diff --git a/test_regress/t/t_alw_split.pl b/test_regress/t/t_alw_split.pl
index d26471e64..abf31a37b 100755
--- a/test_regress/t/t_alw_split.pl
+++ b/test_regress/t/t_alw_split.pl
@@ -11,7 +11,7 @@ compile (
 	 verilator_flags2 => ["--stats"],
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ($Self->{stats}, qr/Optimizations, Split always\s+6/i);
 }
 
diff --git a/test_regress/t/t_alw_splitord.pl b/test_regress/t/t_alw_splitord.pl
index 28664c281..936efb636 100755
--- a/test_regress/t/t_alw_splitord.pl
+++ b/test_regress/t/t_alw_splitord.pl
@@ -11,7 +11,7 @@ compile (
 	 verilator_flags2 => ["--stats"],
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ($Self->{stats}, qr/Optimizations, Split always\s+0/i);
 }
 
diff --git a/test_regress/t/t_assert_basic.pl b/test_regress/t/t_assert_basic.pl
index 95e70fe4a..ef9866039 100755
--- a/test_regress/t/t_assert_basic.pl
+++ b/test_regress/t/t_assert_basic.pl
@@ -8,7 +8,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Version 2.0.
 
 compile (
-	 v_flags2 => [$Self->{v3}?'--assert':($Self->{nc}?'+assert':'')],
+	 verilator_flags2 => ['--assert'],
+	 nc_flags2 => ['+assert'],
 	 );
 
 execute (
diff --git a/test_regress/t/t_assert_basic_cover.pl b/test_regress/t/t_assert_basic_cover.pl
index 492ee141a..e10bc2ed7 100755
--- a/test_regress/t/t_assert_basic_cover.pl
+++ b/test_regress/t/t_assert_basic_cover.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_assert_basic.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'--assert --sp --coverage-user':''],
+	 verilator_flags2 => ['--assert --sp --coverage-user'],
 	 );
 
 execute (
diff --git a/test_regress/t/t_assert_cover.pl b/test_regress/t/t_assert_cover.pl
index b57d8833b..f20a45b66 100755
--- a/test_regress/t/t_assert_cover.pl
+++ b/test_regress/t/t_assert_cover.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_assert_cover.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'--assert --sp --coverage-user':''],
+	 verilator_flags2 => ['--assert --sp --coverage-user'],
 	 nc_flags2 => ["+nccovoverwrite +nccoverage+all +nccovtest+$Self->{name}"]
 	 );
 
diff --git a/test_regress/t/t_assert_synth.pl b/test_regress/t/t_assert_synth.pl
index 95e70fe4a..d4c469bb8 100755
--- a/test_regress/t/t_assert_synth.pl
+++ b/test_regress/t/t_assert_synth.pl
@@ -8,7 +8,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Version 2.0.
 
 compile (
-	 v_flags2 => [$Self->{v3}?'--assert':($Self->{nc}?'+assert':'')],
+	 verilator_flags2 => ['--assert'],
+    	 nc_flags2 => ['+assert'],
 	 );
 
 execute (
diff --git a/test_regress/t/t_assert_synth_full.pl b/test_regress/t/t_assert_synth_full.pl
index 3fcf338c9..46311ebea 100755
--- a/test_regress/t/t_assert_synth_full.pl
+++ b/test_regress/t/t_assert_synth_full.pl
@@ -10,8 +10,9 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_assert_synth.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'--assert':($Self->{nc}?'+assert':''),
-		      '+define+FAILING_FULL',],
+	 v_flags2 => ['+define+FAILING_FULL'],
+	 verilator_flags2 => ['--assert'],
+	 nc_flags2 => ['+assert'],
 	 );
 
 execute (
diff --git a/test_regress/t/t_assert_synth_parallel.pl b/test_regress/t/t_assert_synth_parallel.pl
index 19f0646c1..599eaa232 100755
--- a/test_regress/t/t_assert_synth_parallel.pl
+++ b/test_regress/t/t_assert_synth_parallel.pl
@@ -10,8 +10,9 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_assert_synth.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'--assert':($Self->{nc}?'+assert':''),
-		      '+define+FAILING_PARALLEL',],
+	 v_flags2 => ['+define+FAILING_PARALLEL'],
+	 verilator_flags2 => ['--assert'],
+	 nc_flags2 => ['+assert'],
 	 );
 
 execute (
diff --git a/test_regress/t/t_case_huge.pl b/test_regress/t/t_case_huge.pl
index bbb2119c7..a019b77ac 100755
--- a/test_regress/t/t_case_huge.pl
+++ b/test_regress/t/t_case_huge.pl
@@ -11,7 +11,7 @@ compile (
 	 verilator_flags2 => ["--stats --profile-cfuncs"],
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ($Self->{stats}, qr/Optimizations, Tables created\s+10/i);
     file_grep ($Self->{stats}, qr/Optimizations, Combined CFuncs\s+10/i);
 }
diff --git a/test_regress/t/t_clk_2in.pl b/test_regress/t/t_clk_2in.pl
index 8a167c617..5da9bf0b2 100755
--- a/test_regress/t/t_clk_2in.pl
+++ b/test_regress/t/t_clk_2in.pl
@@ -7,14 +7,18 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
-	 v_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
-	 ) if $Self->{v3};
+	 v_flags2 => ["$Self->{t_dir}/$Self->{name}.cpp"],
+	 verilator_flags2 => ["--exe"],
+	 );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+	 );
+
 ok(1);
 1;
diff --git a/test_regress/t/t_clk_2in_vec.pl b/test_regress/t/t_clk_2in_vec.pl
index df58e96bc..7cc55d8ac 100755
--- a/test_regress/t/t_clk_2in_vec.pl
+++ b/test_regress/t/t_clk_2in_vec.pl
@@ -9,14 +9,17 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_clk_2in.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
-	 v_flags2 => ["+define+T_CLK_2IN_VEC=1 --exe $Self->{t_dir}/t_clk_2in.cpp"],
-	 ) if $Self->{v3};
+	 v_flags2 => ["+define+T_CLK_2IN_VEC=1 $Self->{t_dir}/t_clk_2in.cpp"],
+	 verilator_flags2 => ["--exe"],
+	 );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+	 );
 ok(1);
 1;
diff --git a/test_regress/t/t_clk_gater.pl b/test_regress/t/t_clk_gater.pl
index 4dc82a1a0..c240aee00 100755
--- a/test_regress/t/t_clk_gater.pl
+++ b/test_regress/t/t_clk_gater.pl
@@ -15,7 +15,7 @@ execute (
 	 check_finished=>1,
      );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     #Optimization is disabled
     #file_grep ($Self->{stats}, qr/Optimizations, Gaters inserted\s+3/i);
 }
diff --git a/test_regress/t/t_debug_fatalsrc_bad.pl b/test_regress/t/t_debug_fatalsrc_bad.pl
index 3cee656fa..e8f5acd76 100755
--- a/test_regress/t/t_debug_fatalsrc_bad.pl
+++ b/test_regress/t/t_debug_fatalsrc_bad.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 $Self->{vlt} or $Self->skip("Verilator only test");
 
 compile (
-	 v_flags2 => ["--debug-fatalsrc"],
+	 verilator_flags2 => ["--debug-fatalsrc"],
 	 fails=>$Self->{v3},
 	 expect=>
 '%Error: Internal Error: .*: --debug-fatal-src
diff --git a/test_regress/t/t_debug_sigsegv_bad.pl b/test_regress/t/t_debug_sigsegv_bad.pl
index 65a56e933..2edde7773 100755
--- a/test_regress/t/t_debug_sigsegv_bad.pl
+++ b/test_regress/t/t_debug_sigsegv_bad.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 $Self->{vlt} or $Self->skip("Verilator only test");
 
 compile (
-	 v_flags2 => ["--debug-sigsegv"],
+	 verilator_flags2 => ["--debug-sigsegv"],
 	 fails=>$Self->{v3},
 	 expect=>
 '%Error: Verilator internal fault, sorry.  Consider trying --debug --gdbbt
diff --git a/test_regress/t/t_delay.pl b/test_regress/t/t_delay.pl
index a6361857f..b34db05fc 100755
--- a/test_regress/t/t_delay.pl
+++ b/test_regress/t/t_delay.pl
@@ -8,7 +8,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Version 2.0.
 
