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Commit Graph

303 Commits

Author SHA1 Message Date
Strahinja Petrovic
9cbffd73fc [PowerPC] fix passing long double arguments to function (soft-float)
This patch fixes passing long double type arguments to function in 
soft float mode. If there is less than 4 argument registers free 
(long double type is mapped in 4 gpr registers in soft float mode) 
long double type argument must be passed through stack.
Differential Revision: https://reviews.llvm.org/D20114.

llvm-svn: 277804
2016-08-05 08:47:26 +00:00
Nemanja Ivanovic
80f31713ec [Power9] Add codegen for VSX word insert/extract instructions
This patch corresponds to review:
http://reviews.llvm.org/D20239

It adds exploitation of XXINSERTW and XXEXTRACTUW instructions that
are useful in some cases for inserting and extracting vector elements of
v4[if]32 vectors.

llvm-svn: 275215
2016-07-12 21:00:10 +00:00
Nemanja Ivanovic
9bdd9cede2 [PowerPC] Cannonicalize applicable vector shift immediates as swaps
This patch corresponds to review:
http://reviews.llvm.org/D21358

Vector shifts that have the same semantics as a vector swap are cannonicalized
as such to provide additional opportunities for swap removal optimization to
remove unnecessary swaps.

llvm-svn: 275168
2016-07-12 12:16:27 +00:00
Eric Christopher
21a19f0bb6 Rename argument for consistency.
llvm-svn: 274717
2016-07-07 01:08:23 +00:00
Eric Christopher
c576377764 Remove the plumbing for isDarwinABI from EmitTailCallLoadFPAndRetAddr.
llvm-svn: 274716
2016-07-07 01:08:21 +00:00
Eric Christopher
516f19cc78 Remove unnecessary subtarget parameters in PPCTargetLowering.
llvm-svn: 274709
2016-07-07 00:39:27 +00:00
Nemanja Ivanovic
f7fafe4ce2 [PowerPC] - Legalize vector types by widening instead of integer promotion
This patch corresponds to review:
http://reviews.llvm.org/D20443

It changes the legalization strategy for illegal vector types from integer
promotion to widening. This only applies for vectors with elements of width
that is a multiple of a byte since we have hardware support for vectors with
1, 2, 3, 8 and 16 byte elements.
Integer promotion for vectors is quite expensive on PPC due to the sequence
of breaking apart the vector, extending the elements and reconstituting the
vector. Two of these operations are expensive.
This patch causes between minor and major improvements in performance on most
benchmarks. There are very few benchmarks whose performance regresses. These
regressions can be handled in a subsequent patch with a DAG combine (similar
to how this patch handles int -> fp conversions of illegal vector types).

llvm-svn: 274535
2016-07-05 09:22:29 +00:00
Duncan P. N. Exon Smith
6e80950911 CodeGen: Use MachineInstr& in TargetLowering, NFC
This is a mechanical change to make TargetLowering API take MachineInstr&
(instead of MachineInstr*), since the argument is expected to be a valid
MachineInstr.  In one case, changed a parameter from MachineInstr* to
MachineBasicBlock::iterator, since it was used as an insertion point.

As a side effect, this removes a bunch of MachineInstr* to
MachineBasicBlock::iterator implicit conversions, a necessary step
toward fixing PR26753.

llvm-svn: 274287
2016-06-30 22:52:52 +00:00
Benjamin Kramer
e80783f62f Pass DebugLoc and SDLoc by const ref.
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.

llvm-svn: 272512
2016-06-12 15:39:02 +00:00
Nemanja Ivanovic
d6a1215edc [PowerPC] Generate VSX version of splat word
This patch corresponds to review:
http://reviews.llvm.org/D18592

It allows the PPC back end to generate the xxspltw instruction where we
previously only emitted vspltw.

llvm-svn: 268516
2016-05-04 16:04:02 +00:00
Tim Shen
a12f27cb73 [PPC, SSP] Support PowerPC Linux stack protection.
llvm-svn: 266809
2016-04-19 20:14:52 +00:00
Chuang-Yu Cheng
6e4b4f696f CXX_FAST_TLS calling convention: performance improvement for PPC64
This is the same change on PPC64 as r255821 on AArch64. I have even borrowed
his commit message.

