From 66381f20d789aaf74511c2d6a892093940f34ce5 Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Mon, 27 Apr 2020 12:49:11 +0100
Subject: [PATCH] add CompLDSTOpSubset, contains subset of decode instruction
 for LD/ST

---
 src/soc/experiment/compldst.py | 53 ++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/src/soc/experiment/compldst.py b/src/soc/experiment/compldst.py
index b00edceb..e4f51b60 100644
--- a/src/soc/experiment/compldst.py
+++ b/src/soc/experiment/compldst.py
@@ -21,6 +21,7 @@
 from nmigen.compat.sim import run_simulation
 from nmigen.cli import verilog, rtlil
 from nmigen import Module, Signal, Mux, Cat, Elaboratable, Array
+from nmigen.hdl.rec import Record, Layout
 
 from nmutil.latch import SRLatch, latchregister
 
@@ -30,6 +31,58 @@ from soc.decoder.power_enums import InternalOp
 
 from soc.experiment.alu_hier import CompALUOpSubset
 
+from soc.decoder.power_enums import InternalOp, Function, CryIn
+
+import operator
+
+
+class CompLDSTOpSubset(Record):
+    """CompLDSTOpSubset
+
+    a copy of the relevant subset information from Decode2Execute1Type
+    needed for LD/ST operations.  use with eq_from_execute1 (below) to
+    grab subsets.
+    """
+    def __init__(self, name=None):
+        layout = (('insn_type', InternalOp),
+                  ('imm_data', Layout((("imm", 64), ("imm_ok", 1)))),
+                  ('is_32bit', 1),
+                  ('is_signed', 1),
+                  ('data_len', 4), # TODO: should be in separate CompLDSTSubset
+                  ('byte_reverse', 1),
+                  ('sign_extend', 1),
+                  ('update', 1))
+
+        Record.__init__(self, Layout(layout), name=name)
+
+        # grrr.  Record does not have kwargs
+        self.insn_type.reset_less = True
+        self.is_32bit.reset_less = True
+        self.is_signed.reset_less = True
+        self.data_len.reset_less = True
+        self.byte_reverse.reset_less = True
+        self.sign_extend.reset_less = True
+        self.update.reset_less = True
+
+    def eq_from_execute1(self, other):
+        """ use this to copy in from Decode2Execute1Type
+        """
+        res = []
+        for fname, sig in self.fields.items():
+            eqfrom = other.fields[fname]
+            res.append(sig.eq(eqfrom))
+        return res
+
+    def ports(self):
+        return [self.insn_type,
+                self.is_32bit,
+                self.is_signed,
+                self.data_len,
+                self.byte_reverse,
+                self.sign_extend,
+                self.update,
+        ]
+
 
 class LDSTCompUnit(Elaboratable):
     """ LOAD / STORE / ADD / SUB Computation Unit
-- 
2.30.2