Bisect tool: Support print IR differences before and after bisection
This patch provides an option to print out IR differences before and
after pass/transformation level bisection.
This feature will help if user want to know what exactly does the bad
pass/transformation do to IR. It added two extra run with `-S` and
`-emit-llvm` to generate two IR files and use `diff` to compare them.
Note: `--ir_diff` option only works when pass_bisect is enabled.
BUG=chromium:878954
TEST=Ran test successfully with Android compiler wrapper.
Change-Id: Ia691dc6f23331a3e584eaf9e390edeeb990f3c87
Reviewed-on: https://chromium-review.googlesource.com/1220015
Commit-Ready: Zhizhou Yang <zhizhouy@google.com>
Tested-by: Zhizhou Yang <zhizhouy@google.com>
Reviewed-by: Caroline Tice <cmtice@chromium.org>
Reviewed-by: George Burgess <gbiv@chromium.org>
diff --git a/binary_search_tool/binary_search_state.py b/binary_search_tool/binary_search_state.py
index 0d5810c..f6c8ac7 100755
--- a/binary_search_tool/binary_search_state.py
+++ b/binary_search_tool/binary_search_state.py
@@ -14,6 +14,7 @@
import os
import pickle
import re
+import shutil
import sys
import tempfile
import time
@@ -70,7 +71,8 @@
def __init__(self, get_initial_items, switch_to_good, switch_to_bad,
test_setup_script, test_script, incremental, prune, pass_bisect,
- iterations, prune_iterations, verify, file_args, verbose):
+ ir_diff, iterations, prune_iterations, verify, file_args,
+ verbose):
"""BinarySearchState constructor, see Run for full args documentation."""
self.get_initial_items = get_initial_items
self.switch_to_good = switch_to_good
@@ -80,6 +82,7 @@
self.incremental = incremental
self.prune = prune
self.pass_bisect = pass_bisect
+ self.ir_diff = ir_diff
self.iterations = iterations
self.prune_iterations = prune_iterations
self.verify = verify
@@ -345,7 +348,7 @@
# If pass not found, return None
return None
- def BuildWithPassLimit(self, limit):
+ def BuildWithPassLimit(self, limit, generate_ir=False):
""" Rebuild bad item with pass level bisect limit
Run command line script generated by GenerateBadCommandScript(), with
@@ -357,6 +360,8 @@
pass_name: The debugcounter name of current limit pass.
"""
os.environ['LIMIT_FLAGS'] = '-mllvm -opt-bisect-limit=' + str(limit)
+ if generate_ir:
+ os.environ['LIMIT_FLAGS'] += ' -S -emit-llvm'
self.l.LogOutput(
'Limit flags: %s' % os.environ['LIMIT_FLAGS'],
print_to_console=self.verbose)
@@ -388,7 +393,11 @@
raise ValueError('[Error] While building, limit number does not match.')
return pass_num, self.CollectPassName(last_pass)
- def BuildWithTransformLimit(self, limit, pass_name=None, pass_limit=-1):
+ def BuildWithTransformLimit(self,
+ limit,
+ pass_name=None,
+ pass_limit=-1,
+ generate_ir=False):
""" Rebuild bad item with transformation level bisect limit
Run command line script generated by GenerateBadCommandScript(), with
@@ -407,6 +416,8 @@
' -mllvm -debug-counter=' + counter_name + \
'-count=' + str(limit) + \
' -mllvm -print-debug-counter'
+ if generate_ir:
+ os.environ['LIMIT_FLAGS'] += ' -S -emit-llvm'
self.l.LogOutput(
'Limit flags: %s' % os.environ['LIMIT_FLAGS'],
print_to_console=self.verbose)
@@ -414,6 +425,10 @@
_, _, msg = self.ce.RunCommandWOutput(command, print_to_console=False)
if 'Counters and values:' not in msg:
+ # Print pass level IR diff only if transformation level bisection does
+ # not work.
+ if self.ir_diff:
+ self.PrintIRDiff(pass_limit)
raise RuntimeError('No bisect info printed, DebugCounter may not be '
'supported by the compiler.')
