Commit Graph

668 Commits

Author SHA1 Message Date
Richard Sandiford
b9dcca8265 [SystemZ] Allow integer AND involving high words
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191762 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 14:20:41 +00:00
Richard Sandiford
1ff62e182e [SystemZ] Allow integer XOR involving high words
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191759 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 14:08:44 +00:00
Richard Sandiford
1c831f7f1f [SystemZ] Allow integer OR involving high words
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191755 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 13:22:41 +00:00
Richard Sandiford
645d250b84 [SystemZ] Allow integer insertions with a high-word destination
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191753 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 13:18:56 +00:00
Richard Sandiford
4708657097 [SystemZ] Allow selects with a high-word destination
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191751 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 13:10:16 +00:00
Richard Sandiford
4c8feae136 [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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191750 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 13:02:28 +00:00
Richard Sandiford
79e2ed4d83 [SystemZ] Add register zero extensions involving at least one high word
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191746 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 12:49:07 +00:00
Richard Sandiford
9813dbf396 [SystemZ] Add truncating high-word stores (STCH and STHH)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191743 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 12:22:49 +00:00
Richard Sandiford
9a05f040e7 [SystemZ] Add zero-extending high-word loads (LLCH and LLHH)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191742 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 12:19:08 +00:00
Richard Sandiford
ced450f0e6 [SystemZ] Add sign-extending high-word loads (LBH and LHH)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191740 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 12:11:47 +00:00
Richard Sandiford
55d7d83b6c [SystemZ] Use upper words of GR64s for codegen
This just adds the basics necessary for allocating the upper words to
virtual registers (move, load and store).  The move support is parameterised
in a way that makes it easy to handle zero extensions, but the associated
zero-extend patterns are added by a later patch.

The easiest way of testing this seemed to be add a new "h" register
constraint for high words.  I don't expect the constraint to be useful
in real inline asms, but it should work, so I didn't try to hide it
behind an option.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191739 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 11:26:28 +00:00
Richard Sandiford
7d0b89bedd [SystemZ] Reapply: Add definitions of LFH and STFH
Originally committed as r191661, but reverted because it changed the matching
order of comparisons on some hosts.  That should have been fixed by r191735.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191738 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-01 10:31:04 +00:00
Richard Sandiford
16658af535 [SystemZ] Revert r191661: Add definitions of LFH and STFH
For some reason, adding definitions for these load and store
instructions changed whether some of the build bots matched
comparisons as signed or unsigned.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191663 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-30 12:01:35 +00:00
Richard Sandiford
e09bcad77c [SystemZ] Add definitions of LFH and STFH
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191661 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-30 10:50:33 +00:00
Richard Sandiford
eb2f72f454 [SystemZ] Add GRH32 for the high word of a GR64
The only thing this does on its own is make the definitions of RISB[HL]G
a bit more precise.  Those instructions are only used by the MC layer at
the moment, so no behavioral change is intended.  The class is needed by
later patches though.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191660 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-30 10:45:16 +00:00
Richard Sandiford
745ca1eed7 [SystemZ] Rename subregs and add subreg_h32
Use subreg_hNN and subreg_lNN for the high and low NN bits of a register.
List the low registers first, so that subreg_l32 also means the low 32
bits of a 128-bit register.

Floats are stored in the upper 32 bits of a 64-bit register, so they
should use subreg_h32 rather than subreg_l32.

No behavioral change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191659 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-30 10:28:35 +00:00
Richard Sandiford
3d307b31b6 [SystemZ] Add change missing from previous commit
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191656 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-30 08:54:17 +00:00
Richard Sandiford
514756983e [SystemZ] Rename 32-bit GPR registers
I'm about to add support for high-word operations, so it seemed better
for the low-word registers to have names like R0L rather than R0W.
No behavioral change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191655 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-30 08:48:38 +00:00
Richard Sandiford
0548a5487a [SystemZ] Rein back the use of block operations
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
2013-09-27 15:29:20 +00:00
Richard Sandiford
8dac19c070 [SystemZ] Improve handling of PC-relative addresses
The backend previously folded offsets into PC-relative addresses
whereever possible.  That's the right thing to do when the address
can be used directly in a PC-relative memory reference (using things
like LRL).  But if we have a register-based memory reference and need
to load the PC-relative address separately, it's better to use an anchor
point that could be shared with other accesses to the same area of the
variable.

