support offsets on labels

1 files changed, 7 insertions, 4 deletions

diff --git a/format.py b/format.py
index 7798589..9e0ead0 100755
--- a/format.py
+++ b/format.py
@@ -84,8 +84,12 @@ def default_slice(val, hi, lo):
 
     >>> default_slice(('label', 'imm12'), 12, 1)
     ('label[12:1]', 'imm12')
+    >>> default_slice(('label-4', 'imm12'), 12, 1)
+    ('label-4[12:1]', 'imm12')
     >>> default_slice(('label[14:3]', 'imm12'), 12, 1)
     ('label[14:3]', 'imm12')
+    >>> default_slice(('label+4[14:3]', 'imm12'), 12, 1)
+    ('label+4[14:3]', 'imm12')
     >>> default_slice(('label[14:3]', 'imm12', 'extra'), 12, 1)
     ('label[14:3]', 'imm12', 'extra')
     >>> default_slice(('label[31:0]', 'imm12'), 11, 0)
@@ -97,13 +101,12 @@ def default_slice(val, hi, lo):
     if 'hi' not in parsed:
       parsed['hi'] = hi
       parsed['lo'] = lo
-
-    ref = '{label}[{hi}:{lo}]'.format(**parsed)
+    ref = subv.format_reference(parsed)
 
     p_size = parsed['hi'] - parsed['lo'] + 1
-    assert parsed['size'] == p_size, "expected {} bit slice, got {} ({} bit)".format(parsed['size'], ref, p_size)
+    assert parsed['size'] == p_size, "expected {} bit slice, got {} ({} bit)".format(parsed['size'], ref[0], p_size)
 
-    return (ref, *val[1:])
+    return ref
 
 def slice_bit_or_ref(val, hi, lo):
     """ bit.slice but for bitfields and label references.