start adding bitmanip FU
authorJacob Lifshay <programmerjake@gmail.com>
Wed, 17 Nov 2021 20:49:41 +0000 (12:49 -0800)
committerJacob Lifshay <programmerjake@gmail.com>
Wed, 17 Nov 2021 20:49:41 +0000 (12:49 -0800)
src/soc/fu/bitmanip/__init__.py [new file with mode: 0644]
src/soc/fu/bitmanip/input_record.py [new file with mode: 0644]
src/soc/fu/bitmanip/input_stage.py [new file with mode: 0644]
src/soc/fu/bitmanip/main_stage.py [new file with mode: 0644]
src/soc/fu/bitmanip/output_stage.py [new file with mode: 0644]
src/soc/fu/bitmanip/pipe_data.py [new file with mode: 0644]
src/soc/fu/bitmanip/pipeline.py [new file with mode: 0644]
src/soc/fu/bitmanip/test/__init__.py [new file with mode: 0644]
src/soc/fu/bitmanip/test/test_pipe_caller.py [new file with mode: 0644]

diff --git a/src/soc/fu/bitmanip/__init__.py b/src/soc/fu/bitmanip/__init__.py
new file mode 100644 (file)
index 0000000..e69de29
diff --git a/src/soc/fu/bitmanip/input_record.py b/src/soc/fu/bitmanip/input_record.py
new file mode 100644 (file)
index 0000000..18af8ea
--- /dev/null
@@ -0,0 +1,27 @@
+from soc.fu.base_input_record import CompOpSubsetBase
+from nmigen.hdl.rec import Layout
+
+from openpower.decoder.power_enums import MicrOp, Function, CryIn
+
+
+class CompBitManipOpSubset(CompOpSubsetBase):
+    """CompBitManipOpSubset
+
+    a copy of the relevant subset information from Decode2Execute1Type
+    needed for ALU operations.  use with eq_from_execute1 (below) to
+    grab subsets.
+    """
+
+    def __init__(self, name=None):
+        layout = (('insn_type', MicrOp),
+                  ('fn_unit', Function),
+                  ('imm_data', Layout((("data", 64), ("ok", 1)))),
+                  ('rc', Layout((("rc", 1), ("ok", 1)))),  # Data
+                  ('oe', Layout((("oe", 1), ("ok", 1)))),  # Data
+                  ('write_cr0', 1),
+                  ('is_32bit', 1),
+                  ('is_signed', 1),
+                  ('insn', 32),
+                  )
+
+        super().__init__(layout, name=name)
diff --git a/src/soc/fu/bitmanip/input_stage.py b/src/soc/fu/bitmanip/input_stage.py
new file mode 100644 (file)
index 0000000..e8234c3
--- /dev/null
@@ -0,0 +1,26 @@
+# This stage is intended to adjust the input data before sending it to
+# the acutal ALU. Things like handling inverting the input, carry_in
+# generation for subtraction, and handling of immediates should happen
+# here
+from soc.fu.common_input_stage import CommonInputStage
+from soc.fu.bitmanip.pipe_data import BitManipInputData
+
+
+class BitManipInputStage(CommonInputStage):
+    def __init__(self, pspec):
+        super().__init__(pspec, "input")
+
+    def ispec(self):
+        return BitManipInputData(self.pspec)
+
+    def ospec(self):
+        return BitManipInputData(self.pspec)
+
+    def elaborate(self, platform):
+        m = super().elaborate(platform)  # handles A, carry and sticky overflow
+        comb = m.d.comb
+
+        # operand rc
+        comb += self.o.rc.eq(self.i.rc)
+
+        return m
diff --git a/src/soc/fu/bitmanip/main_stage.py b/src/soc/fu/bitmanip/main_stage.py
new file mode 100644 (file)
index 0000000..b31df43
--- /dev/null
@@ -0,0 +1,59 @@
+# License: LGPLv3+
+# Copyright (C) 2020 Michael Nolan <mtnolan2640@gmail.com>
+# Copyright (C) 2020 Luke Kenneth Casson Leighton <lkcl@lkcl.net>
+# Copyright (C) 2021 Jacob Lifshay <programmerjake@gmail.com>
+
+# This stage is intended to do most of the work of executing bitmanip
+# instructions, as well as overflow generation. This module however should not
+# gate the overflow, that's up to the output stage
+from nmigen.hdl.dsl import Module
+from nmutil.pipemodbase import PipeModBase
+from soc.fu.bitmanip.pipe_data import (BitManipOutputData,
+                                       BitManipInputData)
+from openpower.decoder.power_enums import MicrOp
+from openpower.decoder.power_fields import DecodeFields
+from openpower.decoder.power_fieldsn import SignalBitRange
