Parse (and write) symbolic constants in debug info `flags:` fields.
This prevents a readability (and CHECK-ability) regression with the new
debug info hierarchy.
Old (well, current) assembly, with pretty-printing:
!{!"...\\0016387", ...} ; ... [public] [rvalue reference]
Flags field without this change:
!MDDerivedType(flags: 16387, ...)
Flags field with this change:
!MDDerivedType(flags: DIFlagPublic | DIFlagRValueReference, ...)
As discussed in the review thread, this isn't a final state. Most of
these flags correspond to `DW_AT_` symbolic constants, and we might
eventually want to support arbitrary attributes in some form. However,
as it stands now, some of the flags correspond to other concepts (like
`FlagStaticMember`); until things are refactored this is the simplest
way to move forward without regressing assembly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230111 91177308-0d34-0410-b5e6-96231b3b80d8
In the old (well, current) schema, there are two types of file
references: untagged and tagged (the latter references the former).
!0 = !{!"filename", !"/directory"}
!1 = !{!"0x29", !1} ; DW_TAG_file_type [filename] [/directory]
The interface to `DIBuilder` universally takes the tagged version,
described by `DIFile`. However, most `file:` references actually use
the untagged version directly.
In the new hierarchy, I'm merging this into a single node: `MDFile`.
Originally I'd planned to keep the old schema unchanged until after I
moved the new hierarchy into place.
However, it turns out to be trivial to make `MDFile` match both nodes at
the same time.
- Anyone referencing !1 does so through `DIFile`, whose implementation
I need to gut anyway (as I do the rest of the `DIDescriptor`s).
- Anyone referencing !0 just references an `MDNode`, and expects a
node with two `MDString` operands.
This commit achieves that, and updates all the testcases for the parts
of the new hierarchy that used the two-node schema (I've replaced the
untagged nodes with `distinct !{}` to make the diff clear (otherwise the
metadata all gets renumbered); it might be worthwhile to come back and
delete those nodes and renumber the world, not sure).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230057 91177308-0d34-0410-b5e6-96231b3b80d8
When writing the bitcode serialization for the new debug info hierarchy,
I assumed two fields would never be null.
Drop that assumption, since it's brittle (and crashes the
`BitcodeWriter` if wrong), and is a check better left for the verifier
anyway. (No need for a bitcode upgrade here, since the new hierarchy is
still not in place.)
The fields in question are `MDCompileUnit::getFile()` and
`MDDerivedType::getBaseType()`, the latter of which isn't null in
test/Transforms/Mem2Reg/ConvertDebugInfo2.ll (see !14, a pointer to
nothing). While the testcase might have bitrotted, there's no reason
for the bitcode format to rely on non-null for metadata operands.
This also fixes a bug in `AsmWriter` where if the `file:` is null it
isn't emitted (caught by the double-round trip in the testcase I'm
adding) -- this is a required field in `LLParser`.
I'll circle back to ConvertDebugInfo2. Once the specialized nodes are
in place, I'll be trying to turn the debug info verifier back on by
default (in the newer module pass form committed r206300) and throwing
more logic in there. If the testcase has bitrotted (as opposed to me
not understanding the schema correctly) I'll fix it then.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229960 91177308-0d34-0410-b5e6-96231b3b80d8
When trying to match the current schema with the new debug info
hierarchy, I downgraded `SizeInBits`, `AlignInBits` and `OffsetInBits`
to 32-bits (oops!). Caught this while testing my upgrade script to move
the hierarchy into place. Bump it back up to 64-bits and update tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229933 91177308-0d34-0410-b5e6-96231b3b80d8
Follow-up to r229740, which removed `DITemplate*::getContext()` after my
upgrade script revealed that scopes are always `nullptr` for template
parameters. This is the other shoe: drop `scope:` from
`MDTemplateParameter` and its two subclasses. (Note: a bitcode upgrade
would be pointless, since the hierarchy hasn't been moved into place.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229791 91177308-0d34-0410-b5e6-96231b3b80d8
It turns out that `count: -1` is a special value indicating an empty
array, such as `Values` in:
struct T {
unsigned Count;
int Values[];
};
Handle it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229769 91177308-0d34-0410-b5e6-96231b3b80d8
Put the name before the value in assembly for `MDEnum`. While working
on the testcase upgrade script for the new hierarchy, I noticed that it
"looks nicer" to have the name first, since it lines the names up in the
(somewhat typical) case that they have a common prefix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229747 91177308-0d34-0410-b5e6-96231b3b80d8
Remove unnecessary restriction of 24-bits for line numbers in
`MDLocation`.
