Summary:
The problem here is that an enum class can not be implicitly converted to an
integer. That assumption snuck back into PointerIntPair. This commit fixes the
issue and more importantly adds some unittests to make sure that we do not break
this again.
rdar://23594806
Reviewers: gribozavr
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16131
llvm-svn: 257574
MSVC seems to have problems looking up Value inside of the template. Not
really sure whether that's a bug there or Clang and GCC being too
permissive.
llvm-svn: 257288
type.
This makes it easy and safe to use a set of flags as one elmenet of
a tagged union with pointers. There is quite a bit of code that has
historically done this by casting arbitrary integers to "pointers" and
assuming that this was safe and reliable. It is neither, and has started
to rear its head by triggering safety asserts in various abstractions
like PointerLikeTypeTraits when the integers chosen are invariably poor
choices for *some* platform and *some* situation. Not to mention the
(hopefully unlikely) prospect of one of these integers actually getting
allocated!
With this, it will be straightforward to build type safe abstractions
like this without being error prone. The abstraction itself is also
remarkably simple thanks to the implicit conversion.
This use case and pattern was also independently created by the folks
working on Swift, and they're going to incrementally add any missing
functionality they find.
Differential Revision: http://reviews.llvm.org/D15844
llvm-svn: 257284
This is a much more general and powerful form of PointerUnion. It
provides a reasonably complete sum type (from type theory) for
pointer-like types. It has several significant advantages over the
existing PointerUnion infrastructure:
1) It allows more than two pointer types to participate without awkward
nesting structures.
2) It directly exposes the tag so that it is convenient to write
switches over the possible members.
3) It can re-use the same type for multiple tag values, something that
has been worked around by either abusing PointerIntPair or defining
nonce types and doing unsafe pointer casting.
4) It supports customization of the PointerLikeTypeTraits used for
specific member types. This means it could (in theory) be used even
with types that are over-aligned on allocation to expose larger
numbers of bits to the tag.
All in all, I think it is at least complimentary to the existing
infrastructure, and a strict improvement for some use cases.
Differential Revision: http://reviews.llvm.org/D15843
llvm-svn: 257282
The new leader is known anyway so we can return it for some micro
optimization in code where it is easy to pass along the result to the
next join().
llvm-svn: 257130
to isolate it in a dependent helper class.
Without doing this, we end up requiring all of the pointer traits the
moment you even define a PointerIntPair. That makes them *incredibly*
hard to use, for example you can't use them at all inside a class for
pointers to that class!
This change sinks all the logic into a helper template class that only
needs to be fully instantiated when *using* the PointerIntPair. We still
get compile-time checking, but it is deferred long enough to make
tradition out-of-line method definitions (or just the normal deferred
method body parsing) sufficient to handle cycling references.
llvm-svn: 256618
Add ARMv8.2-A to TargetParser, so that it can be used by the clang
command-line options and the .arch directive.
Most testing of this will be done in clang, checking that the
command-line options that this enables work.
Differential Revision: http://reviews.llvm.org/D15037
llvm-svn: 254400
This just concatenates the common DWP sections without doing any of the
fancy DWP things like:
1) update str_offsets
2) deduplicating strings
3) merging/creating cu/tu_index
Patches for these will follow shortly.
(also not sure about target triple/object file type for this tool - do I
really need a whole triple just to write an object file that contains
purely static/hardcoded bytes in each section? & I guess I should just
pick it based on the first input, maybe, rather than hardcoding for now
- but we only produce .dwo on ELF platforms with objcopy for now anyway)
llvm-svn: 254355
We use to have an odd difference among MapVector and SetVector. The map
used a DenseMop, but the set used a SmallSet, which in turn uses a
std::set.
I have changed SetVector to use a DenseSet. If you were depending on the
old behaviour you can pass an explicit set type or use SmallSetVector.
The common cases for needing to do it are:
* Optimizing for small sets.
* Sets for types not supported by DenseSet.
llvm-svn: 253439
Useful utility function; this wasn't too hard to do before, but also wasn't
obviously discoverable. Make it explicit. Reviewed offline by Michael
Gottesman.
llvm-svn: 253254
Summary:
Document the differences between the isKnownWindowsMSVC() and isWindowsMSVC() methods on Triple.
Also removed the '\brief' Doxygen annotations - now that 'AUTOBRIEF' is set to on, they are unnecessary.
Subscribers: jfb, tberghammer, danalbert, srhines, dschuff
Differential Revision: http://reviews.llvm.org/D14110
llvm-svn: 253159
Re-implement `ilist_node::getNextNode()` and `getPrevNode()` without
relying on the sentinel having a "next" pointer. Instead, get access to
the owning list and compare against the `begin()` and `end()` iterators.
