way_idx may not correct

[linuxbest]

With the default setting, the NUM_WAYS of icache is 1, so the way_idx should always be 0, but it will change to 1. This behavior is acceptable with Verilator but fails with other simulators.

Verilator:

VCS:

                 597: -bank0 tag-fill: addr=0x80000000, way=1, blk_addr=0, tag_id=0x20000.              <<<< way=1, ?
                 599: -bank0 mshr-dequeue: addr=0x80000000, id=0 (#0)
                 599: -bank0 mshr-pop: addr=0x80000000, tag=0x0, req_idx=0 (#0)
                 599: -bank0 data-fill: addr=0x80000000, way=1, blk_addr=0, data=0x2800bfff002930062900b1203031300000317fc1022f313c000ef0002800b001002930ec000ef0002800bfff002930062900b1343031300000317fc1022f3
                 601: -bank0 mshr-table
                 601: -bank0 tag-hit: addr=0x80000000, way=0, blk_addr=0, tag_id=0x20000 (#0)
                 603: -bank0 core-rd-rsp: addr=0x80000000, tag=0x0, req_idx=0, data=0xfc1022f3 (#0)
                 603: -bank0 data-read: addr=0x80000000, way=1, blk_addr=0, data=0xfc1022f3 (#0). <<<<<< way=1, it should be 0 when NUM_WAY=1
                 605: I$0 rsp: wid=0, PC=0x80000000, tmask=0001, instr=0xfc1022f3 (#0)

[linuxbest]

The onehot encoder looks wrong to me.

When N==1, the encoder output data should be always 0.

Thanks.

diff --git a/hw/rtl/libs/VX_onehot_encoder.sv b/hw/rtl/libs/VX_onehot_encoder.sv
index 92c7d1ea..adaa4183 100644
--- a/hw/rtl/libs/VX_onehot_encoder.sv
+++ b/hw/rtl/libs/VX_onehot_encoder.sv
@@ -29,7 +29,7 @@ module VX_onehot_encoder #(
 ); 
     if (N == 1) begin

-        assign data_out  = data_in;
+        assign data_out  = 0;
         assign valid_out = data_in;

     end else if (N == 2) begin

[tinebp]

Good catch! We would love to have you join our development effort, we are looking for hardware developers who can contribute to this open-source effort. Please join our discussion mailing list, we host monthly dev meetings https://vortex.cc.gatech.edu/community

[tinebp]

https://github.com/vortexgpgpu/vortex/commit/3075c1737bf86dfb4a1375ebef84a46492990050