diff --git a/Makefile.in b/Makefile.in
index 93d3ef247..8b89d5d1e 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -462,11 +462,12 @@ analyzer-include:
 
 CLANGFORMAT = clang-format
 CLANGFORMAT_FLAGS = -i
+CLANGFORMAT_FILES = $(CPPCHECK_CPP) $(CPPCHECK_H) $(CPPCHECK_YL) test_regress/t/*.c*
 
 clang-format:
 	@$(CLANGFORMAT) --version | egrep 10.0 > /dev/null \
 		|| echo "*** You are not using clang-format 10.0, indents may differ from master's ***"
-	$(CLANGFORMAT) $(CLANGFORMAT_FLAGS) $(CPPCHECK_CPP) $(CPPCHECK_H) $(CPPCHECK_YL)
+	$(CLANGFORMAT) $(CLANGFORMAT_FLAGS) $(CLANGFORMAT_FILES)
 
 ftp: info
 
diff --git a/test_regress/t/t_dpi_arg_inout_type.cpp b/test_regress/t/t_dpi_arg_inout_type.cpp
index a51d3aef4..a5c346d8f 100644
--- a/test_regress/t/t_dpi_arg_inout_type.cpp
+++ b/test_regress/t/t_dpi_arg_inout_type.cpp
@@ -13,6 +13,7 @@
 #include <cstdlib>
 #include <cstring>
 
+// clang-format off
 #if defined(NCSC)
 // Used by NC's svdpi.h to pick up svLogicVecVal with _.aval and _.bval fields,
 // rather than the IEEE 1800-2005 version which has _.a and _.b fields.
@@ -46,6 +47,7 @@ typedef uint64_t sv_longint_unsigned_t;
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 //======================================================================
 // Implementations of imported functions
diff --git a/test_regress/t/t_dpi_arg_input_type.cpp b/test_regress/t/t_dpi_arg_input_type.cpp
index 6f179d7e9..1593e1dfc 100644
--- a/test_regress/t/t_dpi_arg_input_type.cpp
+++ b/test_regress/t/t_dpi_arg_input_type.cpp
@@ -13,6 +13,7 @@
 #include <cstdlib>
 #include <cstring>
 
+// clang-format off
 #if defined(NCSC)
 // Used by NC's svdpi.h to pick up svLogicVecVal with _.aval and _.bval fields,
 // rather than the IEEE 1800-2005 version which has _.a and _.b fields.
@@ -51,6 +52,7 @@ typedef uint64_t sv_longint_unsigned_t;
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 //======================================================================
 // Implementations of imported functions
diff --git a/test_regress/t/t_dpi_arg_output_type.cpp b/test_regress/t/t_dpi_arg_output_type.cpp
index 40161ed25..cf127ee6e 100644
--- a/test_regress/t/t_dpi_arg_output_type.cpp
+++ b/test_regress/t/t_dpi_arg_output_type.cpp
@@ -13,6 +13,7 @@
 #include <cstdlib>
 #include <cstring>
 
+// clang-format off
 #if defined(NCSC)
 // Used by NC's svdpi.h to pick up svLogicVecVal with _.aval and _.bval fields,
 // rather than the IEEE 1800-2005 version which has _.a and _.b fields.
@@ -46,6 +47,7 @@ typedef uint64_t sv_longint_unsigned_t;
 # else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 //======================================================================
 // Implementations of imported functions
diff --git a/test_regress/t/t_dpi_context_c.cpp b/test_regress/t/t_dpi_context_c.cpp
index 2d1a8fbe4..50534b8e9 100644
--- a/test_regress/t/t_dpi_context_c.cpp
+++ b/test_regress/t/t_dpi_context_c.cpp
@@ -14,6 +14,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # ifdef T_DPI_CONTEXT_NOOPT
 #  include "Vt_dpi_context_noopt__Dpi.h"
@@ -31,6 +32,7 @@
 #ifdef VERILATOR
 # include "verilated.h"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
@@ -126,7 +128,7 @@ int dpic_restore() {
 
 unsigned dpic_getcontext() {
     svScope scope = svGetScope();
-    printf("%%Info: svGetScope returned scope (%p) with name %s\n",
+    printf("%%Info: svGetScope returned scope (%p) with name %s\n",  //
            scope, svGetNameFromScope(scope));
     return (unsigned)(uintptr_t)scope;
 }
diff --git a/test_regress/t/t_dpi_display_c.cpp b/test_regress/t/t_dpi_display_c.cpp
index 0be29e589..41d292027 100644
--- a/test_regress/t/t_dpi_display_c.cpp
+++ b/test_regress/t/t_dpi_display_c.cpp
@@ -14,6 +14,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_dpi_display__Dpi.h"
 #elif defined(VCS)
@@ -23,6 +24,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
@@ -31,12 +33,12 @@ extern void dpii_display_call(const char* c);
 }
 #endif
 
