xref: /llvm-project/llvm/utils/bugpoint_gisel_reducer.py (revision b71edfaa4ec3c998aadb35255ce2f60bba2940b0)
1#!/usr/bin/env python
2
3"""Reduces GlobalISel failures.
4
5This script is a utility to reduce tests that GlobalISel
6fails to compile.
7
8It runs llc to get the error message using a regex and creates
9a custom command to check that specific error. Then, it runs bugpoint
10with the custom command.
11
12"""
13from __future__ import print_function
14import argparse
15import re
16import subprocess
17import sys
18import tempfile
19import os
20
21
22def log(msg):
23    print(msg)
24
25
26def hr():
27    log("-" * 50)
28
29
30def log_err(msg):
31    print("ERROR: {}".format(msg), file=sys.stderr)
32
33
34def 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
41def check_bin(build_dir, bin_name):
42    file_name = "{}/bin/{}".format(build_dir, bin_name)
43    return check_path(file_name)
44
45
46def 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
66def 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
85def 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
101def 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
151if __name__ == "__main__":
152    main()
153