 compile (
-	 v_flags2 => [$Self->{v3}?'-Wno-STMTDLY':''],
+	 verilator_flags2 => ['-Wno-STMTDLY'],
 	 );
 
 execute (
diff --git a/test_regress/t/t_delay_stmtdly_bad.pl b/test_regress/t/t_delay_stmtdly_bad.pl
index de89365d6..c5d133d5f 100755
--- a/test_regress/t/t_delay_stmtdly_bad.pl
+++ b/test_regress/t/t_delay_stmtdly_bad.pl
@@ -9,12 +9,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_delay.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 fails=>1,
 	 expect=>
 '%Warning-STMTDLY: t/t_delay.v:\d+: Ignoring delay on this delayed statement.
 .*%Error: Exiting due to.*',
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_display_noopt.pl b/test_regress/t/t_display_noopt.pl
index 69208a3df..33271f3e6 100755
--- a/test_regress/t/t_display_noopt.pl
+++ b/test_regress/t/t_display_noopt.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_display.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?"-O0":""],
+	 verilator_flags2 => ["-O0"],
 	 );
 
 execute (
diff --git a/test_regress/t/t_display_real_noopt.pl b/test_regress/t/t_display_real_noopt.pl
index 23b06671d..4aa0e825b 100755
--- a/test_regress/t/t_display_real_noopt.pl
+++ b/test_regress/t/t_display_real_noopt.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_display_real.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?"-O0":""],
+	 verilator_flags2 => ["-O0"],
 	 );
 
 execute (
diff --git a/test_regress/t/t_display_signed_noopt.pl b/test_regress/t/t_display_signed_noopt.pl
index 94d477318..c8a06bb6b 100755
--- a/test_regress/t/t_display_signed_noopt.pl
+++ b/test_regress/t/t_display_signed_noopt.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_display_signed.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?"-O0":""],
+	 verilator_flags2 => ["-O0"],
 	 );
 
 execute (
diff --git a/test_regress/t/t_dpi_export.pl b/test_regress/t/t_dpi_export.pl
index 494e1c8fc..2e51f6dff 100755
--- a/test_regress/t/t_dpi_export.pl
+++ b/test_regress/t/t_dpi_export.pl
@@ -11,8 +11,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 compile (
 	 # Amazingly VCS, NC and Verilator all just accept the C file here!
-	 v_flags2 => ["-Wall -Wno-DECLFILENAME t/t_dpi_export_c.cpp"],
-	 verilator_flags2 => ["-no-l2name"],
+	 v_flags2 => ["t/t_dpi_export_c.cpp"],
+	 verilator_flags2 => ["-Wall -Wno-DECLFILENAME -no-l2name"],
 	 );
 
 execute (
diff --git a/test_regress/t/t_dpi_import.pl b/test_regress/t/t_dpi_import.pl
index d9776a553..115378628 100755
--- a/test_regress/t/t_dpi_import.pl
+++ b/test_regress/t/t_dpi_import.pl
@@ -9,7 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 compile (
 	 # Amazingly VCS, NC and Verilator all just accept the C file here!
-	 v_flags2 => ["-Wall -Wno-DECLFILENAME t/t_dpi_import_c.cpp"],
+	 v_flags2 => ["t/t_dpi_import_c.cpp"],
+	 verilator_flags2 => ["-Wall -Wno-DECLFILENAME"],
 	 );
 
 execute (
diff --git a/test_regress/t/t_emit_constw.pl b/test_regress/t/t_emit_constw.pl
index 3c7e13296..48fe87ce0 100755
--- a/test_regress/t/t_emit_constw.pl
+++ b/test_regress/t/t_emit_constw.pl
@@ -8,7 +8,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Version 2.0.
 
 compile (
-	 v_flags2 => [$Self->{v3}?'--Ox':''],
+	 verilator_flags2 => ['--Ox'],
 	 );
 
 execute (
diff --git a/test_regress/t/t_enum_overlap_bad.pl b/test_regress/t/t_enum_overlap_bad.pl
index 1b2cb1858..307c0c994 100755
--- a/test_regress/t/t_enum_overlap_bad.pl
+++ b/test_regress/t/t_enum_overlap_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 fails=>$Self->{v3},
@@ -14,7 +16,7 @@ compile (
 '%Error: t/t_enum_overlap_bad.v:\d+: Overlapping enumeration value: e1b
 %Error: t/t_enum_overlap_bad.v:\d+: ... Location of original declaration
 %Error: Exiting due to',
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_extend_class.pl b/test_regress/t/t_extend_class.pl
index d74329c16..f2d6b5986 100755
--- a/test_regress/t/t_extend_class.pl
+++ b/test_regress/t/t_extend_class.pl
@@ -7,14 +7,15 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
-if ($Self->{v3}) {
-    compile (
-	     make_flags => "CPPFLAGS_ADD=-I$Self->{t_dir}",
-	     );
-    execute (
-	     check_finished=>1,
-	     );
-}
+$Self->{vlt} or $Self->skip("Verilator only test");
+
+compile (
+    make_flags => "CPPFLAGS_ADD=-I$Self->{t_dir}",
+    );
+
+execute (
+    check_finished=>1,
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_flag_bboxsys.pl b/test_regress/t/t_flag_bboxsys.pl
index f6686b258..28debed29 100755
--- a/test_regress/t/t_flag_bboxsys.pl
+++ b/test_regress/t/t_flag_bboxsys.pl
@@ -7,13 +7,15 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
-	 v_flags2 => ["--bbox-sys"],
-	 ) if $Self->{v3};
+	 verilator_flags2 => ["--bbox-sys"],
+	 );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_flag_nomod_bad.pl b/test_regress/t/t_flag_nomod_bad.pl
index 7a8df8cb7..bc8121154 100755
--- a/test_regress/t/t_flag_nomod_bad.pl
+++ b/test_regress/t/t_flag_nomod_bad.pl
@@ -7,13 +7,15 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 fails=>$Self->{v3},
 	 expect=>
 '%Error: No top level module found
 %Error: Exiting due to',
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_flag_skipidentical.pl b/test_regress/t/t_flag_skipidentical.pl
index e7c02432b..8881462db 100755
--- a/test_regress/t/t_flag_skipidentical.pl
+++ b/test_regress/t/t_flag_skipidentical.pl
@@ -7,7 +7,9 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
-if ($Self->{v3}) {
+$Self->{vlt} or $Self->skip("Verilator only test");
+
+{
     compile ();
 
     my $outfile = "$Self->{obj_dir}/V".$Self->{name}.".cpp";
diff --git a/test_regress/t/t_flag_topmod2_bad.pl b/test_regress/t/t_flag_topmod2_bad.pl
index e84bd7d43..9ef6656fc 100755
--- a/test_regress/t/t_flag_topmod2_bad.pl
+++ b/test_regress/t/t_flag_topmod2_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--top-module a "],
 	 fails=>$Self->{v3},
@@ -14,7 +16,7 @@ compile (
 	 expect=>
 '%Error: Specified --top-module \'a\' isn.t at the top level, it.s under another cell.
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_flag_topmodule.pl b/test_regress/t/t_flag_topmodule.pl
index a6348ffee..d8622fec0 100755
--- a/test_regress/t/t_flag_topmodule.pl
+++ b/test_regress/t/t_flag_topmodule.pl
@@ -7,13 +7,15 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--top-module b "],
-	 ) if $Self->{v3};
+	 );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_flag_topmodule_bad.pl b/test_regress/t/t_flag_topmodule_bad.pl
index 8a7e73bbb..2889e0e75 100755
--- a/test_regress/t/t_flag_topmodule_bad.pl
+++ b/test_regress/t/t_flag_topmodule_bad.pl
@@ -9,6 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_flag_topmodule.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 fails=>$Self->{v3},
 	 nc=>0,  # Need to get it not to give the prompt
@@ -16,7 +18,7 @@ compile (
 '%Error-MULTITOP: t/t_flag_topmodule.v:\d+: Unsupported: Multiple top level modules: .*
 %Error-MULTITOP: t/t_flag_topmodule.v:\d+: Fix, or use --top-module option to select which you want.
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_flag_topmodule_bad2.pl b/test_regress/t/t_flag_topmodule_bad2.pl
index b1e20c878..afcdae4f6 100755
--- a/test_regress/t/t_flag_topmodule_bad2.pl
+++ b/test_regress/t/t_flag_topmodule_bad2.pl
@@ -9,6 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_flag_topmodule.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 fails=>$Self->{v3},
 	 v_flags2 => ["--top-module notfound"],
@@ -16,7 +18,7 @@ compile (
 	 expect=>
 '%Error: Specified --top-module \'notfound\' was not found in design.
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_flag_topmodule_inline.pl b/test_regress/t/t_flag_topmodule_inline.pl
index 4426a658e..59c495cb7 100755
--- a/test_regress/t/t_flag_topmodule_inline.pl
+++ b/test_regress/t/t_flag_topmodule_inline.pl
@@ -7,13 +7,15 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--top-module b"],
-	 ) if $Self->{v3};
+	 );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_flag_werror_bad1.pl b/test_regress/t/t_flag_werror_bad1.pl
index d80592b4d..24ead58f9 100755
--- a/test_regress/t/t_flag_werror_bad1.pl
+++ b/test_regress/t/t_flag_werror_bad1.pl
@@ -9,6 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_flag_werror.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 fails=>$Self->{v3},
@@ -16,7 +18,7 @@ compile (
 q{%Warning-WIDTH: t/t_flag_werror.v:\d+: Operator ASSIGNW expects 4 bits on the Assign RHS, but Assign RHS.s CONST '6'h2e' generates 6 bits.
 %Warning-WIDTH: Use .* and lint_on around source to disable this message.
 %Error: Exiting due to},
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_flag_wfatal.pl b/test_regress/t/t_flag_wfatal.pl
index 91e6bb4b4..32b8835b8 100755
--- a/test_regress/t/t_flag_wfatal.pl
+++ b/test_regress/t/t_flag_wfatal.pl
@@ -9,6 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_flag_wfatal.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only -Wno-fatal"],
     fails=>0,
@@ -19,7 +21,7 @@ compile (
 q{%Warning-WIDTH: t/t_flag_wfatal.v:\d+: Operator ASSIGNW expects 4 bits on the Assign RHS, but Assign RHS.s CONST '6'h2e' generates 6 bits.
 %Warning-WIDTH: Use .* and lint_on around source to disable this message.
 },
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_func_public.pl b/test_regress/t/t_func_public.pl
index 379b1fc81..bd8fd8c45 100755
--- a/test_regress/t/t_func_public.pl
+++ b/test_regress/t/t_func_public.pl
@@ -8,7 +8,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Version 2.0.
 
