Commit Graph

6 Commits

Author SHA1 Message Date
Benjamin Kramer
1e6240a85d InstCombine: Teach icmp merging about the equivalence of bit tests and UGE/ULT with a power of 2.
This happens in bitfield code. While there reorganize the existing code
a bit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201176 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-11 21:09:03 +00:00
Stephen Lin
39f4e8d9cc 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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186268 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 01:42:54 +00:00
Benjamin Kramer
47a8607721 InstCombine: Teach foldLogOpOfMaskedICmpsHelper that sign bit tests are bit tests.
This subsumes several other transforms while enabling us to catch more cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147777 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-09 17:23:27 +00:00
Benjamin Kramer
d4242d8ab1 Tweak my last commit to be less conservative about uses.
We still save an instruction when just the "and" part is replaced.
Also change the code to match comments more closely.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147753 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-08 21:12:51 +00:00
Benjamin Kramer
dfb806f6ba InstCombine: If we have a bit test and a sign test anded/ored together, merge the sign bit into the bit test.
This is common in bit field code, e.g. checking if the first or the last bit of a bit field is set.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147749 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-08 18:32:24 +00:00
Benjamin Kramer
9822b869fc InstCombine: Add a few missing combines for ANDs and ORs of sign bit tests.
On x86 we now compile "if (a < 0 && b < 0)" into
	testl	%edi, %esi
	js	IF.THEN

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128496 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-29 22:06:41 +00:00