Commit Graph

218 Commits

Author SHA1 Message Date
Hal Finkel 93d8f59877 XFAIL test/CodeGen/SystemZ/alias-01.ll which requires CodeGen TBAA
llvm-svn: 200094
2014-01-25 19:31:44 +00:00
Alp Toker cb40291100 Fix known typos
Sweep the codebase for common typos. Includes some changes to visible function
names that were misspelt.

llvm-svn: 200018
2014-01-24 17:20:08 +00:00
Richard Sandiford 36b376914d [SystemZ] Flesh out stackrestore test (frame-11.ll)
...so that it does something vaguely sensible.

llvm-svn: 199117
2014-01-13 15:44:44 +00:00
Richard Sandiford 64c0c4c015 [SystemZ] Improve risbg-01.ll test
The old mask in f24 wasn't well chosen because the lshr would always be zero.
CodeGen didn't detect this but InstCombine would.  The new mask ensures
that both shifts are needed.

f26 is specifically testing for a wrap-around mask.  The AND can be applied
to just the shift left, either before or after the shift.  Again, CodeGen
kept it in the original form but InstCombine would mask after the shift
instead.  The exact choice of NILF isn't important for the test so I just
dropped it and kept the rotate.

llvm-svn: 199115
2014-01-13 15:40:25 +00:00
Richard Sandiford 32379b8141 [SystemZ] Optimize (sext (ashr (shl ...), ...))
...into (ashr (shl (anyext X), ...), ...), which requires one fewer
instruction.  The (anyext X) can sometimes be simplified too.

I didn't do this in DAGCombiner because widening shifts isn't a win
on all targets.

llvm-svn: 199114
2014-01-13 15:17:53 +00:00
Richard Sandiford 3875cb60f3 [SystemZ] Fix RNSBG bug introduced by r197802
The zext handling added in r197802 wasn't right for RNSBG.  This patch
restricts it to ROSBG, RXSBG and RISBG.  (The tests for RISBG were added
in r197802 since RISBG was the motivating example.)

llvm-svn: 198862
2014-01-09 11:28:53 +00:00
Richard Sandiford 15cfc1c33c Handle masked rotate amounts
At the moment we expect rotates to have the form:

   (or (shl X, Y), (shr X, Z))

where Y == bitsize(X) - Z or Z == bitsize(X) - Y.  This form means that
the (or ...) is undefined for Y == 0 or Z == 0.  This undefinedness can
be avoided by using Y == (C * bitsize(X) - Z) & (bitsize(X) - 1) or
Z == (C * bitsize(X) - Y) & (bitsize(X) - 1) for any integer C
(including 0, the most natural choice).

llvm-svn: 198861
2014-01-09 10:56:42 +00:00
Richard Sandiford 0f264db3c6 Match the InstCombine form of rotates by X+C
InstCombine converts (sub 32, (add X, C)) into (sub 32-C, X),
so a rotate left of a 32-bit Y by X+C could appear as either:

   (or (shl Y, (add X, C)), (shr Y, (sub 32, (add X, C))))

without InstCombine or:

   (or (shl Y, (add X, C)), (shr Y, (sub 32-C, X)))

with it.

We already matched the first form.  This patch handles the second too.

llvm-svn: 198860
2014-01-09 10:49:40 +00:00
Richard Sandiford 41350a52ca [SystemZ] Use interlocked-access 1 instructions for CodeGen
...namely LOAD AND ADD, LOAD AND AND, LOAD AND OR and LOAD AND EXCLUSIVE OR.
LOAD AND ADD LOGICAL isn't really separately useful for LLVM.

I'll look at adding reusing the CC results in new year.

llvm-svn: 197985
2013-12-24 15:18:04 +00:00
Richard Sandiford 83a0b6abd0 [SystemZ] Optimize comparisons with truncated extended loads
If the extension of a loaded value is compared against zero and used in
other arithmetic, InstCombine will change the comparison to use the
unextended load.  It's also possible that the comparison could be against
the unextended load from the outset.

In DAG form this becomes a truncation of an extending load.  We want to
strip the truncation if possible so that we can use load-and-test instructions.

llvm-svn: 197804
2013-12-20 11:56:02 +00:00
Richard Sandiford 220ee49bce [SystemZ] Extend RISBG optimization
The handling of ANY_EXTEND and ZERO_EXTEND was too strict.  In this context
we can treat ZERO_EXTEND in much the same way as an AND and then also handle
outermost ZERO_EXTENDs.