The access function has a short entry and a short exit, the initialization
block is only run the first time. To improve the performance, we want to
have a short frame at the entry and exit.

We explicitly handle most of the CSRs via copies. Only the CSRs that are not
handled via copies will be in CSR_SaveList.

Frame lowering and prologue/epilogue insertion will generate a short frame
in the entry and exit according to CSR_SaveList. The majority of the CSRs will
be handled by register allcoator. Register allocator will try to spill and
reload them in the initialization block.

We add CSRsViaCopy, it will be explicitly handled during lowering.

1> we first set FunctionLoweringInfo->SplitCSR if conditions are met (the target
   supports it for the given machine function and the function has only return
   exits). We also call TLI->initializeSplitCSR to perform initialization.
2> we call TLI->insertCopiesSplitCSR to insert copies from CSRsViaCopy to
   virtual registers at beginning of the entry block and copies from virtual
   registers to CSRsViaCopy at beginning of the exit blocks.
3> we also need to make sure the explicit copies will not be eliminated.

Author: Tom Jablin (tjablin)
Reviewers: hfinkel kbarton cycheng

http://reviews.llvm.org/D17533

llvm-svn: 265781
2016-04-08 12:04:32 +00:00
Chuang-Yu Cheng
de5217e247 [ppc64] Enable sibling call optimization on ppc64 ELFv1/ELFv2 abi
This patch enable sibling call optimization on ppc64 ELFv1/ELFv2 abi, and
add a couple of test cases. This patch also passed llvm/clang bootstrap
test, and spec2006 build/run/result validation.

Original issue: https://llvm.org/bugs/show_bug.cgi?id=25617

Great thanks to Tom's (tjablin) help, he contributed a lot to this patch.
Thanks Hal and Kit's invaluable opinions!

Reviewers: hfinkel kbarton

http://reviews.llvm.org/D16315

llvm-svn: 265506
2016-04-06 02:04:38 +00:00
James Y Knight
4b163a5aa3 Tweak some atomics functions in preparation for larger changes; NFC.
- Rename getATOMIC to getSYNC, as llvm will soon be able to emit both
  '__sync' libcalls and '__atomic' libcalls, and this function is for
  the '__sync' ones.

- getInsertFencesForAtomic() has been replaced with
  shouldInsertFencesForAtomic(Instruction), so that the decision can be
  made per-instruction. This functionality will be used soon.

- emitLeadingFence/emitTrailingFence are no longer called if
  shouldInsertFencesForAtomic returns false, and thus don't need to
  check the condition themselves.

llvm-svn: 263665
2016-03-16 22:12:04 +00:00
Petar Jovanovic
6b5f6d05bd [Power PC] llvm soft float support for ppc32
This is the second in a set of patches for soft float support for ppc32,
it enables soft float operations.

Patch by Strahinja Petrovic.

Differential Revision: http://reviews.llvm.org/D13700

llvm-svn: 255516
2015-12-14 17:57:33 +00:00
Yury Gribov
8eadab0fdb Introduce new @llvm.get.dynamic.area.offset.i{32, 64} intrinsics.
The @llvm.get.dynamic.area.offset.* intrinsic family is used to get the offset
from native stack pointer to the address of the most recent dynamic alloca on
the caller's stack. These intrinsics are intendend for use in combination with
@llvm.stacksave and @llvm.restore to get a pointer to the most recent dynamic
alloca. This is useful, for example, for AddressSanitizer's stack unpoisoning
routines.

Patch by Max Ostapenko.

Differential Revision: http://reviews.llvm.org/D14983

llvm-svn: 254404
2015-12-01 11:40:55 +00:00
Joseph Tremoulet
6a3a04f00f [WinEH] Update exception pointer registers
Summary:
The CLR's personality routine passes these in rdx/edx, not rax/eax.

Make getExceptionPointerRegister a virtual method parameterized by
personality function to allow making this distinction.

Similarly make getExceptionSelectorRegister a virtual method parameterized
by personality function, for symmetry.


