Commit Graph

13 Commits

Author SHA1 Message Date
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
Cameron McInally 89f9af5487 [SCCP] Add UnaryOperator visitor to SCCP for unary FNeg
Differential Revision: https://reviews.llvm.org/D62819

llvm-svn: 362449
2019-06-03 21:53:56 +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
Davide Italiano 54c683f9e7 [SCCP] Make sure SCCP and ConstantFolding agree on undef >> a.
Currently SCCP folds the value to -1, while ConstantProp folds to
0. This changes SCCP to do what ConstantFolding does.

llvm-svn: 289147
2016-12-08 22:28:53 +00:00
David Majnemer d1fbf48566 [SCCP] Don't assume all Constants are ConstantInt
This fixes PR28269.

llvm-svn: 273521
2016-06-23 00:14:29 +00:00
Stephen Lin c1c7a1309c Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.
This update was done with the following bash script:

  find test/Transforms -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc" $NAME; then
      TEMP=`mktemp -t temp`
      cp $NAME $TEMP
      sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
      while read FUNC; do
        sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP
      done
      mv $TEMP $NAME
    fi
  done

llvm-svn: 186268
2013-07-14 01:42:54 +00:00
Dmitri Gribenko d7beca87f5 Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID
This is done to avoid odd test failures, like the one fixed in r171243.

My previous regex was not good enough to find these.

llvm-svn: 171343
2013-01-01 13:57:25 +00:00
Eli Friedman d7749be2d7 Silly mistake from r137777; restore significant isStructTy() checks. While here, be a bit more defensive
with unknown instructions.

Fixes PR10687.

llvm-svn: 137836
2011-08-17 18:10:43 +00:00
Eli Friedman 0793eb4c46 A bunch of misc fixes to SCCPSolver::ResolvedUndefsIn, including a fix to stop
making random bad assumptions about instructions which are not explicitly listed.  

Includes fix for rdar://9956541, a version of "undef ^ undef should return
0 because it's easier than arguing with users".

llvm-svn: 137777
2011-08-16 22:06:31 +00:00
Chris Lattner 87aa2243e2 fix PR6940: sitofp(undef) folds to 0.0, not undef.
llvm-svn: 102358
2010-04-26 18:21:23 +00:00
Chris Lattner c6c153be45 fix a SCCP miscompilation that could happen when a
forced constant is changed to a constant, we would end
up adding the instruction to the wrong worklist, 
preventing it from being properly revisited.  This fixes
rdar://7832370

llvm-svn: 100837
2010-04-09 01:14:31 +00:00