decodetree: Properly diagnose fields overflowing an insn

Previously this would result in an exception for shifting
the field mask by a negative number.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

4 files changed, 20 insertions, 0 deletions

diff --git a/tests/decode/err_width1.decode b/tests/decode/err_width1.decode
new file mode 100644
index 0000000000..0c14f6d73b
--- /dev/null
+++ b/tests/decode/err_width1.decode
@@ -0,0 +1,5 @@
+# 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 too many bits (33 of 32)
+one	000000000000000000000000000000000
diff --git a/tests/decode/err_width2.decode b/tests/decode/err_width2.decode
new file mode 100644
index 0000000000..47f0acf322
--- /dev/null
+++ b/tests/decode/err_width2.decode
@@ -0,0 +1,5 @@
+# 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 too few bits (31 of 32)
+one	0000000000000000000000000000000
diff --git a/tests/decode/err_width3.decode b/tests/decode/err_width3.decode
new file mode 100644
index 0000000000..c5fb6b3699
--- /dev/null
+++ b/tests/decode/err_width3.decode
@@ -0,0 +1,5 @@
+# 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 too many bits (33 of 32)
+one	0 s:32
diff --git a/tests/decode/err_width4.decode b/tests/decode/err_width4.decode
new file mode 100644
index 0000000000..1588a63698
--- /dev/null
+++ b/tests/decode/err_width4.decode
@@ -0,0 +1,5 @@
+# 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 too few bits (31 of 32)
+one	0 s:30