The rest of the debug info schema (with the exception of local
variables) uses 32-bits for line numbers. As I introduce the
specialized nodes, it makes sense to canonicalize on one size or the
other.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228455 91177308-0d34-0410-b5e6-96231b3b80d8
During `MDNode::deleteTemporary()`, call `replaceAllUsesWith(nullptr)`
to update all tracking references to `nullptr`.
This fixes PR22280, where inverted destruction order between tracking
references and the temporaries themselves caused a use-after-free in
`LLParser`.
An alternative fix would be to add an assertion that there are no users,
and continue to fix inverted destruction order in clients (like
`LLParser`), but instead I decided to make getting-teardown-right easy.
(If someone disagrees let me know.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226866 91177308-0d34-0410-b5e6-96231b3b80d8
This commit moves `MDLocation`, finishing off PR21433. There's an
accompanying clang commit for frontend testcases. I'll attach the
testcase upgrade script I used to PR21433 to help out-of-tree
frontends/backends.
This changes the schema for `DebugLoc` and `DILocation` from:
!{i32 3, i32 7, !7, !8}
to:
!MDLocation(line: 3, column: 7, scope: !7, inlinedAt: !8)
Note that empty fields (line/column: 0 and inlinedAt: null) don't get
printed by the assembly writer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226048 91177308-0d34-0410-b5e6-96231b3b80d8
This adds assembly and bitcode support for `MDLocation`. The assembly
side is rather big, since this is the first `MDNode` subclass (that
isn't `MDTuple`). Part of PR21433.
(If you're wondering where the mountains of testcase updates are, we
don't need them until I update `DILocation` and `DebugLoc` to actually
use this class.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225830 91177308-0d34-0410-b5e6-96231b3b80d8
Propagate whether `MDNode`s are 'distinct' through the other types of IR
(assembly and bitcode). This adds the `distinct` keyword to assembly.
Currently, no one actually calls `MDNode::getDistinct()`, so these nodes
only get created for:
- self-references, which are never uniqued, and
- nodes whose operands are replaced that hit a uniquing collision.
The concept of distinct nodes is still not quite first-class, since
distinct-ness doesn't yet survive across `MapMetadata()`.
Part of PR22111.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225474 91177308-0d34-0410-b5e6-96231b3b80d8
In order to make comdats always explicit in the IR, we decided to make
the syntax a bit more compact for the case of a GlobalObject in a
comdat with the same name.
Just dropping the $name causes problems for
@foo = globabl i32 0, comdat
$bar = comdat ...
and
declare void @foo() comdat
$bar = comdat ...
So the syntax is changed to
@g1 = globabl i32 0, comdat($c1)
@g2 = globabl i32 0, comdat
and
declare void @foo() comdat($c1)
declare void @foo() comdat
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225302 91177308-0d34-0410-b5e6-96231b3b80d8
This test was missing a `Debug Info Version` so it's `not grep` was
passing vacuously. Update it to CHECK for something useful at the same
time so it doesn't bitrot quite so easily in the future.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224324 91177308-0d34-0410-b5e6-96231b3b80d8
Now that `Metadata` is typeless, reflect that in the assembly. These
are the matching assembly changes for the metadata/value split in
r223802.
- Only use the `metadata` type when referencing metadata from a call
intrinsic -- i.e., only when it's used as a `Value`.
- Stop pretending that `ValueAsMetadata` is wrapped in an `MDNode`
when referencing it from call intrinsics.
So, assembly like this:
define @foo(i32 %v) {
call void @llvm.foo(metadata !{i32 %v}, metadata !0)
call void @llvm.foo(metadata !{i32 7}, metadata !0)
call void @llvm.foo(metadata !1, metadata !0)
call void @llvm.foo(metadata !3, metadata !0)
call void @llvm.foo(metadata !{metadata !3}, metadata !0)
ret void, !bar !2
}
!0 = metadata !{metadata !2}
!1 = metadata !{i32* @global}
!2 = metadata !{metadata !3}
!3 = metadata !{}
turns into this:
define @foo(i32 %v) {
call void @llvm.foo(metadata i32 %v, metadata !0)
call void @llvm.foo(metadata i32 7, metadata !0)
call void @llvm.foo(metadata i32* @global, metadata !0)
call void @llvm.foo(metadata !3, metadata !0)
call void @llvm.foo(metadata !{!3}, metadata !0)
ret void, !bar !2
}
!0 = !{!2}
!1 = !{i32* @global}
!2 = !{!3}
!3 = !{}
I wrote an upgrade script that handled almost all of the tests in llvm
and many of the tests in cfe (even handling many `CHECK` lines). I've
attached it (or will attach it in a moment if you're speedy) to PR21532
to help everyone update their out-of-tree testcases.
