diff --git a/configure.ac b/configure.ac
index 90bce2208..76844f6cb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -52,7 +52,7 @@ AC_MSG_CHECKING(whether to use tcmalloc)
 AC_ARG_ENABLE([tcmalloc],
               [AS_HELP_STRING([--enable-tcmalloc],
                               [Use libtcmalloc_minimal for faster dynamic memory
-                               management in Verilator binary@<:@default=check@:>@])],
+                               management in Verilator binary @<:@default=check@:>@])],
               [case "${enableval}" in
                 yes) CFG_WITH_TCMALLOC=yes ;;
                 no)  CFG_WITH_TCMALLOC=no ;;
@@ -61,6 +61,20 @@ AC_ARG_ENABLE([tcmalloc],
               [CFG_WITH_TCMALLOC=check;])
 AC_MSG_RESULT($CFG_WITH_TCMALLOC)
 
+# Flag to enable -m32 build
+AC_MSG_CHECKING(whether to use -m32)
+AC_ARG_ENABLE([m32],
+              [AS_HELP_STRING([--enable-m32],
+                              [Use -m32 for all compilation and link,
+                               including Verialtor and generated models.])],
+              [case "${enableval}" in
+                yes) CFG_ENABLE_M32=yes ;;
+                no)  CFG_ENABLE_M32=no ;;
+                *)   AC_MSG_ERROR([bad value '${enableval}' for --enable-m32]) ;;
+               esac],
+               CFG_ENABLE_M32=no)
+AC_MSG_RESULT($CFG_ENABLE_M32)
+
 # Special Substitutions - CFG_WITH_DEFENV
 AC_MSG_CHECKING(whether to use hardcoded paths)
 AC_ARG_ENABLE([defenv],
@@ -211,24 +225,34 @@ AC_DEFUN([_MY_CXX_CHECK_FLAG],
     CXXFLAGS="$ACO_SAVE_CXXFLAGS"
    ])
 
+AC_DEFUN([_MY_CXX_CHECK_IFELSE],
+   [# _MY_CXX_CHECK_IFELSE(option,action-if-supported,action-if-not-supported)
+    # Check if compiler supports specific option. If it does,
+    # do action-if-supported, otherwise do action-if-not-supported
+    _MY_CXX_CHECK_FLAG($1)
+    if test "$_my_result" = "yes" ; then
+      true
+      $2
+    else
+      true
+      $3
+    fi
+   ])
+
 AC_DEFUN([_MY_CXX_CHECK_SET],
-   [# _MY_CXX_CHECK_SET(variable,flag) -- Check if compiler supports specific options
-    # If it does, set variable to flag, only if not previously set
+   [# _MY_CXX_CHECK_SET(variable,option)
+    # Check if compiler supports specific option. If it does,
+    # set variable to option, only if not previously set.
     if test "$$1" = ""; then
-       _MY_CXX_CHECK_FLAG($2)
-       if test "$_my_result" = "yes" ; then
-          $1="$2"
-       fi
+       _MY_CXX_CHECK_IFELSE($2, $1="$2")
     fi
    ])
 
 AC_DEFUN([_MY_CXX_CHECK_OPT],
-   [# _MY_CXX_CHECK_OPT(flag) -- Check if compiler supports specific options
-    # If it does, append flag to variable
-    _MY_CXX_CHECK_FLAG($2)
-    if test "$_my_result" = "yes" ; then
-       $1="$$1 $2"
-    fi
+   [# _MY_CXX_CHECK_OPT(variable,option)
+    # Check if compiler supports specific option. If it does,
+    # append option to variable
+    _MY_CXX_CHECK_IFELSE($2, $1="$$1 $2")
    ])
 
 AC_DEFUN([_MY_LDLIBS_CHECK_FLAG],
@@ -270,6 +294,14 @@ AC_DEFUN([_MY_LDLIBS_CHECK_OPT],
     _MY_LDLIBS_CHECK_IFELSE($2, $1="$$1 $2")
    ])
 