Fixes a FIXME.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191524 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-27 15:14:04 +00:00
Richard Sandiford
259a6006e8 [SystemZ] Define the GR64 low-word logic instructions as pseudo aliases.
Another patch to avoid duplication of encoding information.  Things like
NILF, NILL and NILH are used as both 32-bit and 64-bit instructions.
Here the 64-bit versions are defined as aliases of the 32-bit ones.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191369 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-25 11:11:53 +00:00
Richard Sandiford
76f8ae87b4 [SystemZ] Define the call instructions as pseudo aliases.
Similar to r191364, but for calls.  This patch also removes the shortening
of BRASL to BRAS within a TU.  Doing that was a bit controversial internally,
since there's a strong expectation with the z assembler that WYWIWYG.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191366 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-25 10:37:17 +00:00
Richard Sandiford
e39a156b92 [SystemZ] Use subregs for 64-bit truncating stores
Another patch to reduce the duplication of encoding information.
Rather than define separate patterns for truncating 64-bit stores,
use the 32-bit stores with a subreg.  No behavioral changed intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191365 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-25 10:29:47 +00:00
Richard Sandiford
9f3f4bf377 [SystemZ] Define the return instruction as a pseudo alias of BR
This is the first of a few patches to reduce the dupliation of encoding
information.  The return instruction is a normal BR in which one of the
registers is fixed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191364 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-25 10:20:08 +00:00
Richard Sandiford
c2b840cb7c [SystemZ] Add instruction-shortening pass
When loading immediates into a GR32, the port prefered LHI, followed by
LLILH or LLILL, followed by IILF.  LHI and IILF are natural 32-bit
operations, but LLILH and LLILL also clear the upper 32 bits of the register.
This was represented as taking a 32-bit subreg of a 64-bit assignment.

Using subregs for something as simple as a move immediate was probably
a bad idea.  Also, I have patches to add support for the high-word facility, 
and we don't want something like LLILH and LLILL to stop the high word of
the same GPR from being used.

This patch therefore uses LHI and IILF to begin with and adds a late
machine-specific pass to use LLILH and LLILL if the other half of the
register is not live.  The high-word patches extend this behavior to
IIHF, LLIHL and LLIHH.

No behavioral change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191363 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-25 10:11:07 +00:00
David Majnemer
8ba3f9c900 MC: Remove vestigial PCSymbol field from AsmInfo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191362 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-25 09:36:11 +00:00
Tim Northover
3e84ad28d4 ISelDAG: spot chain cycles involving MachineNodes
Previously, the DAGISel function WalkChainUsers was spotting that it
had entered already-selected territory by whether a node was a
MachineNode (amongst other things). Since it's fairly common practice
to insert MachineNodes during ISelLowering, this was not the correct
check.

Looking around, it seems that other nodes get their NodeId set to -1
upon selection, so this makes sure the same thing happens to all
MachineNodes and uses that characteristic to determine whether we
should stop looking for a loop during selection.

This should fix PR15840.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191165 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-22 08:21:56 +00:00
Richard Sandiford
e2d6f91d63 [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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190930 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-18 09:56:40 +00:00
Richard Sandiford
219d2b8695 [SystemZ] Improve extload handling
The port originally had special patterns for extload, mapping them to the
same instructions as sextload.  It seemed neater to have patterns that
match "an extension that is allowed to be signed" and "an extension that
is allowed to be unsigned".

This was originally meant to be a clean-up, but it does improve the handling
of promoted integers a little, as shown by args-06.ll.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190777 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-16 09:03:10 +00:00
Benjamin Kramer
94ee55d4b3 Replace some unnecessary vector copies with references.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190770 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-15 22:04:42 +00:00
Richard Sandiford
7c7b431d2f [SystemZ] Use getTarget{Insert,Extract}Subreg rather than getMachineNode
Just a clean-up, no behavioral change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190673 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-13 09:12:44 +00:00
Richard Sandiford
856bf59433 [SystemZ] Try to fold shifts into TMxx
E.g. "SRL %r2, 2; TMLL %r2, 1" => "TMLL %r2, 4".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190672 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-13 09:09:50 +00:00
Joey Gouly
715d98d657 Add an instruction deprecation feature to TableGen.
The 'Deprecated' class allows you to specify a SubtargetFeature that the
instruction is deprecated on.