 compile (
-	 v_flags2 => [$Self->{v3}?'+define+VERILATOR_PUBLIC_TASKS':''],
+	 verilator_flags2 => ['+define+VERILATOR_PUBLIC_TASKS'],
 	 fails => $fail,
 	 );
 
diff --git a/test_regress/t/t_func_rand.pl b/test_regress/t/t_func_rand.pl
index 7735b18dd..db8cb35f9 100755
--- a/test_regress/t/t_func_rand.pl
+++ b/test_regress/t/t_func_rand.pl
@@ -7,15 +7,17 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
-	 v_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
-	 ) if $Self->{v3};
+	 verilator_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
+	 );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_gen_assign.pl b/test_regress/t/t_gen_assign.pl
index 7f988d5c1..d39b6f866 100755
--- a/test_regress/t/t_gen_assign.pl
+++ b/test_regress/t/t_gen_assign.pl
@@ -7,8 +7,10 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_gen_if.pl b/test_regress/t/t_gen_if.pl
index 012a00e15..259d5b775 100755
--- a/test_regress/t/t_gen_if.pl
+++ b/test_regress/t/t_gen_if.pl
@@ -7,8 +7,10 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_inst_tree_inl0_pub1.pl b/test_regress/t/t_inst_tree_inl0_pub1.pl
index 8bfe8677b..3998cae35 100755
--- a/test_regress/t/t_inst_tree_inl0_pub1.pl
+++ b/test_regress/t/t_inst_tree_inl0_pub1.pl
@@ -13,7 +13,7 @@ compile (
 	 verilator_flags2 => ['+define+NOUSE_INLINE', '+define+USE_PUBLIC', '--stats'],
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ($Self->{stats}, qr/Optimizations, Combined CFuncs\s+16/i);
 }
 
diff --git a/test_regress/t/t_leak.pl b/test_regress/t/t_leak.pl
index 8a167c617..7cf2ac161 100755
--- a/test_regress/t/t_leak.pl
+++ b/test_regress/t/t_leak.pl
@@ -7,14 +7,16 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
-	 v_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
-	 ) if $Self->{v3};
+	 verilator_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
+	 );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+	 );
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_blksync_bad.pl b/test_regress/t/t_lint_blksync_bad.pl
index 0ea11d328..e200eafa2 100755
--- a/test_regress/t/t_lint_blksync_bad.pl
+++ b/test_regress/t/t_lint_blksync_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only -Wwarn-BLKSEQ -Wwarn-COMBDLY"],
     fails=>1,
@@ -20,7 +22,7 @@ compile (
 %Warning-COMBDLY: \*\*\* See the manual before disabling this,
 %Warning-COMBDLY: else you may end up with different sim results.
 %Error: Exiting due to.*',
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_blksync_loop.pl b/test_regress/t/t_lint_blksync_loop.pl
index 6bc35463e..2d8ddfb24 100755
--- a/test_regress/t/t_lint_blksync_loop.pl
+++ b/test_regress/t/t_lint_blksync_loop.pl
@@ -7,13 +7,15 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
-    v_flags2 => ["--lint-only -Wwarn-BLKSEQ -Wwarn-COMBDLY"],
+    verilator_flags2 => ["--lint-only -Wwarn-BLKSEQ -Wwarn-COMBDLY"],
     fails=>0,
     verilator_make_gcc => 0,
     make_top_shell => 0,
     make_main => 0,
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_declfilename.pl b/test_regress/t/t_lint_declfilename.pl
index 1cdbc8f7c..82a626b50 100755
--- a/test_regress/t/t_lint_declfilename.pl
+++ b/test_regress/t/t_lint_declfilename.pl
@@ -7,12 +7,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only"],
     verilator_make_gcc => 0,
     make_top_shell => 0,
     make_main => 0,
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_declfilename_bad.pl b/test_regress/t/t_lint_declfilename_bad.pl
index ecff0bf01..464a91fa7 100755
--- a/test_regress/t/t_lint_declfilename_bad.pl
+++ b/test_regress/t/t_lint_declfilename_bad.pl
@@ -9,6 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_lint_declfilename.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only -Wall"],
     fails=>1,
@@ -19,7 +21,7 @@ compile (
 '%Warning-DECLFILENAME: t/t_lint_declfilename.v:6: Filename \'t_lint_declfilename\' does not match MODULE name: t
 %Warning-DECLFILENAME: Use .* to disable this message.
 %Error: Exiting due to.*',
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_defparam.pl b/test_regress/t/t_lint_defparam.pl
index 1cdbc8f7c..82a626b50 100755
--- a/test_regress/t/t_lint_defparam.pl
+++ b/test_regress/t/t_lint_defparam.pl
@@ -7,12 +7,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only"],
     verilator_make_gcc => 0,
     make_top_shell => 0,
     make_main => 0,
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_defparam_bad.pl b/test_regress/t/t_lint_defparam_bad.pl
index 03f8f16d7..9449bdf40 100755
--- a/test_regress/t/t_lint_defparam_bad.pl
+++ b/test_regress/t/t_lint_defparam_bad.pl
@@ -9,6 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_lint_defparam.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only -Wwarn-style -Wno-DECLFILENAME"],
     fails=>1,
@@ -19,7 +21,7 @@ compile (
 '%Warning-DEFPARAM: t/t_lint_defparam.v:\d+: Suggest replace defparam with Verilog 2001 #\(.P\(...etc...\)\)
 %Warning-DEFPARAM: Use .* to disable this message.
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_ifdepth_bad.pl b/test_regress/t/t_lint_ifdepth_bad.pl
index 326d10bd0..6f707bd57 100755
--- a/test_regress/t/t_lint_ifdepth_bad.pl
+++ b/test_regress/t/t_lint_ifdepth_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only -Wall -Wno-DECLFILENAME --if-depth 10"],
     fails=>1,
@@ -17,7 +19,7 @@ compile (
 '%Warning-IFDEPTH: t/t_lint_ifdepth_bad.v:\d+: Deep \'if\' statement; suggest unique/priority to avoid slow logic
 %Warning-IFDEPTH: Use .* to disable this message.
 %Error: Exiting due to.*',
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_implicit.pl b/test_regress/t/t_lint_implicit.pl
index af45b4668..364eaa2cd 100755
--- a/test_regress/t/t_lint_implicit.pl
+++ b/test_regress/t/t_lint_implicit.pl
@@ -7,9 +7,11 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
-	 v_flags2 => ["-Wno-IMPLICIT"],
-	 ) if $Self->{v3};
+    verilator_flags2 => ["-Wno-IMPLICIT"],
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_implicit_bad.pl b/test_regress/t/t_lint_implicit_bad.pl
index 6b3e615db..344ec2011 100755
--- a/test_regress/t/t_lint_implicit_bad.pl
+++ b/test_regress/t/t_lint_implicit_bad.pl
@@ -9,6 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_lint_implicit.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only -Wwarn-IMPLICIT"],
 	 fails=>1,
@@ -19,7 +21,7 @@ compile (
 %Warning-IMPLICIT: t/t_lint_implicit.v:\d+: Signal definition not found, creating implicitly: dummy1
 %Warning-IMPLICIT: t/t_lint_implicit.v:\d+: Signal definition not found, creating implicitly: dummy2
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_implicit_def_bad.pl b/test_regress/t/t_lint_implicit_def_bad.pl
index de69addfe..769ce18a8 100755
--- a/test_regress/t/t_lint_implicit_def_bad.pl
+++ b/test_regress/t/t_lint_implicit_def_bad.pl
@@ -7,15 +7,17 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
-	 v_flags2 => ["--lint-only -Wall -Wno-DECLFILENAME"],
+	 verilator_flags2 => ["--lint-only -Wall -Wno-DECLFILENAME"],
 	 fails=>1,
 	 expect=>
 '%Warning-IMPLICIT: t/t_lint_implicit_def_bad.v:\d+: Signal definition not found, creating implicitly: imp_warn
 %Warning-IMPLICIT: Use "/\* verilator lint_off IMPLICIT \*/" and lint_on around source to disable this message.
 %Error: t/t_lint_implicit_def_bad.v:\d+: Signal definition not found, and implicit disabled with `default_nettype: imp_err
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_incabspath.pl b/test_regress/t/t_lint_incabspath.pl
index 1cdbc8f7c..26120253e 100755
--- a/test_regress/t/t_lint_incabspath.pl
+++ b/test_regress/t/t_lint_incabspath.pl
@@ -7,12 +7,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
-    v_flags2 => ["--lint-only"],
+    verilator_flags2 => ["--lint-only"],
     verilator_make_gcc => 0,
     make_top_shell => 0,
     make_main => 0,
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_incabspath_bad.pl b/test_regress/t/t_lint_incabspath_bad.pl
index 83415a302..35d72f42c 100755
--- a/test_regress/t/t_lint_incabspath_bad.pl
+++ b/test_regress/t/t_lint_incabspath_bad.pl
@@ -9,6 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_lint_incabspath.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only -Wall -Wno-DECLFILENAME"],
     fails=>1,
@@ -19,7 +21,7 @@ compile (
 '%Warning-INCABSPATH: t/t_lint_incabspath.v:\d+: Suggest `include with absolute path be made relative, and use \+include: /dev/null
 %Warning-INCABSPATH: Use .* to disable this message.
 %Error: Exiting due to.*',
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_once_bad.pl b/test_regress/t/t_lint_once_bad.pl
index 3576d17b1..4a23f67b7 100755
--- a/test_regress/t/t_lint_once_bad.pl
+++ b/test_regress/t/t_lint_once_bad.pl
@@ -7,10 +7,12 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
-	 v_flags2 => ["--lint-only -Wwarn-UNUSED"],
+	 verilator_flags2 => ["--lint-only -Wwarn-UNUSED"],
 	 verilator_make_gcc => 0,
 	 fails=>1,
 	 expect=>
@@ -18,7 +20,7 @@ compile (
 %Warning-UNUSED: Use .* to disable this message.
 %Warning-UNUSED: t/t_lint_once_bad.v:\d+: Signal is not driven, nor used: unus2
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_only.pl b/test_regress/t/t_lint_only.pl
index 0ec70b9cf..e0fb17b63 100755
--- a/test_regress/t/t_lint_only.pl
+++ b/test_regress/t/t_lint_only.pl
@@ -7,12 +7,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
 	 v_flags2 => ["--lint-only"],
 	 verilator_make_gcc => 0,
-	 ) if $Self->{v3};
+	 );
 