This only works when the node *can* get access to the owning list. The
new support is in `ilist_node_with_parent<>`, and any class `Ty`
inheriting from `ilist_node<NodeTy>` that wants `getNextNode()` and/or
`getPrevNode()` should inherit from
`ilist_node_with_parent<NodeTy, ParentTy>` instead. The requirements:
- `NodeTy` must have a `getParent()` function that returns the parent.
- `ParentTy` must have a `getSublistAccess()` static that, given a(n
ignored) `NodeTy*` (to determine which list), returns a member field
pointer to the appropriate `ilist<>`.
This isn't the cleanest way to get access to the owning list, but it
leverages the API already used in the IR hierarchy (see, e.g.,
`Instruction::getSublistAccess()`).
If anyone feels like ripping out the calls to `getNextNode()` and
`getPrevNode()` and replacing with direct iterator logic, they can also
remove the access function, etc., but as an incremental step, I'm
maintaining the API where it's currently used in tree.
If these requirements are *not* met, call sites with access to the ilist
can call `iplist<NodeTy>::getNextNode(NodeTy*)` directly, as in
ilistTest.cpp.
Why rewrite this?
The old code was broken, calling `getNext()` on a sentinel that possibly
didn't have a "next" pointer at all! The new code avoids that
particular flavour of UB (see the commit message for r252538 for more
details about the "lucky" memory layout that made this function so
interesting).
There's still some UB here: the end iterator gets downcast to `NodeTy*`,
even when it's a sentinel (which is typically
`ilist_half_node<NodeTy*>`). I'll tackle that in follow-up commits.
See this llvm-dev thread for more details:
http://lists.llvm.org/pipermail/llvm-dev/2015-October/091115.html
What's the danger?
There might be some code that relies on `getNextNode()` or
`getPrevNode()` *never* returning `nullptr` -- i.e., that relies on them
being broken when the sentinel is an `ilist_half_node<NodeTy>`. I tried
to root out those cases with the audits I did leading up to r252380, but
it's possible I missed one or two. I hope not.
(If (1) you have out-of-tree code, (2) you've reverted r252380
temporarily, and (3) you get some weird crashes with this commit, then I
recommend un-reverting r252380 and auditing the compile errors looking
for "strange" implicit conversions.)
llvm-svn: 252694
This reverts commit r252373, reapplying r252372 now that I've updated
clang-tools-extra. Original commit message follows.
ADT: Require explicit ilist iterator/pointer conversions
Disallow implicit conversions between ilist iterators and element
points. Explicit conversions still work of course.
This is the first step toward removing the undefined behaviour in
`ilist` and `iplist`:
http://lists.llvm.org/pipermail/llvm-dev/2015-October/091115.html
The motivation for removing the implicit iterators is that I came across
real bugs (that were *really* getting lucky). More details and some
brief discussion later in that thread:
http://lists.llvm.org/pipermail/llvm-dev/2015-October/091617.html
Note: if you have out-of-tree code, it should be fairly easy to revert
this patch downstream while you update your out-of-tree call sites.
Note that these conversions are occasionally latent bugs (that may
happen to "work" now, but only because of getting lucky with UB;
follow-ups will change your luck). When they are valid, I suggest using
`->getIterator()` to go from pointer to iterator, and `&*` to go from
iterator to pointer.
llvm-svn: 252380
Disallow implicit conversions between ilist iterators and element
points. Explicit conversions still work of course.
This is the first step toward removing the undefined behaviour in
`ilist` and `iplist`:
http://lists.llvm.org/pipermail/llvm-dev/2015-October/091115.html
The motivation for removing the implicit iterators is that I came across
real bugs (that were *really* getting lucky). More details and some
brief discussion later in that thread:
http://lists.llvm.org/pipermail/llvm-dev/2015-October/091617.html
Note: if you have out-of-tree code, it should be fairly easy to revert
this patch downstream while you update your out-of-tree call sites.
Note that these conversions are occasionally latent bugs (that may
happen to "work" now, but only because of getting lucky with UB;
follow-ups will change your luck). When they are valid, I suggest using
`->getIterator()` to go from pointer to iterator, and `&*` to go from
iterator to pointer.
llvm-svn: 252372
We can often end up with conditional stores that cannot be speculated. They can come from fairly simple, idiomatic code:
if (c & flag1)
*a = x;
if (c & flag2)
*a = y;
...
There is no dominating or post-dominating store to a, so it is not legal to move the store unconditionally to the end of the sequence and cache the intermediate result in a register, as we would like to.
It is, however, legal to merge the stores together and do the store once:
tmp = undef;
if (c & flag1)
tmp = x;
if (c & flag2)
tmp = y;
if (c & flag1 || c & flag2)
*a = tmp;
The real power in this optimization is that it allows arbitrary length ladders such as these to be completely and trivially if-converted. The typical code I'd expect this to trigger on often uses binary-AND with constants as the condition (as in the above example), which means the ending condition can simply be truncated into a single binary-AND too: 'if (c & (flag1|flag2))'. As in the general case there are bitwise operators here, the ladder can often be optimized further too.