The 'ComplexDeprecationPredicate' class allows you to define a custom
predicate that is called to check for deprecation.
For example:
  ComplexDeprecationPredicate<"MCR">

would mean you would have to define the following function:
  bool getMCRDeprecationInfo(MCInst &MI, MCSubtargetInfo &STI,
                             std::string &Info)

Which returns 'false' for not deprecated, and 'true' for deprecated
and store the warning message in 'Info'.

The MCTargetAsmParser constructor was chaned to take an extra argument of
the MCInstrInfo class, so out-of-tree targets will need to be changed.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190598 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-12 10:28:05 +00:00
Richard Sandiford
4c708e586e [SystemZ] Update README.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190404 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-10 12:22:45 +00:00
Richard Sandiford
299fdd814f [SystemZ] Add TM and TMY
The main complication here is that TM and TMY (the memory forms) set
CC differently from the register forms.  When the tested bits contain
some 0s and some 1s, the register forms set CC to 1 or 2 based on the
value the uppermost bit.  The memory forms instead set CC to 1
regardless of the uppermost bit.

Until now, I've tried to make it so that a branch never tests for an
impossible CC value.  E.g. NR only sets CC to 0 or 1, so branches on the
result will only test for 0 or 1.  Originally I'd tried to do the same
thing for TM and TMY by using custom matching code in ISelDAGToDAG.
That ended up being very ugly though, and would have meant duplicating
some of the chain checks that the common isel code does.

I've therefore gone for the simpler alternative of adding an extra
operand to the TM DAG opcode to say whether a memory form would be OK.
This means that the inverse of a "TM;JE" is "TM;JNE" rather than the
more precise "TM;JNLE", just like the inverse of "TMLL;JE" is "TMLL;JNE".
I suppose that's arguably less confusing though...


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190400 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-10 10:20:32 +00:00
Bill Wendling
c3cee57f7d Generate compact unwind encoding from CFI directives.
We used to generate the compact unwind encoding from the machine
instructions. However, this had the problem that if the user used `-save-temps'
or compiled their hand-written `.s' file (with CFI directives), we wouldn't
generate the compact unwind encoding.

Move the algorithm that generates the compact unwind encoding into the
MCAsmBackend. This way we can generate the encoding whether the code is from a
`.ll' or `.s' file.

<rdar://problem/13623355>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190290 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-09 02:37:14 +00:00
Richard Sandiford
aff1c6427c [SystemZ] Tweak integer comparison code
The architecture has many comparison instructions, including some that
extend one of the operands.  The signed comparison instructions use sign
extensions and the unsigned comparison instructions use zero extensions.
In cases where we had a free choice between signed or unsigned comparisons,
we were trying to decide at lowering time which would best fit the available
instructions, taking things like extension type into account.  The code
to do that was getting increasingly hairy and was also making some bad
decisions.  E.g. when comparing the result of two LLCs, it is better to use
CR rather than CLR, since CR can be fused with a branch while CLR can't.

This patch removes the lowering code and instead adds an operand to
integer comparisons to say whether signed comparison is required,
whether unsigned comparison is required, or whether either is OK.
We can then leave the choice of instruction up to the normal isel code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190138 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-06 11:51:39 +00:00
Richard Sandiford
867f9501f6 [SystemZ] Use XC for a memset of 0
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190130 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-06 10:25:07 +00:00
Richard Sandiford
16277c4698 [SystemZ] Add NC, OC and XC
For now these are just used to handle scalar ANDs, ORs and XORs in which
all operands are memory.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190041 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-05 10:36:45 +00:00
Richard Sandiford
8bce43648b [SystemZ] Add support for TMHH, TMHL, TMLH and TMLL
For now this just handles simple comparisons of an ANDed value with zero.
The CC value provides enough information to do any comparison for a
2-bit mask, and some nonzero comparisons with more populated masks,
but that's all future work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189819 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-03 15:38:35 +00:00
Richard Sandiford
477168192c [SystemZ] Add support for TMHH, TMHL, TMLH and TMLL
For now just handles simple comparisons of an ANDed value with zero.
The CC value provides enough information to do any comparison for a
2-bit mask, and some nonzero comparisons with more populated masks,
but that's all future work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189469 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-28 10:31:43 +00:00
Richard Sandiford
47e7096094 [SystemZ] Extend memcmp support to all constant lengths
This uses the infrastructure added for memcpy and memmove in r189331.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189458 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-28 09:01:51 +00:00
Richard Sandiford
842a1be06c [SystemZ] Extend memcpy and memset support to all constant lengths
Lengths up to a certain threshold (currently 6 * 256) use a series of MVCs.
Lengths above that threshold use a loop to handle X*256 bytes followed
by a single MVC to handle the excess (if any).  This loop will also be
needed in future when support for variable lengths is added.