 foreach my $file (glob("$Self->{obj_dir}/*t_lint_only*")) {
     next if $file =~ /simx_compile.log/;  # Made by driver.pl, not Verilator
diff --git a/test_regress/t/t_lint_pindup_bad.pl b/test_regress/t/t_lint_pindup_bad.pl
index d0bd790ab..441e9d5b9 100755
--- a/test_regress/t/t_lint_pindup_bad.pl
+++ b/test_regress/t/t_lint_pindup_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only"],
     fails=>1,
@@ -22,7 +24,7 @@ compile (
 %Error: t/t_lint_pindup_bad.v:\d+: Duplicate pin connection: P
 %Error: t/t_lint_pindup_bad.v:\d+: ... Location of original pin connection
 %Error: Exiting due to.*',
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_realcvt_bad.pl b/test_regress/t/t_lint_realcvt_bad.pl
index e52c48808..d2bd9db35 100755
--- a/test_regress/t/t_lint_realcvt_bad.pl
+++ b/test_regress/t/t_lint_realcvt_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
@@ -17,7 +19,7 @@ compile (
 '%Warning-REALCVT: t/t_lint_realcvt_bad.v:\d+: Implicit conversion of real to integer
 %Warning-REALCVT: Use .* to disable this message.
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_restore_bad.pl b/test_regress/t/t_lint_restore_bad.pl
index 9bd82eec2..3e03b32e8 100755
--- a/test_regress/t/t_lint_restore_bad.pl
+++ b/test_regress/t/t_lint_restore_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 fails=>1,
@@ -14,7 +16,7 @@ compile (
 q{.*%Warning-WIDTH: t/t_lint_restore_bad.v:\d+: Operator ASSIGN expects 5 bits on the Assign RHS, but Assign RHS's CONST '64'h1' generates 64 bits.
 %Warning-WIDTH: Use .*
 %Error: Exiting due to.*},
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_setout_bad.pl b/test_regress/t/t_lint_setout_bad.pl
index 88bee08f2..f37983304 100755
--- a/test_regress/t/t_lint_setout_bad.pl
+++ b/test_regress/t/t_lint_setout_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only"],
     fails=>1,
@@ -16,7 +18,7 @@ compile (
     expect=>
 '%Error: t/t_lint_setout_bad.v:\d+: Output port is connected to a constant pin, electrical short
 .*',
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_setout_bad_noinl.pl b/test_regress/t/t_lint_setout_bad_noinl.pl
index f6dd84e21..9d574be3a 100755
--- a/test_regress/t/t_lint_setout_bad_noinl.pl
+++ b/test_regress/t/t_lint_setout_bad_noinl.pl
@@ -9,6 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_lint_setout_bad.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only -Oi"],
     fails=>1,
@@ -18,7 +20,7 @@ compile (
     expect=>
 '%Error: t/t_lint_setout_bad.v:\d+: Output port is connected to a constant pin, electrical short
 .*',
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_syncasyncnet_bad.pl b/test_regress/t/t_lint_syncasyncnet_bad.pl
index 395782f25..960cf65ff 100755
--- a/test_regress/t/t_lint_syncasyncnet_bad.pl
+++ b/test_regress/t/t_lint_syncasyncnet_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only -Wall -Wno-DECLFILENAME --if-depth 10"],
     fails=>1,
@@ -19,7 +21,7 @@ compile (
 %Warning-SYNCASYNCNET: t/t_lint_syncasyncnet_bad.v:\d+: ... Location of async usage
 %Warning-SYNCASYNCNET: t/t_lint_syncasyncnet_bad.v:\d+: ... Location of sync usage
 %Error: Exiting due to.*',
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_unused_bad.pl b/test_regress/t/t_lint_unused_bad.pl
index 8ff39c08c..bfd0c1e5a 100755
--- a/test_regress/t/t_lint_unused_bad.pl
+++ b/test_regress/t/t_lint_unused_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only --bbox-sys -Wall -Wno-DECLFILENAME"],
     fails=>1,
@@ -22,7 +24,7 @@ compile (
 %Warning-UNUSED: t/t_lint_unused_bad.v:\d+: Bits of signal are not used: mixed\[2\]
 %Warning-UNDRIVEN: t/t_lint_unused_bad.v:\d+: Bits of signal are not driven: mixed\[1\]
 %Error: Exiting due to.*',
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_width.pl b/test_regress/t/t_lint_width.pl
index 7f5263655..a823b8d70 100755
--- a/test_regress/t/t_lint_width.pl
+++ b/test_regress/t/t_lint_width.pl
@@ -7,12 +7,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 make_top_shell => 0,
 	 make_main => 0,
 	 verilator_make_gcc => 0,
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_lint_width_bad.pl b/test_regress/t/t_lint_width_bad.pl
index 52717e54a..27b1529ad 100755
--- a/test_regress/t/t_lint_width_bad.pl
+++ b/test_regress/t/t_lint_width_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 fails=>1,
@@ -14,7 +16,7 @@ compile (
 q{.*%Warning-WIDTH: t/t_lint_width_bad.v:\d+: Operator ASSIGNW expects 5 bits on the Assign RHS, but Assign RHS's VARREF 'in' generates 4 bits.
 %Warning-WIDTH: Use .*
 %Error: Exiting due to.*},
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_math_imm2.pl b/test_regress/t/t_math_imm2.pl
index c151ce6a6..e20a5c521 100755
--- a/test_regress/t/t_math_imm2.pl
+++ b/test_regress/t/t_math_imm2.pl
@@ -12,7 +12,7 @@ $Self->skip("Verilator only test") if !$Self->{vlt};
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
-	 v_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
+	 verilator_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
 	 );
 
 execute (
diff --git a/test_regress/t/t_math_svl.pl b/test_regress/t/t_math_svl.pl
index 9300862c6..030802e1f 100755
--- a/test_regress/t/t_math_svl.pl
+++ b/test_regress/t/t_math_svl.pl
@@ -7,8 +7,10 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
-	 ) if $Self->{v3};
+    );
 
 execute (
 	 check_finished=>1,
@@ -16,7 +18,7 @@ execute (
 	 expect=>
 '\*-\* All Finished \*-\*
 Goodbye world, at cycle \d+.*',
-     ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_mem_multidim_Ox.pl b/test_regress/t/t_mem_multidim_Ox.pl
index 919eac4fa..2c4a0b665 100755
--- a/test_regress/t/t_mem_multidim_Ox.pl
+++ b/test_regress/t/t_mem_multidim_Ox.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_mem_multidim.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'--Ox':''],
+	 verilator_flags2 => ['--Ox'],
 	 );
 
 execute (
diff --git a/test_regress/t/t_mem_multidim_trace.pl b/test_regress/t/t_mem_multidim_trace.pl
index 1fee1339a..05a99688c 100755
--- a/test_regress/t/t_mem_multidim_trace.pl
+++ b/test_regress/t/t_mem_multidim_trace.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_mem_multidim.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'--sp --trace':''],
+	 verilator_flags2 => ['--sp --trace'],
 	 );
 
 execute (
diff --git a/test_regress/t/t_mem_packed_bad.pl b/test_regress/t/t_mem_packed_bad.pl
index 024aedf5d..8b097f12f 100755
--- a/test_regress/t/t_mem_packed_bad.pl
+++ b/test_regress/t/t_mem_packed_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 verilator_flags2 => ["--lint-only"],
 	 fails=>1,
@@ -16,7 +18,7 @@ compile (
 %Error: t/t_mem_packed_bad.v:\d+: Unsupported: Assignment between packed arrays of different dimensions
 %Error: t/t_mem_packed_bad.v:\d+: Unsupported: Assignment between packed arrays of different dimensions
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_mem_shift.pl b/test_regress/t/t_mem_shift.pl
index 6be6d65d5..bcfd8800b 100755
--- a/test_regress/t/t_mem_shift.pl
+++ b/test_regress/t/t_mem_shift.pl
@@ -11,7 +11,7 @@ compile (
 	 verilator_flags2 => ["--stats"],
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ($Self->{stats}, qr/Optimizations, Delayed shared-sets\s+14/i);
 }
 