This is part of PR21532.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224257 91177308-0d34-0410-b5e6-96231b3b80d8
Since Value objects can't have null bytes in their name, we shouldn't
allow them in the labels of basic blocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223907 91177308-0d34-0410-b5e6-96231b3b80d8
As indicated by the tests, it is possible to feed the AsmParser an
invalid datalayout string. We should verify the result of parsing this
string regardless of whether or not we have assertions enabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223898 91177308-0d34-0410-b5e6-96231b3b80d8
We don't allow Value* to have names which contain null bytes. The
AsmParser should reject .ll files that try to do this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223869 91177308-0d34-0410-b5e6-96231b3b80d8
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.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223802 91177308-0d34-0410-b5e6-96231b3b80d8
Don't assume that the forward referenced entity was of the same
global-kind as the new entity.
This fixes PR21779.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223754 91177308-0d34-0410-b5e6-96231b3b80d8
Add assembly and bitcode tests that I neglected to add in r223564 (IR:
Disallow complicated function-local metadata) and r223574 (IR: Disallow
function-local metadata attachments).
Found a couple of bugs:
- The error message for function-local attachments gave the wrong line
number -- it indicated the next token (typically on the next line)
instead of the token that started the attachment. Fixed.
- Metadata arguments of the form `!{i32 0, i32 %v}` (or with the
arguments reversed) fired an assertion in `ValueEnumerator` in LLVM
v3.5, so I suppose this never really worked. I suppose this was
"fixed" by r223564.
(Thanks to dblaikie for pointing out my omission.)
Part of PR21532.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223616 91177308-0d34-0410-b5e6-96231b3b80d8
Consider:
void f() {}
void __attribute__((weak)) g() {}
bool b = &f != &g;
It's possble for g to resolve to f if --defsym=g=f is passed on to the
linker.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223585 91177308-0d34-0410-b5e6-96231b3b80d8
Disallow complex types of function-local metadata. The only valid
function-local metadata is an `MDNode` whose sole argument is a
non-metadata function-local value.
Part of PR21532.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223564 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r218918, effectively reapplying r218914 after fixing
an Ocaml bindings test and an Asan crash. The root cause of the latter
was a tightened-up check in `DILexicalBlock::Verify()`, so I'll file a
PR to investigate who requires the loose check (and why).
Original commit message follows.
--
This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString. Integers are stringified and
a `\0` character is used as a separator.
Part of PR17891.
Note: I've attached my testcases upgrade scripts to the PR. If I've
just broken your out-of-tree testcases, they might help.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219010 91177308-0d34-0410-b5e6-96231b3b80d8
This patch addresses the first stage of PR17891 by folding constant
arguments together into a single MDString. Integers are stringified and
a `\0` character is used as a separator.
Part of PR17891.
Note: I've attached my testcases upgrade scripts to the PR. If I've
just broken your out-of-tree testcases, they might help.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218914 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218787 91177308-0d34-0410-b5e6-96231b3b80d8
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!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218778 91177308-0d34-0410-b5e6-96231b3b80d8
follows '~' in a clobber constraint string.
Previously llc would hit an llvm_unreachable when compiling an inline-asm
instruction with malformed constraint string "~x{21}". This commit enables
LLParser to catch the error earlier and print a more helpful diagnostic.
rdar://problem/14206559
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217288 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
There is no functionality change here except in the way we assemble and
dump musttail calls in variadic functions. There's really no need to
separate out the bits for musttail and "is forwarding varargs" on call
instructions. A musttail call by definition has to forward the ellipsis
or it would fail verification.
Reviewers: chandlerc, nlewycky
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D4892
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216423 91177308-0d34-0410-b5e6-96231b3b80d8
Implement `uselistorder` and `uselistorder_bb` assembly directives,
which allow the use-list order to be recovered when round-tripping to
assembly.
This is the bulk of PR20515.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216025 91177308-0d34-0410-b5e6-96231b3b80d8
Global variables that have `extern_weak` linkage may be null, so it's
incorrect to add `inbounds` when constant folding.
This also fixes a bug when parsing global aliases, whose forward
reference placeholders are global variables with `extern_weak` linkage.