Reviewers: pgavlin, majnemer, rnk

Subscribers: jyknight, dsanders, llvm-commits

Differential Revision: http://reviews.llvm.org/D14344

llvm-svn: 252383
2015-11-07 01:11:31 +00:00
Sanjay Patel
f59ca7d0e7 fix TLI's combineRepeatedFPDivisors interface to return the minimum user threshold
This fix was suggested as part of D11345 and is part of fixing PR24141.

With this change, we can avoid walking the uses of a divisor node if the target
doesn't want the combineRepeatedFPDivisors transform in the first place.

There is no NFC-intended other than that.

Differential Revision: http://reviews.llvm.org/D11531

llvm-svn: 243498
2015-07-28 23:05:48 +00:00
Hal Finkel
f91045042a [PowerPC] Support the nest parameter attribute
This adds support for the 'nest' attribute, which allows the static chain
register to be set for functions calls under non-Darwin PPC/PPC64 targets. r11
is the chain register (which the PPC64 ELF ABI calls the "environment
pointer"). For indirect calls under PPC64 ELFv1, this would normally be loaded
from the function descriptor, but providing an explicit 'nest' parameter will
override that process and use the value provided.

This allows __builtin_call_with_static_chain to work as expected on PowerPC.

llvm-svn: 241984
2015-07-12 00:37:44 +00:00
Pat Gavlin
a6d3ba4544 Allow {e,r}bp as the target of {read,write}_register.
This patch allows the read_register and write_register intrinsics to
read/write the RBP/EBP registers on X86 iff the targeted register is
the frame pointer for the containing function.

Differential Revision: http://reviews.llvm.org/D10977

llvm-svn: 241827
2015-07-09 17:40:29 +00:00
Mehdi Amini
d5d8989892 Re-instate the EVT parameter to getScalarShiftAmountTy() for OOT user
A documentation for this function would be nice by the way.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241807
2015-07-09 15:12:23 +00:00
Mehdi Amini
761f22ac31 Make isLegalAddressingMode() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, llvm-commits, rafael, yaron.keren

Differential Revision: http://reviews.llvm.org/D11040

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241778
2015-07-09 02:09:40 +00:00
Mehdi Amini
fd227e0aee Make getByValTypeAlignment() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11038

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241777
2015-07-09 02:09:28 +00:00
Mehdi Amini
547576cef1 Make TargetLowering::getShiftAmountTy() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, llvm-commits, rafael, yaron.keren

Differential Revision: http://reviews.llvm.org/D11037

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241776
2015-07-09 02:09:20 +00:00
Mehdi Amini
abf873c623 Make TargetLowering::getPointerTy() taking DataLayout as an argument
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: jholewinski, ted, yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11028

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 241775
2015-07-09 02:09:04 +00:00
Benjamin Kramer
89b0e53c15 [TargetLowering] StringRefize asm constraint getters.
There is some functional change here because it changes target code from
atoi(3) to StringRef::getAsInteger which has error checking. For valid
constraints there should be no difference.

llvm-svn: 241411
2015-07-05 19:29:18 +00:00
Kit Barton
230223268c [PPC] Implement vmrgew and vmrgow instructions
This patch adds support for the vector merge even word and vector merge odd word
instructions introduced in POWER8.

Phabricator review: http://reviews.llvm.org/D10704

llvm-svn: 240650
2015-06-25 15:17:40 +00:00
Alexander Kornienko
f993659b8f Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
2015-06-23 09:49:53 +00:00
Alexander Kornienko
40cb19d802 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
Matt Arsenault
b0334192af Add address space argument to isLegalAddressingMode
This is important because of different addressing modes
depending on the address space for GPU targets.

This only adds the argument, and does not update
any of the uses to provide the correct address space.

llvm-svn: 238723
2015-06-01 05:31:59 +00:00
Bill Schmidt
e55f451b6f [PPC64] Add support for clrbhrb, mfbhrbe, rfebb.
This patch adds support for the ISA 2.07 additions involving the
branch history rolling buffer and event-based branching.  These will
not be used by typical applications, so built-in support is not
required.  They will only be available via inline assembly.