diff --git a/test_regress/t/t_mem_slice_bad.pl b/test_regress/t/t_mem_slice_bad.pl
index b1f10867e..f62b192da 100755
--- a/test_regress/t/t_mem_slice_bad.pl
+++ b/test_regress/t/t_mem_slice_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 fails=>1,
@@ -19,7 +21,7 @@ compile (
 %Error: t/t_mem_slice_bad.v:\d+: Slices of arrays in assignments must have the same unpacked dimensions
 %Error: t/t_mem_slice_bad.v:\d+: Slices of arrays in assignments must have the same unpacked dimensions
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_mem_slice_conc_bad.pl b/test_regress/t/t_mem_slice_conc_bad.pl
index 82b51da3d..7e422e2df 100755
--- a/test_regress/t/t_mem_slice_conc_bad.pl
+++ b/test_regress/t/t_mem_slice_conc_bad.pl
@@ -7,10 +7,12 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 fails=>1,
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_mem_slot.pl b/test_regress/t/t_mem_slot.pl
index 8a167c617..e1e378296 100755
--- a/test_regress/t/t_mem_slot.pl
+++ b/test_regress/t/t_mem_slot.pl
@@ -7,14 +7,17 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
-	 v_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
-	 ) if $Self->{v3};
+	 verilator_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
+    );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+    );
+
 ok(1);
 1;
diff --git a/test_regress/t/t_param_circ_bad.pl b/test_regress/t/t_param_circ_bad.pl
index 29c96cd94..9b52eb1bd 100755
--- a/test_regress/t/t_param_circ_bad.pl
+++ b/test_regress/t/t_param_circ_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
     v_flags2 => ["--lint-only"],
     fails=>1,
@@ -16,7 +18,7 @@ compile (
     expect=>
 '%Error: t/t_param_circ_bad.v:\d+: Variable\'s initial value is circular: X
 %Error: Exiting due to.*',
-    ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_pipe_exit_bad.pl b/test_regress/t/t_pipe_exit_bad.pl
index f7cf0573d..1831a360b 100755
--- a/test_regress/t/t_pipe_exit_bad.pl
+++ b/test_regress/t/t_pipe_exit_bad.pl
@@ -7,22 +7,20 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->skip("Verilator only test") if !$Self->{vlt};
+
 top_filename("t/t_pipe_filter.v");
 
-if (!$Self->{v3}) {
-    ok(1);
-} else {
-    compile (
-	v_flags2 => ['-E --pipe-filter \'perl t/t_pipe_exit_bad.pf\' '],
-	verilator_make_gcc=>0,
-	stdout_filename => $stdout_filename,
-	fails=>1,
-	expect=>
+compile (
+    verilator_flags2 => ['-E --pipe-filter \'perl t/t_pipe_exit_bad.pf\' '],
+    verilator_make_gcc=>0,
+    stdout_filename => $stdout_filename,
+    fails=>1,
+    expect=>
 '%Error: t_pipe_exit_bad.pf: Intentional bad exit status...
 %Error: File not found: t/t_pipe_filter.v
 %Error: Exiting due to.*',
-	);
-    ok(1);
-}
+    );
+ok(1);
 
 1;
diff --git a/test_regress/t/t_pipe_filter.pl b/test_regress/t/t_pipe_filter.pl
index 37a449333..08a228650 100755
--- a/test_regress/t/t_pipe_filter.pl
+++ b/test_regress/t/t_pipe_filter.pl
@@ -7,18 +7,16 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->skip("Verilator only test") if !$Self->{vlt};
+
 $Self->{golden_out} ||= "t/$Self->{name}.out";
 my $stdout_filename = "$Self->{obj_dir}/$Self->{name}__test.vpp";
 
-if (!$Self->{v3}) {
-    ok(1);
-} else {
-    compile (
-	v_flags2 => ['-E --pipe-filter \'perl t/t_pipe_filter.pf\' '],
-	verilator_make_gcc=>0,
-	stdout_filename => $stdout_filename,
-	);
-    ok(files_identical($stdout_filename, $Self->{golden_out}));
-}
+compile (
+    verilator_flags2 => ['-E --pipe-filter \'perl t/t_pipe_filter.pf\' '],
+    verilator_make_gcc=>0,
+    stdout_filename => $stdout_filename,
+    );
+ok(files_identical($stdout_filename, $Self->{golden_out}));
 
 1;
diff --git a/test_regress/t/t_pp_dupdef.pl b/test_regress/t/t_pp_dupdef.pl
index 5f8d39c5c..a659ac037 100755
--- a/test_regress/t/t_pp_dupdef.pl
+++ b/test_regress/t/t_pp_dupdef.pl
@@ -7,9 +7,11 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
-	 v_flags2 => ["-Wno-REDEFMACRO"],
-	 ) if $Self->{v3};
+    verilator_flags2 => ["-Wno-REDEFMACRO"],
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_pp_dupdef_bad.pl b/test_regress/t/t_pp_dupdef_bad.pl
index 87c722247..90b7ecf10 100755
--- a/test_regress/t/t_pp_dupdef_bad.pl
+++ b/test_regress/t/t_pp_dupdef_bad.pl
@@ -9,6 +9,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_pp_dupdef.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 fails=>1,
@@ -19,7 +21,7 @@ compile (
 %Warning-REDEFMACRO: t/t_pp_dupdef.v:\d+: Redefining existing define: DUPP, with different value: .*
 %Warning-REDEFMACRO: t/t_pp_dupdef.v:\d+: Previous definition is here, with value: .*
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_pp_misdef_bad.pl b/test_regress/t/t_pp_misdef_bad.pl
index 7e9074641..0fb0f0c1c 100755
--- a/test_regress/t/t_pp_misdef_bad.pl
+++ b/test_regress/t/t_pp_misdef_bad.pl
@@ -7,13 +7,15 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 fails=>1,
 	 expect=>
 '%Error: t/t_pp_misdef_bad.v:\d+: Define or directive not defined: `NOTDEF
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_preproc.pl b/test_regress/t/t_preproc.pl
index e261e1b5f..d4c1efdc3 100755
--- a/test_regress/t/t_preproc.pl
+++ b/test_regress/t/t_preproc.pl
@@ -7,20 +7,19 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 $Self->{golden_out} ||= "t/$Self->{name}.out";
 my $stdout_filename = "$Self->{obj_dir}/$Self->{name}__test.vpp";
 
-if (!$Self->{v3}) {
-    ok(1);
-} else {
-    compile (
-	     v_flags2 => ['-DDEF_A0 -DPREDEF_COMMAND_LINE -E'],
-	     verilator_make_gcc=>0,
-	     stdout_filename => $stdout_filename,
-	     );
-    ok(preproc_check($Self->{top_filename}, $stdout_filename)
-       && files_identical($stdout_filename, $Self->{golden_out}));
-}
+compile (
+    verilator_flags2 => ['-DDEF_A0 -DPREDEF_COMMAND_LINE -E'],
+    verilator_make_gcc=>0,
+    stdout_filename => $stdout_filename,
+    );
+
+ok(preproc_check($Self->{top_filename}, $stdout_filename)
+   && files_identical($stdout_filename, $Self->{golden_out}));
 
 sub preproc_check {
     my $filename1 = shift;
diff --git a/test_regress/t/t_preproc_def09.pl b/test_regress/t/t_preproc_def09.pl
index 53b2e582a..606b72845 100755
--- a/test_regress/t/t_preproc_def09.pl
+++ b/test_regress/t/t_preproc_def09.pl
@@ -7,17 +7,16 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 my $stdout_filename = "$Self->{obj_dir}/$Self->{name}__test.vpp";
 
-if (!$Self->{v3}) {
-    ok(1);
-} else {
-    compile (
-	     v_flags2 => ['-E'],
-	     verilator_make_gcc=>0,
-	     stdout_filename => $stdout_filename,
-	     );
-    ok(files_identical($stdout_filename, "t/$Self->{name}.out"));
-}
+compile (
+    verilator_flags2 => ['-E'],
+    verilator_make_gcc=>0,
+    stdout_filename => $stdout_filename,
+    );
+
+ok(files_identical($stdout_filename, "t/$Self->{name}.out"));
 
 1;
diff --git a/test_regress/t/t_preproc_psl_off.pl b/test_regress/t/t_preproc_psl_off.pl
index 2244fdd49..0bea790cf 100755
--- a/test_regress/t/t_preproc_psl_off.pl
+++ b/test_regress/t/t_preproc_psl_off.pl
@@ -7,19 +7,18 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 my $stdout_filename = "$Self->{obj_dir}/$Self->{name}__test.vpp";
 
 top_filename("t/t_preproc_psl.v");
 
-if (!$Self->{v3}) {
-    ok(1);
-} else {
-    compile (
-	     v_flags2 => ['-E'],
-	     verilator_make_gcc=>0,
-	     stdout_filename => $stdout_filename,
-	     );
-    ok(files_identical($stdout_filename, "t/$Self->{name}.out"));
-}
+compile (
+    verilator_flags2 => ['-E'],
+    verilator_make_gcc=>0,
+    stdout_filename => $stdout_filename,
+    );
+
+ok(files_identical($stdout_filename, "t/$Self->{name}.out"));
 
