platforms.
With ELF, the alignment of a global variable in a shared library will
get copied into an executables linked against it, if the executable even
accesss the variable. So, it's not possible to implicitly increase
alignment based on access patterns, or you'll break existing binaries.
This happened to affect libc++'s std::cout symbol, for example. See
thread: http://thread.gmane.org/gmane.comp.compilers.clang.devel/45311
(This is a re-commit of r257719, without the bug reported in
PR26144. I've tweaked the code to not assert-fail in
enforceKnownAlignment when computeKnownBits doesn't recurse far enough
to find the underlying Alloca/GlobalObject value.)
Differential Revision: http://reviews.llvm.org/D16145
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257902 91177308-0d34-0410-b5e6-96231b3b80d8
There are several requirements that ended up with this design;
1. Matching bitreversals is too heavyweight for InstCombine and doesn't really need to be done so early.
2. Bitreversals and byteswaps are very related in their matching logic.
3. We want to implement support for matching more advanced bswap/bitreverse patterns like partial bswaps/bitreverses.
4. Bswaps are best matched early in InstCombine.
The result of these is that a new utility function is created in Transforms/Utils/Local.h that can be configured to search for bswaps, bitreverses or both. InstCombine uses it to find only bswaps, CGP uses it to find only bitreversals.
We can then extend the matching logic in one place only.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257875 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: The dbg.declare -> dbg.value conversion did not check which operand of
the store instruction the alloca was passed to. As a result code that stored the
address of an alloca, rather than storing to the alloca, would still trigger
the conversion routine, leading to the insertion of an incorrect dbg.value
intrinsic.
Reviewers: aprantl
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16169
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257787 91177308-0d34-0410-b5e6-96231b3b80d8
platforms.
With ELF, the alignment of a global variable in a shared library will
get copied into an executables linked against it, if the executable even
accesss the variable. So, it's not possible to implicitly increase
alignment based on access patterns, or you'll break existing binaries.
This happened to affect libc++'s std::cout symbol, for example. See
thread: http://thread.gmane.org/gmane.comp.compilers.clang.devel/45311
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257719 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: The dbg.declare -> dbg.value conversion looks through any zext/sext
to find a value to describe the variable (in the expectation that those
zext/sext instruction will go away later). However, those values do not
cover the entire variable and thus need a DW_OP_bit_piece.
Reviewers: aprantl
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16061
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257534 91177308-0d34-0410-b5e6-96231b3b80d8
JumpThreading's runOnFunction is supposed to return true if it made any
changes. JumpThreading has a call to removeUnreachableBlocks which may
result in changes to the IR but runOnFunction didn't appropriate account
for this possibility, leading to badness.
While we are here, make sure to call LazyValueInfo::eraseBlock in
removeUnreachableBlocks; JumpThreading preserves LVI.
This fixes PR26096.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257279 91177308-0d34-0410-b5e6-96231b3b80d8
In r256814, we managed to remove catchpads which were trivially redudant
because they were the same SSA value. We can do better using the same
algorithm but with a smarter datastructure by hashing the SSA values
within the catchpad and comparing them structurally.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256815 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
First up is instcombine, where in the dbg.declare -> dbg.value conversion,
the llvm.dbg.value needs to be called on the actual loaded value, rather
than the address (since the whole point of this transformation is to be
able to get rid of the alloca). Further, now that that's cleaned up, we
can remove a hack in the backend, that would add an implicit OP_deref if
the argument to dbg.value was an alloca. This stems from before the
existence of DIExpression and is no longer necessary since the deref can
be expressed explicitly.
Now, in order to make sure that the tests pass with this change, we need to
correct the printing of DEBUG_VALUE comments to take into account the
expression, which wasn't taken into account before.
Unfortunately, for both these changes, there were a number of incorrect
test cases (mostly the wrong number of DW_OP_derefs, but also a couple
where the test itself was broken more badly). aprantl and I have gone
through and adjusted these test case in order to make them pass with
these fixes and in some cases to make sure they're actually testing
what they are meant to test.
Reviewers: aprantl
Subscribers: dsanders
Differential Revision: http://reviews.llvm.org/D14186
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256077 91177308-0d34-0410-b5e6-96231b3b80d8
SimplifyCFG allows tail merging with code which terminates in
unreachable which, in turn, makes it possible for an invoke to end up in
a funclet which it was not originally part of.
