Commit Graph

7 Commits

Author SHA1 Message Date
Richard Sandiford 93183ee78c [SystemZ] Add unsigned compare-and-branch instructions
For some reason I never got around to adding these at the same time as
the signed versions.  No idea why.

I'm not sure whether this SystemZII::BranchC* stuff is useful, or whether
it should just be replaced with an "is normal" flag.  I'll leave that
for later though.

There are some boundary conditions that can be tweaked, such as preferring
unsigned comparisons for equality with [128, 256), and "<= 255" over "< 256",
but again I'll leave those for a separate patch.

llvm-svn: 190930
2013-09-18 09:56:40 +00:00
Richard Sandiford 3d768e334b [SystemZ] Be more careful about inverting CC masks
System z branches have a mask to select which of the 4 CC values should
cause the branch to be taken.  We can invert a branch by inverting the mask.
However, not all instructions can produce all 4 CC values, so inverting
the branch like this can lead to some oddities.  For example, integer
comparisons only produce a CC of 0 (equal), 1 (less) or 2 (greater).
If an integer EQ is reversed to NE before instruction selection,
the branch will test for 1 or 2.  If instead the branch is reversed
after instruction selection (by inverting the mask), it will test for
1, 2 or 3.  Both are correct, but the second isn't really canonical.
This patch therefore keeps track of which CC values are possible
and uses this when inverting a mask.

Although this is mostly cosmestic, it fixes undefined behavior
for the CIJNLH in branch-08.ll.  Another fix would have been
to mask out bit 0 when generating the fused compare and branch,
but the point of this patch is that we shouldn't need to do that
in the first place.

The patch also makes it easier to reuse CC results from other instructions.

llvm-svn: 187495
2013-07-31 12:30:20 +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
Richard Sandiford a57e13b670 [SystemZ] Allow immediate moves to be rematerialized
llvm-svn: 185068
2013-06-27 09:38:48 +00:00
Richard Sandiford 0fb90ab0cb [SystemZ] Register compare-and-branch support
This patch adds support for the CRJ and CGRJ instructions.  Support for
the immediate forms will be a separate patch.

The architecture has a large number of comparison instructions.  I think
it's generally better to concentrate on using the "best" comparison
instruction first and foremost, then only use something like CRJ if
CR really was the natual choice of comparison instruction.  The patch
therefore opportunistically converts separate CR and BRC instructions
into a single CRJ while emitting instructions in ISelLowering.

llvm-svn: 182764
2013-05-28 10:41:11 +00:00
Richard Sandiford 586f41777e [SystemZ] Tighten branch tests
After r182274, the branches in these tests must always be short.

llvm-svn: 182358
2013-05-21 08:53:17 +00:00
Ulrich Weigand 9e3577ff44 [SystemZ] Add CodeGen test cases
This adds all CodeGen tests for the SystemZ target.

This version of the patch incorporates feedback from a review by
Sean Silva.  Thanks to all reviewers!

Patch by Richard Sandiford.

llvm-svn: 181204
2013-05-06 16:17:29 +00:00