 1;
diff --git a/test_regress/t/t_preproc_psl_on.pl b/test_regress/t/t_preproc_psl_on.pl
index 96f12411e..92bc4fc00 100755
--- a/test_regress/t/t_preproc_psl_on.pl
+++ b/test_regress/t/t_preproc_psl_on.pl
@@ -7,19 +7,18 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 my $stdout_filename = "$Self->{obj_dir}/$Self->{name}__test.vpp";
 
 top_filename("t/t_preproc_psl.v");
 
-if (!$Self->{v3}) {
-    ok(1);
-} else {
-    compile (
-	     v_flags2 => ['-psl -E'],
-	     verilator_make_gcc=>0,
-	     stdout_filename => $stdout_filename,
-	     );
-    ok(files_identical($stdout_filename, "t/$Self->{name}.out"));
-}
+compile (
+    verilator_flags2 => ['-psl -E'],
+    verilator_make_gcc=>0,
+    stdout_filename => $stdout_filename,
+    );
+
+ok(files_identical($stdout_filename, "t/$Self->{name}.out"));
 
 1;
diff --git a/test_regress/t/t_preproc_undefineall.pl b/test_regress/t/t_preproc_undefineall.pl
index 07f70d571..9324c83cb 100755
--- a/test_regress/t/t_preproc_undefineall.pl
+++ b/test_regress/t/t_preproc_undefineall.pl
@@ -8,8 +8,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Version 2.0.
 
 compile (
-    v_flags2 => ['+define+PREDEF_COMMAND_LINE',
-		 "--lint-only"],
+    v_flags2 => ['+define+PREDEF_COMMAND_LINE'],
+    verilator_flags2 => ["--lint-only"],
     verilator_make_gcc => 0,
     make_top_shell => 0,
     make_main => 0,
diff --git a/test_regress/t/t_psl_basic_cover.pl b/test_regress/t/t_psl_basic_cover.pl
index 48c2546b5..190484a4c 100755
--- a/test_regress/t/t_psl_basic_cover.pl
+++ b/test_regress/t/t_psl_basic_cover.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_psl_basic.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'--psl --sp --coverage-user':''],
+	 verilator_flags2 => ['--psl --sp --coverage-user'],
 	 );
 
 execute (
diff --git a/test_regress/t/t_select_bad_msb.pl b/test_regress/t/t_select_bad_msb.pl
index c4162871d..e81c0312e 100755
--- a/test_regress/t/t_select_bad_msb.pl
+++ b/test_regress/t/t_select_bad_msb.pl
@@ -7,13 +7,15 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 fails=>1,
 	 expect=>
 '%Warning-LITENDIAN: t/t_select_bad_msb.v:\d+: Little bit endian vector: MSB < LSB of bit range: 0:22
 .*
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_sys_file_basic.pl b/test_regress/t/t_sys_file_basic.pl
index e5184e2c6..2cc1da6ba 100755
--- a/test_regress/t/t_sys_file_basic.pl
+++ b/test_regress/t/t_sys_file_basic.pl
@@ -10,9 +10,9 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 unlink("$Self->{obj_dir}/t_sys_file_basic_test.log");
 
 compile (
-    v_flags2 => ['+incdir+../include',
-		 # Build without cached objects, see bug363
-		 "--exe ../$Self->{main_filename}"],
+    v_flags2 => ['+incdir+../include'],
+    # Build without cached objects, see bug363
+    verilator_flags2 => ["--exe ../$Self->{main_filename}"],
     make_flags=>'MAKE_MAIN=0 VM_PARALLEL_BUILDS=0',
     );
 
diff --git a/test_regress/t/t_trace_ena_cc.pl b/test_regress/t/t_trace_ena_cc.pl
index 64e93dc4e..5f72b9acd 100755
--- a/test_regress/t/t_trace_ena_cc.pl
+++ b/test_regress/t/t_trace_ena_cc.pl
@@ -10,14 +10,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_trace_ena.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'-trace':''],
+	 verilator_flags2 => ['-trace'],
 	 );
 
 execute (
 	 check_finished=>1,
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep     ("$Self->{obj_dir}/V$Self->{name}__Trace__Slow.cpp", qr/c_trace_on\"/x);
     file_grep_not ("$Self->{obj_dir}/V$Self->{name}__Trace__Slow.cpp", qr/_trace_off\"/x);
     file_grep     ("$Self->{obj_dir}/simx.vcd", qr/\$enddefinitions/x);
diff --git a/test_regress/t/t_trace_ena_sc.pl b/test_regress/t/t_trace_ena_sc.pl
index 3f5668dca..6945a4113 100755
--- a/test_regress/t/t_trace_ena_sc.pl
+++ b/test_regress/t/t_trace_ena_sc.pl
@@ -10,14 +10,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_trace_ena.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'-trace -sc':''],
+	 verilator_flags2 => ['-trace -sc'],
 	 );
 
 execute (
 	 check_finished=>1,
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     # Note more checks in _cc.pl
     file_grep     ("$Self->{obj_dir}/simx.vcd", qr/\$enddefinitions/x);
 }
diff --git a/test_regress/t/t_trace_ena_sp.pl b/test_regress/t/t_trace_ena_sp.pl
index 156601da7..3ff011883 100755
--- a/test_regress/t/t_trace_ena_sp.pl
+++ b/test_regress/t/t_trace_ena_sp.pl
@@ -10,14 +10,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_trace_ena.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'-trace -sp':''],
+	 verilator_flags2 => ['-trace -sp'],
 	 );
 
 execute (
 	 check_finished=>1,
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     # Note more checks in _cc.pl
     file_grep     ("$Self->{obj_dir}/simx.vcd", qr/\$enddefinitions/x);
 }
diff --git a/test_regress/t/t_trace_off_cc.pl b/test_regress/t/t_trace_off_cc.pl
index 3ee8f7c91..da3f35561 100755
--- a/test_regress/t/t_trace_off_cc.pl
+++ b/test_regress/t/t_trace_off_cc.pl
@@ -10,14 +10,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_trace_ena.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'-notrace':''],
+	 verilator_flags2 => ['-notrace'],
 	 );
 
 execute (
 	 check_finished=>1,
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     !-r "$Self->{obj_dir}/simx.vcd" or $Self->error("Tracing should be off\n");
 }
 
diff --git a/test_regress/t/t_trace_off_sc.pl b/test_regress/t/t_trace_off_sc.pl
index 605c58afd..009dadb33 100755
--- a/test_regress/t/t_trace_off_sc.pl
+++ b/test_regress/t/t_trace_off_sc.pl
@@ -10,14 +10,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_trace_ena.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'-notrace -sc':''],
+	 verilator_flags2 => ['-notrace -sc'],
 	 );
 
 execute (
 	 check_finished=>1,
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     !-r "$Self->{obj_dir}/simx.vcd" or $Self->error("Tracing should be off\n");
 }
 
diff --git a/test_regress/t/t_trace_off_sp.pl b/test_regress/t/t_trace_off_sp.pl
index 62e6ad3f2..91b03c8e1 100755
--- a/test_regress/t/t_trace_off_sp.pl
+++ b/test_regress/t/t_trace_off_sp.pl
@@ -10,14 +10,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_trace_ena.v");
 
 compile (
-	 v_flags2 => [$Self->{v3}?'-notrace -sp':''],
+	 verilator_flags2 => ['-notrace -sp'],
 	 );
 
 execute (
 	 check_finished=>1,
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     !-r "$Self->{obj_dir}/simx.vcd" or $Self->error("Tracing should be off\n");
 }
 
diff --git a/test_regress/t/t_trace_public_func.pl b/test_regress/t/t_trace_public_func.pl
index 04c5ab18d..d9d882a3c 100755
--- a/test_regress/t/t_trace_public_func.pl
+++ b/test_regress/t/t_trace_public_func.pl
@@ -9,20 +9,20 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_trace_public.v");
 
-if ($Self->{v3}) {
-    compile (
-	     make_top_shell => 0,
-	     make_main => 0,
-	     v_flags2 => ["-DPUB_FUNC --trace --exe $Self->{t_dir}/$Self->{name}.cpp"],
-	     );
+$Self->{vlt} or $Self->skip("Verilator only test");
 
-    execute (
-	     check_finished=>1,
-	     );
+compile (
+    make_top_shell => 0,
+    make_main => 0,
+    v_flags2 => ["-DPUB_FUNC --trace --exe $Self->{t_dir}/$Self->{name}.cpp"],
+    );
 
-    vcd_identical ("$Self->{obj_dir}/simx.vcd",
-		   "t/t_trace_public.out");
-}
+execute (
+    check_finished=>1,
+    );
+
+vcd_identical ("$Self->{obj_dir}/simx.vcd",
+	       "t/t_trace_public.out");
 
 ok(1);
 1;
diff --git a/test_regress/t/t_trace_public_sig.pl b/test_regress/t/t_trace_public_sig.pl
index 03927bd73..45eace968 100755
--- a/test_regress/t/t_trace_public_sig.pl
+++ b/test_regress/t/t_trace_public_sig.pl
@@ -9,21 +9,23 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_trace_public.v");
 
-if ($Self->{v3}) {
-    compile (
-	     make_top_shell => 0,
-	     make_main => 0,
-	     v_flags2 => ["--trace --exe $Self->{t_dir}/$Self->{name}.cpp"],
-	     );
+$Self->{vlt} or $Self->skip("Verilator only test");
 