+// clang-format off
 #ifndef VL_PRINTF
 # define VL_PRINTF printf
 #endif
+// clang-format on
 
 //======================================================================
 
-void dpii_display_call(const char* c) {
-    VL_PRINTF("dpii_display_call: '%s'\n", c);
-}
+void dpii_display_call(const char* c) { VL_PRINTF("dpii_display_call: '%s'\n", c); }
diff --git a/test_regress/t/t_dpi_export_c.cpp b/test_regress/t/t_dpi_export_c.cpp
index e858de367..bcebfce0f 100644
--- a/test_regress/t/t_dpi_export_c.cpp
+++ b/test_regress/t/t_dpi_export_c.cpp
@@ -13,6 +13,7 @@
 #include <cstring>
 #include "svdpi.h"
 
+// clang-format off
 #ifdef _WIN32
 # define T_PRI64 "I64"
 #else  // Linux or compliant Unix flavors
@@ -34,6 +35,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 
@@ -67,6 +69,7 @@ extern void dpix_t_time(const svLogicVecVal* i, svLogicVecVal* o);
 
 //======================================================================
 
+// clang-format off
 #define CHECK_RESULT(type, got, exp)            \
     if ((got) != (exp)) {                       \
         printf("%%Error: %s:%d:", __FILE__, __LINE__); \
@@ -77,6 +80,7 @@ extern void dpix_t_time(const svLogicVecVal* i, svLogicVecVal* o);
         printf("  EXP = %" T_PRI64 "x\n", u.l); \
         return __LINE__; \
     }
+// clang-format on
 #define CHECK_RESULT_NNULL(got) \
     if (!(got)) { \
         printf("%%Error: %s:%d: GOT = %p   EXP = !NULL\n", __FILE__, __LINE__, (got)); \
@@ -107,9 +111,9 @@ int dpix_run_tests() {
 #ifdef VERILATOR
     static int didDump = 0;
     if (didDump++ == 0) {
-# ifdef TEST_VERBOSE
+#ifdef TEST_VERBOSE
         Verilated::internalsDump();
-# endif
+#endif
     }
 #endif
 