I couldn't find a test that benefited from the ANY_EXTEND change, but it's
more obvious to write it this way once SIGN_EXTEND and ZERO_EXTEND are
handled differently.

llvm-svn: 197802
2013-12-20 11:49:48 +00:00
Andrew Trick 83a71c076c Revert "Add -mcpu=z10 to SystemZ tests."
This reverts commit r197466.

The MachineCSE fix that required the -mcpu flag has been disabled
until more work can be done to fix downstream issues. Adding -mcpu
wasn't the right workaround anyway.

llvm-svn: 197624
2013-12-18 23:04:37 +00:00
Andrew Trick 375ee3e16a Add -mcpu=z10 to SystemZ tests.
llvm-svn: 197466
2013-12-17 05:27:16 +00:00
Richard Sandiford 0847c450b6 [SystemZ] Optimize X [!=]= Y in cases where X - Y or Y - X is also computed
In those cases it's better to compare the result of the subtraction
against zero.

llvm-svn: 197239
2013-12-13 15:50:30 +00:00
Richard Sandiford c3dc44781b [SystemZ] Make more use of TMHH
This originally came about after noticing that InstCombine turns
some of the TMHH (icmp (and...), ...) tests into plain comparisons.
Since there is no instruction to compare with a 64-bit immediate,
TMHH is generally better than an ordered comparison for the cases
that it can handle.

llvm-svn: 197238
2013-12-13 15:46:55 +00:00
Richard Sandiford 57485472e2 [SystemZ] Extend integer absolute selection
This patch makes more use of LPGFR and LNGFR.  It builds on top of
the LTGFR selection from r197234.  Most of the tests are motivated
by what InstCombine would produce.

llvm-svn: 197236
2013-12-13 15:35:00 +00:00
Richard Sandiford bd2f0e9cd0 [SystemZ] Make more use of LTGFR
InstCombine turns (sext (trunc)) into (ashr (shl)), then converts any
comparison of the ashr against zero into a comparison of the shl against zero.
This makes sense in itself, but we want to undo it for z, since the sign-
extension instruction has a CC-setting form.

I've included tests for both the original and InstCombined variants,
but the former already worked.  The patch fixes the latter.

llvm-svn: 197234
2013-12-13 15:07:39 +00:00
Richard Sandiford 73170f8488 [SystemZ] Optimize fcmp X, 0 in cases where X is also negated
In such cases it's often better to test the result of the negation instead,
since the negation also sets CC.

llvm-svn: 197032
2013-12-11 11:45:08 +00:00
Richard Sandiford d1093636cc Extend (truncate (load)) folding
DAGCombiner could fold (truncate (load)) -> smaller load if the original
load was the width of the truncation result or wider.  This patch extends
it to handle cases where the original load was narrower (and so the
extension type stays the same).

llvm-svn: 197030
2013-12-11 11:37:27 +00:00
Richard Sandiford bef3d7af2b Add TargetLowering::prepareVolatileOrAtomicLoad
One unusual feature of the z architecture is that the result of a
previous load can be reused indefinitely for subsequent loads, even if
a cache-coherent store to that location is performed by another CPU.
A special serializing instruction must be used if you want to force
a load to be reattempted.

Since volatile loads are not supposed to be omitted in this way,
we should insert a serializing instruction before each such load.
The same goes for atomic loads.

The patch implements this at the IR->DAG boundary, in a similar way
to atomic fences.  It is a no-op for targets other than SystemZ.

llvm-svn: 196906
2013-12-10 10:49:34 +00:00
Richard Sandiford 9afe613d12 Add TargetLowering::prepareVolatileOrAtomicLoad
One unusual feature of the z architecture is that the result of a
previous load can be reused indefinitely for subsequent loads, even if
a cache-coherent store to that location is performed by another CPU.
A special serializing instruction must be used if you want to force
a load to be reattempted.

Since volatile loads are not supposed to be omitted in this way,
we should insert a serializing instruction before each such load.
The same goes for atomic loads.

