Add performance counter utils for verilator sims

dv/verilator/pcount/cpp/ibex_pcounts.cc

@@ -0,0 +1,57 @@
+// Copyright lowRISC contributors.
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+
+#include <numeric>
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "ibex_pcounts.h"
+
+// see mhpmcounter_incr signals in rtl/ibex_cs_registers.sv for details
+
+const std::vector<std::string> ibex_counter_names = {
+    "Cycles",
+    "NONE",
+    "Instructions Retired",
+    "LSU Busy",
+    "Fetch Wait",
+    "Loads",
+    "Stores",
+    "Jumps",
+    "Conditional Branches",
+    "Taken Conditional Branches",
+    "Compressed Instructions"};
+
+std::string ibex_pcount_string(uint64_t pcounts[], bool csv) {
+  char seperator = csv ? ',' : ':';
+  std::string::size_type longest_name_length;
+
+  if (!csv) {
+    longest_name_length = 0;
+    for (const std::string &counter_name : ibex_counter_names) {
+      longest_name_length = std::max(longest_name_length, counter_name.length());
+    }
+
+    // Add 1 to always get at least once space after the seperator
+    longest_name_length++;
+  }
+
+  std::stringstream pcount_ss;
+
+  for (int i = 0; i < ibex_counter_names.size(); ++i) {
+    pcount_ss << ibex_counter_names[i] << seperator;
+
+    if (!csv) {
+      int padding = longest_name_length - ibex_counter_names[i].length();
+
+      for (int j = 0; j < padding; ++j)
+        pcount_ss << ' ';
+    }
+
+    pcount_ss << pcounts[i] << std::endl;
+  }
+
+  return pcount_ss.str();
+}

dv/verilator/pcount/cpp/ibex_pcounts.h

@@ -0,0 +1,44 @@
+// Copyright lowRISC contributors.
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+
+#ifndef IBEX_PCOUNTS_H_
+#define IBEX_PCOUNTS_H_
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+extern const std::vector<std::string> ibex_counter_names;
+
+/**
+ * Returns a formatted string of performance counter values
+ *
+ * In Ibex the performance counters are held in the mhpmcounter flops in
+ * ibex_cs_registers. In a verilator simulation the signal type of the
+ * mhpmcounter array should be compatible with the type of pcounts here and so
+ * can be passed in directly to this function.
+ *
+ * There are two options for string formatting, csv or pretty-print. Both
+ * produce one counter name and value per line. csv just seperates them with a
+ * comma and no further formatting. pretty-print uses a colon and aligns the
+ * values.
+ *
+ * csv (csv == true):
+ * countername1, 1234
+ * longercountername1, 43980
+ * ...
+ *
+ * pretty-print (csv == false):
+ * countername1:       1234
+ * longercountername1: 43980
+ * ...
+ *
+ * @param pcounts Array of performance counter values, must be of length
+ *                ibex_pcount_num
+ * @param csv Choose csv or pretty-print formatting
+ * @return String of formatted performance counter values, newline at end
+ */
+std::string ibex_pcount_string(uint64_t pcounts[], bool csv);
+
+#endif  // IBEX_PCOUNTS_H_

dv/verilator/pcount/ibex_pcounts.core

@@ -0,0 +1,19 @@
+CAPI=2:
+# Copyright lowRISC contributors.
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+
+name: "lowrisc:dv_verilator:ibex_pcounts"
+description: "Ibex performance counter utils"
+filesets:
+  files_cpp:
+    files:
+      - cpp/ibex_pcounts.cc
+      - cpp/ibex_pcounts.h: { is_include_file: true }
+    file_type: cppSource
+
+targets:
+  default:
+    filesets:
+      - files_cpp
+

rtl/ibex_cs_registers.sv

@@ -780,6 +780,10 @@ module ibex_cs_registers #(
   // event selection (hardwired) & control
   always_comb begin : gen_mhpmcounter_incr
 
+    // When adding or altering performance counter meanings and default
+    // mappings please update dv/verilator/pcount/cpp/ibex_pcounts.cc
+    // appropriately.
+    //
     // active counters
     mhpmcounter_incr[0]  = 1'b1;                   // mcycle
     mhpmcounter_incr[1]  = 1'b0;                   // reserved