Functions include their arguments in the use-list. Changed function
values mean that the result of the function changed. We only need
to update the call sites with the new function result and do not
have to propagate the call arguments.
To do so, this patch splits up the visitCallSite into handleCallResult
and handleCallArguments and updates markUsersAsChanged to only update
call results for functions.
Reviewers: efriedma, davide
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D75846
Summary: Prevent InstCombine from removing llvm.assume for which the arguement is true when they have operand bundles with usefull information.
Reviewers: jdoerfert, nikic, lebedev.ri
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76147
According to LangRef:
If len is not a positive integer multiple of element_size, then the behaviour of the intrinsic is undefined.
Add InstCombine rule to transform intrinsic to undef operation.
This is a follow-up for D76116.
Reviewers: reames
Reviewed By: reames
Subscribers: hiraditya, jfb, dantrushin, llvm-commits
Differential Revision: https://reviews.llvm.org/D76215
This patch adds a new undef lattice state, which is used to represent
UndefValue constants or instructions producing undef.
The main difference to the unknown state is that merging undef values
with constants (or single element constant ranges) produces the
constant/constant range, assuming all uses of the merge result will be
replaced by the found constant.
Contrary, merging non-single element ranges with undef needs to go to
overdefined. Using unknown for UndefValues currently causes mis-compiles
in CVP/LVI (PR44949) and will become problematic once we use
ValueLatticeElement for SCCP.
Reviewers: efriedma, reames, davide, nikic
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D75120
a tail call
This reapplies the patch in https://reviews.llvm.org/rG1f5b471b8bf4,
which was reverted because it was causing crashes.
https://bugs.chromium.org/p/chromium/issues/detail?id=1061289#c2
Check that HasSafePathToCall is true before checking the call is a tail
call.
Original commit message:
Previosly ARC optimizer removed the autoreleaseRV/retainRV pair in the
following code, which caused the object returned by @something to be
placed in the autorelease pool because the call to @something isn't a
tail call:
```
%call = call i8* @something(...)
%2 = call i8* @objc_retainAutoreleasedReturnValue(i8* %call)
%3 = call i8* @objc_autoreleaseReturnValue(i8* %2)
ret i8* %3
```
Fix the bug by checking whether @something is a tail call.
rdar://problem/59275894
This reverts commit 5c3117b0a9
This should not be necessary after
7593a480db, and Florian Hahn has confirmed
that the problem no longer reproduces with this patch.
I happened to notice this code because the FIXME talks about
OrderedBasicBlock.
Reviewed By: fhahn, dexonsmith
Differential Revision: https://reviews.llvm.org/D76075
Summary:
SLPVectorizer try to vectorize list of scalar instructions of the same type,
instructions already vectorized are rejected through isValidElementType().
Without this patch, tryToVectorizeList() will first try to determine vectorization
factor of a list of Instructions before checking whether each instruction has unsupported
type or not. For instructions already vectorized for SVE, it will crash at getVectorElementSize(),
where it try to return a fixed size.
This patch make sure invalid element types are rejected before trying to get vectorization
factor. This make sure we are not trying to vectorize instructions already vectorized.
Reviewers: sdesmalen, efriedma, spatel, RKSimon, ABataev, apazos, rengolin
Reviewed By: efriedma
Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76017
Summary:
during inling Create and insert an llvm.assume with attributes to preserve them.
to prevent any changes for now generation of llvm.assume is under a flag disabled by default.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75825
This patch add mayContainUnboundedCycle helper function which checks whether a function has any cycle which we don't know if it is bounded or not.
Loops with maximum trip count are considered bounded, any other cycle not.
It also contains some fixed tests and some added tests contain bounded and
unbounded loops and non-loop cycles.
Reviewed By: jdoerfert, uenoku, baziotis
Differential Revision: https://reviews.llvm.org/D74691
Resolution for below fixme:
(ii) Check whether the value is captured in the scope using AANoCapture.