The patch implements this at the IR->DAG boundary, in a similar way
to atomic fences.  It is a no-op for targets other than SystemZ.

llvm-svn: 196905
2013-12-10 10:36:34 +00:00
Richard Sandiford 198ddf83c1 [SystemZ] Use LOAD AND TEST for comparisons with -0
...since it os equivalent to comparison with +0.

llvm-svn: 196580
2013-12-06 09:59:12 +00:00
Richard Sandiford 7b4118a0fc [SystemZ] Extend the use of C(L)GFR
instcombine prefers to put extended operands first, so this patch
handles that case for C(L)GFR.

llvm-svn: 196579
2013-12-06 09:56:50 +00:00
Richard Sandiford 48ef6abddc [SystemZ] Optimize selects between 0 and -1
Since z has no setcc instruction as such, the choice of setBooleanContents
is a bit arbitrary.  Currently it's set to ZeroOrOneBooleanContent,
so we produced a branch-free form when selecting between 0 and 1,
but not when selecting between 0 and -1.  This patch handles the latter
case too.

At some point I'd like to measure whether it's better to use conditional
moves for constant selects on z196, but that's future work.

llvm-svn: 196578
2013-12-06 09:53:09 +00:00
Richard Sandiford ccc2a7c1a0 [SystemZ] Fix choice of known-zero mask in insertion optimization
The backend converts 64-bit ORs into subreg moves if the upper 32 bits
of one operand and the low 32 bits of the other are known to be zero.
It then tries to peel away redundant ANDs from the upper 32 bits.

Since AND masks are canonicalized to exclude known-zero bits,
the test ORs the mask and the known-zero bits together before
checking for redundancy.  The problem was that it was using the
wrong node when checking for known-zero bits, so could drop ANDs
that were still needed.

llvm-svn: 196267
2013-12-03 11:01:54 +00:00
Richard Sandiford dd7dd930d1 [SystemZ] Fix incorrect use of RISBG for a zero-extended right shift
We would wrongly transform the testcase into the equivalent of an AND with 1.
The problem was that, when testing whether the shifted-in bits of the right
shift were significant, we used the width of the final zero-extended result
rather than the width of the shifted value.

llvm-svn: 195731
2013-11-26 10:53:16 +00:00
Richard Sandiford f03789ca3f [SystemZ] Fix TMHH and TMHL usage for z10 with -O0
I've no idea why I decided to handle TMxx differently from all the other
high/low logic operations, but it was a stupid thing to do.  The high
registers aren't available as separate 32-bit registers on z10,
so subreg_h32 can't be used on a GR64 there.

I've normally been testing with z196 and with -O3 and so hadn't noticed
this until now.

llvm-svn: 195473
2013-11-22 17:28:28 +00:00
Richard Sandiford f834ea19db [SystemZ] Automatically detect zEC12 and z196 hosts
As on other hosts, the CPU identification instruction is priveleged,
so we need to look through /proc/cpuinfo.  I copied the PowerPC way of
handling "generic".

Several tests were implicitly assuming z10 and so failed on z196.

llvm-svn: 193742
2013-10-31 12:14:17 +00:00
Richard Sandiford 094e609716 [SystemZ] Set usaAA to true
useAA significantly improves the handling of vector code that has TBAA
information attached.  It also helps other cases, as shown by the testsuite
changes here.  The only real downside I've seen is that it interferes with
MergeConsecutiveStores.  The problem is that that optimization works top
down, starting at the first store in the chain, and looks for cases where
the chain result is only used by a single related store.  These related
stores don't alias, so useAA will have rewritten all the later stores to
use a different chain input (typically the same one as the first store).

I think the advantages outweigh the disadvantages though, so for now I've
just disabled alias analysis for the unaligned-01.ll test.

llvm-svn: 193521
2013-10-28 13:53:37 +00:00
Richard Sandiford 981fdeb477 [DAGCombiner] Respect volatility when checking for aliases
Making useAA() default to true for SystemZ showed that the combiner alias
analysis wasn't handling volatile accesses.  This hit many of the SystemZ
tests, but I arbitrarily picked one for the purpose of this patch.

llvm-svn: 193518
2013-10-28 12:00:00 +00:00
Richard Sandiford 39c1ce4dc1 Keep TBAA info when rewriting SelectionDAG loads and stores
Most SelectionDAG code drops the TBAA info when creating a new form of a
load and store (e.g. during legalization, or when converting a plain
load to an extending one).  This patch tries to catch all cases where
the TBAA information can legitimately be carried over.

