diff --git a/python/taichi/core/util.py b/python/taichi/core/util.py
index a328680f327ed..d50d7f68bc703 100644
--- a/python/taichi/core/util.py
+++ b/python/taichi/core/util.py
@@ -480,6 +480,9 @@ def _print_taichi_header():
     archs_str = ', '.join(sorted(supported_archs))
     header += f'supported archs: [{archs_str}], '
 
+    llvm_version = ti_core.get_llvm_version_string()
+    header += f'llvm {llvm_version}, '
+
     commit_hash = ti_core.get_commit_hash()
     commit_hash = commit_hash[:8]
     header += f'commit {commit_hash}, '
diff --git a/taichi/common/core.cpp b/taichi/common/core.cpp
index 1d9407265c47f..d36934d52dd48 100644
--- a/taichi/common/core.cpp
+++ b/taichi/common/core.cpp
@@ -4,6 +4,9 @@
 *******************************************************************************/
 
 #include "taichi/common/core.h"
+
+#include "llvm/Config/llvm-config.h"
+
 #include "taichi/common/version.h"
 #include "taichi/common/commit_hash.h"
 
@@ -76,4 +79,8 @@ std::string get_cuda_version_string() {
   return TI_CUDAVERSION;
 }
 
+std::string get_llvm_version_string() {
+  return LLVM_VERSION_STRING;
+}
+
 TI_NAMESPACE_END
diff --git a/taichi/common/core.h b/taichi/common/core.h
index 791f5b7138743..b08660ee06ddd 100644
--- a/taichi/common/core.h
+++ b/taichi/common/core.h
@@ -520,4 +520,5 @@ std::string get_commit_hash();
 
 std::string get_cuda_version_string();
 
+std::string get_llvm_version_string();
 TI_NAMESPACE_END
diff --git a/taichi/python/export_lang.cpp b/taichi/python/export_lang.cpp
index 1d5b1db7d5d14..6287099bca17c 100644
--- a/taichi/python/export_lang.cpp
+++ b/taichi/python/export_lang.cpp
@@ -537,6 +537,7 @@ void export_lang(py::module &m) {
   m.def("get_version_major", get_version_major);
   m.def("get_version_minor", get_version_minor);
   m.def("get_version_patch", get_version_patch);
+  m.def("get_llvm_version_string", get_llvm_version_string);
   m.def("test_printf", [] { printf("test_printf\n"); });
   m.def("test_logging", [] { TI_INFO("test_logging\n"); });
   m.def("trigger_crash", [] { *(int *)(1) = 0; });
diff --git a/taichi/transforms/auto_diff.cpp b/taichi/transforms/auto_diff.cpp
index 93982ccdeb20b..b434629295346 100644
--- a/taichi/transforms/auto_diff.cpp
+++ b/taichi/transforms/auto_diff.cpp
@@ -222,7 +222,7 @@ class ReverseOuterLoops : public BasicStmtVisitor {
   using BasicStmtVisitor::visit;
 
  private:
-  ReverseOuterLoops(const std::vector<Block *> &IB) : IB(IB), loop_depth(0) {
+  ReverseOuterLoops(const std::vector<Block *> &IB) : loop_depth(0), IB(IB) {
   }
 
   bool is_IB(Block *block) const {