Because the same tablegen classes are used to define MVC and CLC,
the patch also has the side-effect of defining a pseudo loop instruction
for CLC.  That instruction isn't used yet (and wouldn't be handled correctly
if it were).  I'm planning to use it soon though.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189331 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-27 09:54:29 +00:00
Richard Sandiford
a550b51bac [SystemZ] Add basic prefetch support
Just the instructions and intrinsics for now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189100 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-23 11:36:42 +00:00
Richard Sandiford
35c93e4e42 [SystemZ] Try reversing comparisons whose first operand is in memory
This allows us to make more use of the many compare reg,mem instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189099 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-23 11:27:19 +00:00
Richard Sandiford
65ddcfa8c1 [SystemZ] Prefer LHI;ST... over LAY;MV...
If we had a store of an integer to memory, and the integer and store size
were suitable for a form of MV..., we used MV... no matter what.  We could
then have sequences like:

    lay %r2, 0(%r3,%r4)
    mvi 0(%r2), 4

In these cases it seems better to force the constant into a register
and use a normal store:

    lhi %r2, 4
    stc %r2, 0(%r3, %r4)

since %r2 is more likely to be hoisted and is easier to rematerialize.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189098 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-23 11:18:53 +00:00
Richard Sandiford
a8a7099c18 Turn MipsOptimizeMathLibCalls into a target-independent scalar transform
...so that it can be used for z too.  Most of the code is the same.
The only real change is to use TargetTransformInfo to test when a sqrt
instruction is available.

The pass is opt-in because at the moment it only handles sqrt.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189097 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-23 10:27:02 +00:00
Richard Sandiford
df40f8e8ad [SystemZ] Define remainig *MUL_LOHI patterns
The initial port used MLG(R) for i64 UMUL_LOHI but left the other three
combinations as not-legal-or-custom.  Although 32x32->{32,32}
multiplications exist, they're not as quick as doing a normal 64-bit
multiplication, so it didn't seem like i32 SMUL_LOHI and UMUL_LOHI
would be useful.  There's also no direct instruction for i64 SMUL_LOHI,
so it needs to be implemented in terms of UMUL_LOHI.

However, not defining these patterns means that we don't convert
division by a constant into multiplication, so this patch fills
in the other cases.  The new i64 SMUL_LOHI sequence is simpler
than the one that we used previously for 64x64->128 multiplication,
so int-mul-08.ll now tests the full sequence.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188898 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-21 09:34:56 +00:00
Richard Sandiford
d95865a2a2 [SystemZ] Use FI[EDX]BRA for codegen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188895 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-21 09:04:20 +00:00
Richard Sandiford
d954716e75 [SystemZ] Add FI[EDX]BRA
These are extensions of the existing FI[EDX]BR instructions, but use a spare
bit to suppress inexact conditions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188894 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-21 08:58:08 +00:00
Richard Sandiford
0371d01fb9 [SystemZ] Update README
We now use MVST, CLST and SRST for the obvious cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188781 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-20 09:40:35 +00:00
Richard Sandiford
8c20158fb0 [SystemZ] Use SRST to optimize memchr
SystemZTargetLowering::emitStringWrapper() previously loaded the character
into R0 before the loop and made R0 live on entry.  I'd forgotten that
allocatable registers weren't allowed to be live across blocks at this stage,
and it confused LiveVariables enough to cause a miscompilation of f3 in
memchr-02.ll.

This patch instead loads R0 in the loop and leaves LICM to hoist it
after RA.  This is actually what I'd tried originally, but I went for
the manual optimisation after noticing that R0 often wasn't being hoisted.
This bug forced me to go back and look at why, now fixed as r188774.

We should also try to optimize null checks so that they test the CC result
of the SRST directly.  The select between null and the SRST GPR result could
then usually be deleted as dead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188779 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-20 09:38:48 +00:00
Richard Sandiford
d4a37e6137 [SystemZ] Add negative integer absolute (load negative)
For now this matches the equivalent of (neg (abs ...)), which did hit a few
times in projects/test-suite.  We should probably also match cases where
absolute-like selects are used with reversed arguments.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188671 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-19 12:56:58 +00:00
Richard Sandiford
b0d40a22e5 [SystemZ] Add integer absolute (load positive)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188670 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-19 12:48:54 +00:00
Richard Sandiford
80f54784da [SystemZ] Add support for sibling calls
This first cut is pretty conservative.  The final argument register (R6)
is call-saved, so we would need to make sure that the R6 argument to a
sibling call is the same as the R6 argument to the calling function,
which seems worth keeping as a separate patch.