+from nmutil.lut import BitwiseLut
+
+
+class BitManipMainStage(PipeModBase):
+    def __init__(self, pspec):
+        super().__init__(pspec, "main")
+        self.fields = DecodeFields(SignalBitRange, [self.i.ctx.op.insn])
+        self.fields.create_specs()
+
+    def ispec(self):
+        return BitManipInputData(self.pspec)
+
+    def ospec(self):
+        return BitManipOutputData(self.pspec)
+
+    def elaborate(self, platform):
+        m = Module()
+        comb = m.d.comb
+        op = self.i.ctx.op
+        o = self.o.o
+
+        bitwise_lut = BitwiseLut(input_count=3, width=64)
+        m.submodules.bitwise_lut = bitwise_lut
+        comb += bitwise_lut.inputs[0].eq(self.i.rb)
+        comb += bitwise_lut.inputs[1].eq(self.i.ra)
+        comb += bitwise_lut.inputs[2].eq(self.i.rc)
+
+        comb += o.ok.eq(1)  # defaults to enabled
+
+        with m.Switch(op.insn_type):
+            with m.Case(MicrOp.OP_TERNLOG):
+                # TODO: this only works for ternaryi, change to get lut value
+                # from register when we implement other variants
+                comb += bitwise_lut.lut.eq(self.fields.FormTLI.TLI)
+                comb += o.data.eq(bitwise_lut.output)
+            with m.Default():
+                comb += o.ok.eq(0)  # otherwise disable
+
+        ###### sticky overflow and context, both pass-through #####
+
+        comb += self.o.xer_so.data.eq(self.i.xer_so)
+        comb += self.o.ctx.eq(self.i.ctx)
+
+        return m
diff --git a/src/soc/fu/bitmanip/output_stage.py b/src/soc/fu/bitmanip/output_stage.py
new file mode 100644 (file)
index 0000000..ea2d9de
--- /dev/null
@@ -0,0 +1,15 @@
+# This stage is intended to handle the gating of carry and overflow
+# out, summary overflow generation, and updating the condition
+# register
+from soc.fu.common_output_stage import CommonOutputStage
+from soc.fu.bitmanip.pipe_data import (BitManipOutputData,
+                                       BitManipOutputDataFinal)
+
+
+class BitManipOutputStage(CommonOutputStage):
+
+    def ispec(self):
+        return BitManipOutputData(self.pspec)
+
+    def ospec(self):
+        return BitManipOutputDataFinal(self.pspec)
diff --git a/src/soc/fu/bitmanip/pipe_data.py b/src/soc/fu/bitmanip/pipe_data.py
new file mode 100644 (file)
index 0000000..c0420b7
--- /dev/null
@@ -0,0 +1,47 @@
+from soc.fu.bitmanip.input_record import CompBitManipOpSubset
+from soc.fu.pipe_data import FUBaseData, CommonPipeSpec
+from soc.fu.alu.pipe_data import ALUOutputData
+
+
+class BitManipInputData(FUBaseData):
+    regspec = [
+        ('INT', 'ra', '0:63'),      # RA
+        ('INT', 'rb', '0:63'),      # RB
+        ('INT', 'rc', '0:63'),      # RC
+        ('XER', 'xer_so', '32'),  # XER bit 32: SO
+    ]
+
+    def __init__(self, pspec):
+        super().__init__(pspec, False)
+
+
+# input to bitmanip final stage (common output)
+class BitManipOutputData(FUBaseData):
+    regspec = [
+        ('INT', 'o', '0:63'),        # RT
+        ('CR', 'cr_a', '0:3'),
+        ('XER', 'xer_so', '32'),    # bit0: so
+    ]
+
+    def __init__(self, pspec):
+        super().__init__(pspec, True)
+        # convenience
+        self.cr0 = self.cr_a
+
+
+# output from bitmanip final stage (common output) - note that XER.so
+# is *not* included (the only reason it's in the input is because of CR0)
+class BitManipOutputDataFinal(FUBaseData):
+    regspec = [('INT', 'o', '0:63'),        # RT
+               ('CR', 'cr_a', '0:3'),
+               ]
+
+    def __init__(self, pspec):
+        super().__init__(pspec, True)
+        # convenience
+        self.cr0 = self.cr_a
+
+
+class BitManipPipeSpec(CommonPipeSpec):
+    regspec = (BitManipInputData.regspec, BitManipOutputDataFinal.regspec)
+    opsubsetkls = CompBitManipOpSubset
diff --git a/src/soc/fu/bitmanip/pipeline.py b/src/soc/fu/bitmanip/pipeline.py
new file mode 100644 (file)
index 0000000..c080453
