Commit Graph

5 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
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 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
Richard Sandiford 312425f32d [SystemZ] Add long branch pass
Before this change, the SystemZ backend would use BRCL for all branches
and only consider shortening them to BRC when generating an object file.
E.g. a branch on equal would use the JGE alias of BRCL in assembly output,
but might be shortened to the JE alias of BRC in ELF output.  This was
a useful first step, but it had two problems:

(1) The z assembler isn't traditionally supposed to perform branch shortening
    or branch relaxation.  We followed this rule by not relaxing branches
    in assembler input, but that meant that generating assembly code and
    then assembling it would not produce the same result as going directly
    to object code; the former would give long branches everywhere, whereas
    the latter would use short branches where possible.

(2) Other useful branches, like COMPARE AND BRANCH, do not have long forms.
    We would need to do something else before supporting them.

    (Although COMPARE AND BRANCH does not change the condition codes,
    the plan is to model COMPARE AND BRANCH as a CC-clobbering instruction
    during codegen, so that we can safely lower it to a separate compare
    and long branch where necessary.  This is not a valid transformation
    for the assembler proper to make.)

This patch therefore moves branch relaxation to a pre-emit pass.
For now, calls are still shortened from BRASL to BRAS by the assembler,
although this too is not really the traditional behaviour.

The first test takes about 1.5s to run, and there are likely to be
more tests in this vein once further branch types are added.  The feeling
on IRC was that 1.5s is a bit much for a single test, so I've restricted
it to SystemZ hosts for now.

The patch exposes (and fixes) some typos in the main CodeGen/SystemZ tests.
A later patch will remove the {{g}}s from that directory.

llvm-svn: 182274
2013-05-20 14:23:08 +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