The backend tries to use block operations like MVC, NC, OC and XC for
simple scalar operations. For correctness reasons, it rejects any case
in which the regions might partially overlap. However, for performance
reasons, it should also reject cases where the regions might be equal,
since the instruction might then not use the fast path.
This fixes a performance regression seen in bzip2. We may want to limit
the optimisation even more in future, or even remove it entirely, but I'll
try with this for now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191525 91177308-0d34-0410-b5e6-96231b3b80d8
r186399 aggressively used the RISBG instruction for immediate ANDs,
both because it can handle some values that AND IMMEDIATE can't,
and because it allows the destination register to be different from
the source. I realized later while implementing the distinct-ops
support that it would be better to leave the choice up to
convertToThreeAddress() instead. The AND IMMEDIATE form is shorter
and is less likely to be cracked.
This is a problem for 32-bit ANDs because we assume that all 32-bit
operations will leave the high word untouched, whereas RISBG used in
this way will either clear the high word or copy it from the source
register. The patch uses the z196 instruction RISBLG for this instead.
This means that z10 will be restricted to NILL, NILH and NILF for
32-bit ANDs, but I think that should be OK for now. Although we're
using z10 as the base architecture, the optimization work is going
to be focused more on z196 and zEC12.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187492 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186280 91177308-0d34-0410-b5e6-96231b3b80d8
If the source of these instructions is spilled we should load the destination.
If the destination is spilled we should store the source.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186147 91177308-0d34-0410-b5e6-96231b3b80d8
RISBG can handle some ANDs for which no AND IMMEDIATE exists.
It also acts as a three-operand AND for some cases where an
AND IMMEDIATE could be used instead.
It might be worth adding a pass to replace RISBG with AND IMMEDIATE
in cases where the register operands end up being the same and where
AND IMMEDIATE is smaller.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186072 91177308-0d34-0410-b5e6-96231b3b80d8
Look for patterns of the form (store (load ...), ...) in which the two
locations are known not to partially overlap. (Identical locations are OK.)
These sequences are better implemented by MVC unless either the load or
the store could use RELATIVE LONG instructions.
The testcase showed that we weren't using LHRL and LGHRL for extload16,
only sextloadi16. The patch fixes that too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185919 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181204 91177308-0d34-0410-b5e6-96231b3b80d8
