136 Commits

Author SHA1 Message Date
Richard Sandiford
4fc7355a21 [SystemZ] Use MVST to implement strcpy and stpcpy
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188546 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-16 11:29:37 +00:00
Richard Sandiford
e1b2af731e [SystemZ] Use CLST to implement strcmp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188544 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-16 11:21:54 +00:00
Richard Sandiford
6a079fef4f [SystemZ] Fix handling of 64-bit memcmp results
Generalize r188163 to cope with return types other than MVT::i32, just
as the existing visitMemCmpCall code did.  I've split this out into a
subroutine so that it can be used for other upcoming patches.

I also noticed that I'd used the wrong API to record the out chain.
It's a load that uses DAG.getRoot() rather than getRoot(), so the out
chain should go on PendingLoads.  I don't have a testcase for that because
we don't do any interesting scheduling on z yet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188540 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-16 10:55:47 +00:00
Richard Sandiford
6c51f89498 [SystemZ] Fix sign of integer memcmp result
r188163 used CLC to implement memcmp.  Code that compares the result
directly against zero can test the CC value produced by CLC, but code
that needs an integer result must use IPM.  The sequence I'd used was:

   ipm <reg>
   sll <reg>, 2
   sra <reg>, 30

but I'd forgotten that this inverts the order, so that CC==1 ("less")
becomes an integer greater than zero, and CC==2 ("greater") becomes
an integer less than zero.  This sequence should only be used if the
CLC arguments are reversed to compensate.  The problem then is that
the branch condition must also be reversed when testing the CLC
result directly.

Rather than do that, I went for a different sequence that works with
the natural CLC order:

   ipm <reg>
   srl <reg>, 28
   rll <reg>, <reg>, 31

One advantage of this is that it doesn't clobber CC.  A disadvantage
is that any sign extension to 64 bits must be done separately,
rather than being folded into the shifts.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188538 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-16 10:22:54 +00:00
Daniel Dunbar
24ec2e5a72 [tests] Cleanup initialization of test suffixes.
- Instead of setting the suffixes in a bunch of places, just set one master
   list in the top-level config. We now only modify the suffix list in a few
   suites that have one particular unique suffix (.ml, .mc, .yaml, .td, .py).

 - Aside from removing the need for a bunch of lit.local.cfg files, this enables
   4 tests that were inadvertently being skipped (one in
   Transforms/BranchFolding, a .s file each in DebugInfo/AArch64 and
   CodeGen/PowerPC, and one in CodeGen/SI which is now failing and has been
   XFAILED).

 - This commit also fixes a bunch of config files to use config.root instead of
   older copy-pasted code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188513 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-16 00:37:11 +00:00
Richard Sandiford
ac168b8bc8 [SystemZ] Use CLC and IPM to implement memcmp
For now this is restricted to fixed-length comparisons with a length
in the range [1, 256], as for memcpy() and MVC.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188163 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-12 10:28:10 +00:00
Richard Sandiford
29e873ddb6 [SystemZ] Optimize floating-point comparisons with zero
This follows the same lines as the integer code.  In the end it seemed
easier to have a second 4-bit mask in TSFlags to specify the compare-like
CC values.  That eats one more TSFlags bit than adding a CCHasUnordered
would have done, but it feels more concise.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187883 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-07 11:10:06 +00:00
Richard Sandiford
e0bbf7288c [SystemZ] Add floating-point load-and-test instructions
These instructions can also be used as comparisons with zero.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187882 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-07 11:03:34 +00:00
Richard Sandiford
9379557478 [SystemZ] Use BRCT and BRCTG to eliminate add-&-compare sequences
This patch just uses a peephole test for "add; compare; branch" sequences
within a single block.  The IR optimizers already convert loops to
decrement-and-branch-on-nonzero form in some cases, so even this
simplistic test triggers many times during a clang bootstrap and
projects/test-suite run.  It looks like there are still cases where we
need to more strongly prefer branches on nonzero though.  E.g. I saw a
case where a loop that started out with a check for 0 ended up with a
check for -1.  I'll try to look at that sometime.

