The fixes are to note that AArch64 has additional restrictions on when local
relocations can be used. In particular, ld64 requires that relocations to
cstring/cfstrings use linker visible symbols.
Original message:
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 226503
Remove `MDNodeFwdDecl` (as promised in r226481). Aside from API
changes, there's no real functionality change here.
`MDNode::getTemporary()` now forwards to `MDTuple::getTemporary()`,
which returns a tuple with `isTemporary()` equal to true.
The main point is that we can now add temporaries of other `MDNode`
subclasses, needed for PR22235 (I introduced `MDNodeFwdDecl` in the
first place because I didn't recognize this need, and thought they were
only needed to handle forward references).
A few things left out of (or highlighted by) this commit:
- I've had to remove the (few) uses of `std::unique_ptr<>` to deal
with temporaries, since the destructor is no longer public.
`getTemporary()` should probably return the equivalent of
`std::unique_ptr<T, MDNode::deleteTemporary>`.
- `MDLocation::getTemporary()` doesn't exist yet (worse, it actually
does exist, but does the wrong thing: `MDNode::getTemporary()` is
inherited and returns an `MDTuple`).
- `MDNode` now only has one subclass, `UniquableMDNode`, and the
distinction between them is actually somewhat confusing.
I'll fix those up next.
llvm-svn: 226501
Merge `getDistinct()`'s implementation with those of `get()` and
`getIfExists()` for both `MDTuple` and `MDLocation`. This will make it
easier to scale to supporting temporaries.
llvm-svn: 226497
Analogous to AVX2, these need to be implemented as macros to properly
propagate the immediate index operand.
Part of <rdar://problem/17688758>
llvm-svn: 226496
Use `isUniqued()` instead of `isStoredDistinctInContext()`, and remove
an assertion that won't be valid once temporaries are merged back in.
llvm-svn: 226491
Add an assertion in `UniquableMDNode::resolve()` to prevent temporaries
from being resolved (once they're merged back in). Needed to shuffle
order of `resolve()` and `storeDistinctInContext()` to prevent it from
firing.
llvm-svn: 226489
Unify the definitions of `MDNode::isResolved()` and
`UniquableMDNode::isResolved()`. Previously, `UniquableMDNode` could
answer this question more efficiently, but now that RAUW support has
been unified with `MDNodeFwdDecl`, `MDNode` doesn't need any casts to
figure out the answer.
llvm-svn: 226485
Add an `LLVMContext &` to `ReplaceableMetadataImpl`, create a class that
either holds a reference to an `LLVMContext` or owns a
`ReplaceableMetadataImpl`, and use the new class in `MDNode`.
- This saves a pointer in `UniquableMDNode` at the cost of a pointer
in `ValueAsMetadata` (which didn't used to store the `LLVMContext`).
There are far more of the former.
- Unifies RAUW support between `MDNodeFwdDecl` (which is going away,
see r226481) and `UniquableMDNode`.
llvm-svn: 226484
Change `MDNode::isDistinct()` to only apply to 'distinct' nodes (not
temporaries), and introduce `MDNode::isUniqued()` and
`MDNode::isTemporary()` for the other two possibilities.
llvm-svn: 226482
More clearly describe the type of storage used for `Metadata`.
- `Uniqued`: uniqued, stored in the context.
- `Distinct`: distinct, stored in the context.
- `Temporary`: not owned by anyone.
This is the first in a series of commits to fix a design problem with
`MDNodeFwdDecl` that I need to solve for PR22235. While `MDNodeFwdDecl`
works well as a forward declaration, we use `MDNode::getTemporary()` for
more than forward declarations -- we also need to create early versions
of nodes (with fields not filled in) that we'll fill out later (see
`DIBuilder::finalize()` and `CGDebugInfo::finalize()` for examples).
This was a blind spot I had when I introduced `MDNodeFwdDecl` (which
David Blaikie (indirectly) highlighted in an unrelated review [1]).
[1]: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150112/252381.html
In general, we need `MDTuple::getTemporary()` to give a temporary tuple
(like `MDNodeFwdDecl`), `MDLocation::getTemporary()` to give a temporary
location, and (the problem at hand) `GenericDebugMDNode::getTemporary()`
to give a temporary generic debug node.
So I need to fold the idea of "temporary" nodes back into
`UniquableMDNode`. (More commits to follow as I refactor.)
llvm-svn: 226481
frontends to use a DIExpression with a DW_OP_deref instead.
This is not only a much more natural place for this informationl; there
is also a technical reason: The FlagIndirectVariable is used to mark a
variable that is turned into a reference by virtue of the calling
convention; this happens for example to aggregate return values.
The inliner, for example, may actually need to undo this indirection to
correctly represent the value in its new context. This is impossible to
implement because the DIVariable can't be safely modified. We can however
safely construct a new DIExpression on the fly.
llvm-svn: 226476
Original patch by Luke Iannini. Minor improvements and test added by
Erik de Castro Lopo.
Differential Revision: http://reviews.llvm.org/D6877
From: Erik de Castro Lopo <erikd@mega-nerd.com>
llvm-svn: 226473
An assignment will produce a symbol with a given section and offset. There is
no way to represent something like "1 byte after a common symbol".
This matches the behavior of GNU as.
Part of PR22217.
llvm-svn: 226470
No change in this commit, but clang was changed to also produce trivial comdats when
needed.
Original message:
Don't create new comdats in CodeGen.
This patch stops the implicit creation of comdats during codegen.
Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.
llvm-svn: 226467
TSAN_SHADOW_COUNT is defined to 4 in all environments.
Other values of TSAN_SHADOW_COUNT were never tested and
were broken by recent changes to shadow mapping.
Remove it as there is no reason to fix nor maintain it.
llvm-svn: 226466
and updated.
This may appear to remove handling for things like alias analysis when
splitting critical edges here, but in fact no callers of SplitEdge
relied on this. Similarly, all of them wanted to preserve LCSSA if there
was any update of the loop info. That makes the interface much simpler.
With this, all of BasicBlockUtils.h is free of Pass arguments and
prepared for the new pass manager. This is tho majority of utilities
that relied on pass arguments.
llvm-svn: 226459
APIs and replace it and numerous booleans with an option struct.
The critical edge splitting API has a really large surface of flags and
so it seems worth burning a small option struct / builder. This struct
can be constructed with the various preserved analyses and then flags
can be flipped in a builder style.
The various users are now responsible for directly passing along their
analysis information. This should be enough for the critical edge
splitting to work cleanly with the new pass manager as well.
This API is still pretty crufty and could be cleaned up a lot, but I've
focused on this change just threading an option struct rather than
a pass through the API.
llvm-svn: 226456
InternalAlloc is quite complex and its behavior may depend on the values of
flags. As such, it should not be used while parsing flags.
Sadly, LowLevelAlloc does not support deallocation of memory.
llvm-svn: 226453
Rafael Espindola