-    execute (
-	     check_finished=>1,
-	     );
+compile (
+    make_top_shell => 0,
+    make_main => 0,
+    v_flags2 => ["--trace --exe $Self->{t_dir}/$Self->{name}.cpp"],
+    );
+
+execute (
+    check_finished=>1,
+    );
+
+vcd_identical ("$Self->{obj_dir}/simx.vcd",
+	       "t/t_trace_public.out");
+
+# vcd_identical doesn't detect "$var a.b;" vs "$scope module a; $var b;"
+file_grep ("$Self->{obj_dir}/simx.vcd", qr/module glbl/i);
 
-    vcd_identical ("$Self->{obj_dir}/simx.vcd",
-		   "t/t_trace_public.out");
-    # vcd_identical doesn't detect "$var a.b;" vs "$scope module a; $var b;"
-    file_grep ("$Self->{obj_dir}/simx.vcd", qr/module glbl/i);
-}
 ok(1);
 1;
diff --git a/test_regress/t/t_tri_gate_bufif0.pl b/test_regress/t/t_tri_gate_bufif0.pl
index fa6330ed0..d3b38fe3d 100755
--- a/test_regress/t/t_tri_gate_bufif0.pl
+++ b/test_regress/t/t_tri_gate_bufif0.pl
@@ -9,17 +9,19 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_tri_gate.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
 	 v_flags2 => ['+define+T_BUFIF0',],
 	 make_flags => 'CPPFLAGS_ADD=-DT_BUFIF0',
 	 verilator_flags2 => ["--exe $Self->{t_dir}/t_tri_gate.cpp"],
-	 ) if $Self->{v3};
+    );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_tri_gate_bufif1.pl b/test_regress/t/t_tri_gate_bufif1.pl
index d5310ffa5..45e566012 100755
--- a/test_regress/t/t_tri_gate_bufif1.pl
+++ b/test_regress/t/t_tri_gate_bufif1.pl
@@ -9,17 +9,19 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_tri_gate.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
 	 v_flags2 => ['+define+T_BUFIF1',],
 	 make_flags => 'CPPFLAGS_ADD=-DT_BUFIF1',
 	 verilator_flags2 => ["--exe $Self->{t_dir}/t_tri_gate.cpp"],
-	 ) if $Self->{v3};
+    );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_tri_gate_cond.pl b/test_regress/t/t_tri_gate_cond.pl
index 7973c2085..a86dc81a2 100755
--- a/test_regress/t/t_tri_gate_cond.pl
+++ b/test_regress/t/t_tri_gate_cond.pl
@@ -9,17 +9,19 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_tri_gate.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
 	 v_flags2 => ['+define+T_COND',],
 	 make_flags => 'CPPFLAGS_ADD=-DT_COND',
 	 verilator_flags2 => ["--exe $Self->{t_dir}/t_tri_gate.cpp"],
-	 ) if $Self->{v3};
+    );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_tri_gate_notif0.pl b/test_regress/t/t_tri_gate_notif0.pl
index 3ba57263b..531f9bdf0 100755
--- a/test_regress/t/t_tri_gate_notif0.pl
+++ b/test_regress/t/t_tri_gate_notif0.pl
@@ -9,17 +9,19 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_tri_gate.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
 	 v_flags2 => ['+define+T_NOTIF0',],
 	 make_flags => 'CPPFLAGS_ADD=-DT_NOTIF0',
 	 verilator_flags2 => ["--exe $Self->{t_dir}/t_tri_gate.cpp"],
-	 ) if $Self->{v3};
+    );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_tri_gate_notif1.pl b/test_regress/t/t_tri_gate_notif1.pl
index 24341a45e..88bbc13d5 100755
--- a/test_regress/t/t_tri_gate_notif1.pl
+++ b/test_regress/t/t_tri_gate_notif1.pl
@@ -9,17 +9,19 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_tri_gate.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
 	 v_flags2 => ['+define+T_NOTIF1',],
 	 make_flags => 'CPPFLAGS_ADD=-DT_NOTIF1',
 	 verilator_flags2 => ["--exe $Self->{t_dir}/t_tri_gate.cpp"],
-	 ) if $Self->{v3};
+    );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_tri_inout.pl b/test_regress/t/t_tri_inout.pl
index 7735b18dd..e1b68002f 100755
--- a/test_regress/t/t_tri_inout.pl
+++ b/test_regress/t/t_tri_inout.pl
@@ -7,15 +7,17 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
-	 v_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
-	 ) if $Self->{v3};
+	 verilator_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp"],
+    );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_tri_pullup.pl b/test_regress/t/t_tri_pullup.pl
index 126ac798a..af7e316e8 100755
--- a/test_regress/t/t_tri_pullup.pl
+++ b/test_regress/t/t_tri_pullup.pl
@@ -7,15 +7,17 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
-	 v_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp --debug"],
-	 ) if $Self->{v3};
+	 verilator_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp --debug"],
+    );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_tri_select.pl b/test_regress/t/t_tri_select.pl
index 126ac798a..af7e316e8 100755
--- a/test_regress/t/t_tri_select.pl
+++ b/test_regress/t/t_tri_select.pl
@@ -7,15 +7,17 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
-	 v_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp --debug"],
-	 ) if $Self->{v3};
+	 verilator_flags2 => ["--exe $Self->{t_dir}/$Self->{name}.cpp --debug"],
+    );
 
 execute (
 	 check_finished=>1,
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_unopt_combo_bad.pl b/test_regress/t/t_unopt_combo_bad.pl
index 230a41c3c..109e08aff 100755
--- a/test_regress/t/t_unopt_combo_bad.pl
+++ b/test_regress/t/t_unopt_combo_bad.pl
@@ -10,7 +10,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 top_filename("t/t_unopt_combo.v");
 
 compile (
-	 fails=>$Self->{v3},
+	 fails=>$Self->{vlt},
 	 expect=>
 '%Warning-UNOPTFLAT: t/t_unopt_combo.v:\d+: Signal unoptimizable: Feedback to clock or circular logic: v.c
 %Warning-UNOPTFLAT: Use "/\* verilator lint_off UNOPTFLAT \*/" and lint_on around source to disable this message.
@@ -23,7 +23,7 @@ compile (
 	 );
 
 execute (
-     ) if !$Self->{v3};
+     ) if !$Self->{vlt};
 
 ok(1);
 1;
diff --git a/test_regress/t/t_unopt_combo_isolate.pl b/test_regress/t/t_unopt_combo_isolate.pl
index 814e80865..dd4b17130 100755
--- a/test_regress/t/t_unopt_combo_isolate.pl
+++ b/test_regress/t/t_unopt_combo_isolate.pl
@@ -13,7 +13,7 @@ compile (
 	 verilator_flags2 => ['+define+ISOLATE --stats'],
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ($Self->{stats}, qr/Optimizations, isolate_assignments blocks\s+5/i);
 }
 
diff --git a/test_regress/t/t_unopt_converge_print_bad.pl b/test_regress/t/t_unopt_converge_print_bad.pl
index 2151282c4..95340a4e7 100755
--- a/test_regress/t/t_unopt_converge_print_bad.pl
+++ b/test_regress/t/t_unopt_converge_print_bad.pl
@@ -18,7 +18,7 @@ compile (
 execute (
 	 fails=>1,
 	 expect=> '%Error: \S+:\d+: Verilated model didn\'t converge',
-     ) if $Self->{v3};
+     ) if $Self->{vlt};
 
 ok(1);
 1;
diff --git a/test_regress/t/t_unopt_converge_run_bad.pl b/test_regress/t/t_unopt_converge_run_bad.pl
index 1a05b40c6..2fa20cfd1 100755
--- a/test_regress/t/t_unopt_converge_run_bad.pl
+++ b/test_regress/t/t_unopt_converge_run_bad.pl
@@ -16,7 +16,7 @@ compile (
 execute (
 	 fails=>1,
 	 expect=> '%Error: \S+:\d+: Verilated model didn\'t converge',
-     ) if $Self->{v3};
+     ) if $Self->{vlt};
 
 ok(1);
 1;
diff --git a/test_regress/t/t_unopt_converge_unopt_bad.pl b/test_regress/t/t_unopt_converge_unopt_bad.pl
index 32c5dfc4c..916ac4713 100755
--- a/test_regress/t/t_unopt_converge_unopt_bad.pl
+++ b/test_regress/t/t_unopt_converge_unopt_bad.pl
@@ -9,12 +9,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 
 top_filename("t/t_unopt_converge.v");
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 fails=>1,
 	 expect=> '%Warning-UNOPT: t/t_unopt_converge.v:\d+: Signal unoptimizable: Feedback to public clock or circular logic: x
 .*
 %Error: Exiting due to '
-     ) if $Self->{v3};
+     );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_var_const_bad.pl b/test_regress/t/t_var_const_bad.pl
index 9ceccf307..9441b355c 100755
--- a/test_regress/t/t_var_const_bad.pl
+++ b/test_regress/t/t_var_const_bad.pl
@@ -7,13 +7,15 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only"],
 	 fails=>1,
 	 expect=>
 '%Error: t/t_var_const_bad.v:\d+: Assigning to const variable: five
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+    );
 
 ok(1);
 1;
diff --git a/test_regress/t/t_var_escape.pl b/test_regress/t/t_var_escape.pl
index 6e155aa8d..40047aea4 100755
--- a/test_regress/t/t_var_escape.pl
+++ b/test_regress/t/t_var_escape.pl
@@ -16,7 +16,7 @@ execute (
 	 check_finished=>1,
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep     ("$Self->{obj_dir}/simx.vcd", qr/\$enddefinitions/x);
     my $sig = quotemeta("bra[ket]slash/dash-colon:9");
     file_grep     ("$Self->{obj_dir}/simx.vcd", qr/ $sig/);
diff --git a/test_regress/t/t_var_in_assign_bad.pl b/test_regress/t/t_var_in_assign_bad.pl
index ee6e50436..24e93d6c2 100755
--- a/test_regress/t/t_var_in_assign_bad.pl
+++ b/test_regress/t/t_var_in_assign_bad.pl
@@ -7,6 +7,8 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->{vlt} or $Self->skip("Verilator only test");
+
 compile (
 	 v_flags2 => ["--lint-only --Mdir obj_lint_only"],
 	 fails=>1,
@@ -14,7 +16,7 @@ compile (
 '%Error: t/t_var_in_assign_bad.v:\d+: Assigning to input variable: value
 %Error: t/t_var_in_assign_bad.v:\d+: Assigning to input variable: valueSub
 %Error: Exiting due to.*',
-	 ) if $Self->{v3};
+    );
 