Assembly/disassembly tests are included in the patch.

llvm-svn: 238032
2015-05-22 16:44:10 +00:00
Bill Schmidt
d115a77d30 [PPC64] Add vector pack/unpack support from ISA 2.07
This patch adds support for the following new instructions in the
Power ISA 2.07:

  vpksdss
  vpksdus
  vpkudus
  vpkudum
  vupkhsw
  vupklsw

These instructions are available through the vec_packs, vec_packsu,
vec_unpackh, and vec_unpackl built-in interfaces.  These are
lane-sensitive instructions, so the built-ins have different
implementations for big- and little-endian, and the instructions must
be marked as killing the vector swap optimization for now.

The first three instructions perform saturating pack operations.  The
fourth performs a modulo pack operation, which means it can be
represented with a vector shuffle, and conversely the appropriate
vector shuffles may cause this instruction to be generated.  The other
instructions are only generated via built-in support for now.

Appropriate tests have been added.

There is a companion patch to clang for the rest of this support.

llvm-svn: 237499
2015-05-16 01:02:12 +00:00
Matthias Braun
3b3ecc12b2 Change getTargetNodeName() to produce compiler warnings for missing cases, fix them
llvm-svn: 236775
2015-05-07 21:33:59 +00:00
Nemanja Ivanovic
9d5491e285 Add direct moves to/from VSR and exploit them for FP/INT conversions
This patch corresponds to review:
http://reviews.llvm.org/D8928

It adds direct move instructions to/from VSX registers to GPR's. These are
exploited for FP <-> INT conversions.

llvm-svn: 234682
2015-04-11 10:40:42 +00:00
Bill Schmidt
3f570f996a [PowerPC] Enable splat generation for BUILD_VECTOR with little endian
When enabling PPC64LE, I disabled some optimizations of BUILD_VECTOR
nodes for little endian because wrong results were produced.  I've
subsequently investigated and found this is due to a call to
BuildVectorSDNode::isConstantSplat that was always specifying
big-endian.  With this changed to correctly identify the target
endianness, the optimizations work as expected.

I found another case of a call to the same method with big-endian
hardcoded, in PPC::isAllNegativeZeroVector().  I discovered this was
an orphaned method with no callers, so I've just removed it.

The existing test/CodeGen/PowerPC/vec_constants.ll checks these
optimizations, so for testing I've just added a variant for little
endian.

llvm-svn: 234011
2015-04-03 13:48:24 +00:00
Daniel Sanders
ea09838003 [ppc] Distinguish the 'es', 'o', 'm', 'Q', 'Z', and 'Zy' inline assembly memory constraints.
Summary:
But still handle them the same way since I don't know how they differ on
this target.

Of these, 'es', and 'Q' do not have backend tests but are accepted by
clang.

No functional change intended. Depends on D8173.

Reviewers: hfinkel

Reviewed By: hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8213

llvm-svn: 232466
2015-03-17 11:09:13 +00:00
Daniel Sanders
6dc30f40bf Make each target map all inline assembly memory constraints to InlineAsm::Constraint_m. NFC.
Summary:
This is instead of doing this in target independent code and is the last
non-functional change before targets begin to distinguish between
different memory constraints when selecting code for the ISD::INLINEASM
node.

Next, each target will individually move away from the idea that all
memory constraints behave like 'm'.

Subscribers: jholewinski, llvm-commits

Differential Revision: http://reviews.llvm.org/D8173

llvm-svn: 232373
2015-03-16 13:13:41 +00:00
Nemanja Ivanovic
54958e2a25 Add support for part-word atomics for PPC
http://reviews.llvm.org/D8090#inline-67337

llvm-svn: 231843
2015-03-10 20:51:07 +00:00
Eric Christopher
454cbc40f6 getRegForInlineAsmConstraint wants to use TargetRegisterInfo for
a lookup, pass that in rather than use a naked call to getSubtargetImpl.
This involved passing down and around either a TargetMachine or
TargetRegisterInfo. Update all callers/definitions around the targets
and SelectionDAG.