Saying that integer truncations are free means that we no longer
use the extending instructions LGF and LLGF for spills in int-conv-09.ll
and int-conv-10.ll.  Instead we treat the registers as 64 bits wide and
truncate them to 32-bits where necessary.  I think it's unlikely we'd
use LGF and LLGF for spills in other situations for the same reason,
so I'm removing the tests rather than replacing them.  The associated
code is generic and applies to many more instructions than just
LGF and LLGF, so there is no corresponding code removal.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188669 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-19 12:42:31 +00:00
Richard Sandiford
19262ee072 [SystemZ] Use SRST to implement strlen and strnlen
It would also make sense to use it for memchr; I'm working on that now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188547 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-16 11:41:43 +00:00
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
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
e03a56d62f [SystemZ] Add a definition of the CLC instruction
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188162 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-12 10:17:33 +00:00
Richard Sandiford
f37c8feb46 [SystemZ] Add a definition of the IPM instruction
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188161 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-12 10:05:58 +00:00
Richard Sandiford
6514751d12 [SystemZ] Update README
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188062 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-09 09:25:57 +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
NAKAMURA Takumi
8e1d64666f Target/*/CMakeLists.txt: Add the dependency to CommonTableGen explicitly for each corresponding CodeGen.
Without explicit dependencies, both per-file action and in-CommonTableGen action could run in parallel.
It races to emit *.inc files simultaneously.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187780 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-06 06:38:37 +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
ccdf5cc7bc [SystemZ] Add definitions for BRCT and BRCTG
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187721 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-05 11:07:38 +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
0e4044c233 [SystemZ] Add LOAD AND TEST instructions
Just the definitions and MC support.  The next patch uses them for codegen.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187719 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-05 11:00:53 +00:00
Richard Sandiford
66fbb47818 [SystemZ] Split out comparison elimination into a separate pass
Perhaps predictably, doing comparison elimination on the fly during
SystemZLongBranch turned out to be a bad idea.  The next patches make
use of LOAD AND TEST and BRANCH ON COUNT, both of which require
changes to earlier instructions.

No functionality change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187718 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-05 10:58:53 +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
f3068d02e5 [SystemZ] Add RISBLG and RISBHG instruction definitions
The next patch will make use of RISBLG for codegen.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187490 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-31 11:17:35 +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
Craig Topper
f63ef914b6 Split generated asm mnemonic matching table into a separate table for each asm variant.
This removes the need to store the asm variant in each row of the single table that existed before. Shaves ~16K off the size of X86AsmParser.o.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187026 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-24 07:33:14 +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
eddfaad1ef [SystemZ] Start adding z196 and zEC12 support
This first step just adds definitions for SLLK, SRLK and SRAK.
The next patch will actually make use of them during codegen.

insn-bad.s tests that some form of error is reported when using these
instructions on z10.  More work is needed to get the "instruction requires:
distinct-ops" that we'd ideally like, so I've stubbed that part out for now.
I'll come back and make it mandatory once the necessary changes are in.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186680 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-19 16:09:03 +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
efb6c52efb [SystemZ] Rename and formatting fixes
In hindsight, using "RISBG" for something that can be any type of
R.SBG instruction was a bit confusing, so this renames it to RxSBG.
That might not be the best choice either, since there is an instruction
called RXSBG, but hopefully the lower-case letter stands out enough.

While there I fixed a couple of GNUisms that had crept in --
sorry about that!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186569 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-18 09:45:08 +00:00
Aaron Ballman
7f6d84230c Silencing an MSVC warning about signed vs unsigned comparison mismatches.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186529 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-17 19:43:13 +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
c25d21e05b [SystemZ] Add MC support for R[NOX]SBG
CodeGen support will come later.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186401 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-16 11:28:08 +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
Craig Topper
a0ec3f9b7b Use SmallVectorImpl& instead of SmallVector to avoid repeating small vector size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186274 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 04:42:23 +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
5e00954197 [SystemZ] Fix parsing of inline asm registers
GPR and FPR constraints like "{r2}" and "{f2}" weren't handled correctly
because the name-to-regno mapping depends on the value type and
(because of that) the internal names in RegStrings are not the
same as the AsmName.

