Commit Graph

75 Commits

Author SHA1 Message Date
Marcin Koscielnicki 3fdc257d6a [AArch64] [ARM] Make a target-independent llvm.thread.pointer intrinsic.
Both AArch64 and ARM support llvm.<arch>.thread.pointer intrinsics that
just return the thread pointer.  I have a pending patch that does the same
for SystemZ (D19054), and there are many more targets that could benefit
from one.

This patch merges the ARM and AArch64 intrinsics into a single target
independent one that will also be used by subsequent targets.

Differential Revision: http://reviews.llvm.org/D19098

llvm-svn: 266818
2016-04-19 20:51:05 +00:00
Sanjay Patel fdf0d5ffc6 try to make comments more meaningful; NFC
Retry r266541 without the range-based-for-loop-change that was wrong.

llvm-svn: 266658
2016-04-18 19:11:57 +00:00
Duncan P. N. Exon Smith 93f53c4262 Revert "use range loop, try to make comments more meaningful; NFCI"
This reverts commit r266541 since it introduces a use-after-free:
  http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/11471

llvm-svn: 266550
2016-04-17 03:59:37 +00:00
Sanjay Patel a770a7ec5d use range loop, try to make comments more meaningful; NFCI
llvm-svn: 266541
2016-04-16 23:26:16 +00:00
Adam Nemet 7aab648831 Revert "Support arbitrary addrspace pointers in masked load/store intrinsics"
This reverts commit r266086.

It breaks the LTO build of gcc in SPEC2000.

llvm-svn: 266282
2016-04-14 08:47:17 +00:00
Artur Pilipenko dbe0bc8df4 Support arbitrary addrspace pointers in masked load/store intrinsics
This is a resubmittion of 263158 change.

This patch fixes the problem which occurs when loop-vectorize tries to use @llvm.masked.load/store intrinsic for a non-default addrspace pointer. It fails with "Calling a function with a bad signature!" assertion in CallInst constructor because it tries to pass a non-default addrspace pointer to the pointer argument which has default addrspace.

The fix is to add pointer type as another overloaded type to @llvm.masked.load/store intrinsics.

Reviewed By: reames

Differential Revision: http://reviews.llvm.org/D17270

llvm-svn: 266086
2016-04-12 15:58:04 +00:00
Tim Shen 0012756489 [SSP] Remove llvm.stackprotectorcheck.
This is a cleanup patch for SSP support in LLVM. There is no functional change.
llvm.stackprotectorcheck is not needed, because SelectionDAG isn't
actually lowering it in SelectBasicBlock; rather, it adds check code in
FinishBasicBlock, ignoring the position where the intrinsic is inserted
(See FindSplitPointForStackProtector()).

llvm-svn: 265851
2016-04-08 21:26:31 +00:00
Duncan P. N. Exon Smith efe16c8eb4 IR: Stop upgrading !llvm.loop attachments via MDString
Remove logic to upgrade !llvm.loop by changing the MDString tag
directly.  This old logic would check (and change) arbitrary strings
that had nothing to do with loop metadata.  Instead, check !llvm.loop
attachments directly, and change which strings get attached.

Rather than updating the assembly-based upgrade, drop it entirely.  It
has been quite a while since we supported upgrading textual IR.

llvm-svn: 264373
2016-03-25 00:56:13 +00:00
Matthias Braun 68bb2931cc Revert "Support arbitrary addrspace pointers in masked load/store intrinsics"
This commit broke LTO builds. Reverting it to unbreak the bots while the
issue is investigated. See also:

http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160321/341002.html

This reverts r263158

llvm-svn: 264088
2016-03-22 20:24:34 +00:00
Artur Pilipenko 3c8fc57e16 Support arbitrary addrspace pointers in masked load/store intrinsics
This patch fixes the problem which occurs when loop-vectorize tries to use @llvm.masked.load/store intrinsic for a non-default addrspace pointer. It fails with "Calling a function with a bad signature!" assertion in CallInst constructor because it tries to pass a non-default addrspace pointer to the pointer argument which has default addrspace.

The fix is to add pointer type as another overloaded type to @llvm.masked.load/store intrinsics.

