Summary:
This intrinsic, together with deoptimization operand bundles, allow
frontends to express transfer of control and frame-local state from
one (typically more specialized, hence faster) version of a function
into another (typically more generic, hence slower) version.
In languages with a fully integrated managed runtime this intrinsic can
be used to implement "uncommon trap" like functionality. In unmanaged
languages like C and C++, this intrinsic can be used to represent the
slow paths of specialized functions.
Note: this change does not address how `@llvm.experimental_deoptimize`
is lowered. That will be done in a later change.
Reviewers: chandlerc, rnk, atrick, reames
Subscribers: llvm-commits, kmod, mjacob, maksfb, mcrosier, JosephTremoulet
Differential Revision: http://reviews.llvm.org/D17732
llvm-svn: 263281
Generally speaking, this can only happen with unreachable code.
However, neglecting to check for this condition would lead us to loop
forever.
llvm-svn: 262284
Today, we do not allow cmpxchg operations with pointer arguments. We require the frontend to insert ptrtoint casts and do the cmpxchg in integers. While correct, this is problematic from a couple of perspectives:
1) It makes the IR harder to analyse (for instance, it make capture tracking overly conservative)
2) It pushes work onto the frontend authors for no real gain
This patch implements the simplest form of IR support. As we did with floating point loads and stores, we teach AtomicExpand to convert back to the old representation. This prevents us needing to change all backends in a single lock step change. Over time, we can migrate each backend to natively selecting the pointer type. In the meantime, we get the advantages of a cleaner IR representation without waiting for the backend changes.
Differential Revision: http://reviews.llvm.org/D17413
llvm-svn: 261281
While trying to track down what appears to be a LoopVectorizer bug, I noticed that we had no validation of the correctness of calls emitted to @llvm.masked.load and @llvm.masked.store. This meant malformed IR was showing up much much later than it should. Hopefully, having Verifier rules in place will make this easier to isolate.
llvm-svn: 260296
Summary:
This adds a new kind of operand bundle to LLVM denoted by the
`"gc-transition"` tag. Inputs to `"gc-transition"` operand bundle are
lowered into the "transition args" section of `gc.statepoint` by
`RewriteStatepointsForGC`.
This removes the last bit of functionality that was unsupported in the
deopt bundle based code path in `RewriteStatepointsForGC`.
Reviewers: pgavlin, JosephTremoulet, reames
Subscribers: sanjoy, mcrosier, llvm-commits
Differential Revision: http://reviews.llvm.org/D16342
llvm-svn: 258338
Summary:
Fix a significant performance regression by introducing GlobalValueVisited field and reusing the map.
This is a follow up to r257823 that slowed down linking Chrome with LTO by 2.5x.
If you revert this commit, please, also revert r257823.
BUG=https://llvm.org/bugs/show_bug.cgi?id=26214
Reviewers: pcc, loladiro, joker.eph
Subscribers: krasin1, joker.eph, loladiro, pcc
Differential Revision: http://reviews.llvm.org/D16338
llvm-svn: 258297
This reverts commit r257751, bringing back r256105.
The problem the assert found was fixed in r257915.
Original commit message:
Assert that we have all use/users in the getters.
An error that is pretty easy to make is to use the lazy bitcode reader
and then do something like
if (V.use_empty())
The problem is that uses in unmaterialized functions are not accounted
for.
This patch adds asserts that all uses are known.
llvm-svn: 257920
Yet another wave of buildbot failures (though fewer this time).
I'm only reverting the Verifier changes, as the test cases
will be fine without them as well, and touching them as often
just introduces unnecessary churn.
llvm-svn: 257855
I originally reapplied this in 257550, but had to revert again due to bot
breakage. The only change in this version is to allow either the TypeSize
or the TypeAllocSize of the variable to be the one represented in debug info
(hopefully in the future we can figure out how to encode the difference).