 (!-d "obj_lint_only") or $Self->error("%Error: lint-only shouldn't make output directory");
 ok(1);
diff --git a/test_regress/t/t_var_life.pl b/test_regress/t/t_var_life.pl
index f9a8818de..4b11ddaa9 100755
--- a/test_regress/t/t_var_life.pl
+++ b/test_regress/t/t_var_life.pl
@@ -11,7 +11,7 @@ compile (
 	 verilator_flags2 => ["--stats"],
 	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ($Self->{stats}, qr/Optimizations, Lifetime assign deletions\s+4/i);
     file_grep ($Self->{stats}, qr/Optimizations, Lifetime constant prop\s+2/i);
 }
diff --git a/test_regress/t/t_var_nonamebegin.pl b/test_regress/t/t_var_nonamebegin.pl
index 4280fbef3..57b09328c 100755
--- a/test_regress/t/t_var_nonamebegin.pl
+++ b/test_regress/t/t_var_nonamebegin.pl
@@ -8,7 +8,7 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Version 2.0.
 
 compile (
-    v_flags2 => [$Self->{v3}?'-trace':''],
+    verilator_flags2 => ['-trace'],
     );
 
 execute (
@@ -24,7 +24,7 @@ t2 {mod}.tsk top.v
 *-* All Finished *-*'),
     );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     vcd_identical ("$Self->{obj_dir}/simx.vcd",
 		   "t/$Self->{name}.out");
 }
diff --git a/test_regress/t/t_var_pins_cc.pl b/test_regress/t/t_var_pins_cc.pl
index 8f8385b71..f37155e78 100755
--- a/test_regress/t/t_var_pins_cc.pl
+++ b/test_regress/t/t_var_pins_cc.pl
@@ -12,11 +12,11 @@ $Self->{vlt} or $Self->skip("Verilator only test");
 top_filename("t/t_var_pinsizes.v");
 
 compile (
-	 v_flags2 => ['-cc'],
+	 verilator_flags2 => ['-cc'],
 	 verilator_make_gcc => 0,
-	 ) if $Self->{v3};
+	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ("$Self->{obj_dir}/Vt_var_pins_cc.h", qr/VL_IN8  \(i1,0,0\);/x);
     file_grep ("$Self->{obj_dir}/Vt_var_pins_cc.h", qr/VL_IN8  \(i8,7,0\);/x);
     file_grep ("$Self->{obj_dir}/Vt_var_pins_cc.h", qr/VL_IN16 \(i16,15,0\);/x);
diff --git a/test_regress/t/t_var_pins_sc1.pl b/test_regress/t/t_var_pins_sc1.pl
index 163d12056..aaad9f3fd 100755
--- a/test_regress/t/t_var_pins_sc1.pl
+++ b/test_regress/t/t_var_pins_sc1.pl
@@ -12,11 +12,11 @@ $Self->{vlt} or $Self->skip("Verilator only test");
 top_filename("t/t_var_pinsizes.v");
 
 compile (
-	 v_flags2 => ["-sp -pins-bv 1 --trace --exe $Self->{t_dir}/t_var_pinsizes.cpp"],
+	 verilator_flags2 => ["-sp -pins-bv 1 --trace --exe $Self->{t_dir}/t_var_pinsizes.cpp"],
 	 make_main => 0,
-	 ) if $Self->{v3};
+	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<sc_bv<1>\s> \s+ i1;/x);
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<sc_bv<8>\s> \s+ i8;/x);
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<sc_bv<16>\s> \s+ i16;/x);
diff --git a/test_regress/t/t_var_pins_sc2.pl b/test_regress/t/t_var_pins_sc2.pl
index e3a8522f0..847019505 100755
--- a/test_regress/t/t_var_pins_sc2.pl
+++ b/test_regress/t/t_var_pins_sc2.pl
@@ -12,11 +12,11 @@ $Self->{vlt} or $Self->skip("Verilator only test");
 top_filename("t/t_var_pinsizes.v");
 
 compile (
-	 v_flags2 => ["-sp -pins-bv 2 --trace --exe $Self->{t_dir}/t_var_pinsizes.cpp"],
+	 verilator_flags2 => ["-sp -pins-bv 2 --trace --exe $Self->{t_dir}/t_var_pinsizes.cpp"],
 	 make_main => 0,
-	 ) if $Self->{v3};
+	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<bool> \s+ i1;/x);
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<sc_bv<8>\s> \s+ i8;/x);
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<sc_bv<16>\s> \s+ i16;/x);
diff --git a/test_regress/t/t_var_pins_sc32.pl b/test_regress/t/t_var_pins_sc32.pl
index feca995f4..35df4c6c0 100755
--- a/test_regress/t/t_var_pins_sc32.pl
+++ b/test_regress/t/t_var_pins_sc32.pl
@@ -12,11 +12,11 @@ $Self->{vlt} or $Self->skip("Verilator only test");
 top_filename("t/t_var_pinsizes.v");
 
 compile (
-	 v_flags2 => ["-sp -no-pins64 --trace --exe $Self->{t_dir}/t_var_pinsizes.cpp"],
+	 verilator_flags2 => ["-sp -no-pins64 --trace --exe $Self->{t_dir}/t_var_pinsizes.cpp"],
 	 make_main => 0,
-	 ) if $Self->{v3};
+	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<bool> \s+ i1;/x);
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<uint32_t> \s+ i8;/x);
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<uint32_t> \s+ i16;/x);
diff --git a/test_regress/t/t_var_pins_sc64.pl b/test_regress/t/t_var_pins_sc64.pl
index d0ecf9d1d..3e9e1af1d 100755
--- a/test_regress/t/t_var_pins_sc64.pl
+++ b/test_regress/t/t_var_pins_sc64.pl
@@ -12,11 +12,11 @@ $Self->{vlt} or $Self->skip("Verilator only test");
 top_filename("t/t_var_pinsizes.v");
 
 compile (
-	 v_flags2 => ["-sp -pins64 --trace --exe $Self->{t_dir}/t_var_pinsizes.cpp"],
+	 verilator_flags2 => ["-sp -pins64 --trace --exe $Self->{t_dir}/t_var_pinsizes.cpp"],
 	 make_main => 0,
-	 ) if $Self->{v3};
+	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<bool> \s+ i1;/x);
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<uint32_t> \s+ i8;/x);
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<uint32_t> \s+ i16;/x);
diff --git a/test_regress/t/t_var_pins_scui.pl b/test_regress/t/t_var_pins_scui.pl
index 97bdafb71..1c168edd3 100755
--- a/test_regress/t/t_var_pins_scui.pl
+++ b/test_regress/t/t_var_pins_scui.pl
@@ -12,11 +12,11 @@ $Self->{vlt} or $Self->skip("Verilator only test");
 top_filename("t/t_var_pinsizes.v");
 
 compile (
-	 v_flags2 => ["-sp -pins-uint8 --trace --exe $Self->{t_dir}/t_var_pinsizes.cpp"],
+	 verilator_flags2 => ["-sp -pins-uint8 --trace --exe $Self->{t_dir}/t_var_pinsizes.cpp"],
 	 make_main => 0,
-	 ) if $Self->{v3};
+	 );
 
-if ($Self->{v3}) {
+if ($Self->{vlt}) {
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<bool> \s+ i1;/x);
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<uint8_t> \s+ i8;/x);
     file_grep ("$Self->{obj_dir}/$Self->{VM_PREFIX}.sp", qr/sc_in<uint16_t> \s+ i16;/x);
diff --git a/test_regress/t/t_vlt_warn.pl b/test_regress/t/t_vlt_warn.pl
index 2e06ace09..df822d44f 100755
--- a/test_regress/t/t_vlt_warn.pl
+++ b/test_regress/t/t_vlt_warn.pl
@@ -7,12 +7,14 @@ if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); di
 # Lesser General Public License Version 3 or the Perl Artistic License
 # Version 2.0.
 
+$Self->skip("Verilator only test") if !$Self->{vlt};
+
 compile (
 	 make_top_shell => 0,
 	 make_main => 0,
 	 verilator_make_gcc => 0,
 	 v_flags2 => ["--lint-only t/t_vlt_warn.vlt"],
-	 ) if $Self->{v3};
+	 );
 
 ok(1);
 1;