Commit Graph

59 Commits

Author SHA1 Message Date
Sean Fertile a2f095f1a3 [PowerPC][MC] Support expressions in getMemRIX16Encoding.
Loosens an assert in getMemRIX16Encoding that restricts DQ-form instructions to
using an immediate, so that we can assemble instructions like lxv/stxv where the
offset is an expression.

Differential Revision: https://reviews.llvm.org/D51122

llvm-svn: 340761
2018-08-27 17:37:43 +00:00
Fangrui Song f78650a8de Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338293
2018-07-30 19:41:25 +00:00
Peter Collingbourne e3f652973e Support: Simplify endian stream interface. NFCI.
Provide some free functions to reduce verbosity of endian-writing
a single value, and replace the endianness template parameter with
a field.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47032

llvm-svn: 332757
2018-05-18 19:46:24 +00:00
Nemanja Ivanovic 3c7e276d24 [PowerPC] Ensure displacements for DQ-Form instructions are multiples of 16
As outlined in the PR, we didn't ensure that displacements for DQ-Form
instructions are multiples of 16. Since the instruction encoding encodes
a quad-word displacement, a sub-16 byte displacement is meaningless and
ends up being encoded incorrectly.

Fixes https://bugs.llvm.org/show_bug.cgi?id=33671.

Differential Revision: https://reviews.llvm.org/D35007

llvm-svn: 307934
2017-07-13 18:17:10 +00:00
Eugene Zelenko 8187c192c6 [PowerPC] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 291872
2017-01-13 00:58:58 +00:00
Daniel Sanders 72db2a390a Check that emitted instructions meet their predicates on all targets except ARM, Mips, and X86.
Summary:
* ARM is omitted from this patch because this check appears to expose bugs in this target.
* Mips is omitted from this patch because this check either detects bugs or deliberate
  emission of instructions that don't satisfy their predicates. One deliberate
  use is the SYNC instruction where the version with an operand is correctly
  defined as requiring MIPS32 while the version without an operand is defined
  as an alias of 'SYNC 0' and requires MIPS2.
* X86 is omitted from this patch because it doesn't use the tablegen-erated
  MCCodeEmitter infrastructure.

Patches for ARM and Mips will follow.

Depends on D25617

Reviewers: tstellarAMD, jmolloy

Subscribers: wdng, jmolloy, aemerson, rengolin, arsenm, jyknight, nemanjai, nhaehnle, tstellarAMD, llvm-commits

Differential Revision: https://reviews.llvm.org/D25618

llvm-svn: 287439
2016-11-19 13:05:44 +00:00
Nemanja Ivanovic 11049f8f07 [Power9] Part-word VSX integer scalar loads/stores and sign extend instructions
This patch corresponds to review:
https://reviews.llvm.org/D23155

This patch removes the VSHRC register class (based on D20310) and adds
exploitation of the Power9 sub-word integer loads into VSX registers as well
as vector sign extensions.
The new instructions are useful for a few purposes:

    Int to Fp conversions of 1 or 2-byte values loaded from memory
    Building vectors of 1 or 2-byte integers with values loaded from memory
    Storing individual 1 or 2-byte elements from integer vectors

This patch implements all of those uses.

llvm-svn: 283190
2016-10-04 06:59:23 +00:00
Marcin Koscielnicki 7b32957852 [PowerPC] Fix the EH_SjLj_Setup pseudo.
This instruction is just a control flow marker - it should not
actually exist in the object file.  Unfortunately, nothing catches
it before it gets to AsmPrinter.  If integrated assembler is used,
it's considered to be a normal 4-byte instruction, and emitted as
an all-0 word, crashing the program.  With external assembler,
a comment is emitted.

Fixed by setting Size to 0 and handling it in MCCodeEmitter - this
means the comment will still be emitted if integrated assembler
is not used.