Additionally, several bot failures following r257550, were due to
optimizer bugs now fixed in r257787 and r257795.
r257550 commit message was:
```
The follow extra changes were made to test cases:
Manually making the variable be the actual type instead of a pointer
to avoid pointer-size differences in generic code:
LLVM :: DebugInfo/Generic/2010-03-24-MemberFn.ll
LLVM :: DebugInfo/Generic/2010-04-06-NestedFnDbgInfo.ll
LLVM :: DebugInfo/Generic/2010-05-03-DisableFramePtr.ll
LLVM :: DebugInfo/Generic/varargs.ll
Delete sizing information from debug info for the same reason
(but the presence of the pointer was important to the test case):
LLVM :: DebugInfo/Generic/restrict.ll
LLVM :: DebugInfo/Generic/tu-composite.ll
LLVM :: Linker/type-unique-type-array-a.ll
LLVM :: Linker/type-unique-simple2.ll
Fixing an incorrect DW_OP_deref
LLVM :: DebugInfo/Generic/2010-05-03-OriginDIE.ll
Fixing a missing DW_OP_deref
LLVM :: DebugInfo/Generic/incorrect-variable-debugloc.ll
Additionally, clang should no longer complain during bootstrap should no
longer happen after r257534.
The original commit message was:
``
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.
One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.
Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
variable as that would depend on the target, even though this test is
supposed to be generic
- I had to manually declared size/align for reference type. See also the
discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref
``
```
llvm-svn: 257850
Summary:
Before this the Verifier didn't complain if the GlobalVariable
referenced from a DIGlobalVariable was not in fact in the correct
module (it would crash while writing bitcode though). Fix this by
always checking parantage of GlobalValues while walking constant
expressions and changing the DIGlobalVariable visitor to also
visit the constant it contains.
Reviewers: rafael
Differential Revision: http://reviews.llvm.org/D16059
llvm-svn: 257825
Summary:
We already have the inverse verification that we only use globals
that are defined in this module. This essentially catches the
same mistake, but when verifying the module that contains the
definition.
Reviewers: rafael
Differential Revision: http://reviews.llvm.org/D15272
llvm-svn: 257823
The follow extra changes were made to test cases:
Manually making the variable be the actual type instead of a pointer
to avoid pointer-size differences in generic code:
LLVM :: DebugInfo/Generic/2010-03-24-MemberFn.ll
LLVM :: DebugInfo/Generic/2010-04-06-NestedFnDbgInfo.ll
LLVM :: DebugInfo/Generic/2010-05-03-DisableFramePtr.ll
LLVM :: DebugInfo/Generic/varargs.ll
Delete sizing information from debug info for the same reason
(but the presence of the pointer was important to the test case):
LLVM :: DebugInfo/Generic/restrict.ll
LLVM :: DebugInfo/Generic/tu-composite.ll
LLVM :: Linker/type-unique-type-array-a.ll
LLVM :: Linker/type-unique-simple2.ll
Fixing an incorrect DW_OP_deref
LLVM :: DebugInfo/Generic/2010-05-03-OriginDIE.ll
Fixing a missing DW_OP_deref
LLVM :: DebugInfo/Generic/incorrect-variable-debugloc.ll
Additionally, clang should no longer complain during bootstrap should no
longer happen after r257534.
The original commit message was:
```
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.
One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.
Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
variable as that would depend on the target, even though this test is
supposed to be generic
- I had to manually declared size/align for reference type. See also the
discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref
```
llvm-svn: 257550
Summary:
The code was simply ensuring that the catchpad's pred is its catchswitch,
which was letting cases slip through where the flow edge was the unwind
edge of the catchswitch rather than one of its catch clauses.
Reviewers: andrew.w.kaylor, rnk, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16011
llvm-svn: 257275
Summary:
Funclet-based EH personalities/tables likely can't handle these, and they
can't be generated at source, so make them officially illegal in IR as
well.
Reviewers: andrew.w.kaylor, rnk, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15963
llvm-svn: 257274
Summary:
A funclet EH pad may be exited by an unwind edge, which may be a
cleanupret exiting its cleanuppad, an invoke exiting a funclet, or an
unwind out of a nested funclet transitively exiting its parent. Funclet
EH personalities require all such exceptional exits from a given funclet to
have the same unwind destination, and EH preparation / state numbering /
table generation implicitly depends on this. Formalize it as a rule of
the IR in the LangRef and verifier.
Reviewers: rnk, majnemer, andrew.w.kaylor
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15962
llvm-svn: 257273
Summary:
Funclet EH personalities require a tree-like nesting among funclets
(enforced by the ParentPad linkage in the IR), and also require that
unwind edges conform to certain rules with respect to the tree:
- An unwind edge may exit 0 or more ancestor pads
- An unwind edge must enter exactly one EH pad, which must be distinct
from any exited pads
- A cleanupret's edge must exit its cleanuppad
Describe these rules in the LangRef, and enforce them in the verifier.