CC constraints like "{cc}" didn't work either because there was no
associated register class.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186148 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-12 09:08:12 +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
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
3ee0673e4f [SystemZ] Allow 8-bit operands to RISBG
RISBG has three 8-bit operands (I3, I4 and I5).  I'd originally
restricted all three to 6 bits, since that's the only range we intended
to use at the time.  However, the top bit of I4 acts as a "zero" flag for
RISBG, while the top bit of I3 acts as a "test" flag for RNSBG & co.
This patch therefore allows them to have the full 8-bit range.
I've left the fifth operand as a 6-bit value for now since the
upper 2 bits have no defined meaning.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186070 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-11 08:37:13 +00:00
Stephen Lin
e54885af9b AArch64/PowerPC/SystemZ/X86: This patch fixes the interface, usage, and all
in-tree implementations of TargetLoweringBase::isFMAFasterThanMulAndAdd in
order to resolve the following issues with fmuladd (i.e. optional FMA)
intrinsics:

1. On X86(-64) targets, ISD::FMA nodes are formed when lowering fmuladd
intrinsics even if the subtarget does not support FMA instructions, leading
to laughably bad code generation in some situations.

2. On AArch64 targets, ISD::FMA nodes are formed for operations on fp128,
resulting in a call to a software fp128 FMA implementation.

3. On PowerPC targets, FMAs are not generated from fmuladd intrinsics on types
like v2f32, v8f32, v4f64, etc., even though they promote, split, scalarize,
etc. to types that support hardware FMAs.

The function has also been slightly renamed for consistency and to force a
merge/build conflict for any out-of-tree target implementing it. To resolve,
see comments and fixed in-tree examples.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185956 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-09 18:16:56 +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
ce1c30ce39 [SystemZ] Remove unwanted part from last commit
I was originally going to use MVC for memmove too, but that's less of
a clear win.  Remove some accidental left-overs in the previous commit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185804 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-08 09:55:36 +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
e684b96e3c [SystemZ] Remove redundant frame MMOs
This fixes foldMemoryOperandImpl() so that it doesn't create duplicated
frame MMOs.  I hadn't realized when writing r185434 that it was the caller's
responsibility to add these.

No behavioural change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185704 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-05 14:31:24 +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
7271ac2c03 [SystemZ] Clean up register scavenging code
SystemZ wants normal register scavenging slots, as close to the stack or
frame pointer as possible.  The only reason it was using custom code was
because PrologEpilogInserter assumed an x86-like layout, where the frame
pointer is at the opposite end of the frame from the stack pointer.
This meant that when frame pointer elimination was disabled,
the slots ended up being as close as possible to the incoming
stack pointer, which is the opposite of what we want on SystemZ.

This patch adds a new knob to say which layout is used and converts
SystemZ to use target-independent scavenging slots.  It's one of the pieces
needed to support frame-to-frame MVCs, where two slots might be required.

The ABI requires us to allocate 160 bytes for calls, so one approach
would be to use that area as temporary spill space instead.  It would need
some surgery to make sure that the slot isn't live across a call though.

I stuck to the "isFPCloseToIncomingSP - ..." style comment on the
"do what the surrounding code does" principle.  The FP case is already
covered by several Systemz/frame-* tests, which fail without the
PrologueEpilogueInserter change, so no new ones are needed.

No behavioural change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185696 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-05 12:55:00 +00:00
Jakob Stoklund Olesen
f349a6e9e6 Remove the EXCEPTIONADDR, EHSELECTION, and LSDAADDR ISD opcodes.
These exception-related opcodes are not used any longer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185625 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-04 13:54:20 +00:00
Craig Topper
6227d5c690 Use SmallVectorImpl::iterator/const_iterator instead of SmallVector to avoid specifying the vector size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185606 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-04 01:31:24 +00:00
Jakob Stoklund Olesen
c93822901a Revert r185595-185596 which broke buildbots.
Revert "Simplify landing pad lowering."
Revert "Remove the EXCEPTIONADDR, EHSELECTION, and LSDAADDR ISD opcodes."