llvm-svn: 230699
2015-02-26 22:38:43 +00:00
Hal Finkel
49a12f79c1 [PowerPC] Make LDtocL and friends invariant loads
LDtocL, and other loads that roughly correspond to the TOC_ENTRY SDAG node,
represent loads from the TOC, which is invariant. As a result, these loads can
be hoisted out of loops, etc. In order to do this, we need to generate
GOT-style MMOs for TOC_ENTRY, which requires treating it as a legitimate memory
intrinsic node type. Once this is done, the MMO transfer is automatically
handled for TableGen-driven instruction selection, and for nodes generated
directly in PPCISelDAGToDAG, we need to transfer the MMOs manually.

Also, we were not transferring MMOs associated with pre-increment loads, so do
that too.

Lastly, this fixes an exposed bug where R30 was not added as a defined operand of
UpdateGBR.

This problem was highlighted by an example (used to generate the test case)
posted to llvmdev by Francois Pichet.

llvm-svn: 230553
2015-02-25 21:36:59 +00:00
Hal Finkel
5752cff585 [PowerPC] Cleanup unused target-specific SDAG nodes
We had somehow accumulated a few target-specific SDAG nodes dealing with PPC64
TOC access that were referenced only in TableGen patterns. The associated
(pseudo-)instructions are used, but are being generated directly. NFC.

llvm-svn: 230518
2015-02-25 18:06:45 +00:00
Hal Finkel
67b5b15e9e [PowerPC] Add support for the QPX vector instruction set
This adds support for the QPX vector instruction set, which is used by the
enhanced A2 cores on the IBM BG/Q supercomputers. QPX vectors are 256 bytes
wide, holding 4 double-precision floating-point values. Boolean values, modeled
here as <4 x i1> are actually also represented as floating-point values
(essentially  { -1, 1 } for { false, true }). QPX shares many features with
Altivec and VSX, but is distinct from both of them. One major difference is
that, instead of adding completely-separate vector registers, QPX vector
registers are extensions of the scalar floating-point registers (lane 0 is the
corresponding scalar floating-point value). The operations supported on QPX
vectors mirrors that supported on the scalar floating-point values (with some
additional ones for permutations and logical/comparison operations).

I've been maintaining this support out-of-tree, as part of the bgclang project,
for several years. This is not the entire bgclang patch set, but is most of the
subset that can be cleanly integrated into LLVM proper at this time. Adding
this to the LLVM backend is part of my efforts to rebase bgclang to the current
LLVM trunk, but is independently useful (especially for codes that use LLVM as
a JIT in library form).

The assembler/disassembler test coverage is complete. The CodeGen test coverage
is not, but I've included some tests, and more will be added as follow-up work.

llvm-svn: 230413
2015-02-25 01:06:45 +00:00
Bill Schmidt
37700f757e [PowerPC] Fix reverted patch r227976 to avoid register assignment issues
See full discussion in http://reviews.llvm.org/D7491.

We now hide the add-immediate and call instructions together in a
separate pseudo-op, which is tagged to define GPR3 and clobber the
call-killed registers.  The PPCTLSDynamicCall pass prior to RA now
expands this op into the two separate addi and call ops, with explicit
definitions of GPR3 on both instructions, and explicit clobbers on the
call instruction.  The pass is now marked as requiring and preserving
the LiveIntervals and SlotIndexes analyses, and fixes these up after
the replacement sequences are introduced.

Self-hosting has been verified on LE P8 and BE P7 with various
optimization levels, etc.  It has also been verified with the
--no-tls-optimize flag workaround removed.

llvm-svn: 228725
2015-02-10 19:09:05 +00:00
Hal Finkel
54eff20ea7 Revert "r227976 - [PowerPC] Yet another approach to __tls_get_addr" and related fixups
Unfortunately, even with the workaround of disabling the linker TLS
optimizations in Clang restored (which has already been done), this still
breaks self-hosting on my P7 machine (-O3 -DNDEBUG -mcpu=native).