Reviewed By: reames

Differential Revision: http://reviews.llvm.org/D17270

llvm-svn: 263158
2016-03-10 20:39:22 +00:00
Pete Cooper 67cf9a723b Revert "Change memcpy/memset/memmove to have dest and source alignments."
This reverts commit r253511.

This likely broke the bots in
http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787

llvm-svn: 253543
2015-11-19 05:56:52 +00:00
Pete Cooper 72bc23ef02 Change memcpy/memset/memmove to have dest and source alignments.
Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

These intrinsics currently have an explicit alignment argument which is
required to be a constant integer.  It represents the alignment of the
source and dest, and so must be the minimum of those.

This change allows source and dest to each have their own alignments
by using the alignment attribute on their arguments.  The alignment
argument itself is removed.

There are a few places in the code for which the code needs to be
checked by an expert as to whether using only src/dest alignment is
safe.  For those places, they currently take the minimum of src/dest
alignments which matches the current behaviour.

For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 500, i32 8, i1 false)
will now read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dest, i8* align 8 %src, i32 500, i1 false)

For out of tree owners, I was able to strip alignment from calls using sed by replacing:
  (call.*llvm\.memset.*)i32\ [0-9]*\,\ i1 false\)
with:
  $1i1 false)

and similarly for memmove and memcpy.

I then added back in alignment to test cases which needed it.

A similar commit will be made to clang which actually has many differences in alignment as now
IRBuilder can generate different source/dest alignments on calls.

In IRBuilder itself, a new argument was added.  Instead of calling:
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, /* isVolatile */ false)
you now call
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, SrcAlign, /* isVolatile */ false)

There is a temporary class (IntegerAlignment) which takes the source alignment and rejects
implicit conversion from bool.  This is to prevent isVolatile here from passing its default
parameter to the source alignment.

Note, changes in future can now be made to codegen.  I didn't change anything here, but this
change should enable better memcpy code sequences.

Reviewed by Hal Finkel.

llvm-svn: 253511
2015-11-18 22:17:24 +00:00
Simon Pilgrim e88dc04c48 [X86][XOP] Add support for the matching of the VPCMOV bit select instruction
XOP has the VPCMOV instruction that performs the common vector bit select operation OR( AND( SRC1, SRC3 ), AND( SRC2, ~SRC3 ) )

This patch adds tablegen pattern matching for this instruction.

Differential Revision: http://reviews.llvm.org/D8841

llvm-svn: 251975
2015-11-03 20:27:01 +00:00
Craig Topper 2626094fa1 Make a bunch of static arrays const.
llvm-svn: 250642
2015-10-18 05:15:34 +00:00
Duncan P. N. Exon Smith 52888a6738 IR: Remove implicit iterator conversions from lib/IR, NFC
Stop converting implicitly between iterators and pointers/references in
lib/IR.  For convenience, I've added a `getIterator()` accessor to
`ilist_node` so that callers don't need to know how to spell the
iterator class (i.e., they can use `X.getIterator()` instead of
`Function::iterator(X)`).

I'll eventually disallow these implicit conversions entirely, but
there's a lot of code, so it doesn't make sense to do it all in one
patch.  One library or so at a time.

Why?  To root out cases of `getNextNode()` and `getPrevNode()` being
used in iterator logic.  The design of `ilist` makes that invalid when
the current node could be at the back of the list, but it happens to
"work" right now because of a bug where those functions never return
`nullptr` if you're using a half-node sentinel.  Before I can fix the
function, I have to remove uses of it that rely on it misbehaving.
(Maybe the function should just be deleted anyway?  But I don't want
deleting it -- potentially a huge project -- to block fixing
ilist/iplist.)

llvm-svn: 249782
2015-10-08 23:49:46 +00:00
Jeroen Ketema ab99b59e8c [ARM][NEON] Use address space in vld([1234]|[234]lane) and vst([1234]|[234]lane) instructions
This commit changes the interface of the vld[1234], vld[234]lane, and vst[1234],
vst[234]lane ARM neon intrinsics and associates an address space with the
pointer that these intrinsics take. This changes, e.g.,

<2 x i32> @llvm.arm.neon.vld1.v2i32(i8*, i32)

to

<2 x i32> @llvm.arm.neon.vld1.v2i32.p0i8(i8*, i32)

This change ensures that address spaces are fully taken into account in the ARM
target during lowering of interleaved loads and stores.