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185600 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-04 00:26:30 +00:00
Jakob Stoklund Olesen
62204220e1 Remove the EXCEPTIONADDR, EHSELECTION, and LSDAADDR ISD opcodes.
These exception-related opcodes are not used any longer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185596 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-03 23:56:31 +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
b997b56383 [SystemZ] Rename mapping table fields
Rename Function->DispKey and PairType->DispSize.  I'd originally used
"Function" because I thought it might be useful for other InstMappings.
However, it turns out that having two very similar instructions with the
same Function makes it pretty useless for anything other than the displacement
size key.  Other InstMappings will want the key to be defined for only one
instruction in the pair.

No behavioural change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185526 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-03 09:19:58 +00:00
Richard Sandiford
52c28b07f0 [SystemZ] Fix caller-allocated save slot FIXME
Get rid of some old code (and associated FIXME) for handling the
caller-allocated register save area.  No behavioural change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185525 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-03 09:11:00 +00:00
NAKAMURA Takumi
985148ea87 SystemZInstrInfo.cpp: Tweak an assertion. [-Wunused-variable]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185499 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-03 02:20:49 +00:00
Benjamin Kramer
24dd7dbe7f SystemZ: Fold variable into assertion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185475 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-02 21:17:31 +00:00
Rafael Espindola
a3863ea2da Remove address spaces from MC.
This is dead code since PIC16 was removed in 2010. The result was an odd mix,
where some parts would carefully pass it along and others would assert it was
zero (most of the object streamer for example).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185436 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-02 15:49:13 +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
Richard Sandiford
9188443a2d [SystemZ] Add the MVC instruction
This is the first use of D(L,B) addressing, which required a fair bit
of surgery.  For that reason, the patch just adds the instruction
definition and the associated assembler and disassembler support.
A later patch will actually make use of it for codegen.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185433 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-02 14:56:45 +00:00
Richard Sandiford
7d884e4636 [SystemZ] Allow LA and LARL to be rematerialized
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185069 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 09:42:10 +00:00
Richard Sandiford
a6e12b5756 [SystemZ] Allow immediate moves to be rematerialized
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185068 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 09:38:48 +00:00
Richard Sandiford
722e9e6d0a [SystemZ] Add conditional store patterns
Add pseudo conditional store instructions, so that we use:

    branch foo:
    store
foo:

instead of:

    load
    branch foo:
    move
foo:
    store

z196 has real 32-bit and 64-bit conditional stores, but we don't use
any z196 instructions yet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185065 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-27 09:27:40 +00:00
Chad Rosier
5b3fca50a0 The getRegForInlineAsmConstraint function should only accept MVT value types.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184642 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-22 18:37:38 +00:00
Bill Wendling
99cb622041 Use pointers to the MCAsmInfo and MCRegInfo.
Someone may want to do something crazy, like replace these objects if they
change or something.

No functionality change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184175 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-18 07:20:20 +00:00
Bill Wendling
fc61b6f111 Don't cache the instruction and register info from the TargetMachine, because
the internals of TargetMachine could change.

No functionality change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183567 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-07 20:42:15 +00:00
Ahmed Bougacha
23ed37a6b7 Make SubRegIndex size mandatory, following r183020.
This also makes TableGen able to compute sizes/offsets of synthesized
indices representing tuples.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183061 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-31 23:45:26 +00:00
Ahmed Bougacha
bed2308186 Add a way to define the bit range covered by a SubRegIndex.
NOTE: If this broke your out-of-tree backend, in *RegisterInfo.td, change
the instances of SubRegIndex that have a comps template arg to use the
ComposedSubRegIndex class instead.

In TableGen land, this adds Size and Offset attributes to SubRegIndex,
and the ComposedSubRegIndex class, for which the Size and Offset are
computed by TableGen. This also adds an accessor in MCRegisterInfo, and
Size/Offsets for the X86 and ARM subreg indices.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183020 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-31 17:08:36 +00:00
Richard Sandiford
b6606e46ab [SystemZ] Don't use LOAD and STORE REVERSED for volatile accesses
Unlike most -- hopefully "all other", but I'm still checking -- memory
instructions we support, LOAD REVERSED and STORE REVERSED may access
the memory location several times.  This means that they are not suitable
for volatile loads and stores.

This patch is a prerequisite for better atomic load and store support.
The same principle applies there: almost all memory instructions we
support are inherently atomic ("block concurrent"), but LOAD REVERSED
and STORE REVERSED are exceptions.