I ended up adding the Reference class because MachineInstr::readsRegister()
doesn't check for subregisters (by design, as far as I could tell).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187723 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-05 11:23:46 +00:00
Richard Sandiford
9b05c709c6 [SystemZ] Use LOAD AND TEST to eliminate comparisons against zero
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187720 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-05 11:03:20 +00:00
Richard Sandiford
8f0ad5ae8f [SystemZ] Reuse CC results for integer comparisons with zero
This also fixes a bug in the predication of LR to LOCR: I'd forgotten
that with these in-place instruction builds, the implicit operands need
to be added manually.  I think this was latent until now, but is tested
by int-cmp-45.c.  It also adds a CC valid mask to STOC, again tested by
int-cmp-45.c.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187573 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-01 10:39:40 +00:00
Richard Sandiford
3237f88882 [SystemZ] Prefer comparisons with zero
Convert >= 1 to > 0, etc.  Using comparison with zero isn't a win on its own,
but it exposes more opportunities for CC reuse (the next patch).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187571 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-01 10:29:45 +00:00
Richard Sandiford
04ded924f3 [SystemZ] Implement isLegalAddressingMode()
The loop optimizers were assuming that scales > 1 were OK.  I think this
is actually a bug in TargetLoweringBase::isLegalAddressingMode(),
since it seems to be trying to reject anything that isn't r+i or r+r,
but it has no default case for scales other than 0, 1 or 2.  Implementing
the hook for z means that z can no longer test any change there though.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187497 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-31 12:58:26 +00:00
Richard Sandiford
15715fb689 [SystemZ] Be more careful about inverting CC masks (conditional loads)
Extend r187495 to conditional loads.  I split this out because the
easiest way seemed to be to force a particular operand order in
SystemZISelDAGToDAG.cpp.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187496 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-31 12:38:08 +00:00
Richard Sandiford
6824f127f9 [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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187495 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-31 12:30:20 +00:00
Richard Sandiford
0416e3c599 [SystemZ] Move compare-and-branch generation even later
r187116 moved compare-and-branch generation from the instruction-selection
pass to the peephole optimizer (via optimizeCompare).  It turns out that even
this is a bit too early.  Fused compare-and-branch instructions don't
interact well with predication, where a CC result is needed.  They also
make it harder to reuse the CC side-effects of earlier instructions
(not yet implemented, but the subject of a later patch).

Another problem was that the AnalyzeBranch family of routines weren't
handling compares and branches, so we weren't able to reverse the fused
form in cases where we would reverse a separate branch.  This could have
been fixed by extending AnalyzeBranch, but given the other problems,
I've instead moved the fusing to the long-branch pass, which is also
responsible for the opposite transformation: splitting out-of-range
compares and branches into separate compares and long branches.

I've added a test for the AnalyzeBranch problem.  A test for the
predication problem is included in the next patch, which fixes a bug
in the choice of CC mask.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187494 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-31 12:11:07 +00:00
Richard Sandiford
b3f912b510 [SystemZ] Postpone NI->RISBG conversion to convertToThreeAddress()
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
2013-07-31 11:36:35 +00:00
Richard Sandiford
ea14085be5 [SystemZ] Rework compare and branch support
Before the patch we took advantage of the fact that the compare and
branch are glued together in the selection DAG and fused them together
(where possible) while emitting them.  This seemed to work well in practice.
However, fusing the compare so early makes it harder to remove redundant
compares in cases where CC already has a suitable value.  This patch
therefore uses the peephole analyzeCompare/optimizeCompareInstr pair of
functions instead.

No behavioral change intended, but it paves the way for a later patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187116 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-25 09:34:38 +00:00
Richard Sandiford
bf99364f81 [SystemZ] Add LOCR and LOCGR
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187113 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-25 09:11:15 +00:00
Richard Sandiford
cf20e45cc4 [SystemZ] Add LOC and LOCG
As with the stores, these instructions can trap when the condition is false,
so they are only used for things like (cond ? x : *ptr).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187112 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-25 09:04:52 +00:00
Richard Sandiford
b284e1bf08 [SystemZ] Add STOC and STOCG
These instructions are allowed to trap even if the condition is false,
so for now they are only used for "*ptr = (cond ? x : *ptr)"-style
constructs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187111 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-25 08:57:02 +00:00
Richard Sandiford
6dae7ae765 [SystemZ] Add tests for ALHSIK and ALGHSIK
The insn definitions themselves crept into r186689, sorry.
This should be the last of the distinct-ops instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186690 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:44:32 +00:00
Richard Sandiford
c7c7e1502a [SystemZ] Add ALRK, AGLRK, SLRK and SGLRK
Follows the same lines as r186686, but much more limited, since we only
use ADD LOGICAL for multi-i64 additions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186689 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:37:00 +00:00
Richard Sandiford
70d3e71f2e [SystemZ] Add AHIK and AGHIK
I did these as a separate patch because it uses a slightly different
form of RIE layout.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186687 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:32:12 +00:00
Richard Sandiford
dc05e0bff6 [SystemZ] Add ARK, AGRK, SRK and SGRK
The testsuite changes follow the same lines as for r186683.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186686 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:26:39 +00:00
Richard Sandiford
52b2774577 [SystemZ] Add NGRK, OGRK and XGRK
Like r186683, but for 64 bits.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186685 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:24:22 +00:00
Richard Sandiford
db92fb0716 [SystemZ] Add NRK, ORK and XRK
The atomic tests assume the two-operand forms, so I've restricted them to z10.

