Commit Graph

10 Commits

Author SHA1 Message Date
Rafael Espindola d1a2c2d905 Add back commit r210029.
The code was actually correct. Sorry for the confusion. I have expanded the
comment saying why the analysis is valid to avoid me misunderstaning it
again in the future.

llvm-svn: 210052
2014-06-02 22:01:04 +00:00
Rafael Espindola 582c890fbe Revert "Add the nsw flag when we detect that an add will not signed overflow."
This reverts commit r210029.

It was not correctly handling cases where LHS and RHS had multiple but different
sign bits.

llvm-svn: 210048
2014-06-02 21:12:19 +00:00
Rafael Espindola 82899febf0 Add the nsw flag when we detect that an add will not signed overflow.
We already had a function for checking this, we were just using it only in
specialized cases.

llvm-svn: 210029
2014-06-02 14:32:58 +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
Paul Redmond 9d86a4a3b6 Transform (sub 0, (zext bool to A)) to (sext bool to A) and
(sub 0, (sext bool to A)) to (zext bool to A).

Patch by Muhammad Ahmad
Reviewed by Duncan Sands

llvm-svn: 173093
2013-01-21 21:57:20 +00:00
Evan Cheng 319be53a1f Remove a instcombine transform that (no longer?) makes sense:
// C - zext(bool) -> bool ? C - 1 : C
    if (ZExtInst *ZI = dyn_cast<ZExtInst>(Op1))
      if (ZI->getSrcTy()->isIntegerTy(1))
        return SelectInst::Create(ZI->getOperand(0), SubOne(C), C);

This ends up forming sext i1 instructions that codegen to terrible code. e.g.
int blah(_Bool x, _Bool y) {
  return (x - y) + 1;
}
=>
        movzbl  %dil, %eax
        movzbl  %sil, %ecx
        shll    $31, %ecx
        sarl    $31, %ecx
        leal    1(%rax,%rcx), %eax
        ret


Without the rule, llvm now generates:
        movzbl  %sil, %ecx
        movzbl  %dil, %eax
        incl    %eax
        subl    %ecx, %eax
        ret

It also helps with ARM (and pretty much any target that doesn't have a sext i1 :-).

The transformation was done as part of Eli's r75531. He has given the ok to
remove it.

rdar://11748024

llvm-svn: 159230
2012-06-26 22:03:13 +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
Dan Gohman 9737a63ed8 Change these tests to feed the assembly files to opt directly, instead
of using llvm-as, now that opt supports this.

llvm-svn: 81226
2009-09-08 16:50:01 +00:00
Eli Friedman 116e3b3ef1 Fix bug in run-line.
llvm-svn: 75534
2009-07-13 22:31:30 +00:00
Eli Friedman 7e1716dc9d Canonicalize boolean +/- a constant to a select.
(I think it's reasonably clear that we want to have a canonical form for 
constructs like this; if anyone thinks that a select is not the best 
canonical form, please tell me.)

llvm-svn: 75531
2009-07-13 22:27:52 +00:00