Other instructions continue to allow volatile operands.  I will add
positive "allows volatile" tests at the same time as the "allows atomic
load or store" tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183002 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-31 13:25:22 +00:00
Richard Sandiford
14a926f13b [SystemZ] Enable unaligned accesses
The code to distinguish between unaligned and aligned addresses was
already there, so this is mostly just a switch-on-and-test process.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182920 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-30 09:45:42 +00:00
Andrew Trick
6e0b2a0cb0 Order CALLSEQ_START and CALLSEQ_END nodes.
Fixes PR16146: gdb.base__call-ar-st.exp fails after
pre-RA-sched=source fixes.

Patch by Xiaoyi Guo!

This also fixes an unsupported dbg.value test case. Codegen was
previously incorrect but the test was passing by luck.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182885 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-29 22:03:55 +00:00
Richard Sandiford
2d664abbfc [SystemZ] Immediate compare-and-branch support
This patch adds support for the CIJ and CGIJ instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182846 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-29 11:58:52 +00:00
Richard Sandiford
d50bcb2162 [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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182764 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-28 10:41:11 +00:00
Richard Sandiford
06c3c9a9e1 [SystemZ] Tweak SystemZInstrInfo::isBranch() interface
This is needed for the upcoming compare-and-branch patch.  No functional
change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182762 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-28 10:13:54 +00:00
Andrew Trick
ac6d9bec67 Track IR ordering of SelectionDAG nodes 2/4.
Change SelectionDAG::getXXXNode() interfaces as well as call sites of
these functions to pass in SDLoc instead of DebugLoc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182703 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-25 02:42:55 +00:00
Richard Sandiford
bfe3212dd8 [SystemZ] Improve AsmParser handling of invalid instructions
Previously, an invalid instruction like:

	foo     %r1, %r0

would generate the rather odd error message:

....: error: unknown token in expression
	foo     %r1, %r0
		^

We now get the more informative:

....: error: invalid instruction
	foo     %r1, %r0
	^

The same would happen if an address were used where a register was expected.
We now get "invalid operand for instruction" instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182644 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-24 14:26:46 +00:00
Richard Sandiford
f386961da3 [SystemZ] Improve AsmParser register parsing
The idea is to make sure that:

(1) "register expected" is restricted to cases where ParseRegister()
    is called and the token obviously isn't a register.

(2) "invalid register" is restricted to cases where a register-like "%..."
    sequence is found, but the "..." makes no sense.

(3) the generic "invalid operand for instruction" is used in cases where
    the wrong register type is used (GPR instead of FPR, etc.).

(4) the new "invalid register pair" is used if the register has the right type,
    but is not a valid register pair.

Testing of (1)-(3) is now restricted to regs-bad.s.  It uses a representative
instruction for each register class to make sure that only registers from
that class are accepted.

(4) is tested by both regs-bad.s (which checks all invalid register pairs)
and insn-bad.s (which tests one invalid pair for each instruction that
requires a pair).

While there, I changed "Number" to "Num" for consistency with the
operand class.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182643 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-24 14:14:38 +00:00
Benjamin Kramer
49a6a8d8f2 Remove the Copied parameter from MemoryObject::readBytes.
There was exactly one caller using this API right, the others were relying on
specific behavior of the default implementation. Since it's too hard to use it
right just remove it and standardize on the default behavior.

Defines away PR16132.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182636 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-24 10:54:58 +00:00
Richard Sandiford
dbd8eb26ce [SystemZ] Rename PSW to CC
Addresses a review comment from Ulrich Weigand.  No functional change intended.

I'm not sure whether the old TODO that this patch touches still holds,
but that's something we'd get to when adding a targetted scheduling
description.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182474 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-22 13:38:45 +00:00
Richard Sandiford
487399a60f [SystemZ] Fix thinko in long branch pass
The original version of the pass could underestimate the length of a backward
branch in cases like:

    alignment to N bytes or more
    ...
    relaxable branch A
    ...
 foo: (aligned to M<N bytes)
    ...
 bar: (aligned to N bytes)
    ...
    relaxable branch B to foo

We don't add any misalignment gap for "bar" because N bytes of alignment
had already been reached earlier in the function.  In this case, assuming
that A is relaxed can push "foo" closer to "bar", and make B appear to be
in range.  Similar problems can occur for forward branches.

I don't think it's possible to create blocks with mixed alignments as
things stand, not least because we haven't yet defined getPrefLoopAlignment()
for SystemZ (that would need benchmarking).  So I don't think we can test
this yet.

Thanks to Rafael Espíndola for spotting the bug.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182460 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-22 09:57:57 +00:00