llvm/utils/bugpoint_gisel_reducer.py

   1 #!/usr/bin/env python
   2
   3 """Reduces GlobalISel failures.
   4
   5 This script is a utility to reduce tests that GlobalISel
   6 fails to compile.
   7
   8 It runs llc to get the error message using a regex and creates
   9 a custom command to check that specific error. Then, it runs bugpoint
  10 with the custom command.
  11
  12 """
  13 from __future__ import print_function
  14 import argparse
  15 import re
  16 import subprocess
  17 import sys
  18 import tempfile
  19 import os
  20
  21
  22 def log(msg):
  23     print(msg)
  24
  25
  26 def hr():
  27     log("-" * 50)
  28
  29
  30 def log_err(msg):
  31     print("ERROR: {}".format(msg), file=sys.stderr)
  32
  33
  34 def check_path(path):
  35     if not os.path.exists(path):
  36         log_err("{} does not exist.".format(path))
  37         raise
  38     return path
  39
  40
  41 def check_bin(build_dir, bin_name):
  42     file_name = "{}/bin/{}".format(build_dir, bin_name)
  43     return check_path(file_name)
  44
  45
  46 def run_llc(llc, irfile):
  47     pr = subprocess.Popen(
  48         [llc, "-o", "-", "-global-isel", "-pass-remarks-missed=gisel", irfile],
  49         stdout=subprocess.PIPE,
  50         stderr=subprocess.PIPE,
  51     )
  52     out, err = pr.communicate()
  53     res = pr.wait()
  54     if res == 0:
  55         return 0
  56     re_err = re.compile(
  57         r"LLVM ERROR: ([a-z\s]+):.*(G_INTRINSIC[_A-Z]* <intrinsic:@[a-zA-Z0-9\.]+>|G_[A-Z_]+)"
  58     )
  59     match = re_err.match(err)
  60     if not match:
  61         return 0
  62     else:
  63         return [match.group(1), match.group(2)]
  64
  65
  66 def run_bugpoint(bugpoint_bin, llc_bin, opt_bin, tmp, ir_file):
  67     compileCmd = "-compile-command={} -c {} {}".format(
  68         os.path.realpath(__file__), llc_bin, tmp
  69     )
  70     pr = subprocess.Popen(
  71         [
  72             bugpoint_bin,
  73             "-compile-custom",
  74             compileCmd,
  75             "-opt-command={}".format(opt_bin),
  76             ir_file,
  77         ]
  78     )
  79     res = pr.wait()
  80     if res != 0:
  81         log_err("Unable to reduce the test.")
  82         raise
  83
  84
  85 def run_bugpoint_check():
  86     path_to_llc = sys.argv[2]
  87     path_to_err = sys.argv[3]
  88     path_to_ir = sys.argv[4]
  89     with open(path_to_err, "r") as f:
  90         err = f.read()
  91         res = run_llc(path_to_llc, path_to_ir)
  92         if res == 0:
  93             return 0
  94         log("GlobalISed failed, {}: {}".format(res[0], res[1]))
  95         if res != err.split(";"):
  96             return 0
  97         else:
  98             return 1
  99
 100
 101 def main():
 102     # Check if this is called by bugpoint.
 103     if len(sys.argv) == 5 and sys.argv[1] == "-c":
 104         sys.exit(run_bugpoint_check())
 105
 106     # Parse arguments.
 107     parser = argparse.ArgumentParser(
 108         description=__doc__, formatter_class=argparse.RawTextHelpFormatter
 109     )
 110     parser.add_argument("BuildDir", help="Path to LLVM build directory")
 111     parser.add_argument("IRFile", help="Path to the input IR file")
 112     args = parser.parse_args()
 113
 114     # Check if the binaries exist.
 115     build_dir = check_path(args.BuildDir)
 116     ir_file = check_path(args.IRFile)
 117     llc_bin = check_bin(build_dir, "llc")
 118     opt_bin = check_bin(build_dir, "opt")
 119     bugpoint_bin = check_bin(build_dir, "bugpoint")
 120
 121     # Run llc to see if GlobalISel fails.
 122     log("Running llc...")
 123     res = run_llc(llc_bin, ir_file)
 124     if res == 0:
 125         log_err("Expected failure")
 126         raise
 127     hr()
 128     log("GlobalISel failed, {}: {}.".format(res[0], res[1]))
 129     tmp = tempfile.NamedTemporaryFile()
 130     log("Writing error to {} for bugpoint.".format(tmp.name))
 131     tmp.write(";".join(res))
 132     tmp.flush()
 133     hr()
 134
 135     # Run bugpoint.
 136     log("Running bugpoint...")
 137     run_bugpoint(bugpoint_bin, llc_bin, opt_bin, tmp.name, ir_file)
 138     hr()
 139     log("Done!")
 140     hr()
 141     output_file = "bugpoint-reduced-simplified.bc"
 142     log("Run llvm-dis to disassemble the output:")
 143     log("$ {}/bin/llvm-dis -o - {}".format(build_dir, output_file))
 144     log("Run llc to reproduce the problem:")
 145     log(
 146         "$ {}/bin/llc -o - -global-isel "
 147         "-pass-remarks-missed=gisel {}".format(build_dir, output_file)
 148     )
 149
 150
 151 if __name__ == "__main__":
 152     main()