Reviewers: rnk, majnemer, andrew.w.kaylor
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15961
llvm-svn: 257272
Summary:
Teach the Verifier to make sure that the storage size given to llvm.dbg.declare
or the value size given to llvm.dbg.value agree with what is declared in
DebugInfo. This is implicitly assumed in a number of passes (e.g. in SROA).
Additionally this catches a number of common mistakes, such as passing a
pointer when a value was intended or vice versa.
One complication comes from stack coloring which modifies the original IR when
it merges allocas in order to make sure that if AA falls back to the IR it gets
the correct result. However, given this new invariant, indiscriminately
replacing one alloca by a different (differently sized one) is no longer valid.
Fix this by just undefing out any use of the alloca in a dbg.declare in this
case.
Additionally, I had to fix a number of test cases. Of particular note:
- I regenerated dbg-changes-codegen-branch-folding.ll from the given source as
it was affected by the bug fixed in r256077
- two-cus-from-same-file.ll was changed to avoid having a variable-typed debug
variable as that would depend on the target, even though this test is
supposed to be generic
- I had to manually declared size/align for reference type. See also the
discussion for D14275/r253186.
- fpstack-debuginstr-kill.ll required changing `double` to `long double`
- most others were just a question of adding OP_deref
Reviewers: aprantl
Differential Revision: http://reviews.llvm.org/D14276
llvm-svn: 257105
Currently, we try to split vectors of pointers back into their component pointer elements during rewrite-statepoints-for-gc. This is less than ideal since presumably the vectorizer chose to vectorize for a reason. :) It's also been a source of bugs - in particular, the relocation logic as currently implemented was recently discovered to be wrong.
The alternate approach is to allow gc.relocates of vector-of-pointer type and update the backend to handle them. That's what this patch tries to do. This won't actually enable vector-of-pointers in practice - there are some RS4GC changes needed - but the lowering is standalone and testable so it makes sense to separate.
Note that there are some known cases around vector constants which this patch does not handle. Once this is in, I'll send another patch with individual fixes and test cases.
Differential Revision: http://reviews.llvm.org/D15632
llvm-svn: 257022
Summary:
This commit renames GCRelocateOperands to GCRelocateInst and makes it an
intrinsic wrapper, similar to e.g. MemCpyInst. Also, all users of
GCRelocateOperands were changed to use the new intrinsic wrapper instead.
Reviewers: sanjoy, reames
Subscribers: reames, sanjoy, llvm-commits
Differential Revision: http://reviews.llvm.org/D15762
llvm-svn: 256811
Summary:
The handler list must be nonempty and consist solely of CatchPads.
Reviewers: rnk, andrew.w.kaylor, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15842
llvm-svn: 256691
Summary: A catchswitch cannot be a parent of a cleanuppad or another catchswitch.
Reviewers: rnk, andrew.w.kaylor, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15841
llvm-svn: 256690
Summary: This patch changes gc.statepoint intrinsic's return type to token type instead of i32 type. Using token types could prevent LLVM to merge different gc.statepoint nodes into PHI nodes and cause further problems with gc relocations. The patch also changes the way on how gc.relocate and gc.result look for their corresponding gc.statepoint on unwind path. The current implementation uses the selector value extracted from a { i8*, i32 } landingpad as a hook to find the gc.statepoint, while the patch directly uses a token type landingpad (http://reviews.llvm.org/D15405) to find the gc.statepoint.
Reviewers: sanjoy, JosephTremoulet, pgavlin, igor-laevsky, mjacob
Subscribers: reames, mjacob, sanjoy, llvm-commits
Differential Revision: http://reviews.llvm.org/D15662
llvm-svn: 256443
Summary:
These were deprecated 11 months ago when a generic
llvm.experimental.gc.result intrinsic, which works for all types, was added.
Reviewers: sanjoy, reames
Subscribers: sanjoy, chenli, llvm-commits
Differential Revision: http://reviews.llvm.org/D15719
llvm-svn: 256262
An error that is pretty easy to make is to use the lazy bitcode reader
and then do something like
if (V.use_empty())
The problem is that uses in unmaterialized functions are not accounted
for.
This patch adds asserts that all uses are known.
llvm-svn: 256105
Summary:
I didn't realize that we already allowed atomic load/store of pointers,
it was added in 2012 by r162146. This patch updates the documentation
and tightens the verifier by using DataLayout to make sure that the
stored size is byte-sized and power-of-two. DataLayout is also used for
integers, and while I'm here I updated the corresponding code for
cmpxchg and rmw.