This broke an ASan test, which has been disabled for a long time
as a result (see the discussion on D19657).  We can reenable it
once this lands.

llvm-svn: 267943
2016-04-28 21:24:37 +00:00
Ulrich Weigand 1931b01a64 [PowerPC] Remove incorrect use of COPY_TO_REGCLASS in fast isel
The fast isel pass currently emits a COPY_TO_REGCLASS node to convert
from a F4RC to a F8RC register class during conversion of a
floating-point number to integer. There is actually no support in the
common code instruction printers to emit COPY_TO_REGCLASS nodes, so the
PowerPC back-end has special code there to simply ignore
COPY_TO_REGCLASS.

This is correct *if and only if* the source and destination registers of
COPY_TO_REGCLASS are the same (except for the different register class).
But nothing guarantees this to be the case, and if the register
allocator does end up allocating source and destination to different
registers after all, the back-end simply generates incorrect code. I've
included a test case that shows such incorrect code generation.

However, it seems that COPY_TO_REGCLASS is actually not intended to be
used at the MI layer at all. It is used during SelectionDAG, but always
lowered to a plain COPY before emitting MI. Other back-end's fast isel
passes never emit COPY_TO_REGCLASS at all. I suspect it is simply wrong
for the PowerPC back-end to emit it here.

This patch changes the PowerPC back-end to directly emit COPY instead of
COPY_TO_REGCLASS and removes the special handling in the instruction
printers.

Differential Revision: http://reviews.llvm.org/D18605

llvm-svn: 265020
2016-03-31 14:44:50 +00:00
Kit Barton ba532dc816 [Power9] Implement new vsx instructions: load, store instructions for vector and scalar
We follow the comments mentioned in http://reviews.llvm.org/D16842#344378 to
implement this new patch.

This patch implements the following vsx instructions:

Vector load/store:
lxv lxvx lxvb16x lxvl lxvll lxvh8x lxvwsx
stxv stxvb16x stxvh8x stxvl stxvll stxvx
Scalar load/store:
lxsd lxssp lxsibzx lxsihzx
stxsd stxssp stxsibx stxsihx
21 instructions

Phabricator: http://reviews.llvm.org/D16919
llvm-svn: 262906
2016-03-08 03:49:13 +00:00
Daniel Sanders 50f17235dd Revert r247692: Replace Triple with a new TargetTuple in MCTargetDesc/* and related. NFC.
Eric has replied and has demanded the patch be reverted.

llvm-svn: 247702
2015-09-15 16:17:27 +00:00
Daniel Sanders 153010c52d Re-commit r247683: Replace Triple with a new TargetTuple in MCTargetDesc/* and related. NFC.
Summary:
This is the first patch in the series to migrate Triple's (which are ambiguous)
to TargetTuple's (which aren't).

For the moment, TargetTuple simply passes all requests to the Triple object it
holds. Once it has replaced Triple, it will start to implement the interface in
a more suitable way.

This change makes some changes to the public C++ API. In particular,
InitMCSubtargetInfo(), createMCRelocationInfo(), and createMCSymbolizer()
now take TargetTuples instead of Triples. The other public C++ API's have
been left as-is for the moment to reduce patch size.

This commit also contains a trivial patch to clang to account for the C++ API
change. Thanks go to Pavel Labath for fixing LLDB for me.

Reviewers: rengolin

Subscribers: jyknight, dschuff, arsenm, rampitec, danalbert, srhines, javed.absar, dsanders, echristo, emaste, jholewinski, tberghammer, ted, jfb, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D10969

llvm-svn: 247692
2015-09-15 14:08:28 +00:00
Daniel Sanders c40de48041 Revert r247684 - Replace Triple with a new TargetTuple ...
LLDB needs to be updated in the same commit.

llvm-svn: 247686
2015-09-15 13:46:21 +00:00
Daniel Sanders 18d4b0dab7 Replace Triple with a new TargetTuple in MCTargetDesc/* and related. NFC.
Summary:
This is the first patch in the series to migrate Triple's (which are ambiguous)
to TargetTuple's (which aren't).

For the moment, TargetTuple simply passes all requests to the Triple object it
holds. Once it has replaced Triple, it will start to implement the interface in
a more suitable way.