This optimization involves potentially increasing register pressure. Even in the simplest case, the lifetime of the first predicate is extended. This can be elided in some cases such as using binary-AND on constants, but not in the general case. Threading 'tmp' through all branches can also increase register pressure.
The optimization as in this patch is enabled by default but kept in a very conservative mode. It will only optimize if it thinks the resultant code should be if-convertable, and additionally if it can thread 'tmp' through at least one existing PHI, so it will only ever in the worst case create one more PHI and extend the lifetime of a predicate.
This doesn't trigger much in LNT, unfortunately, but it does trigger in a big way in a third party test suite.
llvm-svn: 252051
These MachO file directives are used by linkers and other tools to provide
compatibility information, much like the existing .ios_version_min and
.macosx_version_min.
llvm-svn: 251569
GNU tools require elfiamcu to take up the entire OS field, so, e.g.
i?86-*-linux-elfiamcu is not considered a legal triple.
Make us compatible.
Differential Revision: http://reviews.llvm.org/D14081
llvm-svn: 251390
This adds support for the i?86-*-elfiamcu triple, which indicates the IAMCU psABI is used.
Differential Revision: http://reviews.llvm.org/D13977
llvm-svn: 251222
Sometimes it is more natural to use a ArrayRef<uint8_t> than a StringRef to
represent a range of bytes that is not, semantically, a string.
This will be used in lld in a sec.
llvm-svn: 250658
This patch adds the underlying infrastructure for an AVR backend to be included into LLVM. It is the first of a series of patches aimed at moving the out-of-tree AVR backend into the tree.
It consists of adding a new`Triple` target 'avr'.
llvm-svn: 250492
Remove implicit ilist iterator conversions from MachineBasicBlock.cpp.
I've also added an overload of `splice()` that takes a pointer, since
it's a natural API. This is similar to the overloads I added for
`remove()` and `erase()` in r249867.
llvm-svn: 249883
Remove a few more implicit ilist iterator conversions, this time from
Analysis.cpp and BranchFolding.cpp.
I added a few overloads for `remove()` and `erase()`, which quite
naturally take pointers as well as iterators as parameters. This will
reduce the churn at least in the short term, but I don't really have a
problem with these existing for longer.
llvm-svn: 249867
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
Create `SymbolTableList`, a wrapper around `iplist` for lists that
automatically manage a symbol table. This commit reduces a ton of code
duplication between the six traits classes that were used previously.
As a drive by, reduce the number of template parameters from 2 to 1 by
using a SymbolTableListParentType metafunction (I originally had this as
a separate commit, but it touched most of the same lines so I squashed
them).
I'm in the process of trying to remove the UB in `createSentinel()` (see
the FIXMEs I added for `ilist_embedded_sentinel_traits` and
`ilist_half_embedded_sentinel_traits`). My eventual goal is to separate
the list logic into a base class layer that knows nothing about (and
isn't templated on) the downcasted nodes -- removing the need to invoke
UB -- but for now I'm just trying to get a handle on all the current use
cases (and cleaning things up as I see them).
Besides these six SymbolTable lists, there are two others that use the
addNode/removeNode/transferNodes() hooks: the `MachineInstruction` and
`MachineBasicBlock` lists. Ideally there'll be a way to factor these
hooks out of the low-level API entirely, but I'm not quite there yet.
llvm-svn: 249602
Because mod is always exact, this function should have never taken a rounding mode argument. The actual implementation still has issues, which I'll look at resolving in a subsequent patch.
llvm-svn: 248195
Based on conversations with Justin and a few others, these constructors
are really useful to have in the executable so that you can call them
from the debugger. After some measurements, these *particular* calls
aren't so problematic as to make them a good tradeoff for always inline.
Please let me know if there are other functions really needed for
debugging. The always inline attribute is a hack that we should only
really employ when it doesn't hurt.
llvm-svn: 248188
and assert when mask is too large to apply in the small case,
previously the extra words were silently ignored.
clang-format the entire function to match current code standards.
This is a rewrite of r247972 which was reverted in r247983 due to
warning and possible UB on 32-bits hosts.
llvm-svn: 247993
We shifted the MachineBasicBlocks to the end of the MachineFunction in
DFS order. This will not ensure that MachineBasicBlocks which fell
through to one another will remain contiguous. Instead, implement
a stable sort algorithm for iplist.
This partially reverts commit r214150.
llvm-svn: 247978
Extend mask value to 64 bits before taking its complement and assert when mask is
too large to apply in the small case (previously the extra words were silently ignored).
http://reviews.llvm.org/D11890
Patch by James Touton!
llvm-svn: 247972