Running and-01.ll, or-01.ll and xor-01.ll for z196 as well as z10 shows why
using convertToThreeAddress() is better than exposing the three-operand forms
first and then converting back to two operands where possible (which is what
I'd originally tried).  Using the three-operand form first stops us from
taking advantage of NG, OG and XG for spills.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186683 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:21:55 +00:00
Richard Sandiford
93c2125c39 [SystemZ] Use SLLK, SRLK and SRAK for codegen
This patch uses the instructions added in r186680 for codegen.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186681 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:12:08 +00:00
Richard Sandiford
722a26d63e [SystemZ] Use RNSBG
This should be the last of the R.SBG patches for now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186573 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 10:40:35 +00:00
Richard Sandiford
9dffd71d0a [SystemZ] Generalize RxSBG SRA case
The original code only folded SRA into ROTATE ... SELECTED BITS
if there was no outer shift.  This patch splits out that check
and generalises it slightly.  The extra cases aren't really that
interesting, but this is paving the way for RNSBG support.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186571 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 10:14:55 +00:00
Richard Sandiford
30a132f767 [SystemZ] Use RXSBG
Extend the previous R.SBG patches to handle XORs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186570 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 10:06:15 +00:00
Richard Sandiford
de25544a73 [SystemZ] Use ROSBG and non-zero form of RISBG for OR nodes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186405 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-16 11:55:57 +00:00
Richard Sandiford
3764521658 [SystemZ] Use RISBG for (shift (and ...))
Another patch in the series to make more use of R.SBG.  This one extends
r186072 and r186073 to handle cases where the AND is inside the shift.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186399 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-16 11:02:24 +00:00
Stephen Lin
8b2b8a1835 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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186280 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 06:24:09 +00:00
Richard Sandiford
566fb9fe3e [SystemZ] Add test missing from r186148
Sigh, twice in two days sorry.  One day I'll remember...


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186150 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-12 09:20:14 +00:00
Richard Sandiford
9bcad42c3a [SystemZ] Optimize sign-extends of vector setccs
Normal (sext (setcc ...)) sequences are optimised into
(select_cc ..., -1, 0) by DAGCombiner::visitSIGN_EXTEND.
However, this is deliberately not done for vectors, and after
vector type legalization we have (sext_inreg (setcc ...)) instead.

I wondered about trying to extend DAGCombiner to handle this case too,
but it seemed to be a loss on some other targets I tried, even those for
which SETCC isn't "legal" and SELECT_CC is.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186149 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-12 09:17:10 +00:00
Richard Sandiford
6cf3cfa0ab [SystemZ] Improve spilling of LGDR and LDGR
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
2013-07-12 08:37:17 +00:00
Richard Sandiford
67a6b1c40c [SystemZ] Add testcase missing from r186073
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186074 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-11 09:10:38 +00:00
Richard Sandiford
261e2877eb [SystemZ] Use zeroing form of RISBG for shift-and-AND sequences
Extend r186072 to handle shifts and ANDs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186073 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-11 09:10:09 +00:00
Richard Sandiford
b3cabb44c3 [SystemZ] Use zeroing form of RISBG for some AND sequences
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
2013-07-11 08:59:12 +00:00
Richard Sandiford
2e015ef9bb [SystemZ] Use MVC for simple load/store pairs
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
2013-07-09 09:46:39 +00:00
Richard Sandiford
f6ea5e0d80 [SystemZ] Use "STC;MVC" for memset
Use "STC;MVC" for memsets that are too big for two STCs or MV...Is yet
small enough for a single MVC.  As with memcpy, I'm leaving longer cases
till later.