This change makes some changes to the public C++ API. In particular,
InitMCSubtargetInfo(), createMCRelocationInfo(), and createMCSymbolizer()
now take TargetTuples instead of Triples. The other public C++ API's have
been left as-is for the moment to reduce patch size.

This commit also contains a trivial patch to clang to account for the C++ API
change.

Reviewers: rengolin

Subscribers: jyknight, dschuff, arsenm, rampitec, danalbert, srhines, javed.absar, dsanders, echristo, emaste, jholewinski, tberghammer, ted, jfb, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D10969

llvm-svn: 247683
2015-09-15 13:17:40 +00:00
Daniel Sanders c81f450f1a Clean up redundant copies of Triple objects. NFC
Summary:

Reviewers: rengolin

Reviewed By: rengolin

Subscribers: llvm-commits, rengolin, jholewinski

Differential Revision: http://reviews.llvm.org/D10382

llvm-svn: 239823
2015-06-16 15:44:21 +00:00
Benjamin Kramer 50e2a29385 Replace custom fixed endian to raw_ostream emission with EndianStream.
Less code, clearer and more efficient. No functionality change intended.

llvm-svn: 239040
2015-06-04 15:03:02 +00:00
Pete Cooper 3de83e4098 Remove 3 includes from MCInstrDesc.h and explicitly include them where needed
llvm-svn: 237481
2015-05-15 21:58:42 +00:00
Jim Grosbach 91df21f740 MC: Update MCCodeEmitter naming. NFC.
s/EncodeInstruction/encodeInstruction/

llvm-svn: 237469
2015-05-15 19:13:16 +00:00
Jim Grosbach 63661f8d73 MC: Update MCFixup naming. NFC.
s/MCFixup::Create/MCFixup::create/

llvm-svn: 237468
2015-05-15 19:13:05 +00:00
Alexander Kornienko f817c1cb9a Use 'override/final' instead of 'virtual' for overridden methods
The patch is generated using clang-tidy misc-use-override check.

This command was used:

  tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py \
    -checks='-*,misc-use-override' -header-filter='llvm|clang' \
    -j=32 -fix -format

http://reviews.llvm.org/D8925

llvm-svn: 234679
2015-04-11 02:11:45 +00:00
Eric Christopher 0169e42c3b Remove the use of the subtarget in MCCodeEmitter creation and
update all ports accordingly. Required a couple of small rewrites
in handling subtarget features during creation in PPC.

llvm-svn: 231861
2015-03-10 22:03:14 +00:00
Aaron Ballman f9a1897c72 Removing LLVM_DELETED_FUNCTION, as MSVC 2012 was the last reason for requiring the macro. NFC; LLVM edition.
llvm-svn: 229340
2015-02-15 22:54:22 +00:00
Joerg Sonnenberger 0013b9292d Add support for SPE load/store from memory.
llvm-svn: 215220
2014-08-08 16:43:49 +00:00
Ulrich Weigand 7c3f0dc7e4 [PowerPC] Fix emitting instruction pairs on LE
My patch r204634 to emit instructions in little-endian format failed to
handle those special cases where we emit a pair of instructions from a
single LLVM MC instructions (like the bl; nop pairs used to implement
the call sequence).

In those cases, we still need to emit the "first" instruction (the one
in the more significant word) first, on both big and little endian,
and not swap them.

llvm-svn: 211171
2014-06-18 15:37:07 +00:00
Craig Topper 0d3fa92514 [C++11] Add 'override' keywords and remove 'virtual'. Additionally add 'final' and leave 'virtual' on some methods that are marked virtual without overriding anything and have no obvious overrides themselves. PowerPC edition
llvm-svn: 207504
2014-04-29 07:57:37 +00:00
Chandler Carruth 84e68b2994 [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE
definition below all of the header #include lines, lib/Target/...
edition.

llvm-svn: 206842
2014-04-22 02:41:26 +00:00
Ulrich Weigand cae3a17a21 [PowerPC] Generate little-endian object files
As a first step towards real little-endian code generation, this patch
changes the PowerPC MC layer to actually generate little-endian object
files.  This involves passing the little-endian flag through the various
layers, including down to createELFObjectWriter so we actually get basic
little-endian ELF objects, emitting instructions in little-endian order,
and handling fixups and relocations as appropriate for little-endian.

