From: Michael Nolan <mtnolan2640@gmail.com>
Date: Tue, 19 May 2020 15:58:19 +0000 (-0400)
Subject: Actually implement cntlzd
X-Git-Tag: div_pipeline~1077
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=91b19f6f7b258ddfd7d77b8ed8447e4737265c5e;p=soc.git

Actually implement cntlzd
---

diff --git a/src/soc/fu/logical/main_stage.py b/src/soc/fu/logical/main_stage.py
index bb6efaf2..96ace02e 100644
--- a/src/soc/fu/logical/main_stage.py
+++ b/src/soc/fu/logical/main_stage.py
@@ -7,6 +7,7 @@
 
 from nmigen import (Module, Signal, Cat, Repl, Mux, Const, Array)
 from nmutil.pipemodbase import PipeModBase
+from nmutil.clz import CLZ
 from soc.fu.logical.pipe_data import ALUInputData
 from soc.fu.alu.pipe_data import ALUOutputData
 from ieee754.part.partsig import PartitionedSignal
@@ -110,11 +111,11 @@ class LogicalMainStage(PipeModBase):
             ###### cntlz #######
             with m.Case(InternalOp.OP_CNTZ):
                 XO = self.fields.FormX.XO[0:-1]
-                m.submodules.countz = countz = ZeroCounter()
-                comb += countz.rs_i.eq(a)
-                comb += countz.is_32bit_i.eq(op.is_32bit)
-                comb += countz.count_right_i.eq(XO[-1])
-                comb += o.eq(countz.result_o)
+                count_right = Signal(reset_less=True)
+                comb += count_right.eq(XO[-1])
+                m.submodules.clz = clz = CLZ(64)
+                comb += clz.sig_in.eq(Mux(count_right, a[::-1], a))
+                comb += o.eq(clz.lz)
 
             ###### bpermd #######
             # TODO with m.Case(InternalOp.OP_BPERM): - not in microwatt
diff --git a/src/soc/fu/logical/test/test_pipe_caller.py b/src/soc/fu/logical/test/test_pipe_caller.py
index d414997e..f3760c7c 100644
--- a/src/soc/fu/logical/test/test_pipe_caller.py
+++ b/src/soc/fu/logical/test/test_pipe_caller.py
@@ -123,10 +123,9 @@ class LogicalTestCase(FHDLTestCase):
             initial_regs[1] = random.randint(0, (1<<64)-1)
             self.run_tst_program(Program(lst), initial_regs)
 
-    @unittest.skip("broken")
     def test_cntz(self):
         insns = ["cntlzd", "cnttzd"]
-        for i in range(10):
+        for i in range(100):
             choice = random.choice(insns)
             lst = [f"{choice} 3, 1"]
             print(lst)