Commit Graph

19 Commits

Author SHA1 Message Date
Sanjay Patel 5f8451afad [InstCombine] use m_APInt to allow ashr folds for vectors with splat constants
llvm-svn: 292064
2017-01-15 16:38:19 +00:00
Sanjay Patel 12a2af447b [InstCombine] add test to show missing vector optimization; NFC
llvm-svn: 287982
2016-11-26 16:13:23 +00:00
Sanjay Patel db400baa80 [InstCombine] add tests to show missing vector folds
llvm-svn: 281219
2016-09-12 15:51:42 +00:00
Sanjay Patel 58109abe91 [InstCombine] use m_APInt to allow icmp ult X, C folds for splat constant vectors
llvm-svn: 281107
2016-09-09 21:59:37 +00:00
Sanjay Patel 0d70831d73 [InstCombine] allow icmp (shr exact X, C2), C fold for splat constant vectors
The enhancement to foldICmpDivConstant ( http://llvm.org/viewvc/llvm-project?view=revision&revision=280299 )
allows us to remove the ConstantInt check; no other changes needed.

llvm-svn: 280300
2016-08-31 22:18:43 +00:00
Sanjay Patel 541aef4661 [InstCombine] allow icmp (div X, Y), C folds for splat constant vectors
Converting all of the overflow ops to APInt looked risky, so I've left that as a TODO.

llvm-svn: 280299
2016-08-31 21:57:21 +00:00
Sanjay Patel 7d98be81cc [InstCombine] add tests for vector icmp folds
llvm-svn: 278726
2016-08-15 19:58:21 +00:00
Sanjay Patel d391b0d69e [InstCombine] add tests for missing vector icmp folds
llvm-svn: 278704
2016-08-15 18:26:56 +00:00
Sanjay Patel c6ada53be5 [InstCombine] use m_APInt for div --> ashr fold
The APInt matcher works with splat vectors, so we get this fold for vectors too.

llvm-svn: 273897
2016-06-27 17:25:57 +00:00
Sanjay Patel 70aa568c4e regenerate checks
llvm-svn: 271903
2016-06-06 15:55:00 +00:00
Chad Rosier 131a42ccdf [InstCombine] Fold icmp eq/ne (udiv i32 A, B), 0 -> icmp ugt/ule B, A.
Differential Revision: http://reviews.llvm.org/D20036

llvm-svn: 268960
2016-05-09 19:30:20 +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
Arnaud A. de Grandmaison 61c167c62b Teach InstCombine to work with smaller legal types in icmp (shl %v, C1), C2
It enables to work with a smaller constant, which is target friendly for those which can compare to immediates.
It also avoids inserting a shift in favor of a trunc, which can be free on some targets.

This used to work until LLVM-3.1, but regressed with the 3.2 release.

llvm-svn: 175270
2013-02-15 14:35:47 +00:00
Eli Friedman 865866e7fe PR9998: ashr exact %x, 31 is not equivalent to sdiv exact %x, -2147483648.
llvm-svn: 132097
2011-05-25 23:26:20 +00:00
Chris Lattner 333e27d74b add PR#
llvm-svn: 125455
2011-02-13 08:27:31 +00:00
Chris Lattner 43273affb9 implement instcombine folding for things like (x >> c) < 42.
We were previously simplifying divisions, but not right shifts!

llvm-svn: 125454
2011-02-13 08:07:21 +00:00
Chris Lattner 6b657aed33 Enhance a bunch of transformations in instcombine to start generating
exact/nsw/nuw shifts and have instcombine infer them when it can prove
that the relevant properties are true for a given shift without them.

Also, a variety of refactoring to use the new patternmatch logic thrown
in for good luck.  I believe that this takes care of a bunch of related
code quality issues attached to PR8862.

llvm-svn: 125267
2011-02-10 05:36:31 +00:00
Chris Lattner 98457101fc Enhance the "compare with shift" and "compare with div"
optimizations to be much more aggressive in the face of
exact/nsw/nuw div and shifts.  For example, these (which
are the same except the first is 'exact' sdiv:

define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
  %A = sdiv exact i64 %X, -5   ; X/-5 == 0 --> x == 0
  %B = icmp eq i64 %A, 0
  ret i1 %B
}

define i1 @sdiv_icmp4(i64 %X) nounwind {
  %A = sdiv i64 %X, -5   ; X/-5 == 0 --> x == 0
  %B = icmp eq i64 %A, 0
  ret i1 %B
}

compile down to:

define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
  %1 = icmp eq i64 %X, 0
  ret i1 %1
}

define i1 @sdiv_icmp4(i64 %X) nounwind {
  %X.off = add i64 %X, 4
  %1 = icmp ult i64 %X.off, 9
  ret i1 %1
}

This happens when you do something like:
  (ptr1-ptr2) == 42

where the pointers are pointers to non-unit types.

llvm-svn: 125266
2011-02-10 05:23:05 +00:00
Chris Lattner 35315d065b enhance vmcore to know that udiv's can be exact, and add a trivial
instcombine xform to exercise this.

Nothing forms exact udivs yet though.  This is progress on PR8862

llvm-svn: 124992
2011-02-06 21:44:57 +00:00