The bulk of the patch is to update most test cases in test/MC/PowerPC
to verify both big- and little-endian encodings.  (The only test cases
*not* updated are those that create actual big-endian ABI code, like
the TLS tests.)

Note that while the object files are now little-endian, the generated
code itself is not yet updated, in particular, it still does not adhere
to the ELFv2 ABI.

llvm-svn: 204634
2014-03-24 18:16:09 +00:00
Hal Finkel a7bbaf6de6 Replace PPC instruction-size code with MCInstrDesc getSize
As part of the cleanup done to enable the disassembler, the PPC instructions
now have a valid Size description field. This can now be used to replace some
custom logic in a few places to compute instruction sizes.

Patch by David Wiberg!

llvm-svn: 200623
2014-02-02 06:12:27 +00:00
David Woodhouse d2cca113df Delete MCSubtargetInfo data members from target MCCodeEmitter classes
The subtarget info is explicitly passed to the EncodeInstruction
method and we should use that subtarget info to influence any
encoding decisions.

llvm-svn: 200350
2014-01-28 23:13:25 +00:00
David Woodhouse 3fa98a65e9 Propagate MCSubtargetInfo through TableGen's getBinaryCodeForInstr()
llvm-svn: 200349
2014-01-28 23:13:18 +00:00
David Woodhouse 9784cef38d Explictly pass MCSubtargetInfo to MCCodeEmitter::EncodeInstruction()
llvm-svn: 200348
2014-01-28 23:13:07 +00:00
Roman Divacky bc1655b4b0 Use r2 when encoding tls on ppc32. Fixes PR18305.
llvm-svn: 197878
2013-12-22 10:45:37 +00:00
Bill Schmidt c763c22469 [PowerPC] Fix PR17155 - Ignore COPY_TO_REGCLASS during emit.
Fast-isel generates a COPY_TO_REGCLASS for widening f32 to f64, which
is a nop on PPC64.  This is needed to keep the register class system
happy, but on the fast-isel path it is not removed before emit as it
is for DAG select.  Ignore this op when emitting instructions.

llvm-svn: 190795
2013-09-16 17:25:12 +00:00
Ulrich Weigand 5b427591d6 [PowerPC] Support @tls in the asm parser
This adds support for the last missing construct to parse TLS-related
assembler code:
   add 3, 4, symbol@tls

The ADD8TLS currently hard-codes the @tls into the assembler string.
This cannot be handled by the asm parser, since @tls is parsed as
a symbol variant.  This patch changes ADD8TLS to have the @tls suffix
printed as symbol variant on output too, which allows us to remove
the isCodeGenOnly marker from ADD8TLS.  This in turn means that we
can add a AsmOperand to accept @tls marked symbols on input.

As a side effect, this means that the fixup_ppc_tlsreg fixup type
is no longer necessary and can be merged into fixup_ppc_nofixup.

llvm-svn: 185692
2013-07-05 12:22:36 +00:00
Ulrich Weigand 49f487e6cd [PowerPC] Use mtocrf when available
Just as with mfocrf, it is also preferable to use mtocrf instead of
mtcrf when only a single CR register is to be written.

Current code however always emits mtcrf.  This probably does not matter
when using an external assembler, since the GNU assembler will in fact
automatically replace mtcrf with mtocrf when possible.  It does create
inefficient code with the integrated assembler, however.

To fix this, this patch adds MTOCRF/MTOCRF8 instruction patterns and
uses those instead of MTCRF/MTCRF8 everything.  Just as done in the
MFOCRF patch committed as 185556, these patterns will be converted
back to MTCRF if MTOCRF is not available on the machine.

As a side effect, this allows to modify the MTCRF pattern to accept
the full range of mask operands for the benefit of the asm parser.

llvm-svn: 185561
2013-07-03 17:59:07 +00:00
Ulrich Weigand d5ebc626d5 [PowerPC] Always use mfocrf if available
When accessing just a single CR register, it is always preferable to
use mfocrf instead of mfcr, if the former is available on the CPU.

