Commit Graph

17 Commits

Author SHA1 Message Date
Sanjay Patel b6404a8ca6 [InstCombine] canonicalize constant-minus-boolean to select-of-constants
This restores the half of:
https://reviews.llvm.org/rL75531
that was reverted at:
https://reviews.llvm.org/rL159230

For the x86 case mentioned there, we now produce:
leal 1(%rdi), %eax
subl %esi, %eax

We have target hooks to invert this in DAGCombiner (and x86 is enabled) with:
https://reviews.llvm.org/rL296977
https://reviews.llvm.org/rL311731

AArch64 and possibly other targets would probably benefit from enabling those hooks too. 
See PR30327:
https://bugs.llvm.org/show_bug.cgi?id=30327#c2

Differential Revision: https://reviews.llvm.org/D40612

llvm-svn: 319964
2017-12-06 21:22:57 +00:00
Sanjay Patel e0f906c915 [InstCombine] add tests for select-of-constants; NFC
These are variants of a test that was originally added in:
https://reviews.llvm.org/rL75531
...but removed with:
https://reviews.llvm.org/rL159230

llvm-svn: 319327
2017-11-29 17:21:39 +00:00
Sanjay Patel 2150651ac3 [InstCombine] allow zext(bool) + C --> select bool, C+1, C for vector types
The backend should be prepared for this transform after:
https://reviews.llvm.org/rL311731

llvm-svn: 315701
2017-10-13 16:29:38 +00:00
Sanjay Patel 45d5568010 [InstCombine] add tests for boolean extend + add; NFC
llvm-svn: 315681
2017-10-13 14:09:45 +00:00
Sanjay Patel ff00fae8e6 add more tests for PR30273
llvm-svn: 281270
2016-09-12 22:28:29 +00:00
Sanjay Patel dea26950a0 [InstCombine] add test for PR30327
llvm-svn: 281248
2016-09-12 19:50:08 +00:00
Sanjay Patel 2eea9a1d58 [InstCombine] regenerate checks
llvm-svn: 281247
2016-09-12 19:29:26 +00:00
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