If GEPs to these aliases are encountered before the alias itself, the
GEPs would incorrectly gain the `inbounds` keyword as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215803 91177308-0d34-0410-b5e6-96231b3b80d8
Change the default for `-num-shuffles` to 5 and better document the
algorithm in the header docs of `verify-uselistorder`.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214419 91177308-0d34-0410-b5e6-96231b3b80d8
Correctly sort self-users (such as PHI nodes). I added a targeted test
in `test/Bitcode/use-list-order.ll` and the final missing RUN line to
tests in `test/Assembly`.
This is part of PR5680.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214417 91177308-0d34-0410-b5e6-96231b3b80d8
Since initializers of GlobalValues are being assigned IDs before
GlobalValues themselves, explicitly exclude GlobalValues from the
constant pool. Added targeted test in `test/Bitcode/use-list-order.ll`
and added two more RUN lines in `test/Assembly`.
This is part of PR5680.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214368 91177308-0d34-0410-b5e6-96231b3b80d8
Add RUN line for `verify-uselistorder` to every test in `test/Assembly`,
unless it's a negative check (assembler rejects it) or verification
fails.
There are three files that verification fails on (so I've left out the
RUN lines):
- 2002-08-22-DominanceProblem.ll
- ConstantExprFold.ll
- ConstantExprFoldCast.ll
This is part of PR5680.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214365 91177308-0d34-0410-b5e6-96231b3b80d8
Before this patch we had
@a = weak global ...
but
@b = alias weak ...
The patch changes aliases to look more like global variables.
Looking at some really old code suggests that the reason was that the old
bison based parser had a reduction for alias linkages and another one for
global variable linkages. Putting the alias first avoided the reduce/reduce
conflict.
The days of the old .ll parser are long gone. The new one parses just "linkage"
and a later check is responsible for deciding if a linkage is valid in a
given context.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214355 91177308-0d34-0410-b5e6-96231b3b80d8
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.
COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.
This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.
Differential Revision: http://reviews.llvm.org/D4178
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211920 91177308-0d34-0410-b5e6-96231b3b80d8
As a follow-up to r210375 which canonicalizes addrspacecast
instructions, this patch canonicalizes addrspacecast constant
expressions.
Given clang uses ConstantExpr::getAddrSpaceCast to emit addrspacecast
cosntant expressions, this patch is also a step towards having the
frontend emit canonicalized addrspacecasts.
Piggyback a minor refactor in InstCombineCasts.cpp
Update three affected tests in addrspacecast-alias.ll,
access-non-generic.ll and constant-fold-gep.ll and added one new test in
constant-fold-address-space-pointer.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211004 91177308-0d34-0410-b5e6-96231b3b80d8
This commit adds a weak variant of the cmpxchg operation, as described
in C++11. A cmpxchg instruction with this modifier is permitted to
fail to store, even if the comparison indicated it should.
As a result, cmpxchg instructions must return a flag indicating
success in addition to their original iN value loaded. Thus, for
uniformity *all* cmpxchg instructions now return "{ iN, i1 }". The
second flag is 1 when the store succeeded.
At the DAG level, a new ATOMIC_CMP_SWAP_WITH_SUCCESS node has been
added as the natural representation for the new cmpxchg instructions.
It is a strong cmpxchg.
By default this gets Expanded to the existing ATOMIC_CMP_SWAP during
Legalization, so existing backends should see no change in behaviour.
If they wish to deal with the enhanced node instead, they can call
setOperationAction on it. Beware: as a node with 2 results, it cannot
be selected from TableGen.
Currently, no use is made of the extra information provided in this
patch. Test updates are almost entirely adapting the input IR to the
new scheme.
Summary for out of tree users:
------------------------------
+ Legacy Bitcode files are upgraded during read.
+ Legacy assembly IR files will be invalid.
+ Front-ends must adapt to different type for "cmpxchg".
+ Backends should be unaffected by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210903 91177308-0d34-0410-b5e6-96231b3b80d8
This patch changes GlobalAlias to point to an arbitrary ConstantExpr and it is
up to MC (or the system assembler) to decide if that expression is valid or not.
This reduces our ability to diagnose invalid uses and how early we can spot
them, but it also lets us do things like
@test5 = alias inttoptr(i32 sub (i32 ptrtoint (i32* @test2 to i32),
i32 ptrtoint (i32* @bar to i32)) to i32*)
An important implication of this patch is that the notion of aliased global
doesn't exist any more. The alias has to encode the information needed to
access it in its metadata (linkage, visibility, type, etc).
Another consequence to notice is that getSection has to return a "const char *".
It could return a NullTerminatedStringRef if there was such a thing, but when
that was proposed the decision was to just uses "const char*" for that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210062 91177308-0d34-0410-b5e6-96231b3b80d8
