Merge pull request #1345 from stineje/main

add Python script used to analyze an ELF file to see instructions from ELF file

Author: rosethompson

bin/analyze_riscv_elf.py

@@ -0,0 +1,83 @@
+#!/usr/bin/env python3
+
+###########################################
+## analyze_riscv_elf.py
+##
+## Written: james.stine@okstate.edu
+## Created: April 7, 2025
+##
+## Purpose: Analyze a RISC-V ELF file and report which instructions are used,
+##          along with their frequency. The script disassembles the ELF using
+##          riscv64-unknown-elf-objdump, filters real instructions (excluding
+##          pseudo-ops and section headers), and displays a histogram of 
+##          instruction use.Simulate a L1 D$ or I$ for comparison with Wally
+##
+## A component of the CORE-V-WALLY configurable RISC-V project.
+## https://github.com/openhwgroup/cvw
+##
+## Copyright (C) 2021-25 Harvey Mudd College & Oklahoma State University
+##
+## SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
+##
+## Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file
+## except in compliance with the License, or, at your option, the Apache License version 2.0. You
+## may obtain a copy of the License at
+##
+## https:##solderpad.org/licenses/SHL-2.1/
+##
+## Unless required by applicable law or agreed to in writing, any work 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.
+################################################################################################
+
+import re
+import subprocess
+import sys
+from collections import Counter
+
+
+def disassemble_elf(elf_path):
+    try:
+        result = subprocess.run(
+            ["riscv64-unknown-elf-objdump", "-d", "-M", "no-aliases", elf_path],
+            capture_output=True,
+            text=True,
+            check=True
+        )
+        return result.stdout
+    except subprocess.CalledProcessError as e:
+        print(f"Error running objdump: {e.stderr}")
+        sys.exit(1)
+
+def extract_instructions(disassembly):
+    instructions = []
+    for line in disassembly.splitlines():
+        # Match instruction lines only: address: machine-code instruction [operands...]
+        match = re.match(r'^\s*[0-9a-f]+:\s+([0-9a-f]{8}|\s{8})\s+(\S+)', line)
+        if match:
+            instr = match.group(2)
+            instructions.append(instr)
+    return instructions
+
+def main():
+    if len(sys.argv) != 2:
+        print("Usage: python3 analyze_riscv_elf.py <file.elf>")
+        sys.exit(1)
+
+    elf_path = sys.argv[1]
+    disassembly = disassemble_elf(elf_path)
+    instructions = extract_instructions(disassembly)
+    counter = Counter(instructions)
+
+    print(f"\nInstruction usage in {elf_path}:\n")
+    if not counter:
+        print("No instructions found (did you use the correct target ELF file?)")
+    else:
+        for instr, count in counter.most_common():
+            count_str = f"{count:,}"  # Add comma as thousands separator
+            print(f"{instr:<10} {count_str}")
+
+if __name__ == "__main__":
+    main()
+