@@ -439,6 +454,35 @@
# transformation count.
return 0
+ def PrintIRDiff(self, pass_index, pass_name=None, trans_index=-1):
+ bad_item = list(self.found_items)[0]
+ self.l.LogOutput(
+ 'IR difference before and after bad pass/transformation:',
+ print_to_console=self.verbose)
+
+ if trans_index == -1:
+ # Pass level IR diff
+ self.BuildWithPassLimit(pass_index, self.ir_diff)
+ good_ir = os.path.join(tempfile.tempdir, 'good.s')
+ shutil.copyfile(bad_item, good_ir)
+ pass_index += 1
+ self.BuildWithPassLimit(pass_index, self.ir_diff)
+ else:
+ # Transformation level IR diff
+ self.BuildWithTransformLimit(trans_index, pass_name, pass_index,
+ self.ir_diff)
+ good_ir = os.path.join(tempfile.tempdir, 'good.s')
+ shutil.copyfile(bad_item, good_ir)
+ trans_index += 1
+ self.BuildWithTransformLimit(trans_index, pass_name, pass_index,
+ self.ir_diff)
+
+ bad_ir = os.path.join(tempfile.tempdir, 'bad.s')
+ shutil.copyfile(bad_item, bad_ir)
+
+ command = 'diff %s %s' % (good_ir, bad_ir)
+ _, _, _ = self.ce.RunCommandWOutput(command, print_to_console=self.verbose)
+
def DoSearchBadPass(self):
"""Perform full search for bad pass of bad item."""
logger.GetLogger().LogOutput('Starting to bisect bad pass for bad item.')
@@ -471,6 +515,10 @@
trans_index, _ = self.DoBinarySearchBadPass(pass_index, pass_name)
if (trans_index == 0):
raise ValueError('Bisecting %s cannot reproduce good result.' % pass_name)
+
+ if self.ir_diff:
+ self.PrintIRDiff(pass_index, pass_name, trans_index)
+
logger.GetLogger().LogOutput(
'Bisection result for bad item %s:\n'
'Bad pass: %s at number %d\n'
@@ -699,6 +747,7 @@
'incremental': True,
'prune': False,
'pass_bisect': None,
+ 'ir_diff': False,
'iterations': 50,
'prune_iterations': 100,
'verify': True,
@@ -731,6 +780,7 @@
iterations=50,
prune=False,
pass_bisect=None,
+ ir_diff=False,
noincremental=False,
file_args=False,
verify=True,
@@ -760,6 +810,9 @@
pass/ transformation level bisection for the bad item. Requires that
'prune' be set to False, and needs support of `-opt-bisect-limit`(pass)
and `-print-debug-counter`(transformation) from LLVM.
+ ir_diff: Whether to print IR differences before and after bad
+ pass/transformation to verbose output. Defaults to False, only works when
+ pass_bisect is enabled.
noincremental: Whether to send "diffs" of good/bad items to switch scripts.
file_args: If True then arguments to switch scripts will be a file name
containing a newline separated list of the items to switch.
@@ -796,6 +849,10 @@
logger.GetLogger().LogOutput('"--pass_bisect" only works when '
'"--prune" is set to be False.')
return 1
+ if not pass_bisect and ir_diff:
+ logger.GetLogger().LogOutput('"--ir_diff" only works when '
+ '"--pass_bisect" is enabled.')
+
switch_to_good = _CanonicalizeScript(switch_to_good)
switch_to_bad = _CanonicalizeScript(switch_to_bad)
if test_setup_script:
@@ -810,8 +867,8 @@
bss = BinarySearchState(get_initial_items, switch_to_good, switch_to_bad,
test_setup_script, test_script, incremental, prune,
- pass_bisect, iterations, prune_iterations, verify,
- file_args, verbose)
+ pass_bisect, ir_diff, iterations, prune_iterations,
+ verify, file_args, verbose)
bss.DoVerify()
try:
diff --git a/binary_search_tool/common.py b/binary_search_tool/common.py
index 2850801..40660b5 100644
--- a/binary_search_tool/common.py
+++ b/binary_search_tool/common.py
@@ -203,6 +203,22 @@
'For now it only supports one single bad item, so to use it, '
'prune must be set to False.')
# No input (evals to False),
+ # --ir_diff (evals to True),
+ # --ir_diff=False,
+ # --ir_diff=True
+ args.AddArgument(
+ '-d',
+ '--ir_diff',
+ dest='ir_diff',
+ nargs='?',
+ const=True,
+ default=False,
+ type=StrToBool,
+ metavar='bool',
+ help='Whether to print IR differences before and after bad '
+ 'pass/transformation to verbose output. Defaults to False, '
+ 'only works when pass_bisect is enabled.')
+ # No input (evals to False),
# --noincremental (evals to True),
# --noincremental=False,
# --noincremental=True