FIXME: This is conservative though, it is better to look at CFG and
check only uses possibly executed before this callsite.
Propagates caller argument's noalias attribute to callee.
Reviewed by: jdoerfert, uenoku
Reviewers: jdoerfert, sstefan1, uenoku
Subscribers: uenoku, sstefan1, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D71617
Summary:
Support ConstantInt::get() and Constant::getAllOnesValue() for scalable
vector type, this requires ConstantVector::getSplat() to take in 'ElementCount',
instead of 'unsigned' number of element count.
This change is needed for D73753.
Reviewers: sdesmalen, efriedma, apazos, spatel, huntergr, willlovett
Reviewed By: efriedma
Subscribers: tschuett, hiraditya, rkruppe, psnobl, cfe-commits, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74386
This patch switches SCCP to use ValueLatticeElement for lattice values,
instead of the local LatticeVal, as first step to enable integer range support.
This patch does not make use of constant ranges for additional operations
and the only difference for now is that integer constants are represented by
single element ranges. To preserve the existing behavior, the following helpers
are used
* isConstant(LV): returns true when LV is either a constant or a constant range with a single element. This should return true in the same cases where LV.isConstant() returned true previously.
* getConstant(LV): returns a constant if LV is either a constant or a constant range with a single element. This should return a constant in the same cases as LV.getConstant() previously.
* getConstantInt(LV): same as getConstant, but additionally casted to ConstantInt.
Reviewers: davide, efriedma, mssimpso
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D60582
Summary:
This patch replaces incorrectt assert with a check. Previously it asserts that
if SCEV cannot prove `isKnownPredicate(A != B)`, then it should be able to prove
`isKnownPredicate(A == B)`.
Both these fact may be not provable. It is shown in the provided test:
Could not prove: `{-294,+,-2}<%bb1> != 0`
Asserting: `{-294,+,-2}<%bb1> == 0`
Obviously, this SCEV is not equal to zero, but 0 is in its range so we cannot
also prove that it is not zero.
Instead of assert, we should be checking the required conditions explicitly.
Reviewers: lebedev.ri, fhahn, sanjoy, fedor.sergeev
Reviewed By: lebedev.ri
Subscribers: hiraditya, zzheng, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76050
This patch adds support for propagating matrix expressions along the
inlined-at chain and emitting remarks at the traversed function scopes.
To motivate this new behavior, consider the example below. Without the
remark 'up-leveling', we would only get remarks in load.h and store.h,
but we cannot generate a remark describing the full expression in
toplevel.cpp, which is the place where the user has the best chance of
spotting/fixing potential problems.
With this patch, we generate a remark for the load in load.h, one for
the store in store.h and one for the complete expression in
toplevel.cpp. For a bigger example, please see remarks-inlining.ll.
load.h:
template <typename Ty, unsigned R, unsigned C> Matrix<Ty, R, C> load(Ty *Ptr) {
Matrix<Ty, R, C> Result;
Result.value = *reinterpret_cast <typename Matrix<Ty, R, C>::matrix_t *>(Ptr);
return Result;
}
store.h:
template <typename Ty, unsigned R, unsigned C> void store(Matrix<Ty, R, C> M1, Ty *Ptr) {
*reinterpret_cast<typename decltype(M1)::matrix_t *>(Ptr) = M1.value;
}
toplevel.cpp
void test(double *A, double *B, double *C) {
store(add(load<double, 3, 5>(A), load<double, 3, 5>(B)), C);
}
For a given function, we traverse the inlined-at chain for each
matrix instruction (= instructions with shape information). We collect
the matrix instructions in each DISubprogram we visit. This produces a
mapping of DISubprogram -> (List of matrix instructions visible in the
subpogram). We then generate remarks using the list of instructions for
each subprogram in the inlined-at chain. Note that the list of instructions
for a subprogram includes the instructions from its own subprograms
recursively. For example using the example above, for the subprogram
'test' this includes inline functions 'load' and 'store'. This allows
surfacing the remarks at a level useful to users.
