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([llc,
  48                            '-o',
  49                            '-',
  50                            '-global-isel',
  51                            '-pass-remarks-missed=gisel',
  52                            irfile],
  53                           stdout=subprocess.PIPE,
  54                           stderr=subprocess.PIPE)
  55     out, err = pr.communicate()
  56     res = pr.wait()
  57     if res == 0:
  58         return 0
  59     re_err = re.compile(
  60         r'LLVM ERROR: ([a-z\s]+):.*(G_INTRINSIC[_A-Z]* <intrinsic:@[a-zA-Z0-9\.]+>|G_[A-Z_]+)')
  61     match = re_err.match(err)
  62     if not match:
  63         return 0
  64     else:
  65         return [match.group(1), match.group(2)]
  66
  67
  68 def run_bugpoint(bugpoint_bin, llc_bin, opt_bin, tmp, ir_file):
  69     compileCmd = '-compile-command={} -c {} {}'.format(
  70         os.path.realpath(__file__), llc_bin, tmp)
  71     pr = subprocess.Popen([bugpoint_bin,
  72                            '-compile-custom',
  73                            compileCmd,
  74                            '-opt-command={}'.format(opt_bin),
  75                            ir_file])
  76     res = pr.wait()
  77     if res != 0:
  78         log_err("Unable to reduce the test.")
  79         raise
  80
  81
  82 def run_bugpoint_check():
  83     path_to_llc = sys.argv[2]
  84     path_to_err = sys.argv[3]
  85     path_to_ir = sys.argv[4]
  86     with open(path_to_err, 'r') as f:
  87         err = f.read()
  88         res = run_llc(path_to_llc, path_to_ir)
  89         if res == 0:
  90             return 0
  91         log('GlobalISed failed, {}: {}'.format(res[0], res[1]))
  92         if res != err.split(';'):
  93             return 0
  94         else:
  95             return 1
  96
  97
  98 def main():
  99     # Check if this is called by bugpoint.
 100     if len(sys.argv) == 5 and sys.argv[1] == '-c':
 101         sys.exit(run_bugpoint_check())
 102
 103     # Parse arguments.
 104     parser = argparse.ArgumentParser(
 105         description=__doc__, formatter_class=argparse.RawTextHelpFormatter)
 106     parser.add_argument('BuildDir', help="Path to LLVM build directory")
 107     parser.add_argument('IRFile', help="Path to the input IR file")
 108     args = parser.parse_args()
 109
 110     # Check if the binaries exist.
 111     build_dir = check_path(args.BuildDir)
 112     ir_file = check_path(args.IRFile)
 113     llc_bin = check_bin(build_dir, 'llc')
 114     opt_bin = check_bin(build_dir, 'opt')
 115     bugpoint_bin = check_bin(build_dir, 'bugpoint')
 116
 117     # Run llc to see if GlobalISel fails.
 118     log('Running llc...')
 119     res = run_llc(llc_bin, ir_file)
 120     if res == 0:
 121         log_err("Expected failure")
 122         raise
 123     hr()
 124     log('GlobalISel failed, {}: {}.'.format(res[0], res[1]))
 125     tmp = tempfile.NamedTemporaryFile()
 126     log('Writing error to {} for bugpoint.'.format(tmp.name))
 127     tmp.write(';'.join(res))
 128     tmp.flush()
 129     hr()
 130
 131     # Run bugpoint.
 132     log('Running bugpoint...')
 133     run_bugpoint(bugpoint_bin, llc_bin, opt_bin, tmp.name, ir_file)
 134     hr()
 135     log('Done!')
 136     hr()
 137     output_file = 'bugpoint-reduced-simplified.bc'
 138     log('Run llvm-dis to disassemble the output:')
 139     log('$ {}/bin/llvm-dis -o - {}'.format(build_dir, output_file))
 140     log('Run llc to reproduce the problem:')
 141     log('$ {}/bin/llc -o - -global-isel '
 142         '-pass-remarks-missed=gisel {}'.format(build_dir, output_file))
 143
 144
 145 if __name__ == '__main__':
 146     main()