Differential Revision: http://reviews.llvm.org/D12985

llvm-svn: 248887
2015-09-30 10:56:37 +00:00
Simon Pilgrim 9cb018b6b6 [X86][SSE] Replace 128-bit SSE41 PMOVSX intrinsics with native IR
This patches removes the x86.sse41.pmovsx* intrinsics, provides a suitable upgrade path and updates relevant tests to sign extend a subvector instead.

LLVM counterpart to D12835

Differential Revision: http://reviews.llvm.org/D13002

llvm-svn: 248368
2015-09-23 08:48:33 +00:00
Ahmed Bougacha b03ea02479 [X86] Require 32-byte alignment for 32-byte VMOVNTs.
We used to accept (and even test, and generate) 16-byte alignment
for 32-byte nontemporal stores, but they require 32-byte alignment,
per SDM. Found by inspection.

Instead of hardcoding 16 in the patfrag, check for natural alignment.
Also fix the autoupgrade and the various tests.

Also, use explicit -mattr instead of -mcpu: I stared at the output
several minutes wondering why I get 2x movntps for the unaligned
case (which is the ideal output, but needs some work: see FIXME),
until I remembered corei7-avx implies +slow-unaligned-mem-32.

llvm-svn: 246733
2015-09-02 23:25:39 +00:00
Ahmed Bougacha 1a498705e4 [X86] Replace avx2 broadcast intrinsics with native IR.
Since r245605, the clang headers don't use these anymore.
r245165 updated some of the tests already; update the others, add
an autoupgrade, remove the intrinsics, and cleanup the definitions.

Differential Revision: http://reviews.llvm.org/D10555

llvm-svn: 245606
2015-08-20 20:36:19 +00:00
Filipe Cabecinhas 0011c58444 Remove always-true comparison, NFC.
Summary:
Looking at r241279, I noticed that UpgradedIntrinsics only gets written
to in the following code:

    if (UpgradeIntrinsicFunction(&F, NewFn))
      UpgradedIntrinsics[&F] = NewFn;

Looking through UpgradeIntrinsicFunction, we always return false OR
NewFn will be set to a different function from our source.

This patch pulls the F != NewFn into UpgradeIntrinsicFunction as an
assert, and removes the check from callers of UpgradeIntrinsicFunction.

Reviewers: rafael, chandlerc

Subscribers: llvm-commits-list

Differential Revision: http://reviews.llvm.org/D10915

llvm-svn: 241369
2015-07-03 20:12:01 +00:00
David Blaikie 0c28fd7fda [opaque pointer type] Pass explicit type to Load instruction creation in AutoUpgrade
llvm-svn: 237838
2015-05-20 21:46:30 +00:00
Pete Cooper 9e1d335697 Change Function::getIntrinsicID() to return an Intrinsic::ID. NFC.
Now that Intrinsic::ID is a typed enum, we can forward declare it and so return it from this method.

This updates all users which were either using an unsigned to store it, or had a now unnecessary cast.

llvm-svn: 237810
2015-05-20 17:16:39 +00:00
David Blaikie ff6409d096 Simplify IRBuilder::CreateCall* by using ArrayRef+initializer_list/braced init only
llvm-svn: 237624
2015-05-18 22:13:54 +00:00
Elena Demikhovsky 3822af0715 AVX-512: Changed CC parameter in "cmp" intrinsic
from i8 to i32 according to the Intel Spec

by Igor Breger (igor.breger@intel.com)

llvm-svn: 236979
2015-05-11 09:03:14 +00:00
Elena Demikhovsky 29792e9a80 AVX-512: Added all forms of FP compare instructions for KNL and SKX.
Added intrinsics for the instructions. CC parameter of the intrinsics was changed from i8 to i32 according to the spec.