Current code makes that distinction in many, but not all places
where a single CR register value is retrieved.  One missing
location is PPCRegisterInfo::lowerCRSpilling.

To fix this and make this simpler in the future, this patch changes
the bulk of the back-end to always assume mfocrf is available and
simply generate it when needed.

On machines that actually do not support mfocrf, the instruction
is replaced by mfcr at the very end, in EmitInstruction.

This has the additional benefit that we no longer need the
MFCRpseud hack, since before EmitInstruction we always have
a MFOCRF instruction pattern, which already models data flow
as required.

The patch also adds the MFOCRF8 version of the instruction,
which was missing so far.

Except for the PPCRegisterInfo::lowerCRSpilling case, no change
in generated code intended.

llvm-svn: 185556
2013-07-03 17:05:42 +00:00
Ulrich Weigand 5143bab2f9 [PowerPC] Rework TLS call operand processing
As part of the global-dynamic and local-dynamic TLS sequences, we need
to use a special form of the call instruction:

 bl __tls_get_addr(sym@tlsld)
 bl __tls_get_addr(sym@tlsgd)

which generates two fixups.  The current implementation of this causes
problems with recognizing this form in the asm parser.  To fix this,
this patch reworks operand processing for this special form by using
a single operand to hold both __tls_get_addr and sym@tlsld and defining
a print method to output the above form, and an encoding method to
generate the two fixups.

As a side simplification, the patch replaces the two instruction
patterns BL8_NOP_TLSGD and BL8_NOP_TLSLD by a single BL8_NOP_TLS,
since the patterns already operate in an identical fashion (whether
we have a local-dynamic or global-dynamic symbol is already encoded
in the symbol modifier).

No change in code generation intended.

llvm-svn: 185477
2013-07-02 21:31:04 +00:00
Ulrich Weigand fd3ad693e8 [PowerPC] Support symbolic u16imm operands
Currently, all instructions taking s16imm operands support symbolic
operands.  However, for u16imm operands, we only support actual
immediate integers.  This causes the assembler to reject code like

  ori %r5, %r5, symbol@l

This patch changes the u16imm operand definition to likewise
accept symbolic operands.  In fact, s16imm and u16imm can
share the same encoding routine, now renamed to getImm16Encoding.

llvm-svn: 184944
2013-06-26 13:49:15 +00:00
Ulrich Weigand b6a30d159e [PowerPC] Support absolute branches
There is currently only limited support for the "absolute" variants
of branch instructions.  This patch adds support for the absolute
variants of all branches that are currently otherwise supported.

This requires adding new fixup types so that the correct variant
of relocation type can be selected by the object writer.

While the compiler will continue to usually choose the relative
branch variants, this will allow the asm parser to fully support
the absolute branches, with either immediate (numerical) or
symbolic target addresses.

No change in code generation intended.

llvm-svn: 184721
2013-06-24 11:03:33 +00:00
Bill Wendling bc07a8900c 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.

llvm-svn: 184175
2013-06-18 07:20:20 +00:00
Ulrich Weigand 2dbe06a987 [PowerPC] Fix hi/lo encoding in old-style code emitter
This patch implements the equivalent change to r182091/r182092
in the old-style code emitter.  Instead of having two separate
16-bit immediate encoding routines depending on the instruction,
this patch introduces a single encoder that checks the machine
operand flags to decide whether the low or high half of a
symbol address is required.

Since now both encoders make no further distinction between
"symbolLo" and "symbolHi", the .td operand can now use a
single getS16ImmEncoding method.

Tested by running the old-style JIT tests on 32-bit Linux.

llvm-svn: 182097
2013-05-17 14:14:12 +00:00
Ulrich Weigand 6e23ac606e [PowerPC] Merge/rename PPC fixup types
Now that fixup_ppc_ha16 and fixup_ppc_lo16 are being treated exactly
the same everywhere, it no longer makes sense to have two fixup types.