+# When using -m32. Check this first as later checks may fail with the -m32 flag.
+if test "$CFG_ENABLE_M32" = "yes"; then
+  _MY_CXX_CHECK_IFELSE(
+    -m32,
+    [CXX="$CXX -m32"],
+    [AC_MSG_ERROR([--enable-m32 was given but compiler does not support -m32])])
+fi
+
 # Flag to select newest language standard supported
 # Macros work such that first option that passes is the one we take
 # Currently enabled gnu++14/c++14 due to packaged SystemC dependency
diff --git a/test_regress/driver.pl b/test_regress/driver.pl
index 37a7d309e..679906687 100755
--- a/test_regress/driver.pl
+++ b/test_regress/driver.pl
@@ -601,6 +601,7 @@ sub new {
                         ? " -Wl,-undefined,dynamic_lookup"
                         : " -export-dynamic")
                       .($opt_verbose ? " -DTEST_VERBOSE=1":"")
+                      .(cfg_with_m32() ? " -m32" : "")
                       ." -o $self->{obj_dir}/libvpi.so"],
         tool_c_flags => [],
         # ATSIM
@@ -2304,8 +2305,16 @@ sub cfg_with_threaded {
     return 1;  # C++11 now always required
 }
 
+our $_Cfg_with_ccache;
 sub cfg_with_ccache {
-    return `grep "OBJCACHE \?= ccache" "$ENV{VERILATOR_ROOT}/include/verilated.mk"` ne "";
+    $_Cfg_with_ccache ||= `grep "OBJCACHE \?= ccache" "$ENV{VERILATOR_ROOT}/include/verilated.mk"` ne "";
+    return $_Cfg_with_ccache;
+}
+
+our $_Cfg_with_m32;
+sub cfg_with_m32 {
+    $_Cfg_with_m32 ||= `grep "CXX.*=.*-m32" "$ENV{VERILATOR_ROOT}/include/verilated.mk"` ne "";
+    return $_Cfg_with_m32;
 }
 
 sub tries {
diff --git a/test_regress/t/t_flag_ldflags.pl b/test_regress/t/t_flag_ldflags.pl
index db80da480..1701a0b90 100755
--- a/test_regress/t/t_flag_ldflags.pl
+++ b/test_regress/t/t_flag_ldflags.pl
@@ -10,14 +10,16 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 scenarios(vlt => 1);
 
+my $m32 = $Self->cfg_with_m32 ? "-m32" : "";
+
 run(cmd => ["cd $Self->{obj_dir}"
-            ." && $ENV{CXX} -c ../../t/t_flag_ldflags_a.cpp"
+            ." && $ENV{CXX} $m32 -c ../../t/t_flag_ldflags_a.cpp"
             ." && ar -cr t_flag_ldflags_a.a t_flag_ldflags_a.o"
             ." && ranlib t_flag_ldflags_a.a "],
     check_finished => 0);
 run(cmd => ["cd $Self->{obj_dir}"
-            ." && $ENV{CXX} -fPIC -c ../../t/t_flag_ldflags_so.cpp"
-            ." && $ENV{CXX} -shared -o t_flag_ldflags_so.so -lc t_flag_ldflags_so.o"],
+            ." && $ENV{CXX} $m32 -fPIC -c ../../t/t_flag_ldflags_so.cpp"
+            ." && $ENV{CXX} $m32 -shared -o t_flag_ldflags_so.so -lc t_flag_ldflags_so.o"],
     check_finished => 0);
 
 compile(
diff --git a/test_regress/t/t_threads_crazy.pl b/test_regress/t/t_threads_crazy.pl
index 1d54c9e0a..54641105d 100755
--- a/test_regress/t/t_threads_crazy.pl
+++ b/test_regress/t/t_threads_crazy.pl
@@ -10,6 +10,10 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 scenarios(vltmt => 1);
 
+if ($Self->cfg_with_m32) {
+  skip("Does not work with -m32 (resource unavailable)");
+}
+
 compile(
     verilator_flags2 => ['--cc --threads 1024'],
     );