By Igor Breger (igor.breger@intel.com)

llvm-svn: 236714
2015-05-07 11:24:42 +00:00
David Blaikie 5bacf3722c [opaque pointer type] Verifier/AutoUpgrade: Remove a few uses of PointerType::getElementType
llvm-svn: 235777
2015-04-24 21:16:07 +00:00
Duncan P. N. Exon Smith 5342c6ceab AutoUpgrade: Remove obsolete dbg.declare/value upgrade
This upgrade of `@llvm.dbg.declare` and `@llvm.dbg.value` isn't useful,
since it's for an old debug info version.  The calls will get stripped
anyway by `UpgradeDebugInfo()`.

llvm-svn: 234181
2015-04-06 17:17:47 +00:00
Yaron Keren d1fdbe7c32 Trying to fix the Hexagon and debian-fast bots arm32_neon_vcnt_upgrade.ll test.
llvm-svn: 233558
2015-03-30 16:10:39 +00:00
Yaron Keren 075759aadd Remove more superfluous .str() and replace std::string concatenation with Twine.
Following r233392, http://llvm.org/viewvc/llvm-project?rev=233392&view=rev.

llvm-svn: 233555
2015-03-30 15:42:36 +00:00
Sanjay Patel 4339abe66f [X86, AVX2] Replace inserti128 and extracti128 intrinsics with generic shuffles
This should complete the job started in r231794 and continued in r232045:
We want to replace as much custom x86 shuffling via intrinsics
as possible because pushing the code down the generic shuffle
optimization path allows for better codegen and less complexity
in LLVM.

AVX2 introduced proper integer variants of the hacked integer insert/extract
C intrinsics that were created for this same functionality with AVX1.

This should complete the removal of insert/extract128 intrinsics.

The Clang precursor patch for this change was checked in at r232109.

llvm-svn: 232120
2015-03-12 23:16:18 +00:00
Sanjay Patel 7b079fb219 make an array of constants explicitly const
Suggested by Craig Topper in D8184.

This goes with r232047.

llvm-svn: 232056
2015-03-12 16:29:58 +00:00
Sanjay Patel 2db6d3899b IRBuilder: add a CreateShuffleVector function that takes an ArrayRef of int
This is a convenience function to ease mask creation of ShuffleVectors
in AutoUpgrade and other places.

Differential Revision: http://reviews.llvm.org/D8184

llvm-svn: 232047
2015-03-12 15:27:07 +00:00
Sanjay Patel af1846c097 [X86, AVX] replace vextractf128 intrinsics with generic shuffles
Now that we've replaced the vinsertf128 intrinsics, 
do the same for their extract twins.

This is very much like D8086 (checked in at r231794):
We want to replace as much custom x86 shuffling via intrinsics
as possible because pushing the code down the generic shuffle
optimization path allows for better codegen and less complexity
in LLVM.

This is also the LLVM sibling to the cfe D8275 patch.

Differential Revision: http://reviews.llvm.org/D8276

llvm-svn: 232045
2015-03-12 15:15:19 +00:00
Sanjay Patel 19792fb270 [X86, AVX] replace vinsertf128 intrinsics with generic shuffles
We want to replace as much custom x86 shuffling via intrinsics
as possible because pushing the code down the generic shuffle
optimization path allows for better codegen and less complexity
in LLVM.

This is the sibling patch for the Clang half of this change:
http://reviews.llvm.org/D8088

Differential Revision: http://reviews.llvm.org/D8086

llvm-svn: 231794
2015-03-10 16:08:36 +00:00
Juergen Ributzka 1f7a17661c Remove 'llvm.x86.avx2.vbroadcasti128' intrinsic.
The intrinsic is no longer generated by the front-end. Remove the intrinsic and
auto-upgrade it to a vector shuffle.