Please note that the current approach may create a lot of extra remarks.
Additional heuristics to cut-off the traversal can be implemented in the
future. For example, it might make sense to stop 'up-leveling' once all
matrix instructions are at the same debug location.
Reviewers: anemet, Gerolf, thegameg, hfinkel, andrew.w.kaylor, LuoYuanke
Reviewed By: anemet
Differential Revision: https://reviews.llvm.org/D73600
Refines the gather/scatter cost model, but also changes the TTI
function getIntrinsicInstrCost to accept an additional parameter
which is needed for the gather/scatter cost evaluation.
This did require trivial changes in some non-ARM backends to
adopt the new parameter.
Extending gathers and truncating scatters are now priced cheaper.
Differential Revision: https://reviews.llvm.org/D75525
This essentially reverts some of the SimplifyLibcalls part changes of D45736 [SimplifyLibcalls] Replace locked IO with unlocked IO.
C11 7.21.5.2 The fflush function
> If stream is a null pointer, the fflush function performs this flushing action on all streams for which the behavior is defined above.
i.e. fopen'ed FILE* is inherently captured.
POSIX.1-2017 getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - stdio with explicit client locking
> These functions can safely be used in a multi-threaded program if and only if they are called while the invoking thread owns the ( FILE *) object, as is the case after a successful call to the flockfile() or ftrylockfile() functions.
After a thread fopen'ed a FILE*, when it is calling foobar() which is now replaced by foobar_unlocked(),
if another thread is concurrently calling fflush(0), the behavior is undefined.
C11 7.22.4.4 The exit function
> Next, all open streams with unwritten buffered data are flushed, all open streams are closed, and all files created by the tmpfile function are removed.
The replacement is only feasible if the program is single threaded, or exit or fflush(0) is never called.
See also http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20180528/556615.html
for how the replacement makes libc interceptors difficult to implement.
dalias: in a worst case, it's unbounded data corruption because of concurrent access to pointers
without synchronization. f->wpos or rpos could get outside of the buffer, thread A could do
f->wpos += j after knowing j is in bounds, while thread B also changes it concurrently.
This can produce exploitable conditions depending on libc internals.
Revert the SimplifyLibcalls part change because the cons obviously
overweigh the pros. Even when the replacement is feasible, the benefit
is indemonstrable, more so in an application instead of an artificial
glibc benchmark. Theoretically the replacement could be beneficial when
calling getc_unlocked/putc_unlocked in a loop, but then it is better
using a blocked IO operation and the user is likely aware of that.
The function attribute inference is still useful and thus kept.
Reviewed By: xbolva00
Differential Revision: https://reviews.llvm.org/D75933
Summary: Rewrite the fsub-0.0 idiom to fneg and always emit fneg for fp
negation. This also extends the scalarization cost in instcombine for unary
operators to result in the same IR rewrites for fneg as for the idiom.
Reviewed By: cameron.mcinally
Differential Revision: https://reviews.llvm.org/D75467
SimplifyAddWithRemainder currently also matches for vector types, but
tries to create an integer constant, which causes a crash.
By using Constant::getIntegerValue() we can support both the scalar and
vector cases.
The 2 added test cases crash without the fix.
Reviewers: spatel, lebedev.ri
Reviewed By: spatel, lebedev.ri
Differential Revision: https://reviews.llvm.org/D75906
SimplifyCFG should not merge empty return blocks and leave a CallBr behind
with a duplicated destination since the verifier will then trigger an
assert. This patch checks for this case and avoids the transformation.
CodeGenPrepare has a similar check which also has a FIXME comment about why
this is needed. It seems perhaps better if these two passes would eventually
instead update the CallBr instruction instead of just checking and avoiding.
This fixes https://bugs.llvm.org/show_bug.cgi?id=45062.
Review: Craig Topper
Differential Revision: https://reviews.llvm.org/D75620
It seems like the SLPVectorizer is currently not aware of vector
versions of functions provided by libraries like Accelerate [1].