Bill is currently working on an alternate implementation to address the TLS
issue in a way that also fully elides the linker bug (which, unfortunately,
this approach did not fully), so I'm reverting this now.

llvm-svn: 228460
2015-02-06 23:07:40 +00:00
Bill Schmidt
c18bf56926 [PowerPC] Yet another approach to __tls_get_addr
This patch is a third attempt to properly handle the local-dynamic and
global-dynamic TLS models.

In my original implementation, calls to __tls_get_addr were hidden
from view until the asm-printer phase, at which point the underlying
branch-and-link instruction was created with proper relocations.  This
mostly worked well, but I used some repellent techniques to ensure
that the TLS_GET_ADDR nodes at the SD and MI levels correctly received
input from GPR3 and produced output into GPR3.  This proved to work
badly in the presence of multiple TLS variable accesses, with the
copies to and from GPR3 being scheduled incorrectly and generally
creating havoc.

In r221703, I addressed that problem by representing the calls to
__tls_get_addr as true calls during instruction lowering.  This had
the advantage of removing all of the bad hacks and relying on the
existing call machinery to properly glue the copies in place. It
looked like this was going to be the right way to go.

However, as a side effect of the recent discovery of problems with
linker optimizations for TLS, we discovered cases of suboptimal code
generation with this strategy.  The problem comes when tls_get_addr is
called for the same address, and there is a resulting CSE
opportunity.  It turns out that in such cases MachineCSE will common
the addis/addi instructions that set up the input value to
tls_get_addr, but will not common the calls themselves.  MachineCSE
does not have any machinery to common idempotent calls.  This is
perfectly sensible, since presumably this would be done at the IR
level, and introducing calls in the back end isn't commonplace.  In
any case, we end up with two calls to __tls_get_addr when one would
suffice, and that isn't good.

I presumed that the original design would have allowed commoning of
the machine-specific nodes that hid the __tls_get_addr calls, so as
suggested by Ulrich Weigand, I went back to that design and cleaned it
up so that the copies were properly held together by glue
nodes.  However, it turned out that this didn't work either...the
presence of copies to physical registers kept the machine-specific
nodes from being commoned also.

All of which leads to the design presented here.  This is a return to
the original design, except that no attempt is made to introduce
copies to and from GPR3 during instruction lowering.  Virtual registers
are used until prior to register allocation.  At that point, a special
pass is run that identifies the machine-specific nodes that hide the
tls_get_addr calls and introduces the copies to and from GPR3 around
them.  The register allocator then coalesces these copies away.  With
this design, MachineCSE succeeds in commoning tls_get_addr calls where
possible, and we get nice optimal code generation (better than GCC at
the moment, which does not common these calls).

One additional problem must be dealt with:  After introducing the
mentions of the physical register GPR3, the aggressive anti-dependence
breaker sees opportunities to improve scheduling by selecting a
different register instead.  Flags must be used on the instruction
descriptions to tell the anti-dependence breaker to keep its hands in
its pockets.

One thing missing from the original design was recording a definition
of the link register on the GET_TLS_ADDR nodes.  Doing this was found
to be insufficient to force a stack frame to be created, which led to
looping behavior because two different LR values were stored at the
same address.  This appears to have been an oversight in
PPCFrameLowering::determineFrameLayout(), which is repaired here.

Because MustSaveLR() returns true for calls to builtin_return_address,
this changed the expected behavior of
test/CodeGen/PowerPC/retaddr2.ll, which now stacks a frame but
formerly did not.  I've fixed the test case to reflect this.

There are existing TLS tests to catch regressions; the checks in
test/CodeGen/PowerPC/tls-store2.ll proved to be too restrictive in the
face of instruction scheduling with these changes, so I fixed that
up.

