Commit Graph

13 Commits

Author SHA1 Message Date
Michael Kuperstein 3e3652aef2 Recommit r274692 - [X86] Transform setcc + movzbl into xorl + setcc
xorl + setcc is generally the preferred sequence due to the partial register
stall setcc + movzbl suffers from. As a bonus, it also encodes one byte smaller.
This fixes PR28146.

The original commit tried inserting an 8bit-subreg into a GR32 (not GR32_ABCD)
which was not appreciated by fast regalloc on 32-bit.

llvm-svn: 274802
2016-07-07 22:50:23 +00:00
Michael Kuperstein edb38a94f8 Revert r274692 to check whether this is what breaks windows selfhost.
llvm-svn: 274771
2016-07-07 16:55:35 +00:00
Michael Kuperstein 1ef6c59b1d [X86] Transform setcc + movzbl into xorl + setcc
xorl + setcc is generally the preferred sequence due to the partial register
stall setcc + movzbl suffers from. As a bonus, it also encodes one byte smaller.

This fixes PR28146.

Differential Revision: http://reviews.llvm.org/D21774

llvm-svn: 274692
2016-07-06 21:56:18 +00:00
David Majnemer 911d0e3c21 [X86] Use the right type when folding xor (truncate (shift)) -> setcc
The result type of setcc is dependent on whether or not AVX512 is
present.
We had an X86-specific DAG-combine which assumed that the result type
should be i8 when it could be i1.
This meant that we would generate illegal setccs which LowerSETCC did
not like.

Instead, use an appropriate type and zero extend to i8.

Also, there were some scenarios where the fold should have fired but
didn't because we were overly cautious about the types.  This meant that
we generated:

        shrl    $31, %edi
        andl    $1, %edi
        kmovw   %edi, %k0
        kxnorw  %k0, %k0, %k1
        kshiftrw        $15, %k1, %k1
        kxorw   %k1, %k0, %k0
        kmovw   %k0, %eax

instead of:

        testl   %edi, %edi
        setns   %al

This fixes PR27638.

llvm-svn: 268609
2016-05-05 06:00:56 +00:00
David Majnemer cfc1df553e [X86] Fix the (shl (and (setcc_c), c1), c2) -> (and setcc_c, (c1 << c2)) fold
We didn't check for the necessary preconditions before folding a
mask/shift into a single mask.

This fixes PR24516.

llvm-svn: 245544
2015-08-20 09:00:56 +00:00
Craig Topper 9012028738 [X86] Don't use GR64 register 'and with immediate' instructions if the immediate is zero in the upper 33-bits or upper 57-bits. Use GR32 instructions instead.
Previously the patterns didn't have high enough priority and we would only use the GR32 form if the only the upper 32 or 56 bits were zero.

Fixes PR23100.

llvm-svn: 234075
2015-04-04 02:08:20 +00:00
Stephen Lin d24ab20e9b Mass update to CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change and all updated tests passed locally.
This update was done with the following bash script:

  find test/CodeGen -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc.*debug" $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
      sed -i '' "s/;\(.*\)-LABEL-LABEL:/;\1-LABEL:/" $TEMP
      sed -i '' "s/;\(.*\)-NEXT-LABEL:/;\1-NEXT:/" $TEMP
      sed -i '' "s/;\(.*\)-NOT-LABEL:/;\1-NOT:/" $TEMP
      sed -i '' "s/;\(.*\)-DAG-LABEL:/;\1-DAG:/" $TEMP
      mv $TEMP $NAME
    fi
  done

llvm-svn: 186280
2013-07-14 06:24:09 +00:00
Bill Wendling 410ec4aad1 As Dan pointed out, movzbl, movsbl, and friends are nicer than their alias
(movzx/movsx) because they give more information. Revert that part of the patch.

llvm-svn: 129498
2011-04-14 01:46:37 +00:00
Bill Wendling 7e07d6fb69 Have the X86 back-end emit the alias instead of what's being aliased. In most
cases, it's much nicer and more informative reading the alias.

llvm-svn: 129497
2011-04-14 01:11:51 +00:00
Evan Cheng 1be6286028 Re-enable 91381 with fixes.
llvm-svn: 91489
2009-12-16 00:53:11 +00:00
Evan Cheng fcb5453dc7 Disable 91381 for now. It's miscompiling ARMISelDAG2DAG.cpp.
llvm-svn: 91405
2009-12-15 03:07:11 +00:00
Evan Cheng 0e8b9e32d1 Use sbb x, x to materialize carry bit in a GPR. The result is all one's or all zero's.
llvm-svn: 91381
2009-12-15 00:53:42 +00:00
Evan Cheng ca7c690d3b Propagate zest through logical shift.
llvm-svn: 91378
2009-12-15 00:41:36 +00:00