--- /dev/null
@@ -0,0 +1,34 @@
+from nmutil.singlepipe import ControlBase
+from nmutil.pipemodbase import PipeModBaseChain
+from soc.fu.bitmanip.input_stage import BitManipInputStage
+from soc.fu.bitmanip.main_stage import BitManipMainStage
+from soc.fu.bitmanip.output_stage import BitManipOutputStage
+
+
+class BitManipStages(PipeModBaseChain):
+    def get_chain(self):
+        inp = BitManipInputStage(self.pspec)
+        main = BitManipMainStage(self.pspec)
+        return [inp, main]
+
+
+class BitManipStageEnd(PipeModBaseChain):
+    def get_chain(self):
+        out = BitManipOutputStage(self.pspec)
+        return [out]
+
+
+class BitManipBasePipe(ControlBase):
+    def __init__(self, pspec):
+        ControlBase.__init__(self)
+        self.pspec = pspec
+        self.pipe1 = BitManipStages(pspec)
+        self.pipe2 = BitManipStageEnd(pspec)
+        self._eqs = self.connect([self.pipe1, self.pipe2])
+
+    def elaborate(self, platform):
+        m = ControlBase.elaborate(self, platform)
+        m.submodules.pipe1 = self.pipe1
+        m.submodules.pipe2 = self.pipe2
+        m.d.comb += self._eqs
+        return m
diff --git a/src/soc/fu/bitmanip/test/__init__.py b/src/soc/fu/bitmanip/test/__init__.py
new file mode 100644 (file)
index 0000000..e69de29
diff --git a/src/soc/fu/bitmanip/test/test_pipe_caller.py b/src/soc/fu/bitmanip/test/test_pipe_caller.py
new file mode 100644 (file)
index 0000000..a669020
--- /dev/null
@@ -0,0 +1,191 @@
+import random
+from soc.fu.bitmanip.pipe_data import BitManipPipeSpec
+from soc.fu.bitmanip.pipeline import BitManipBasePipe
+from openpower.test.common import TestAccumulatorBase, TestCase, ALUHelpers
+from openpower.endian import bigendian
+from openpower.decoder.isa.all import ISA
+from openpower.simulator.program import Program
+from openpower.decoder.power_enums import (XER_bits, Function, CryIn)
+from openpower.decoder.power_decoder2 import (PowerDecode2)
+from openpower.decoder.power_decoder import (create_pdecode)
+import unittest
+from nmigen.cli import rtlil
+from nmigen import Module, Signal
+
+# NOTE: to use cxxsim, export NMIGEN_SIM_MODE=cxxsim from the shell
+# Also, check out the cxxsim nmigen branch, and latest yosys from git
+from nmutil.sim_tmp_alternative import Simulator, Settle
+
+from openpower.test.bitmanip.bitmanip_cases import BitManipTestCase
+
+
+def get_cu_inputs(dec2, sim):
+    """naming (res) must conform to BitManipFunctionUnit input regspec
+    """
+    res = {}
+
+    yield from ALUHelpers.get_sim_int_ra(res, sim, dec2)  # RA
+    yield from ALUHelpers.get_sim_int_rb(res, sim, dec2)  # RB
+    yield from ALUHelpers.get_sim_int_rc(res, sim, dec2)  # RC
+    yield from ALUHelpers.get_sim_xer_so(res, sim, dec2)  # XER.so
+
+    print("alu get_cu_inputs", res)
+
+    return res
+
+
+def set_alu_inputs(alu, dec2, sim):
+    inp = yield from get_cu_inputs(dec2, sim)
+    yield from ALUHelpers.set_int_ra(alu, dec2, inp)
+    yield from ALUHelpers.set_int_rb(alu, dec2, inp)
+    yield from ALUHelpers.set_int_rc(alu, dec2, inp)
+    yield from ALUHelpers.set_xer_so(alu, dec2, inp)
+
+
+# This test bench is a bit different than is usual. Initially when I
+# was writing it, I had all of the tests call a function to create a
+# device under test and simulator, initialize the dut, run the
+# simulation for ~2 cycles, and assert that the dut output what it
+# should have. However, this was really slow, since it needed to
+# create and tear down the dut and simulator for every test case.
+
+# Now, instead of doing that, every test case in BitManipTestCase puts some
+# data into the test_data list below, describing the instructions to
+# be tested and the initial state. Once all the tests have been run,
+# test_data gets passed to TestRunner which then sets up the DUT and
+# simulator once, runs all the data through it, and asserts that the
+# results match the pseudocode sim at every cycle.