Reviewed by Nadav

This is related to rdar://problem/18742778.

llvm-svn: 231182
2015-03-04 00:13:25 +00:00
Sanjay Patel 1c3eaecc09 fix typo; NFC
llvm-svn: 230876
2015-02-28 22:25:06 +00:00
Craig Topper 782d620657 [X86] Remove the blendpd/blendps/pblendw/pblendd intrinsics. They can represented by shuffle_vector instructions.
llvm-svn: 230860
2015-02-28 19:33:17 +00:00
Craig Topper b324e43aed [X86] Remove AVX2 and SSE2 pslldq and psrldq intrinsics. We can represent them in IR with vector shuffles now. All their uses have been removed from clang in favor of shuffles.
llvm-svn: 229640
2015-02-18 06:24:44 +00:00
Craig Topper 49df44e2e2 [X86] Remove the multiply by 8 that goes into the shift constant for X86ISD::VSHLDQ and X86ISD::VSRLDQ. This simplifies the pattern matching in isel and allows these nodes to become the patterns embedded in the instruction.
llvm-svn: 229431
2015-02-16 20:52:07 +00:00
Craig Topper 44026efa88 [X86] Remove x86.avx2.psll.dq.bs and x86.avx2.psrl.dq.bs intrinsics.
llvm-svn: 229430
2015-02-16 20:51:59 +00:00
Craig Topper e32546dd29 [X86] Fix XOP vpcom intrinsic autoupgrade to map 'true' and 'false' to the correct immediates. Seems they were swapped.
llvm-svn: 229077
2015-02-13 07:42:15 +00:00
Craig Topper 4e0700f365 [X86] Remove int_x86_sse2_psll_dq_bs and int_x86_sse2_psrl_dq_bs intrinsics. The builtins aren't used by clang.
llvm-svn: 229069
2015-02-13 06:07:24 +00:00
Craig Topper 29f2e95185 [X86] Use i8 immediate for comparison type on AVX512 packed integer instructions. This matches floating point equivalents. Includes autoupgrade support to convert old code.
llvm-svn: 227063
2015-01-25 23:26:02 +00:00
Craig Topper f4bf9119a1 [x86] Change AVX512 intrinsics to take a 8-bit immediate for the comparision kind instead of a 32-bit immediate. This better aligns with the emitted instruction. It also matches SSE and AVX1 equivalents. Also add auto upgrade support.
llvm-svn: 226430
2015-01-19 06:07:27 +00:00
Chandler Carruth d9903888d9 [cleanup] Re-sort all the #include lines in LLVM using
utils/sort_includes.py.

I clearly haven't done this in a while, so more changed than usual. This
even uncovered a missing include from the InstrProf library that I've
added. No functionality changed here, just mechanical cleanup of the
include order.

llvm-svn: 225974
2015-01-14 11:23:27 +00:00
Duncan P. N. Exon Smith 5bf8fef580 IR: Split Metadata from Value
Split `Metadata` away from the `Value` class hierarchy, as part of
PR21532.  Assembly and bitcode changes are in the wings, but this is the
bulk of the change for the IR C++ API.

I have a follow-up patch prepared for `clang`.  If this breaks other
sub-projects, I apologize in advance :(.  Help me compile it on Darwin
I'll try to fix it.  FWIW, the errors should be easy to fix, so it may
be simpler to just fix it yourself.

This breaks the build for all metadata-related code that's out-of-tree.
Rest assured the transition is mechanical and the compiler should catch
almost all of the problems.

Here's a quick guide for updating your code:

  - `Metadata` is the root of a class hierarchy with three main classes:
    `MDNode`, `MDString`, and `ValueAsMetadata`.  It is distinct from
    the `Value` class hierarchy.  It is typeless -- i.e., instances do
    *not* have a `Type`.

  - `MDNode`'s operands are all `Metadata *` (instead of `Value *`).

  - `TrackingVH<MDNode>` and `WeakVH` referring to metadata can be
    replaced with `TrackingMDNodeRef` and `TrackingMDRef`, respectively.

    If you're referring solely to resolved `MDNode`s -- post graph
    construction -- just use `MDNode*`.

  - `MDNode` (and the rest of `Metadata`) have only limited support for
    `replaceAllUsesWith()`.

    As long as an `MDNode` is pointing at a forward declaration -- the
    result of `MDNode::getTemporary()` -- it maintains a side map of its
    uses and can RAUW itself.  Once the forward declarations are fully
    resolved RAUW support is dropped on the ground.  This means that
    uniquing collisions on changing operands cause nodes to become
    "distinct".  (This already happened fairly commonly, whenever an
    operand went to null.)

