modules/zstd: Add RawLiteralsDecoder

Internal-tag: [#56124]
Signed-off-by: Ryszard Rozak <[email protected]>

Author: RRozak

xls/modules/zstd/BUILD

@@ -1008,3 +1008,76 @@ place_and_route(
     synthesized_rtl = ":rle_literals_dec_synth_asap7",
     target_die_utilization_percentage = "10",
 )
+
+xls_dslx_library(
+    name = "raw_literals_dec_dslx",
+    srcs = ["raw_literals_dec.x"],
+    deps = [
+        ":common_dslx",
+    ],
+)
+
+xls_dslx_test(
+    name = "raw_literals_dec_dslx_test",
+    library = ":raw_literals_dec_dslx",
+)
+
+xls_dslx_verilog(
+    name = "raw_literals_dec_verilog",
+    codegen_args = {
+        "module_name": "RawLiteralsDecoder",
+        "delay_model": "asap7",
+        "pipeline_stages": "1",
+        "reset": "rst",
+        "use_system_verilog": "false",
+    },
+    dslx_top = "RawLiteralsDecoder",
+    library = ":raw_literals_dec_dslx",
+    verilog_file = "raw_literals_dec.v",
+)
+
+xls_benchmark_ir(
+    name = "raw_literals_dec_opt_ir_benchmark",
+    src = ":raw_literals_dec_verilog.opt.ir",
+    benchmark_ir_args = {
+        "pipeline_stages": "10",
+        "delay_model": "asap7",
+    },
+)
+
+xls_benchmark_verilog(
+    name = "raw_literals_dec_verilog_benchmark",
+    verilog_target = "raw_literals_dec_verilog",
+)
+
+verilog_library(
+    name = "raw_literals_dec_lib",
+    srcs = [
+        ":raw_literals_dec.v",
+    ],
+)
+
+synthesize_rtl(
+    name = "raw_literals_dec_asap7",
+    standard_cells = "@org_theopenroadproject_asap7sc7p5t_28//:asap7-sc7p5t_rev28_rvt",
+    top_module = "RawLiteralsDecoder",
+    deps = [
+        ":raw_literals_dec_lib",
+    ],
+)
+
+benchmark_synth(
+    name = "raw_literals_dec_benchmark_synth",
+    synth_target = ":raw_literals_dec_asap7",
+)
+
+place_and_route(
+    name = "raw_literals_dec_place_and_route",
+    clock_period = "750",
+    core_padding_microns = 2,
+    min_pin_distance = "0.09",
+    placement_density = "0.30",
+    stop_after_step = "global_routing",
+    synthesized_rtl = ":raw_literals_dec_asap7",
+    target_die_utilization_percentage = "10",
+)

xls/modules/zstd/raw_literals_dec.x

@@ -0,0 +1,79 @@
+// Copyright 2024 The XLS Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// The proc should just pass incoming data as literals to LiteralsBuffer.
+// Packets of 0 length are not passed further and a warning is log instead.
+
+import xls.modules.zstd.common;
+
+type LiteralsData = common::LiteralsData;
+type LitData = common::LitData;
+type LitLength = common::LitLength;
+
+proc RawLiteralsDecoder {
+    dispatcher_r: chan<LiteralsData> in;
+    buffer_s: chan<LiteralsData> out;
+
+    config(dispatcher_r: chan<LiteralsData> in, buffer_s: chan<LiteralsData> out) {
+        (dispatcher_r, buffer_s)
+    }
+
+    init {  }
+
+    next(tok: token, state: ()) {
+        let (tok, resp) = recv(tok, dispatcher_r);
+        let do_send = if resp.length == LitLength:0 {
+            trace_fmt!("[WARNING] Packet of 0 length received by RawLiteralsDecoder");
+            false
+        } else {
+            true
+        };
+        let tok = send_if(tok, buffer_s, do_send, resp);
+    }
+}
+
+#[test_proc]
+proc RawLiteralsDecoderTest {
+    terminator: chan<bool> out;
+    dispatcher_s: chan<LiteralsData> out;
+    buffer_r: chan<LiteralsData> in;
+
+    config(terminator: chan<bool> out) {
+        let (dispatcher_s, dispatcher_r) = chan<LiteralsData>("dispatcher");
+        let (buffer_s, buffer_r) = chan<LiteralsData>("buffer");
+
+        spawn RawLiteralsDecoder(dispatcher_r, buffer_s);
+
+        (terminator, dispatcher_s, buffer_r)
+    }
+
+    init {  }
+
+    next(tok: token, state: ()) {
+        let data = LiteralsData { data: LitData:0x11_22_33_44_55_66, length: LitLength:6, last: true };
+        let tok = send(tok, dispatcher_s, data);
+        let (tok, resp) = recv(tok, buffer_r);
+        assert_eq(resp, data);
+
+        let empty_data = LiteralsData { data: LitData:0, length: LitLength:0, last: true };
+        let tok = send(tok, dispatcher_s, empty_data);
+
+        // Resend the first packet to verify that the empty packet is dropped correctly.
+        let tok = send(tok, dispatcher_s, data);
+        let (tok, resp) = recv(tok, buffer_r);
+        assert_eq(resp, data);
+
+        let tok = send(tok, terminator, true);
+    }
+}