Using operand bundles on invokes allows us to determine whether or not
an invoke was part of a funclet in the source program.
Furthermore, it allows us to unambiguously answer questions about the
legality of inlining into call sites which the personality may have
trouble with.
Differential Revision: http://reviews.llvm.org/D15517
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255674 91177308-0d34-0410-b5e6-96231b3b80d8
It turns out that terminatepad gives little benefit over a cleanuppad
which calls the termination function. This is not sufficient to
implement fully generic filters but MSVC doesn't support them which
makes terminatepad a little over-designed.
Depends on D15478.
Differential Revision: http://reviews.llvm.org/D15479
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255522 91177308-0d34-0410-b5e6-96231b3b80d8
While we have successfully implemented a funclet-oriented EH scheme on
top of LLVM IR, our scheme has some notable deficiencies:
- catchendpad and cleanupendpad are necessary in the current design
but they are difficult to explain to others, even to seasoned LLVM
experts.
- catchendpad and cleanupendpad are optimization barriers. They cannot
be split and force all potentially throwing call-sites to be invokes.
This has a noticable effect on the quality of our code generation.
- catchpad, while similar in some aspects to invoke, is fairly awkward.
It is unsplittable, starts a funclet, and has control flow to other
funclets.
- The nesting relationship between funclets is currently a property of
control flow edges. Because of this, we are forced to carefully
analyze the flow graph to see if there might potentially exist illegal
nesting among funclets. While we have logic to clone funclets when
they are illegally nested, it would be nicer if we had a
representation which forbade them upfront.
Let's clean this up a bit by doing the following:
- Instead, make catchpad more like cleanuppad and landingpad: no control
flow, just a bunch of simple operands; catchpad would be splittable.
- Introduce catchswitch, a control flow instruction designed to model
the constraints of funclet oriented EH.
- Make funclet scoping explicit by having funclet instructions consume
the token produced by the funclet which contains them.
- Remove catchendpad and cleanupendpad. Their presence can be inferred
implicitly using coloring information.
N.B. The state numbering code for the CLR has been updated but the
veracity of it's output cannot be spoken for. An expert should take a
look to make sure the results are reasonable.
Reviewers: rnk, JosephTremoulet, andrew.w.kaylor
Differential Revision: http://reviews.llvm.org/D15139
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255422 91177308-0d34-0410-b5e6-96231b3b80d8
- This simplifies the CallSite class, arg_begin / arg_end are now
simple wrapper getters.
- In several places, we were creating CallSite instances solely to call
arg_begin and arg_end. With this change, that's no longer required.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255226 91177308-0d34-0410-b5e6-96231b3b80d8
Continuing the work from last week to remove implicit ilist iterator
conversions. First related commit was probably r249767, with some more
motivation in r249925. This edition gets LLVMTransformUtils compiling
without the implicit conversions.
No functional change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250142 91177308-0d34-0410-b5e6-96231b3b80d8
The most important part required to make clang
devirtualization works ( ͡°͜ʖ ͡°).
The code is able to find non local dependencies, but unfortunatelly
because the caller can only handle local dependencies, I had to add
some restrictions to look for dependencies only in the same BB.
http://reviews.llvm.org/D12992
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249196 91177308-0d34-0410-b5e6-96231b3b80d8
Place new and update dbg.declare calls immediately after the
corresponding alloca.
Current code in replaceDbgDeclareForAlloca puts the new dbg.declare
at the end of the basic block. LLVM codegen has problems emitting
debug info in a situation when dbg.declare appears after all uses of
the variable. This usually kinda works for inlining and ASan (two
users of this function) but not for SafeStack (see the pending change
in http://reviews.llvm.org/D13178).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248769 91177308-0d34-0410-b5e6-96231b3b80d8
1. Use a worklist, not a recursive approach, to avoid needless
revisitation and being repeatedly forced to jump back to the
start of the BB if a handle is invalidated.
2. Only insert operands to the worklist if they become unused
after a dead instruction is removed, so we don’t have to
visit them again in most cases.
3. Use a SmallSetVector to track the worklist.
4. Instead of pre-initting the SmallSetVector like in
DeadCodeEliminationPass, only put things into the worklist
if they have to be revisited after the first run-through.