@@ -183,7 +187,9 @@ int dpix_run_tests() {
         CHECK_RESULT(svLogic, o, 0);
     }
     {
-        svLogicVecVal i[1]; i[0].aval = 0x12; i[0].bval = 0;
+        svLogicVecVal i[1];
+        i[0].aval = 0x12;
+        i[0].bval = 0;
         svLogicVecVal o[1];
         dpix_t_reg15(i, o);
         CHECK_RESULT(int, o[0].aval, (~i[0].aval) & 0x7fff);
@@ -191,9 +197,12 @@ int dpix_run_tests() {
     }
     {
         svLogicVecVal i[3];
-        i[0].aval = 0x72912312; i[0].bval = 0;
-        i[1].aval = 0xab782a12; i[1].bval = 0;
-        i[2].aval = 0x8a413bd9; i[2].bval = 0;
+        i[0].aval = 0x72912312;
+        i[0].bval = 0;
+        i[1].aval = 0xab782a12;
+        i[1].bval = 0;
+        i[2].aval = 0x8a413bd9;
+        i[2].bval = 0;
         svLogicVecVal o[3];
         dpix_t_reg95(i, o);
         CHECK_RESULT(int, o[0].aval, ~i[0].aval);
@@ -206,8 +215,10 @@ int dpix_run_tests() {
 #if !defined(VCS) && !defined(CADENCE)
     {
         svLogicVecVal i[2];
-        i[0].aval = 0x72912312; i[0].bval = 0;
-        i[1].aval = 0xab782a12; i[1].bval = 0;
+        i[0].aval = 0x72912312;
+        i[0].bval = 0;
+        i[1].aval = 0xab782a12;
+        i[1].bval = 0;
         svLogicVecVal o[2];
         dpix_t_time(i, o);
         CHECK_RESULT(int, o[0].aval, ~i[0].aval);
diff --git a/test_regress/t/t_dpi_export_context_bad.cpp b/test_regress/t/t_dpi_export_context_bad.cpp
index 86e6fcc1f..a42ceff51 100644
--- a/test_regress/t/t_dpi_export_context_bad.cpp
+++ b/test_regress/t/t_dpi_export_context_bad.cpp
@@ -11,6 +11,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_dpi_export_context_bad__Dpi.h"
 #elif defined(VCS)
@@ -20,6 +21,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
diff --git a/test_regress/t/t_dpi_imp_gen_c.cpp b/test_regress/t/t_dpi_imp_gen_c.cpp
index f7a6b5d1a..15a03eea5 100644
--- a/test_regress/t/t_dpi_imp_gen_c.cpp
+++ b/test_regress/t/t_dpi_imp_gen_c.cpp
@@ -15,6 +15,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_dpi_imp_gen__Dpi.h"
 #elif defined(VCS)
@@ -24,6 +25,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
diff --git a/test_regress/t/t_dpi_import_c.cpp b/test_regress/t/t_dpi_import_c.cpp
index e23a2a599..2771b70f1 100644
--- a/test_regress/t/t_dpi_import_c.cpp
+++ b/test_regress/t/t_dpi_import_c.cpp
@@ -15,6 +15,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_dpi_import__Dpi.h"
 #elif defined(VCS)
@@ -24,6 +25,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 typedef struct {
     int a;
diff --git a/test_regress/t/t_dpi_lib_c.cpp b/test_regress/t/t_dpi_lib_c.cpp
index 04ad63bad..7113909ce 100644
--- a/test_regress/t/t_dpi_lib_c.cpp
+++ b/test_regress/t/t_dpi_lib_c.cpp
@@ -16,6 +16,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_dpi_lib__Dpi.h"
 #elif defined(VCS)
@@ -25,6 +26,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
diff --git a/test_regress/t/t_dpi_open_c.cpp b/test_regress/t/t_dpi_open_c.cpp
index 806555f74..b4aa42c56 100644
--- a/test_regress/t/t_dpi_open_c.cpp
+++ b/test_regress/t/t_dpi_open_c.cpp
@@ -16,6 +16,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_dpi_open__Dpi.h"
 #elif defined(VCS)
@@ -27,6 +28,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
@@ -90,11 +92,13 @@ extern int dpii_failure();
 int failure = 0;
 int dpii_failure() { return failure; }
 
+// clang-format off
 #ifdef _WIN32
 # define T_PRI64 "I64"
 #else  // Linux or compliant Unix flavors
 # define T_PRI64 "ll"
 #endif
+// clang-format on
 
 #define CHECK_RESULT_HEX(got, exp) \
     do { \
diff --git a/test_regress/t/t_dpi_open_query.cpp b/test_regress/t/t_dpi_open_query.cpp
index 21f7eab1c..021e6ef53 100644
--- a/test_regress/t/t_dpi_open_query.cpp
+++ b/test_regress/t/t_dpi_open_query.cpp
@@ -9,10 +9,9 @@
 //
 //*************************************************************************
 
-// clang-format off
-
 #include "svdpi.h"
 
+// clang-format off
 #if defined(VERILATOR)  // Verilator
 # include "Vt_dpi_open_query__Dpi.h"
 #elif defined(VCS)  // VCS
@@ -24,7 +23,6 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
-
 // clang-format on
 
 //======================================================================
diff --git a/test_regress/t/t_dpi_openfirst_c.cpp b/test_regress/t/t_dpi_openfirst_c.cpp
index 0a18aa736..3b60a4129 100644
--- a/test_regress/t/t_dpi_openfirst_c.cpp
+++ b/test_regress/t/t_dpi_openfirst_c.cpp
@@ -16,6 +16,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_dpi_openfirst__Dpi.h"
 #elif defined(VCS)
@@ -25,6 +26,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
diff --git a/test_regress/t/t_dpi_qw_c.cpp b/test_regress/t/t_dpi_qw_c.cpp
index 802f87991..01a927848 100644
--- a/test_regress/t/t_dpi_qw_c.cpp
+++ b/test_regress/t/t_dpi_qw_c.cpp
@@ -23,6 +23,7 @@
 void poke_value(int i) {
     printf("poke_value(%d)\n", i);
 
