From 39a0dc7397c592b4b53631b2284d142fd20ac485 Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Mon, 30 Aug 2021 13:03:53 +0100
Subject: [PATCH] fix pattern-match for an expression such as "XLEN-16" when
 looking for concat substitutions

[item] * NUMBER was replaced with
concat(item, repeat=NUMBER)

but [item] * (XLEN-16) was not matching

by adding a HACK which spots ast.Binop then [item]*(XLEN-16) can be
recognised
---
 src/openpower/decoder/power_pseudo.py  | 12 +++++++++++-
 src/openpower/decoder/pseudo/parser.py | 13 ++++++++++++-
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/openpower/decoder/power_pseudo.py b/src/openpower/decoder/power_pseudo.py
index 99f3ca47..ec9bf085 100644
--- a/src/openpower/decoder/power_pseudo.py
+++ b/src/openpower/decoder/power_pseudo.py
@@ -194,7 +194,17 @@ XLEN_test = """
 RA[XLEN:XLEN - 1]
 """
 
-code = XLEN_test
+concat_test1 = """
+[0]*16
+"""
+
+concat_test2 = """
+[0]*(XLEN-16)
+"""
+
+code = concat_test2
+#code = concat_test1
+#code = XLEN_test
 #code = logictest
 #code = SVSTATE_next
 #code = hextest
diff --git a/src/openpower/decoder/pseudo/parser.py b/src/openpower/decoder/pseudo/parser.py
index 03d0fd5e..b9779b0d 100644
--- a/src/openpower/decoder/pseudo/parser.py
+++ b/src/openpower/decoder/pseudo/parser.py
@@ -176,10 +176,21 @@ def check_concat(node):  # checks if the comparison is already a concat
 
 # identify SelectableInt pattern [something] * N
 # must return concat(something, repeat=N)
+# here is a TEMPORARY hack to support minimal expressions
+# such as (XLEN-16), looking for ast.BinOp
+# have to keep an eye on this
 def identify_sint_mul_pattern(p):
+    """here we are looking for patterns of this type:
+        [item] * something
+    these must specifically be returned as concat(item, repeat=something)
+    """
+    #print ("identify_sint_mul_pattern")
+    #for pat in p:
+    #    print("    ", astor.dump_tree(pat))
     if p[2] != '*':  # multiply
         return False
-    if not isinstance(p[3], ast.Constant):  # rhs = Num
+    if (not isinstance(p[3], ast.Constant) and  # rhs = Num
+        not isinstance(p[3], ast.BinOp)):       # rhs = (XLEN-something)
         return False
     if not isinstance(p[1], ast.List):  # lhs is a list
         return False
-- 
2.30.2