Commit Graph

7 Commits

Author SHA1 Message Date
Philip Reames 2e5bcbe8d5 [RewriteStatepointsForGC] Fix another order of iteration bug
It turns out the naming of inserted phis and selects is sensative to the order in which two sets are iterated.  We need to nail this down to avoid non-deterministic output and possible test failures.  

The modified test is the one I first noticed something odd in.  The change is making it more strict to report the error.  With the test change, but without the code change, the test fails roughly 1 in 5.  With the code change, I've run ~30 runs without error.

Long term, the right fix here is to adjust the naming scheme.  I'm checking in this hack to avoid any possible non-determinism in the tests over the weekend.  HJust because I only noticed one case doesn't mean it's actually the only case.  I hope to get to the right change Monday.

std->llvm data structure changes bugfix change #3

llvm-svn: 230835
2015-02-28 01:52:09 +00:00
Philip Reames a5aeaf4b4f [RewriteStatepointsForGC] Add tests for the base pointer identification algorithm
These tests cover the 'base object' identification and rewritting portion of RewriteStatepointsForGC.  These aren't completely exhaustive, but they've proven to be reasonable effective over time at finding regressions.

In the process of porting these tests over, I found my first "cleanup per llvm code style standards" bug.  We were relying on the order of iteration when testing the base pointers found for a derived pointer.  When we switched from std::set to DenseSet, this stopped being a safe assumption.  I'm suspecting I'm going to find more of those.  In particular, I'm now really wondering about the main iteration loop for this algorithm.  I need to go take a closer look at the assumptions there.

I'm not really happy with the fact these are testing what is essentially debug output (i.e. enabled via command line flags).  Suggestions for how to structure this better are very welcome.  

llvm-svn: 230818
2015-02-28 00:20:48 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
David Blaikie 79e6c74981 [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

llvm-svn: 230786
2015-02-27 19:29:02 +00:00
Philip Reames 2ef029c7ae Bugfix for 229954
Before calling Function::getGC to test for enablement, we need to make sure there's actually a GC at all via Function::hasGC.  Otherwise, we'd crash on functions without a GC.  Thankfully, this only mattered if you manually scheduled the pass, but still, oops. :(

llvm-svn: 230040
2015-02-20 18:56:14 +00:00
Philip Reames 6faacf4772 Adjust enablement of RewriteStatepointsForGC
When back merging the changes in 229945 I noticed that I forgot to mark the test cases with the appropriate GC.  We want the rewriting to be off by default (even when manually added to the pass order), not on-by default.  To keep the current test working, mark them as using the statepoint-example GC and whitelist that GC.  

Longer term, we need a better selection mechanism here for both actual usage and testing.  As I migrate more tests to the in tree version of this pass, I will probably need to update the enable/disable logic as well. 

llvm-svn: 229954
2015-02-20 02:34:49 +00:00
Philip Reames d16a9b1fdc Add a pass for constructing gc.statepoint sequences w/explicit relocations
This patch consists of a single pass whose only purpose is to visit previous inserted gc.statepoints which do not have gc.relocates inserted yet, and insert them. This can be used either immediately after IR generation to perform 'early safepoint insertion' or late in the pass order to perform 'late insertion'.

This patch is setting the stage for work to continue in tree.  In particular, there are known naming and style violations in the current patch.  I'll try to get those resolved over the next week or so.  As I touch each area to make style changes, I need to make sure we have adequate testing in place.  As part of the cleanup, I will be cleaning up a collection of test cases we have out of tree and submitting them upstream. The tests included in this change are very basic and mostly to provide examples of usage.

The pass has several main subproblems it needs to address:
- First, it has identify any live pointers. In the current code, the use of address spaces to distinguish pointers to GC managed objects is hard coded, but this will become parametrizable in the near future.  Note that the current change doesn't actually contain a useful liveness analysis.  It was seperated into a followup change as the code wasn't ready to be shared.  Instead, the current implementation just considers any dominating def of appropriate pointer type to be live.
- Second, it has to identify base pointers for each live pointer. This is a fairly straight forward data flow algorithm. 
- Third, the information in the previous steps is used to actually introduce rewrites. Rather than trying to do this by hand, we simply re-purpose the code behind Mem2Reg to do this for us.

llvm-svn: 229945
2015-02-20 01:06:44 +00:00