From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Sat, 16 May 2020 01:10:30 +0000 (+0100)
Subject: add comment in branch test_pipe_caller.py about decoding needed of op
X-Git-Tag: div_pipeline~1148
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ea5eb08d03b3baae0bb1acbe47dc67f5be7dbd64;p=soc.git

add comment in branch test_pipe_caller.py about decoding needed of op
to set spr1/2/3 correctly
---

diff --git a/src/soc/branch/test/test_pipe_caller.py b/src/soc/branch/test/test_pipe_caller.py
index 1553514b..335b63ed 100644
--- a/src/soc/branch/test/test_pipe_caller.py
+++ b/src/soc/branch/test/test_pipe_caller.py
@@ -97,7 +97,6 @@ class BranchTestCase(FHDLTestCase):
             self.run_tst_program(Program(lst),
                                  initial_sprs=initial_sprs,
                                  initial_cr=cr)
-        
 
     def test_ilang(self):
         rec = CompBROpSubset()
@@ -159,12 +158,18 @@ class TestRunner(FHDLTestCase):
                     yield instruction.eq(ins)          # raw binary instr.
                     yield branch.p.data_i.cia.eq(simulator.pc.CIA.value)
                     yield branch.p.data_i.cr.eq(simulator.cr.get_range().value)
+                    # note, here, the op will need further decoding in order
+                    # to set the correct SPRs on SPR1/2/3.  op_bc* require
+                    # spr2 to be set to CTR, op_bctar require spr1 to be
+                    # set to TAR, op_bclr* require spr1 to be set to LR.
+                    # if op_sc*, op_rf* and op_hrfid are to be added here
+                    # then additional op-decoding is required, accordingly
                     yield branch.p.data_i.spr2.eq(simulator.spr['CTR'].value)
                     print(f"cr0: {simulator.crl[0].get_range()}")
                     yield Settle()
                     fn_unit = yield pdecode2.e.fn_unit
                     self.assertEqual(fn_unit, Function.BRANCH.value, code)
-                    yield 
+                    yield
                     yield
                     opname = code.split(' ')[0]
                     prev_nia = simulator.pc.NIA.value