This minimizes how much the actual SmallSetVector gets used,
which saves a lot of time.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248727 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Factor the code that rewrites invokes to calls and rewrites WinEH
terminators to their "unwind to caller" equivalents into a helper in
Utils/Local, and use it in the three places I'm aware of that need to do
this.
Reviewers: andrew.w.kaylor, majnemer, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13152
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248677 91177308-0d34-0410-b5e6-96231b3b80d8
This makes RemoveDuplicatePHINodes more effective and fixes an assertion
failure. Triggering the assertions requires a DenseSet reallocation
so this change only contains a constructive test.
I'll explain the issue with a small example. In the following function
there's a duplicate PHI, %4 and %5 are identical. When this is found
the DenseSet in RemoveDuplicatePHINodes contains %2, %3 and %4.
define void @F() {
br label %1
; <label>:1 ; preds = %1, %0
%2 = phi i32 [ 42, %0 ], [ %4, %1 ]
%3 = phi i32 [ 42, %0 ], [ %5, %1 ]
%4 = phi i32 [ 42, %0 ], [ 23, %1 ]
%5 = phi i32 [ 42, %0 ], [ 23, %1 ]
br label %1
}
after RemoveDuplicatePHINodes runs the function looks like this. %3 has
changed and is now identical to %2, but RemoveDuplicatePHINodes never
saw this.
define void @F() {
br label %1
; <label>:1 ; preds = %1, %0
%2 = phi i32 [ 42, %0 ], [ %4, %1 ]
%3 = phi i32 [ 42, %0 ], [ %4, %1 ]
%4 = phi i32 [ 42, %0 ], [ 23, %1 ]
br label %1
}
If the DenseSet does a reallocation now it will reinsert all
keys and stumble over %3 now having a different hash value than it had
when inserted into the map for the first time. This change clears the
set whenever a PHI is deleted and starts the progress from the
beginning, allowing %3 to be deleted and avoiding inconsistent DenseSet
state. This potentially has a negative performance impact because
it rescans all PHIs, but I don't think that this ever makes a difference
in practice.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246694 91177308-0d34-0410-b5e6-96231b3b80d8
and make it always preserve debug locations, since all callers wanted this
behavior anyway.
This is addressing a post-commit review feedback for r245589.
NFC (inside the LLVM tree).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245622 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: llvm::ConstantFoldTerminator function can convert SwitchInst with single case (and default) to a conditional BranchInst. This patch adds support to preserve make.implicit metadata on this conversion.
Reviewers: sanjoy, weimingz, chenli
Subscribers: mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D11841
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244348 91177308-0d34-0410-b5e6-96231b3b80d8
After r244074, we now have a successors() method to iterate over
all the successors of a TerminatorInst. This commit changes a bunch
of eligible loops to use it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244260 91177308-0d34-0410-b5e6-96231b3b80d8
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support. Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.
Differential Revision: http://reviews.llvm.org/D11097
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243766 91177308-0d34-0410-b5e6-96231b3b80d8
Previously we would refrain from attempting to increase the linkage of
available_externally globals because they were considered weak for the
linker. Now they are treated more like a declaration instead of a weak
definition.
This was causing SSE alignment faults in Chromuim, when some code
assumed it could increase the alignment of a dllimported global that it
didn't control. http://crbug.com/509256
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242091 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support. Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.
Reviewers: rnk, JosephTremoulet, reames, nlewycky, rjmccall
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D11041
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241888 91177308-0d34-0410-b5e6-96231b3b80d8
The personality routine currently lives in the LandingPadInst.
This isn't desirable because:
- All LandingPadInsts in the same function must have the same
personality routine. This means that each LandingPadInst beyond the
first has an operand which produces no additional information.
- There is ongoing work to introduce EH IR constructs other than
LandingPadInst. Moving the personality routine off of any one
particular Instruction and onto the parent function seems a lot better
than have N different places a personality function can sneak onto an
exceptional function.
Differential Revision: http://reviews.llvm.org/D10429
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239940 91177308-0d34-0410-b5e6-96231b3b80d8
This patch extends EarlyCSE to take advantage of the information that a controlling branch gives us about the value of a Value within this and dominated basic blocks. If the current block has a single predecessor with a controlling branch, we can infer what the branch condition must have been to execute this block. The actual change to support this is downright simple because EarlyCSE's existing scoped hash table logic deals with most of the complexity around merging.