+// clang-format off
 #ifdef VERILATOR
     static int didDump = 0;
     if (didDump++ == 0) {
@@ -31,6 +32,7 @@ void poke_value(int i) {
 # endif
     }
 #endif
+    // clang-format on
 
     svScope scope = svGetScopeFromName("top.t.a");
     if (scope == NULL) {
diff --git a/test_regress/t/t_dpi_result_type.cpp b/test_regress/t/t_dpi_result_type.cpp
index 1ecbf0d94..21ea9e772 100644
--- a/test_regress/t/t_dpi_result_type.cpp
+++ b/test_regress/t/t_dpi_result_type.cpp
@@ -15,6 +15,7 @@
 
 #include "svdpi.h"
 
+// clang-format off
 #if defined(VERILATOR)  // Verilator
 # include "Vt_dpi_result_type__Dpi.h"
 typedef long long sv_longint_t;
@@ -41,6 +42,7 @@ typedef uint64_t sv_longint_unsigned_t;
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 //======================================================================
 // Implementations of imported functions
diff --git a/test_regress/t/t_dpi_shortcircuit_c.cpp b/test_regress/t/t_dpi_shortcircuit_c.cpp
index 211231a8a..dad4af8aa 100644
--- a/test_regress/t/t_dpi_shortcircuit_c.cpp
+++ b/test_regress/t/t_dpi_shortcircuit_c.cpp
@@ -15,6 +15,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # if defined(T_DPI_SHORTCIRCUIT)
 #  include "Vt_dpi_shortcircuit__Dpi.h"
@@ -30,6 +31,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
diff --git a/test_regress/t/t_dpi_string_c.cpp b/test_regress/t/t_dpi_string_c.cpp
index b357c65b6..ba6583d79 100644
--- a/test_regress/t/t_dpi_string_c.cpp
+++ b/test_regress/t/t_dpi_string_c.cpp
@@ -15,6 +15,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_dpi_string__Dpi.h"
 #elif defined(VCS)
@@ -24,6 +25,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
diff --git a/test_regress/t/t_dpi_sys_c.cpp b/test_regress/t/t_dpi_sys_c.cpp
index 6e904fad1..156609f16 100644
--- a/test_regress/t/t_dpi_sys_c.cpp
+++ b/test_regress/t/t_dpi_sys_c.cpp
@@ -14,6 +14,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_dpi_sys__Dpi.h"
 #elif defined(VCS)
@@ -23,6 +24,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
diff --git a/test_regress/t/t_dpi_threads_c.cpp b/test_regress/t/t_dpi_threads_c.cpp
index 3f06f2d64..0b2900352 100644
--- a/test_regress/t/t_dpi_threads_c.cpp
+++ b/test_regress/t/t_dpi_threads_c.cpp
@@ -17,6 +17,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # ifdef T_DPI_THREADS_COLLIDE
 #  include "Vt_dpi_threads_collide__Dpi.h"
@@ -30,6 +31,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
diff --git a/test_regress/t/t_dpi_vams.cpp b/test_regress/t/t_dpi_vams.cpp
index 0abce4a58..4722f8636 100644
--- a/test_regress/t/t_dpi_vams.cpp
+++ b/test_regress/t/t_dpi_vams.cpp
@@ -11,6 +11,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_dpi_vams__Dpi.h"
 #elif defined(VCS)
@@ -20,6 +21,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #ifdef NEED_EXTERNS
 extern "C" {
diff --git a/test_regress/t/t_dpi_var.cpp b/test_regress/t/t_dpi_var.cpp
index dad42dcc1..bbab2e36c 100644
--- a/test_regress/t/t_dpi_var.cpp
+++ b/test_regress/t/t_dpi_var.cpp
@@ -120,11 +120,13 @@ int main(int argc, char** argv, char** env) {
 
     VM_PREFIX* topp = new VM_PREFIX("");  // Note null name - we're flattening it out
 
+// clang-format off
 #ifdef VERILATOR
 # ifdef TEST_VERBOSE
     Verilated::scopesDump();
 # endif
 #endif
+    // clang-format on
 
     topp->eval();
     topp->clk = 0;
diff --git a/test_regress/t/t_embed1_c.cpp b/test_regress/t/t_embed1_c.cpp
index 78ae95cb0..51ffbe375 100644
--- a/test_regress/t/t_embed1_c.cpp
+++ b/test_regress/t/t_embed1_c.cpp
@@ -16,6 +16,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_embed1__Dpi.h"
 #elif defined(VCS)
@@ -25,6 +26,7 @@
 #else
 # error "Unknown simulator for DPI test"
 #endif
+// clang-format on
 
