diff --git a/tests/decode/err_field10.decode b/tests/decode/err_field10.decode
new file mode 100644
index 0000000000..3e672b7459
--- /dev/null
+++ b/tests/decode/err_field10.decode
@@ -0,0 +1,7 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose formats which refer to undefined fields
+%field1        field2:3
+@fmt ........ ........ ........ ........ %field1
+insn 00000000 00000000 00000000 00000000 @fmt
diff --git a/tests/decode/err_field7.decode b/tests/decode/err_field7.decode
new file mode 100644
index 0000000000..51fad7ccea
--- /dev/null
+++ b/tests/decode/err_field7.decode
@@ -0,0 +1,7 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose fields whose definitions form a loop
+%field1        field2:3
+%field2        field1:4
+insn 00000000 00000000 00000000 00000000 %field1 %field2
diff --git a/tests/decode/err_field8.decode b/tests/decode/err_field8.decode
new file mode 100644
index 0000000000..cc47c08a45
--- /dev/null
+++ b/tests/decode/err_field8.decode
@@ -0,0 +1,8 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose patterns which refer to undefined fields
+&f1 f1 a
+%field1        field2:3
+@fmt ........ ........ ........ .... a:4 &f1
+insn 00000000 00000000 00000000 0000 .... @fmt f1=%field1
diff --git a/tests/decode/err_field9.decode b/tests/decode/err_field9.decode
new file mode 100644
index 0000000000..e7361d521b
--- /dev/null
+++ b/tests/decode/err_field9.decode
@@ -0,0 +1,14 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose fields where the format refers to a field defined in the
+# pattern and the pattern refers to a field defined in the format.
+# This is theoretically not impossible to implement, but is not
+# supported by the script at this time.
+&abcd a b c d
+%refa        a:3
+%refc        c:4
+# Format defines 'c' and sets 'b' to an indirect ref to 'a'
+@fmt ........ ........ ........ c:8 &abcd b=%refa
+# Pattern defines 'a' and sets 'd' to an indirect ref to 'c'
+insn 00000000 00000000 00000000 ........ @fmt d=%refc a=6
diff --git a/tests/decode/meson.build b/tests/decode/meson.build
index b4850562f9..38a0629d67 100644
--- a/tests/decode/meson.build
+++ b/tests/decode/meson.build
@@ -7,6 +7,10 @@ err_tests = [
     'err_field4.decode',
     'err_field5.decode',
     'err_field6.decode',
+    'err_field7.decode',
+    'err_field8.decode',
+    'err_field9.decode',
+    'err_field10.decode',
     'err_init1.decode',
     'err_init2.decode',
     'err_init3.decode',
@@ -37,6 +41,7 @@ succ_tests = [
     'succ_argset_type1.decode',
     'succ_function.decode',
     'succ_ident1.decode',
+    'succ_named_field.decode',
     'succ_pattern_group_nest1.decode',
     'succ_pattern_group_nest2.decode',
     'succ_pattern_group_nest3.decode',
diff --git a/tests/decode/succ_named_field.decode b/tests/decode/succ_named_field.decode
new file mode 100644
index 0000000000..e64b3f9356
--- /dev/null
+++ b/tests/decode/succ_named_field.decode
@@ -0,0 +1,19 @@
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# field using a named_field
+%imm_sz	8:8 sz:3
+insn 00000000 00000000 ........ 00000000 imm_sz=%imm_sz sz=1
+
+# Ditto, via a format. Here a field in the format
+# references a named field defined in the insn pattern:
+&imm_a imm alpha
+%foo 0:16 alpha:4
+@foo 00000001 ........ ........ ........ &imm_a imm=%foo
+i1   ........ 00000000 ........ ........ @foo alpha=1
+i2   ........ 00000001 ........ ........ @foo alpha=2
+
+# Here the named field is defined in the format and referenced
+# from the insn pattern:
+@bar 00000010 ........ ........ ........ &imm_a alpha=4
+i3   ........ 00000000 ........ ........ @bar imm=%foo