The patch actually implements two optimizations.
1) The first is analogous to JumpThreading in that it enables EarlyCSE's CSE handling to fold branches which are exactly redundant due to a previous branch to branches on constants. (It doesn't actually replace the branch or change the CFG.) This is pretty clearly a win since it enables substantial CFG simplification before we start trying to inline.
2) The second is analogous to CVP in that it exploits the knowledge gained to replace dominated *uses* of the original value. EarlyCSE does not otherwise reason about specific uses, so this is the more arguable one. It does enable further simplication and constant folding within the rest of the visit by EarlyCSE.
In both cases, the added code only handles the easy dominance based case of each optimization. The general case is deferred to the existing passes.
Differential Revision: http://reviews.llvm.org/D9763
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238071 91177308-0d34-0410-b5e6-96231b3b80d8
Finish off PR23080 by renaming the debug info IR constructs from `MD*`
to `DI*`. The last of the `DIDescriptor` classes were deleted in
r235356, and the last of the related typedefs removed in r235413, so
this has all baked for about a week.
Note: If you have out-of-tree code (like a frontend), I recommend that
you get everything compiling and tests passing with the *previous*
commit before updating to this one. It'll be easier to keep track of
what code is using the `DIDescriptor` hierarchy and what you've already
updated, and I think you're extremely unlikely to insert bugs. YMMV of
course.
Back to *this* commit: I did this using the rename-md-di-nodes.sh
upgrade script I've attached to PR23080 (both code and testcases) and
filtered through clang-format-diff.py. I edited the tests for
test/Assembler/invalid-generic-debug-node-*.ll by hand since the columns
were off-by-three. It should work on your out-of-tree testcases (and
code, if you've followed the advice in the previous paragraph).
Some of the tests are in badly named files now (e.g.,
test/Assembler/invalid-mdcompositetype-missing-tag.ll should be
'dicompositetype'); I'll come back and move the files in a follow-up
commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236120 91177308-0d34-0410-b5e6-96231b3b80d8
Remove early returns for when `getVariable()` is null, and just assert
that it never happens. The Verifier already confirms that there's a
valid variable on these intrinsics, so we should assume the debug info
isn't broken. I also updated a check for a `!dbg` attachment, which the
Verifier similarly guarantees.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235400 91177308-0d34-0410-b5e6-96231b3b80d8
Change `DIBuilder::insertDeclare()` and `insertDbgValueIntrinsic()` to
take an `MDLocation*`/`DebugLoc` parameter which it attaches to the
created intrinsic. Assert at creation time that the `scope:` field's
subprogram matches the variable's. There's a matching `clang` commit to
use the API.
The context for this is PR22778, which is removing the `inlinedAt:`
field from `MDLocalVariable`, instead deferring to the `!dbg` location
attached to the debug info intrinsic. The best way to ensure we always
have a `!dbg` attachment is to require one at creation time. I'll be
adding verifier checks next, but this API change is the best way to
shake out frontend bugs.
Note: I added an `llvm_unreachable()` in `bindings/go` and passed in
`nullptr` for the `DebugLoc`. The `llgo` folks will eventually need to
pass a valid `DebugLoc` here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235041 91177308-0d34-0410-b5e6-96231b3b80d8
Completely gut `DIExpression`, turning it into a simple wrapper around
`MDExpression *`. There are two bits of magic left:
- It's constructed from `const MDExpression*` but convertible to
`MDExpression*`.
- It's default-constructed to `nullptr`.
Otherwise, it should behave quite like a raw pointer. Once I've done
the same to the rest of the `DIDescriptor` subclasses, I'll come back to
delete them entirely (and update call sites as necessary to deal with
the missing magic).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234832 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.
This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.
I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.
I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.
Test Plan:
Reviewers: echristo
Subscribers: llvm-commits
From: Mehdi Amini <mehdi.amini@apple.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231740 91177308-0d34-0410-b5e6-96231b3b80d8
If the landingpad of the invoke is using a personality function that
catches asynch exceptions, then it can catch a trap.
Also add some landingpads to invalid LLVM IR test cases that lack them.
Over-the-shoulder reviewed by David Majnemer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228782 91177308-0d34-0410-b5e6-96231b3b80d8
