ b/llvm/test/lit.site.cfg.py.in
@@ -50,6 +50,7 @@
 config.linked_bye_extension = @LLVM_BYE_LINK_INTO_TOOLS@
 config.have_tf_aot = @LLVM_HAVE_TF_AOT@
 config.have_tf_api = @LLVM_HAVE_TF_API@
+config.expensive_checks = @LLVM_ENABLE_EXPENSIVE_CHECKS@
 
 # Support substitution of the tools_dir with user parameters. This is
 # used when we can't determine the tool dir at configuration time.