See the following discussion for context and upcoming changes to
add floating-point and vector atomics:
https://groups.google.com/forum/#!topic/llvm-dev/Nh0P_E3CRoo/discussion
Reviewers: reames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15512
llvm-svn: 255931
Summary:
This patch introduces two new function attributes
InaccessibleMemOnly: This attribute indicates that the function may only access memory that is not accessible by the program/IR being compiled. This is a weaker form of ReadNone.
inaccessibleMemOrArgMemOnly: This attribute indicates that the function may only access memory that is either not accessible by the program/IR being compiled, or is pointed to by its pointer arguments. This is a weaker form of ArgMemOnly
Test cases have been updated. This revision uses this (d001932f3a) as reference.
Reviewers: jmolloy, hfinkel
Subscribers: reames, joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D15499
llvm-svn: 255778
This patch allows atomic loads and stores of floating point to be specified in the IR and adds an adapter to allow them to be lowered via existing backend support for bitcast-to-equivalent-integer idiom.
Previously, the only way to specify a atomic float operation was to bitcast the pointer to a i32, load the value as an i32, then bitcast to a float. At it's most basic, this patch simply moves this expansion step to the point we start lowering to the backend.
This patch does not add canonicalization rules to convert the bitcast idioms to the appropriate atomic loads. I plan to do that in the future, but for now, let's simply add the support. I'd like to get instruction selection working through at least one backend (x86-64) without the bitcast conversion before canonicalizing into this form.
Similarly, I haven't yet added the target hooks to opt out of the lowering step I added to AtomicExpand. I figured it would more sense to add those once at least one backend (x86) was ready to actually opt out.
As you can see from the included tests, the generated code quality is not great. I plan on submitting some patches to fix this, but help from others along that line would be very welcome. I'm not super familiar with the backend and my ramp up time may be material.
Differential Revision: http://reviews.llvm.org/D15471
llvm-svn: 255737
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
llvm-svn: 255674
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
llvm-svn: 255522
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
llvm-svn: 255422
Avoid O(N^2) behaviour when checking for bad bitcasts in `ConstantExpr`s
buried inside of aggregate initializers to `GlobalVariable`s. I've:
- centralized the "visited" set for recursing through `ConstantExpr`s so
that expressions are only visited once per Verifier run,
- removed the duplicate logic for the stack visit, and
- avoided recursing into other `GlobalValue`s.
This recovers roughly a 100x time difference in clang compiles of a
particular input file (filled with large cross-referencing tables) that
depends on whether `-disable-llvm-verifier` is on. This slowdown was
caused by r187506, which introduced these checks.
Now, avoiding `-disable-llvm-verifier` only causes a 2x slowdown for
this case.
(Interestingly, dumping the textual IR for this file starts at least
50GB of global variable initializers (I don't know the total, since I
killed the dump)...)
llvm-svn: 255269
Introduced DIMacro and DIMacroFile debug info metadata in the LLVM IR to support macros.
Differential Revision: http://reviews.llvm.org/D14687
llvm-svn: 255245
Summary:
We are inserting both Scope and SP into the Seen map and check whether
it was already there in which case we skip the validation (the idea
being that we already checked this Subprogram before). However,
if (Scope == SP) as MDNodes, then inserting the Scope, will trigger
the Seen check causing us to incorrectly not validate this !dbg
attachment. Fix this by not performing the SP Seen check if Scope == SP
Reviewers: pcc, dexonsmith, dblaikie
Subscribers: dblaikie, llvm-commits
Differential Revision: http://reviews.llvm.org/D14697
llvm-svn: 254887
By including the module name in the error message.
This makes the error message much more useful and
saves a trip to the debugger.
Reviewers: dexonsmith
Subscribers: dexonsmith, llvm-commits
Differential Revision: http://reviews.llvm.org/D14473
llvm-svn: 254437
They are as much trouble as aliases to declarations. They are requiring
the code generator to define a symbol with the same value as another
symbol, but the second symbol is undefined.
If representing this is important for some optimization, we could add
support for available_externally aliases. They would be *required* to
point to a declaration (or available_externally definition).
llvm-svn: 254170
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
Summary: The Old personality function gets copied over, but the
Materializer didn't have a chance to inspect it (e.g. to fix up
references to the correct module for the target function).
Also add a verifier check that makes sure the personality routine
is in the same module as the function whose personality it is.
Reviewers: majnemer
Subscribers: jevinskie, llvm-commits
Differential Revision: http://reviews.llvm.org/D14474
llvm-svn: 253183
Sanjoy Das