This patch updates SLPVectorizer to use the same infrastructure
the LoopVectorizer uses to detect vectorizable library functions.
For calls, it computes the cost of an intrinsic call (existing behavior)
and the cost of a vector function library call, if available. Like
LoopVectorizer, it assumes the cost of the vector function is simply the
cost of a call to a vector function.
[1] https://developer.apple.com/documentation/accelerate
Reviewers: ABataev, RKSimon, spatel
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D75878
a tail call
Previosly ARC optimizer removed the autoreleaseRV/retainRV pair in the
following code, which caused the object returned by @something to be
placed in the autorelease pool because the call to @something isn't a
tail call:
```
%call = call i8* @something(...)
%2 = call i8* @objc_retainAutoreleasedReturnValue(i8* %call)
%3 = call i8* @objc_autoreleaseReturnValue(i8* %2)
ret i8* %3
```
Fix the bug by checking whether @something is a tail call.
rdar://problem/59275894
When simplifying a call without uses, replaceInstUsesWith() is
going to do nothing, but we'll skip all following folds. We can
only run into this problem with calls that both simplify and are
not trivially dead if unused, which currently seems to happen only
with calls to undef, as the test diff shows. When extending
SimplifyCall() to handle "returned" attributes, this becomes a much
bigger problem, so I'm fixing this first.
Differential Revision: https://reviews.llvm.org/D75814
This patch introduces the propagation of known information based on path exploration.
For example,
```
int u(int c, int *p){
if(c) {
return *p;
} else {
return *p + 1;
}
}
```
An argument `p` is dereferenced whatever c's value is.
For an instruction `CtxI`, we accumulate branch instructions in the must-be-executed-context of `CtxI` and then, we take the conjunction of the successors' known state.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D65593
opcode (extelt V0, Ext0), (ext V1, Ext1) --> extelt (opcode (splat V0, Ext0), V1), Ext1
The first part of this patch generalizes the cost calculation to accept
different extraction indexes. The second part creates a shuffle+extract
before feeding into the existing code to create a vector op+extract.
The patch conservatively uses "TargetTransformInfo::SK_PermuteSingleSrc"
rather than "TargetTransformInfo::SK_Broadcast" (splat specifically
from element 0) because we do not have a more general "SK_Splat"
currently. That does not affect any of the current regression tests,
but we might be able to find some cost model target specialization where
that comes into play.
I suspect that we can expose some missing x86 horizontal op codegen with
this transform, so I'm speculatively adding a debug flag to disable the
binop variant of this transform to allow easier testing.
The test changes show that we're sensitive to cost model diffs (as we
should be), so that means that patches like D74976
should have better coverage.
Differential Revision: https://reviews.llvm.org/D75689
Summary:
Assume bundles need to be usable by Analysis and Transforms/Utils isn't.
so this commit moves utilities to deal with asusme bundles to IR.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75618
Summary: Finding what information is know about a value from a use is generally useful and can be done quickly.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75616
Fixes a regression from D75801. SimplifyDemandedUseBits() is also
supposed to compute the known bits (of the demanded subset) of the
instruction. For unknown instructions it does so by directly calling
computeKnownBits(). For known instructions it will compute known
bits itself. However, for instructions where only some cases are
handled directly (e.g. a constant shift amount) the known bits
invocation for the unhandled case is sometimes missing. This patch
adds the missing calls and thus removes the main discrepancy with
ExpensiveCombines mode.
Differential Revision: https://reviews.llvm.org/D75804
It is possible that an instruction to be changed to unreachable is
in the same block with a terminator that can be constant-folded.
In this case, as of now, the instruction will be changed to
unreachable before the terminator is folded. But, then the
whole BB becomes invalidated and so when we go ahead to fold
the terminator, we trap.
Change the order of these two.
Differential Revision: https://reviews.llvm.org/D75780
Florian Hahn