This patch merges them both into a single type fixup_ppc_half16,
and renames fixup_ppc_lo16_ds to fixup_ppc_half16ds for consistency.
(The half16 and half16ds names are taken from the description of
relocation types in the PowerPC ABI.)

No change in code generation expected.

llvm-svn: 182092
2013-05-17 12:37:21 +00:00
Ulrich Weigand 9d980cbdb9 [PowerPC] Use true offset value in "memrix" machine operands
This is the second part of the change to always return "true"
offset values from getPreIndexedAddressParts, tackling the
case of "memrix" type operands.

This is about instructions like LD/STD that only have a 14-bit
field to encode immediate offsets, which are implicitly extended
by two zero bits by the machine, so that in effect we can access
16-bit offsets as long as they are a multiple of 4.

The PowerPC back end currently handles such instructions by
carrying the 14-bit value (as it will get encoded into the
actual machine instructions) in the machine operand fields
for such instructions.  This means that those values are
in fact not the true offset, but rather the offset divided
by 4 (and then truncated to an unsigned 14-bit value).

Like in the case fixed in r182012, this makes common code
operations on such offset values not work as expected.
Furthermore, there doesn't really appear to be any strong
reason why we should encode machine operands this way.

This patch therefore changes the encoding of "memrix" type
machine operands to simply contain the "true" offset value
as a signed immediate value, while enforcing the rules that
it must fit in a 16-bit signed value and must also be a
multiple of 4.

This change must be made simultaneously in all places that
access machine operands of this type.  However, just about
all those changes make the code simpler; in many cases we
can now just share the same code for memri and memrix
operands.

llvm-svn: 182032
2013-05-16 17:58:02 +00:00
Ulrich Weigand 2fb140ef31 [PowerPC] Remove need for adjustFixupOffst hack
Now that applyFixup understands differently-sized fixups, we can define
fixup_ppc_lo16/fixup_ppc_lo16_ds/fixup_ppc_ha16 to properly be 2-byte
fixups, applied at an offset of 2 relative to the start of the 
instruction text.

This has the benefit that if we actually need to generate a real
relocation record, its address will come out correctly automatically,
without having to fiddle with the offset in adjustFixupOffset.

Tested on both 64-bit and 32-bit PowerPC, using external and
integrated assembler.

llvm-svn: 181894
2013-05-15 15:07:06 +00:00
Hal Finkel feea653974 PPC: Use HWEncoding and TRI->getEncodingValue
As pointed out by Jakob, we don't need to maintain a separate
register-numbering table. Instead we should let TableGen generate the table for
us from the information (already present) in PPCRegisterInfo.td.
TRI->getEncodingValue is now used to access register-encoding values.

No functionality change intended.

llvm-svn: 178067
2013-03-26 20:08:20 +00:00
Ulrich Weigand 3e1860150d PowerPC: Simplify handling of fixups.
MCTargetDesc/PPCMCCodeEmitter.cpp current has code like:

 if (isSVR4ABI() && is64BitMode())
   Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
                                    (MCFixupKind)PPC::fixup_ppc_toc16));
 else
   Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
                                    (MCFixupKind)PPC::fixup_ppc_lo16));

This is a problem for the asm parser, since it requires knowledge of
the ABI / 64-bit mode to be set up.  However, more fundamentally,
at this point we shouldn't make such distinctions anyway; in an assembler
file, it always ought to be possible to e.g. generate TOC relocations even
when the main ABI is one that doesn't use TOC.

Fortunately, this is actually completely unnecessary; that code was added
to decide whether to generate TOC relocations, but that information is in
fact already encoded in the VariantKind of the underlying symbol.

This commit therefore merges those fixup types into one, and then decides
which relocation to use based on the VariantKind.