 #include "verilated.h"
 
@@ -80,14 +82,9 @@ void t_embed_child_eval() {
     __modelp->eval();
 }
 
-void t_embed_child_io_eval(unsigned char clk,
-                           unsigned char bit_in,
-                           const svBitVecVal* vec_in,
-                           const svBitVecVal* wide_in,
-                           unsigned char is_ref,
-                           unsigned char* bit_out,
-                           svBitVecVal* vec_out,
-                           svBitVecVal* wide_out,
+void t_embed_child_io_eval(unsigned char clk, unsigned char bit_in, const svBitVecVal* vec_in,
+                           const svBitVecVal* wide_in, unsigned char is_ref,
+                           unsigned char* bit_out, svBitVecVal* vec_out, svBitVecVal* wide_out,
                            unsigned char* did_init_out) {
     VL_DEBUG_IF(VL_PRINTF("    t_embed1_child_io_eval\n"););
     Vt_embed1_child* __modelp = __get_modelp();
diff --git a/test_regress/t/t_flag_ldflags_c.cpp b/test_regress/t/t_flag_ldflags_c.cpp
index fa62acc3f..6b32be9b9 100644
--- a/test_regress/t/t_flag_ldflags_c.cpp
+++ b/test_regress/t/t_flag_ldflags_c.cpp
@@ -14,6 +14,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # include "Vt_flag_ldflags__Dpi.h"
 #else
@@ -28,5 +29,6 @@
 #ifndef CFLAGS2_FROM_CMDLINE
 # error "CFLAGS2_FROM_CMDLINE not set - not passed down?"
 #endif
+// clang-format on
 
 void dpii_c_library() {}
diff --git a/test_regress/t/t_leak.cpp b/test_regress/t/t_leak.cpp
index 6bb6cfe28..8553bfccd 100644
--- a/test_regress/t/t_leak.cpp
+++ b/test_regress/t/t_leak.cpp
@@ -30,13 +30,12 @@ long long get_memory_usage() {
 
     int ps_ign;
     vluint64_t ps_vsize, ps_rss;
-    int items = fscanf(fp, ("%d (%*[^) ]) %*1s %d %*d %*d %*d %*d %u"
-                            " %u %u %u %u %d %d %d %d"
-                            " %*d %*d %*u %*u %d %" VL_PRI64 "u %" VL_PRI64 "u "),
-                       &ps_ign, &ps_ign, &ps_ign,
-                       &ps_ign, &ps_ign, &ps_ign, &ps_ign,
-                       &ps_ign, &ps_ign, &ps_ign, &ps_ign,
-                       &ps_ign, &ps_vsize, &ps_rss);
+    int items = fscanf(fp,
+                       ("%d (%*[^) ]) %*1s %d %*d %*d %*d %*d %u"
+                        " %u %u %u %u %d %d %d %d"
+                        " %*d %*d %*u %*u %d %" VL_PRI64 "u %" VL_PRI64 "u "),
+                       &ps_ign, &ps_ign, &ps_ign, &ps_ign, &ps_ign, &ps_ign, &ps_ign, &ps_ign,
+                       &ps_ign, &ps_ign, &ps_ign, &ps_ign, &ps_vsize, &ps_rss);
     fclose(fp);
     if (items >= 14) {
         return ps_vsize;
@@ -79,7 +78,7 @@ int main(int argc, char* argv[]) {
     }
 
     vluint64_t leaked = get_memory_usage() - firstUsage;
-    if (leaked > 64*1024) {  // Have to allow some slop for this code.
+    if (leaked > 64 * 1024) {  // Have to allow some slop for this code.
         printf("Leaked %" VL_PRI64 "d bytes, or ~ %" VL_PRI64 "d bytes/construt\n",  //
                leaked, leaked / loops);
         vl_fatal(__FILE__, __LINE__, "top", "Leaked memory\n");
diff --git a/test_regress/t/t_mem_multi_io2.cpp b/test_regress/t/t_mem_multi_io2.cpp
index c12e8330a..145b02ba3 100644
--- a/test_regress/t/t_mem_multi_io2.cpp
+++ b/test_regress/t/t_mem_multi_io2.cpp
@@ -48,15 +48,17 @@ int main()
 #endif
 