The patch adds alternative forms of getLoad() and getExtLoad() that take
a MachineMemOperand instead of individual fields.  (The corresponding
getTruncStore() already exists.)  The idea is to use the MachineMemOperand
forms when all fields are carried over (size, pointer info, isVolatile,
isNonTemporal, alignment and TBAA info).  If some adjustment is being
made, e.g. to narrow the load, then we still pass the individual fields
but also pass the TBAA info.

llvm-svn: 193517
2013-10-28 11:17:59 +00:00
Richard Sandiford 95f7ba988b Replace sra with srl if a single sign bit is required
E.g. (and (sra (i32 x) 31) 2) -> (and (srl (i32 x) 30) 2).

llvm-svn: 192884
2013-10-17 11:16:57 +00:00
Richard Sandiford 3e382972d9 [SystemZ] Handle extensions in RxSBG optimizations
The input to an RxSBG operation can be narrower as long as the upper bits
are don't care.  This fixes a FIXME added in r192783.

llvm-svn: 192790
2013-10-16 13:35:13 +00:00
Richard Sandiford f722a8e30e [SystemZ] Improve handling of SETCC
We previously used the default expansion to SELECT_CC, which in turn would
expand to "LHI; BRC; LHI".  In most cases it's better to use an IPM-based
sequence instead.

llvm-svn: 192784
2013-10-16 11:10:55 +00:00
Richard Sandiford 374a0e50c4 Handle (shl (anyext (shr ...))) in SimpilfyDemandedBits
This is really an extension of the current (shl (shr ...)) -> shl optimization.
The main difference is that certain upper bits must also not be demanded.

The motivating examples are the first two in the testcase, which occur
in llvmpipe output.

llvm-svn: 192783
2013-10-16 10:26:19 +00:00
Richard Sandiford 6af6ff1e15 [SystemZ] Use A(G)SI when spilling the target of a constant addition
llvm-svn: 192681
2013-10-15 08:42:59 +00:00
Richard Sandiford b63e300b67 [SystemZ] Add comparisons of high words and memory
llvm-svn: 191777
2013-10-01 15:00:44 +00:00
Richard Sandiford a9ac0e0f75 [SystemZ] Add comparisons of large immediates using high words
There are no corresponding patterns for small immediates because they would
prevent the use of fused compare-and-branch instructions.

llvm-svn: 191775
2013-10-01 14:56:23 +00:00
Richard Sandiford 42a694f44e [SystemZ] Add immediate addition involving high words
llvm-svn: 191774
2013-10-01 14:53:46 +00:00
Richard Sandiford 2cac763544 [SystemZ] Extend test-under-mask support to high GR32s
llvm-svn: 191773
2013-10-01 14:41:52 +00:00
Richard Sandiford 3ad5a15b72 [SystemZ] Extend 32-bit RISBG optimizations to high words
This involves using RISB[LH]G, whereas the equivalent z10 optimization
uses RISBG.

llvm-svn: 191770
2013-10-01 14:36:20 +00:00
Richard Sandiford 2896d044bd [SystemZ] Extend pseudo conditional 8- and 16-bit stores to high words
As the comment says, we always want to use STOC for 32-bit stores.

llvm-svn: 191767
2013-10-01 14:33:55 +00:00
Richard Sandiford 96f013b827 [SystemZ] Add test missing from r191764.
llvm-svn: 191765
2013-10-01 14:31:50 +00:00
Richard Sandiford 7028428c2c [SystemZ] Allow integer AND involving high words
llvm-svn: 191762
2013-10-01 14:20:41 +00:00
Richard Sandiford 5718dacbdd [SystemZ] Allow integer XOR involving high words
llvm-svn: 191759
2013-10-01 14:08:44 +00:00
Richard Sandiford 6e96ac600f [SystemZ] Allow integer OR involving high words
llvm-svn: 191755
2013-10-01 13:22:41 +00:00
Richard Sandiford 1a56931b22 [SystemZ] Allow integer insertions with a high-word destination
llvm-svn: 191753
2013-10-01 13:18:56 +00:00
Richard Sandiford 7c5c0eabc9 [SystemZ] Allow selects with a high-word destination
llvm-svn: 191751
2013-10-01 13:10:16 +00:00
Richard Sandiford 012402346f [SystemZ] Add patterns to load a constant into a high word (IIHF)
Similar to low words, we can use the shorter LLIHL and LLIHH if it turns
out that the other half of the GR64 isn't live.

llvm-svn: 191750
2013-10-01 13:02:28 +00:00
Richard Sandiford 21235a256f [SystemZ] Add register zero extensions involving at least one high word
llvm-svn: 191746
2013-10-01 12:49:07 +00:00