Commit Graph

12 Commits

Author SHA1 Message Date
Florian Hahn f8045b250d Recommit "[SCCP] Remove forcedconstant, go to overdefined instead"
This includes a fix for cases where things get marked as overdefined in
ResolvedUndefsIn, but we later discover a constant. To avoid crashing,
we consistently bail out on overdefined values in the visitors. This is
similar to the previous behavior with forcedconstant.

This reverts the revert commit 02b72f564c.
2020-02-15 18:36:44 +01:00
Vedant Kumar 02b72f564c Revert "Recommit "[SCCP] Remove forcedconstant, go to overdefined instead""
This reverts commit bb310b3f73. This
breaks the stage2 ASan build, see:

https://bugs.llvm.org/show_bug.cgi?id=44898

rdar://59431448
2020-02-13 11:55:18 -08:00
Florian Hahn bb310b3f73 Recommit "[SCCP] Remove forcedconstant, go to overdefined instead"
This version includes a fix for a set of crashes caused by marking
values depending on a yet unknown & tracked call as overdefined.

In some cases, we would later discover that the call has a constant
result and try to mark a user of it as constant, although it was already
marked as overdefined. Most instruction handlers bail out early if the
instruction is already overdefined. But that is not necessary for
CastInsts for example. By skipping values that depend on skipped
calls, we resolve the crashes and also improve the precision in some
cases (see resolvedundefsin-tracked-fn.ll).

Note that we may not skip PHI nodes that may depend on a skipped call,
but they can be safely marked as overdefined, as we bail out early if
the PHI node is overdefined.

This reverts the revert commit
a74b31a3e9cd844c7ce2087978568e3f5ec8519.
2020-02-12 18:02:18 +00:00
Florian Hahn fa74b31a3e Revert "[SCCP] Remove forcedconstant, go to overdefined instead"
This causes a crash for the reproducer below

 enum { a };
 enum b { c, d };
 e;
 static _Bool g(struct f *h, enum b i) {
   i &&j();
   return a;
 }
 static k(char h, enum b i) {
   _Bool l = g(e, i);
   l;
 }
 m(h) {
   k(h, c);
   g(h, d);
 }

This reverts commit aadb635e04.
2020-02-12 09:41:19 +00:00
Florian Hahn aadb635e04 [SCCP] Remove forcedconstant, go to overdefined instead
This patch removes forcedconstant to simplify things for the
move to ValueLattice, which includes constant ranges, but no
forced constants.

This patch removes forcedconstant and changes ResolvedUndefsIn
to mark instructions with unknown operands as overdefined. This
means we do not do simplifications based on undef directly in SCCP
any longer, but this seems to hardly come up in practice (see stats
below), presumably because InstCombine & others take care
of most of the relevant folds already.

It is still beneficial to keep ResolvedUndefIn, as it allows us delaying
going to overdefined until we propagated all known information.

I also built MultiSource, SPEC2000 and SPEC2006 and compared
sccp.IPNumInstRemoved and sccp.NumInstRemoved. It looks like the impact
is quite low:

Tests: 244
Same hash: 238 (filtered out)
Remaining: 6
Metric: sccp.IPNumInstRemoved

Program                                        base     patch    diff
 test-suite...arks/VersaBench/dbms/dbms.test     4.00    3.00  -25.0%
 test-suite...TimberWolfMC/timberwolfmc.test    38.00   34.00  -10.5%
 test-suite...006/453.povray/453.povray.test   158.00  155.00  -1.9%
 test-suite.../CINT2000/176.gcc/176.gcc.test   668.00  668.00   0.0%
 test-suite.../CINT2006/403.gcc/403.gcc.test   1209.00 1209.00  0.0%
 test-suite...arks/mafft/pairlocalalign.test    76.00   76.00   0.0%

Tests: 244
Same hash: 238 (filtered out)
Remaining: 6
Metric: sccp.NumInstRemoved

Program                                        base    patch     diff
 test-suite...arks/mafft/pairlocalalign.test   185.00  175.00  -5.4%
 test-suite.../CINT2006/403.gcc/403.gcc.test   2059.00 2056.00 -0.1%
 test-suite.../CINT2000/176.gcc/176.gcc.test   2358.00 2357.00 -0.0%
 test-suite...006/453.povray/453.povray.test   317.00  317.00   0.0%
 test-suite...TimberWolfMC/timberwolfmc.test    12.00   12.00   0.0%

Reviewers: davide, efriedma, mssimpso

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D61314
2020-02-11 15:24:15 +00:00
Eric Christopher cee313d288 Revert "Temporarily Revert "Add basic loop fusion pass.""
The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552
2019-04-17 04:52:47 +00:00
Eric Christopher a863435128 Temporarily Revert "Add basic loop fusion pass."
As it's causing some bot failures (and per request from kbarton).

This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.

llvm-svn: 358546
2019-04-17 02:12:23 +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
Dan Gohman 0f3ef7be50 Eliminate more redundant llvm-as calls.
llvm-svn: 81540
2009-09-11 18:17:12 +00:00
Dan Gohman 72a13d2476 Use opt -S instead of piping bitcode output through llvm-dis.
llvm-svn: 81257
2009-09-08 22:34:10 +00:00
Reid Spencer a551c041f9 For PR1319:
Upgrade to use new Tcl exec based test harness. This exposes 3 bugs that
were previously not being reported:
test/Transforms/GlobalDCE/2002-08-17-FunctionDGE.ll
test/Transforms/GlobalOpt/memset.ll
test/Transforms/IndVarsSimplify/exit_value_tests.llx

llvm-svn: 36065
2007-04-15 09:21:47 +00:00
Reid Spencer 9f9fe70b11 Add the SCCP regression tests for APInt expressions. These test cases
turned up some regressions that have since been fixed. We don't want to
loose the regression tests.

Test cases by Guoling Han.

llvm-svn: 35974
2007-04-13 22:33:10 +00:00