     // loop through every possibility and check the result
+// clang-format off
 #ifdef SYSTEMC_VERSION
     sc_start(1, SC_NS);
-#  define ASSIGN(s,v) s.write(v)
-#  define READ(s) s.read()
+# define ASSIGN(s, v) s.write(v)
+# define READ(s) s.read()
 #else
     tb->eval();
-#  define ASSIGN(s,v) tb->s = (v)
-#  define READ(s) tb->s
+# define ASSIGN(s, v) tb->s = (v)
+# define READ(s) tb->s
 #endif
+    // clang-format on
 
     ASSIGN(i3, 13);
     for (int i = 0; i < 4; i++) {
diff --git a/test_regress/t/t_mem_slot.cpp b/test_regress/t/t_mem_slot.cpp
index 7d367925e..86d3b984e 100644
--- a/test_regress/t/t_mem_slot.cpp
+++ b/test_regress/t/t_mem_slot.cpp
@@ -46,9 +46,9 @@ int main(int argc, char* argv[]) {
 
     Verilated::debug(0);
 
-    /* clear all bits in the array */
+    // clear all bits in the array
     for (slot = 0; slot < 3; slot++)
-        for (bit = 0; bit < 2; bit++)
+        for (bit = 0; bit < 2; bit++)  //
             StepSim(sim, slot, bit, 0, 0);
 
     printf("\nTesting\n");
diff --git a/test_regress/t/t_protect_ids_c.cpp b/test_regress/t/t_protect_ids_c.cpp
index 36198253e..484ba07b8 100644
--- a/test_regress/t/t_protect_ids_c.cpp
+++ b/test_regress/t/t_protect_ids_c.cpp
@@ -15,6 +15,7 @@
 
 //======================================================================
 
+// clang-format off
 #if defined(VERILATOR)
 # ifdef T_PROTECT_IDS_KEY
 #  include "Vt_protect_ids_key__Dpi.h"
@@ -32,6 +33,7 @@
 #ifdef NEED_EXTERNS
 # error "Not supported"
 #endif
+// clang-format on
 
 //======================================================================
 
diff --git a/test_regress/t/t_trace_cat.cpp b/test_regress/t/t_trace_cat.cpp
index f1f5aed79..b4a9c6125 100644
--- a/test_regress/t/t_trace_cat.cpp
+++ b/test_regress/t/t_trace_cat.cpp
@@ -50,7 +50,7 @@ int main(int argc, char** argv, char** env) {
             top->trace(tfp, 99);
             tfp->open(trace_name());
 #else
-# error "Unknown test"
+#error "Unknown test"
 #endif
         }
         tfp->dump((unsigned int)(main_time));
diff --git a/test_regress/t/t_trace_public_func.cpp b/test_regress/t/t_trace_public_func.cpp
index 8f4de6e76..c43a13dbc 100644
--- a/test_regress/t/t_trace_public_func.cpp
+++ b/test_regress/t/t_trace_public_func.cpp
@@ -9,6 +9,7 @@
 #include <verilated.h>
 #include <verilated_vcd_c.h>
 
+// clang-format off
 #include VM_PREFIX_INCLUDE
 #ifdef T_TRACE_PUBLIC_FUNC_VLT
 # include "Vt_trace_public_func_vlt_t.h"
@@ -17,6 +18,7 @@
 # include "Vt_trace_public_func_t.h"
 # include "Vt_trace_public_func_glbl.h"
 #endif
+// clang-format on
 
 unsigned long long main_time = 0;
 double sc_time_stamp() { return (double)main_time; }
diff --git a/test_regress/t/t_trace_public_sig.cpp b/test_regress/t/t_trace_public_sig.cpp
index 7733c2eca..2c996203f 100644
--- a/test_regress/t/t_trace_public_sig.cpp
+++ b/test_regress/t/t_trace_public_sig.cpp
@@ -9,6 +9,7 @@
 #include <verilated.h>
 #include <verilated_vcd_c.h>
 