    If you're constructing complex (non self-reference) `MDNode` cycles,
    you need to call `MDNode::resolveCycles()` on each node (or on a
    top-level node that somehow references all of the nodes).  Also,
    don't do that.  Metadata cycles (and the RAUW machinery needed to
    construct them) are expensive.

  - An `MDNode` can only refer to a `Constant` through a bridge called
    `ConstantAsMetadata` (one of the subclasses of `ValueAsMetadata`).

    As a side effect, accessing an operand of an `MDNode` that is known
    to be, e.g., `ConstantInt`, takes three steps: first, cast from
    `Metadata` to `ConstantAsMetadata`; second, extract the `Constant`;
    third, cast down to `ConstantInt`.

    The eventual goal is to introduce `MDInt`/`MDFloat`/etc. and have
    metadata schema owners transition away from using `Constant`s when
    the type isn't important (and they don't care about referring to
    `GlobalValue`s).

    In the meantime, I've added transitional API to the `mdconst`
    namespace that matches semantics with the old code, in order to
    avoid adding the error-prone three-step equivalent to every call
    site.  If your old code was:

        MDNode *N = foo();
        bar(isa             <ConstantInt>(N->getOperand(0)));
        baz(cast            <ConstantInt>(N->getOperand(1)));
        bak(cast_or_null    <ConstantInt>(N->getOperand(2)));
        bat(dyn_cast        <ConstantInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<ConstantInt>(N->getOperand(4)));

    you can trivially match its semantics with:

        MDNode *N = foo();
        bar(mdconst::hasa               <ConstantInt>(N->getOperand(0)));
        baz(mdconst::extract            <ConstantInt>(N->getOperand(1)));
        bak(mdconst::extract_or_null    <ConstantInt>(N->getOperand(2)));
        bat(mdconst::dyn_extract        <ConstantInt>(N->getOperand(3)));
        bay(mdconst::dyn_extract_or_null<ConstantInt>(N->getOperand(4)));

    and when you transition your metadata schema to `MDInt`:

        MDNode *N = foo();
        bar(isa             <MDInt>(N->getOperand(0)));
        baz(cast            <MDInt>(N->getOperand(1)));
        bak(cast_or_null    <MDInt>(N->getOperand(2)));
        bat(dyn_cast        <MDInt>(N->getOperand(3)));
        bay(dyn_cast_or_null<MDInt>(N->getOperand(4)));

  - A `CallInst` -- specifically, intrinsic instructions -- can refer to
    metadata through a bridge called `MetadataAsValue`.  This is a
    subclass of `Value` where `getType()->isMetadataTy()`.

    `MetadataAsValue` is the *only* class that can legally refer to a
    `LocalAsMetadata`, which is a bridged form of non-`Constant` values
    like `Argument` and `Instruction`.  It can also refer to any other
    `Metadata` subclass.

(I'll break all your testcases in a follow-up commit, when I propagate
this change to assembly.)

llvm-svn: 223802
2014-12-09 18:38:53 +00:00
Duncan P. N. Exon Smith de36e8040f Revert "IR: MDNode => Value"
Instead, we're going to separate metadata from the Value hierarchy.  See
PR21532.

This reverts commit r221375.
This reverts commit r221373.
This reverts commit r221359.
This reverts commit r221167.
This reverts commit r221027.
This reverts commit r221024.
This reverts commit r221023.
This reverts commit r220995.
This reverts commit r220994.

llvm-svn: 221711
2014-11-11 21:30:22 +00:00
Steven Wu d994b8aaa4 Remove obsolete ARM intrinsics vclz and vcnt
Both of the intrinsics get autoupgraded to target independent
intrinsics.

llvm-svn: 221396
2014-11-05 21:02:55 +00:00
Duncan P. N. Exon Smith 3872d0084c IR: MDNode => Value: Instruction::getMetadata()
Change `Instruction::getMetadata()` to return `Value` as part of
PR21433.

Update most callers to use `Instruction::getMDNode()`, which wraps the
result in a `cast_or_null<MDNode>`.

llvm-svn: 221024
2014-11-01 00:10:31 +00:00
Adrian Prantl 87b7eb9d0f Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

Note: I accidentally committed a bogus older version of this patch previously.
llvm-svn: 218787
2014-10-01 18:55:02 +00:00