From 26fa8a7a013d553609bde3a1a9b0a7e96c8c8e9a Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Fri, 26 Nov 2021 16:45:23 +0000
Subject: [PATCH] convert score6600_multi over to using RegSpecs (in a fake
 way) which by slow code-morphing the entire score6600_multi code can be
 converted to be like core.py

---
 src/soc/experiment/alu_hier.py        | 50 ++++++++++++++++++++++++++-
 src/soc/experiment/score6600_multi.py | 11 +++---
 2 files changed, 54 insertions(+), 7 deletions(-)

diff --git a/src/soc/experiment/alu_hier.py b/src/soc/experiment/alu_hier.py
index b44c17ba..c88689e7 100644
--- a/src/soc/experiment/alu_hier.py
+++ b/src/soc/experiment/alu_hier.py
@@ -28,6 +28,10 @@ from openpower.decoder.power_enums import MicrOp, Function, CryIn
 from soc.fu.alu.alu_input_record import CompALUOpSubset
 from soc.fu.cr.cr_input_record import CompCROpSubset
 
+from soc.fu.pipe_data import FUBaseData
+from soc.fu.alu.pipe_data import CommonPipeSpec
+from soc.fu.compunits.compunits import FunctionUnitBaseSingle
+
 import operator
 
 
@@ -177,9 +181,53 @@ class DummyALU(Elaboratable):
     def ports(self):
         return list(self)
 
+#####################
+# converting even this dummy ALU over to the FunctionUnit RegSpecs API
+# which, errr, note that the regspecs are totally ignored below, but
+# at least the widths are all 64-bit so it's okay.
+#####################
+
+# input (and output) for logical initial stage (common input)
+class ALUInputData(FUBaseData):
+    regspec = [('INT', 'a', '0:63'), # RA
+               ('INT', 'b', '0:63'), # RB/immediate
+               ]
+    def __init__(self, pspec):
+        super().__init__(pspec, False)
+
+
+# output from ALU final stage
+class ALUOutputData(FUBaseData):
+    regspec = [('INT', 'o', '0:63'),        # RT
+               ]
+    def __init__(self, pspec):
+        super().__init__(pspec, True)
+
+
+# ALU pipe specification class
+class ALUPipeSpec(CommonPipeSpec):
+    regspec = (ALUInputData.regspec, ALUOutputData.regspec)
+    opsubsetkls = CompALUOpSubset
+
+
+class ALUFunctionUnit(FunctionUnitBaseSingle):
+#class ALUFunctionUnit(FunctionUnitBaseMulti):
+    fnunit = Function.ALU
+
+    def __init__(self, idx):
+        super().__init__(ALUPipeSpec, ALU, 1)
+
 
 class ALU(Elaboratable):
     def __init__(self, width):
+        # XXX major temporary hack: attempting to convert
+        # ALU over to RegSpecs API, FunctionUnitBaseSingle passes in
+        # a regspec here which we can't cope with.  therefore, errr...
+        # just throw it away and set the width to 64
+        if not isinstance(width, int):
+            width = 64
+        # TODO, really this should just inherit from ControlBase it would
+        # be a lot less messy.
         self.p = Dummy()  # make look like nmutil pipeline API
         self.p.i_data = Dummy()
         self.p.i_data.ctx = Dummy()
@@ -203,7 +251,7 @@ class ALU(Elaboratable):
         self.o = self.out[0]
         self.cr = self.out[1]
         self.width = width
-        # more "look like nmutil pipeline API"
+        # more "look like nmutil ControlBase pipeline API" stuff
         self.p.i_data.ctx.op = self.op
         self.p.i_data.a = self.a
         self.p.i_data.b = self.b
diff --git a/src/soc/experiment/score6600_multi.py b/src/soc/experiment/score6600_multi.py
index 4c9b5505..633de571 100644
--- a/src/soc/experiment/score6600_multi.py
+++ b/src/soc/experiment/score6600_multi.py
@@ -22,7 +22,7 @@ from soc.experiment.l0_cache import TstL0CacheBuffer
 
 # for testing purposes
 from soc.config.test.test_loadstore import TestMemPspec
-from soc.experiment.alu_hier import ALU, BranchALU
+from soc.experiment.alu_hier import ALUFunctionUnit, BranchALU
 from soc.fu.alu.alu_input_record import CompALUOpSubset
 
 from openpower.decoder.power_enums import MicrOp, Function
@@ -265,13 +265,12 @@ class CompUnitALUs(CompUnitsBase):
 
         # Int ALUs
         alus = []
-        for i in range(n_alus):
-            alus.append(ALU(rwid))
 
         units = []
-        for alu in alus:
-            aluopwid = 3  # extra bit for immediate mode
-            units.append(MultiCompUnit(rwid, alu, CompALUOpSubset))
+        for i in range(n_alus):
+            fu = ALUFunctionUnit(i)
+            units.append(fu)
+            alus.append(fu.alu)
 
         CompUnitsBase.__init__(self, rwid, units)
 
-- 
2.30.2