+// clang-format off
 #include VM_PREFIX_INCLUDE
 #ifdef T_TRACE_PUBLIC_SIG_VLT
 # include "Vt_trace_public_sig_vlt_t.h"
@@ -17,6 +18,7 @@
 # include "Vt_trace_public_sig_t.h"
 # include "Vt_trace_public_sig_glbl.h"
 #endif
+// clang-format on
 
 unsigned long long main_time = 0;
 double sc_time_stamp() { return (double)main_time; }
diff --git a/test_regress/t/t_trace_two_cc.cpp b/test_regress/t/t_trace_two_cc.cpp
index e339c6a24..3cfd0ef46 100644
--- a/test_regress/t/t_trace_two_cc.cpp
+++ b/test_regress/t/t_trace_two_cc.cpp
@@ -6,6 +6,7 @@
 // Version 2.0.
 // SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
 
+// clang-format off
 #include "verilatedos.h"
 #include VM_PREFIX_INCLUDE
 #include "Vt_trace_two_b.h"
@@ -17,6 +18,7 @@
 #  include "verilated_vcd_c.h"
 # endif
 #endif
+// clang-format on
 
 // Compile in place
 #include "Vt_trace_two_b.cpp"
@@ -39,6 +41,7 @@ int main(int argc, char** argv, char** env) {
     ap = new VM_PREFIX("topa");
     bp = new Vt_trace_two_b("topb");
 
+// clang-format off
 #ifdef TEST_HDR_TRACE
     Verilated::traceEverOn(true);
 # ifdef TEST_FST
@@ -53,6 +56,7 @@ int main(int argc, char** argv, char** env) {
     tfp->open(VL_STRINGIFY(TEST_OBJ_DIR) "/simx.vcd");
 # endif
 #endif
+    // clang-format on
 
 #ifdef TEST_HDR_TRACE
     ap->eval_step();
diff --git a/test_regress/t/t_trace_two_sc.cpp b/test_regress/t/t_trace_two_sc.cpp
index 66e145145..ebfffc68d 100644
--- a/test_regress/t/t_trace_two_sc.cpp
+++ b/test_regress/t/t_trace_two_sc.cpp
@@ -6,6 +6,7 @@
 // Version 2.0.
 // SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
 
+// clang-format off
 #include "verilatedos.h"
 #include VM_PREFIX_INCLUDE
 #include "Vt_trace_two_b.h"
@@ -13,6 +14,7 @@
 #ifdef TEST_HDR_TRACE
 # include "verilated_vcd_sc.h"
 #endif
+// clang-format on
 
 // Compile in place
 #include "Vt_trace_two_b.cpp"
diff --git a/test_regress/t/t_vpi_time_cb.cpp b/test_regress/t/t_vpi_time_cb.cpp
index c0a170ac2..210abb609 100644
--- a/test_regress/t/t_vpi_time_cb.cpp
+++ b/test_regress/t/t_vpi_time_cb.cpp
@@ -167,7 +167,9 @@ static int _end_of_sim_cb(p_cb_data cb_data) {
 extern "C"
 #endif
 
+    // clang-format off
 void vpi_compat_bootstrap(void) {
+    // clang-format on
     t_cb_data cb_data;
     bzero(&cb_data, sizeof(cb_data));
 
@@ -197,11 +199,13 @@ int main(int argc, char** argv, char** env) {
 
     VM_PREFIX* topp = new VM_PREFIX("");  // Note null name - we're flattening it out
 
+// clang-format off
 #ifdef VERILATOR
 # ifdef TEST_VERBOSE
     Verilated::scopesDump();
 # endif
 #endif
+    // clang-format on
 
 #if VM_TRACE
     Verilated::traceEverOn(true);
diff --git a/test_regress/t/t_vpi_zero_time_cb.cpp b/test_regress/t/t_vpi_zero_time_cb.cpp
index a553bec45..54303e04f 100644
--- a/test_regress/t/t_vpi_zero_time_cb.cpp
+++ b/test_regress/t/t_vpi_zero_time_cb.cpp
@@ -117,7 +117,9 @@ static int _end_of_sim_cb(p_cb_data cb_data) {
 extern "C"
 #endif
 
+    // clang-format off
 void vpi_compat_bootstrap(void) {
+    // clang-format on
     t_cb_data cb_data;
     bzero(&cb_data, sizeof(cb_data));
 
@@ -147,11 +149,13 @@ int main(int argc, char** argv, char** env) {
 
     VM_PREFIX* topp = new VM_PREFIX("");  // Note null name - we're flattening it out
 
+// clang-format off
 #ifdef VERILATOR
 # ifdef TEST_VERBOSE
     Verilated::scopesDump();
 # endif
 #endif
+    // clang-format on
 
 #if VM_TRACE
     Verilated::traceEverOn(true);