+
+# By doing this, I've reduced the time it takes to run the test suite
+# massively. Before, it took around 1 minute on my computer, now it
+# takes around 3 seconds
+
+
+class BitManipIlangCase(TestAccumulatorBase):
+
+    def case_ilang(self):
+        pspec = BitManipPipeSpec(id_wid=2)
+        alu = BitManipBasePipe(pspec)
+        vl = rtlil.convert(alu, ports=alu.ports())
+        with open("bitmanip_pipeline.il", "w") as f:
+            f.write(vl)
+
+
+class TestRunner(unittest.TestCase):
+    def __init__(self, test_data):
+        super().__init__("run_all")
+        self.test_data = test_data
+
+    def execute(self, alu, instruction, pdecode2, test):
+        program = test.program
+        simulator = ISA(pdecode2, test.regs, test.sprs, test.cr,
+                        test.mem, test.msr,
+                        bigendian=bigendian)
+        gen = program.generate_instructions()
+        instructions = list(zip(gen, program.assembly.splitlines()))
+
+        index = simulator.pc.CIA.value//4
+        while index < len(instructions):
+            ins, code = instructions[index]
+
+            print("0x{:X}".format(ins & 0xffffffff))
+            print(code)
+
+            # ask the decoder to decode this binary data (endian'd)
+            yield pdecode2.dec.bigendian.eq(bigendian)  # little / big?
+            yield instruction.eq(ins)          # raw binary instr.
+            yield Settle()
+            fn_unit = yield pdecode2.e.do.fn_unit
+            self.assertEqual(fn_unit, Function.BITMANIP.value)
+            yield from set_alu_inputs(alu, pdecode2, simulator)
+
+            # set valid for one cycle, propagate through pipeline...
+            yield alu.p.i_valid.eq(1)
+            yield
+            yield alu.p.i_valid.eq(0)
+
+            opname = code.split(' ')[0]
+            yield from simulator.call(opname)
+            index = simulator.pc.CIA.value//4
+
+            vld = yield alu.n.o_valid
+            while not vld:
+                yield
+                vld = yield alu.n.o_valid
+            yield
+            alu_out = yield alu.n.o_data.o.data
+
+            yield from self.check_alu_outputs(alu, pdecode2,
+                                              simulator, code)
+            yield Settle()
+
+    def run_all(self):
+        m = Module()
+        comb = m.d.comb
+        instruction = Signal(32)
+
+        fn_name = "BITMANIP"
+        opkls = BitManipPipeSpec.opsubsetkls
+
+        m.submodules.pdecode2 = pdecode2 = PowerDecode2(None, opkls, fn_name)
+        pdecode = pdecode2.dec
+
+        pspec = BitManipPipeSpec(id_wid=2)
+        m.submodules.alu = alu = BitManipBasePipe(pspec)
+
+        comb += alu.p.i_data.ctx.op.eq_from_execute1(pdecode2.do)
+        comb += alu.n.i_ready.eq(1)
+        comb += pdecode2.dec.raw_opcode_in.eq(instruction)
+        sim = Simulator(m)
+
+        sim.add_clock(1e-6)
+
+        def process():
+            for test in self.test_data:
+                print(test.name)
+                program = test.program
+                with self.subTest(test.name):
+                    yield from self.execute(alu, instruction, pdecode2, test)
+
+        sim.add_sync_process(process)
+        with sim.write_vcd("bitmanip_simulator.vcd"):
+            sim.run()
+
+    def check_alu_outputs(self, alu, dec2, sim, code):
+
+        rc = yield dec2.e.do.rc.rc
+        cridx_ok = yield dec2.e.write_cr.ok
+        cridx = yield dec2.e.write_cr.data
+
+        print("check extra output", repr(code), cridx_ok, cridx)
+        if rc:
+            self.assertEqual(cridx, 0, code)
+
+        sim_o = {}
+        res = {}
+
+        yield from ALUHelpers.get_cr_a(res, alu, dec2)
+        yield from ALUHelpers.get_xer_ca(res, alu, dec2)
+        yield from ALUHelpers.get_int_o(res, alu, dec2)
+
+        print("hw outputs", res)
+
+        yield from ALUHelpers.get_sim_int_o(sim_o, sim, dec2)
+        yield from ALUHelpers.get_wr_sim_cr_a(sim_o, sim, dec2)
+        yield from ALUHelpers.get_wr_sim_xer_ca(sim_o, sim, dec2)
+
+        print("sim outputs", sim_o)
+
+        ALUHelpers.check_cr_a(self, res, sim_o, "CR%d %s" % (cridx, code))
+        ALUHelpers.check_xer_ca(self, res, sim_o, code)
+        ALUHelpers.check_int_o(self, res, sim_o, code)
+
+
+if __name__ == "__main__":
+    unittest.main(exit=False)
+    suite = unittest.TestSuite()
+    suite.addTest(TestRunner(BitManipTestCase().test_data))
+    suite.addTest(TestRunner(BitManipIlangCase().test_data))
+
+    runner = unittest.TextTestRunner()
+    runner.run(suite)