Re-commit optimization bisect support (r267022) without new pass manager support.

The original commit was reverted because of a buildbot problem with LazyCallGraph::SCC handling (not related to the OptBisect handling).

Differential Revision: http://reviews.llvm.org/D19172

llvm-svn: 267231

1 files changed, 39 insertions, 0 deletions

diff --git a/llvm/test/Other/opt-bisect-helper.py b/llvm/test/Other/opt-bisect-helper.py
new file mode 100755
index 00000000000..d75950f11d8
--- /dev/null
+++ b/llvm/test/Other/opt-bisect-helper.py
@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+
+import os
+import sys
+import argparse
+import subprocess
+
+parser = argparse.ArgumentParser()
+
+parser.add_argument('--start', type=int, default=0)
+parser.add_argument('--end', type=int, default=(1 << 32))
+parser.add_argument('--optcmd', default=("opt"))
+parser.add_argument('--filecheckcmd', default=("FileCheck"))
+parser.add_argument('--prefix', default=("CHECK-BISECT"))
+parser.add_argument('--test', default=(""))
+
+args = parser.parse_args()
+
+start = args.start
+end = args.end
+
+opt_command = [args.optcmd, "-O2", "-opt-bisect-limit=%(count)s", "-S", args.test]
+check_command = [args.filecheckcmd, args.test, "--check-prefix=%s" % args.prefix]
+last = None
+while start != end and start != end-1:
+    count = int(round(start + (end - start)/2))
+    cmd = [x % {'count':count} for x in opt_command]
+    print("opt: " + str(cmd))
+    opt_result = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    filecheck_result = subprocess.Popen(check_command, stdin=opt_result.stdout)
+    opt_result.stdout.close()
+    opt_result.stderr.close()
+    filecheck_result.wait()
+    if filecheck_result.returncode == 0:
+        start = count
+    else:
+        end = count
+
+print("Last good count: %d" % start)