The number of tests might seem excessive, but f33 & f34 from memset-04.ll
failed the first cut because I'd not added the "?:" on the calculation
of Size1.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185918 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-09 09:32:42 +00:00
Richard Sandiford
dff0009d0c [SystemZ] Use MVC for memcpy
Use MVC for memcpy in cases where a single MVC is enough.  Using MVC is
a win for longer copies too, but I'll leave that for later.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185802 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-08 09:35:23 +00:00
Richard Sandiford
71804149a3 [SystemZ] Remove no-op MVCs
The stack coloring pass has code to delete stores and loads that become
trivially dead after coloring.  Extend it to cope with single instructions
that copy from one frame index to another.

The testcase happens to show an example of this kicking in at the moment.
It did occur in Real Code too though.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185705 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-05 14:38:48 +00:00
Richard Sandiford
5f1c7e5eac Fix double renaming bug in stack coloring pass
The stack coloring pass renumbered frame indexes with a loop of the form:

  for each frame index FI
    for each instruction I that uses FI
      for each use of FI in I
        rename FI to FI'

This caused problems if an instruction used two frame indexes F0 and F1
and if F0 was renamed to F1 and F1 to F2.  The first time we visited the
instruction we changed F0 to F1, then we changed both F1s to F2.

In other words, the problem was that SSRefs recorded which instructions
used an FI, but not which MachineOperands and MachineMemOperands within
that instruction used it.

This is easily fixed for MachineOperands by walking the instructions
once and processing each operand in turn.  There's already a loop to
do that for dead store elimination, so it seemed more efficient to
fuse the two at the block level.

MachineMemOperands are more tricky because they can be shared between
instructions.  The patch handles them by making SSRefs an array of
MachineMemOperands rather than an array of MachineInstrs.  We might end
up processing the same MachineMemOperand twice, but that's OK because
we always know from the SSRefs index what the original frame index was.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185703 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-05 14:24:47 +00:00
Richard Sandiford
cf1b5bd60a [SystemZ] Enable the use of MVC for frame-to-frame spills
...now that the problem that prompted the restriction has been fixed.

The original spill-02.py was a compromise because at the time I couldn't
find an example that actually failed without the two scavenging slots.
The version included here did.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185701 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-05 14:02:01 +00:00
Richard Sandiford
47734db936 [SystemZ] Allocate a second register scavenging slot
This is another prerequisite for frame-to-frame MVC copies.
I'll commit the patch that makes use of the slot separately.

The downside of trying to test many corner cases with each of the
available addressing modes is that a fair few tests need to account
for the new frame layout.  I do still think it's useful to have all
these tests though, since it's something that wouldn't get much coverage
otherwise.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185698 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-05 13:11:52 +00:00
Richard Sandiford
fa487e83a8 [SystemZ] Fold more spills
Add a mapping from register-based <INSN>R instructions to the corresponding
memory-based <INSN>.  Use it to cut down on the number of spill loads.

Some instructions extend their operands from smaller fields, so this
required a new TSFlags field to say how big the unextended operand is.

This optimisation doesn't trigger for C(G)R and CL(G)R because in practice
we always combine those instructions with a branch.  Adding a test for every
other case probably seems excessive, but it did catch a missed optimisation
for DSGF (fixed in r185435).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185529 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-03 10:10:02 +00:00
Richard Sandiford
35b7bebe11 [SystemZ] Use DSGFR over DSGR in more cases
Fixes some cases where we were using full 64-bit division for (sdiv i32, i32)
and (sdiv i64, i32).

The "32" in "SDIVREM32" just refers to the second operand.  The first operand
of all *DIVREM*s is a GR128.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185435 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-02 15:40:22 +00:00
Richard Sandiford
1ce4894a3f [SystemZ] Use MVC to spill loads and stores
Try to use MVC when spilling the destination of a simple load or the source
of a simple store.  As explained in the comment, this doesn't yet handle
the case where the load or store location is also a frame index, since
that could lead to two simultaneous scavenger spills, something the
backend can't handle yet.  spill-02.py tests that this restriction kicks in,
but unfortunately I've not yet found a case that would fail without it.
The volatile trick I used for other scavenger tests doesn't work here
because we can't use MVC for volatile accesses anyway.

I'm planning on relaxing the restriction later, hopefully with a test
that does trigger the problem...

Tests @f8 and @f9 also showed that L(G)RL and ST(G)RL were wrongly
classified as SimpleBDX{Load,Store}.  It wouldn't be easy to test for
that bug separately, which is why I didn't split out the fix as a
separate patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185434 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-02 15:28:56 +00:00