No changes in generated code.

llvm-svn: 178007
2013-03-26 10:56:47 +00:00
Ulrich Weigand f62e83f415 Remove ABI-duplicated call instruction patterns.
We currently have a duplicated set of call instruction patterns depending
on the ABI to be followed (Darwin vs. Linux).  This is a bit odd; while the
different ABIs will result in different instruction sequences, the actual
instructions themselves ought to be independent of the ABI.  And in fact it
turns out that the only nontrivial difference between the two sets of
patterns is that in the PPC64 Linux ABI, the instruction used for indirect
calls is marked to take X11 as extra input register (which is indeed used
only with that ABI to hold an incoming environment pointer for nested
functions).  However, this does not need to be hard-coded at the .td
pattern level; instead, the C++ code expanding calls can simply add that
use, just like it adds uses for argument registers anyway.

No change in generated code expected.

llvm-svn: 177735
2013-03-22 15:24:13 +00:00
Bill Schmidt 9f0b4ec0f5 This patch improves the 64-bit PowerPC InitialExec TLS support by providing
for a wider range of GOT entries that can hold thread-relative offsets.
This matches the behavior of GCC, which was not documented in the PPC64 TLS
ABI.  The ABI will be updated with the new code sequence.

Former sequence:

  ld 9,x@got@tprel(2)
  add 9,9,x@tls

New sequence:

  addis 9,2,x@got@tprel@ha
  ld 9,x@got@tprel@l(9)
  add 9,9,x@tls

Note that a linker optimization exists to transform the new sequence into
the shorter sequence when appropriate, by replacing the addis with a nop
and modifying the base register and relocation type of the ld.

llvm-svn: 170209
2012-12-14 17:02:38 +00:00
Bill Schmidt 24b8dd6eb7 This patch implements local-dynamic TLS model support for the 64-bit
PowerPC target.  This is the last of the four models, so we now have 
full TLS support.

This is mostly a straightforward extension of the general dynamic model.
I had to use an additional Chain operand to tie ADDIS_DTPREL_HA to the
register copy following ADDI_TLSLD_L; otherwise everything above the
ADDIS_DTPREL_HA appeared dead and was removed.

As before, there are new test cases to test the assembly generation, and
the relocations output during integrated assembly.  The expected code
gen sequence can be read in test/CodeGen/PowerPC/tls-ld.ll.

There are a couple of things I think can be done more efficiently in the
overall TLS code, so there will likely be a clean-up patch forthcoming;
but for now I want to be sure the functionality is in place.

Bill

llvm-svn: 170003
2012-12-12 19:29:35 +00:00
Bill Schmidt c56f1d34bc This patch implements the general dynamic TLS model for 64-bit PowerPC.
Given a thread-local symbol x with global-dynamic access, the generated
code to obtain x's address is:

     Instruction                            Relocation            Symbol
  addis ra,r2,x@got@tlsgd@ha           R_PPC64_GOT_TLSGD16_HA       x
  addi  r3,ra,x@got@tlsgd@l            R_PPC64_GOT_TLSGD16_L        x
  bl __tls_get_addr(x@tlsgd)           R_PPC64_TLSGD                x
                                       R_PPC64_REL24           __tls_get_addr
  nop
  <use address in r3>

The implementation borrows from the medium code model work for introducing
special forms of ADDIS and ADDI into the DAG representation.  This is made
slightly more complicated by having to introduce a call to the external
function __tls_get_addr.  Using the full call machinery is overkill and,
more importantly, makes it difficult to add a special relocation.  So I've
introduced another opcode GET_TLS_ADDR to represent the function call, and
surrounded it with register copies to set up the parameter and return value.

Most of the code is pretty straightforward.  I ran into one peculiarity
when I introduced a new PPC opcode BL8_NOP_ELF_TLSGD, which is just like
BL8_NOP_ELF except that it takes another parameter to represent the symbol
("x" above) that requires a relocation on the call.  Something in the 
TblGen machinery causes BL8_NOP_ELF and BL8_NOP_ELF_TLSGD to be treated
identically during the emit phase, so this second operand was never
visited to generate relocations.  This is the reason for the slightly
messy workaround in PPCMCCodeEmitter.cpp:getDirectBrEncoding().

Two new tests are included to demonstrate correct external assembly and
correct generation of relocations using the integrated assembler.

Comments welcome!

Thanks,
Bill

llvm-svn: 169910
2012-12-11 20:30:11 +00:00