I've added a new test case based on the PrettyStackTrace module that
demonstrated the original problem. This checks that we get correct
code generation and that CSE of the calls to __get_tls_addr has taken
place.

llvm-svn: 227976
2015-02-03 16:16:01 +00:00
Eric Christopher
b94d514063 Remove extraneous forward declaration.
llvm-svn: 227623
2015-01-30 22:02:34 +00:00
Eric Christopher
8b69db6dc2 Use the cached subtargets and remove calls to getSubtarget/getSubtargetImpl
without a Function argument.

llvm-svn: 227622
2015-01-30 22:02:31 +00:00
Hal Finkel
dcf8b14857 [PowerPC] Loosen ELFv1 PPC64 func descriptor loads for indirect calls
Function pointers under PPC64 ELFv1 (which is used on PPC64/Linux on the
POWER7, A2 and earlier cores) are really pointers to a function descriptor, a
structure with three pointers: the actual pointer to the code to which to jump,
the pointer to the TOC needed by the callee, and an environment pointer. We
used to chain these loads, and make them opaque to the rest of the optimizer,
so that they'd always occur directly before the call. This is not necessary,
and in fact, highly suboptimal on embedded cores. Once the function pointer is
known, the loads can be performed ahead of time; in fact, they can be hoisted
out of loops.

Now these function descriptors are almost always generated by the linker, and
thus the contents of the descriptors are invariant. As a result, by default,
we'll mark the associated loads as invariant (allowing them to be hoisted out
of loops). I've added a target feature to turn this off, however, just in case
someone needs that option (constructing an on-stack descriptor, casting it to a
function pointer, and then calling it cannot be well-defined C/C++ code, but I
can imagine some JIT-compilation system doing so).

Consider this simple test:
  $ cat call.c

  typedef void (*fp)();
  void bar(fp x) {
    for (int i = 0; i < 1600000000; ++i)
      x();
  }

  $ cat main.c

  typedef void (*fp)();
  void bar(fp x);
  void foo() {}
  int main() {
    bar(foo);
  }

On the PPC A2 (the BG/Q supercomputer), marking the function-descriptor loads
as invariant brings the execution time down to ~8 seconds from ~32 seconds with
the loads in the loop.

The difference on the POWER7 is smaller. Compiling with:

  gcc -std=c99 -O3 -mcpu=native call.c main.c : ~6 seconds [this is 4.8.2]

  clang -O3 -mcpu=native call.c main.c : ~5.3 seconds

  clang -O3 -mcpu=native call.c main.c -mno-invariant-function-descriptors : ~4 seconds
  (looks like we'd benefit from additional loop unrolling here, as a first
   guess, because this is faster with the extra loads)

The -mno-invariant-function-descriptors will be added to Clang shortly.

llvm-svn: 226207
2015-01-15 21:17:34 +00:00
Hal Finkel
a11b7ea471 Revert "r225811 - Revert "r225808 - [PowerPC] Add StackMap/PatchPoint support""
This re-applies r225808, fixed to avoid problems with SDAG dependencies along
with the preceding fix to ScheduleDAGSDNodes::RegDefIter::InitNodeNumDefs.
These problems caused the original regression tests to assert/segfault on many
(but not all) systems.

Original commit message:

This commit does two things:

 1. Refactors PPCFastISel to use more of the common infrastructure for call
    lowering (this lets us take advantage of this common code for lowering some
    common intrinsics, stackmap/patchpoint among them).

 2. Adds support for stackmap/patchpoint lowering. For the most part, this is
    very similar to the support in the AArch64 target, with the obvious differences
    (different registers, NOP instructions, etc.). The test cases are adapted
    from the AArch64 test cases.

One difference of note is that the patchpoint call sequence takes 24 bytes, so
you can't use less than that (on AArch64 you can go down to 16). Also, as noted
in the docs, we take the patchpoint address to be the actual code address
(assuming the call is local in the TOC-sharing sense), which should yield
higher performance than generating the full cross-DSO indirect-call sequence
and is likely just as useful for JITed code (if not, we'll change it).

StackMaps and Patchpoints are still marked as experimental, and so this support
is doubly experimental. So go ahead and experiment!

llvm-svn: 225909
2015-01-14 01:07:51 +00:00
Hal Finkel
c6fdfe466f Revert "r225808 - [PowerPC] Add StackMap/PatchPoint support"
Reverting this while I investiage buildbot failures (segfaulting in
GetCostForDef at ScheduleDAGRRList.cpp:314).

llvm-svn: 225811
2015-01-13 18:25:05 +00:00