Currently, clang ignores the 0 initialisation in finite math
For example:
```
double f_prod = 0;
double arr[1000];
for (size_t i = 0; i < 1000; i++) {
f_prod *= arr[i];
}
```
Clang will ignore that `f_prod` is set to zero and it will generate assembly to iterate over the loop.
Reviewed By: fhahn, spatel
Differential Revision: https://reviews.llvm.org/D131672
Handle cases where a forked pointer has an add or sub instruction
before reaching a select.
Reviewed By: fhahn
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D130278
If computeKnownBits encounters a phi node, and we fail to determine any known bits through direct analysis, see if the incoming value is part of a branch condition feeding the phi.
Handle cases where icmp(IncomingValue PRED Constant) is driving a branch instruction feeding that phi node - at the moment this only handles EQ/ULT/ULE predicate cases as they are the most straightforward to handle and most likely for branch-loop 'max upper bound' cases - we can extend this if/when necessary.
I investigated a more general icmp(LHS PRED RHS) KnownBits system, but the hard limits we put on value tracking depth through phi nodes meant that we were mainly catching constants anyhow.
Fixes the pointless vectorization in PR38280 / Issue #37628 (excessive unrolling still needs handling though)
Differential Revision: https://reviews.llvm.org/D131838
This reverts commit 354fa0b480.
Returning as is. The patch was reverted due to a miscompile, but
this patch is not causing it. This patch made it possible to infer
some nuw flags in code guarded by `false` condition, and then someone
else to managed to propagate the flag from dead code outside.
Returning the patch to be able to reproduce the issue.
We already support SGE, so the same logic should hold for SLE with
the LHS and RHS swapped.
I didn't see this in the wild. Just happened to walk past this code
and thought it was odd that it was asymmetric in what condition
codes it handled.
Reviewed By: spatel, reames
Differential Revision: https://reviews.llvm.org/D131805
This reverts commit 34ae308c73.
Our internal testing found a miscompile. Not sure if it's caused by
this patch or it revealed something else. Reverting while investigating.
The value of the attribute is a size in bytes. It has the effect of
suppressing inlining of functions whose stacksizes exceed the given value.
Reviewed By: mtrofin
Differential Revision: https://reviews.llvm.org/D129904
Contextual knowledge may be used to prove invariance of some conditions.
For example, in this case:
```
; %len >= 0
guard(%iv = {start,+,1}<nuw> <s %len)
guard(%iv = {start,+,1}<nuw> <u %len)
```
the 2nd check always fails if `start` is negative and always passes otherwise.
It looks like there are more opportunities of this kind that are still to be
implemented in the future.
Differential Revision: https://reviews.llvm.org/D129753
Reviewed By: apilipenko
My most recent change for D131607 had a formatting error that I didn't
notice until after I committed it. Let me fix it now so changes to this
file will be back-to-back from me.
Another ticket split out of D107285, this extends the optimization
of 0.0 - -X to just X when using constrained intrinsics and the
optimization is allowed.
If the negation of X is done with fsub then the match fails because of
the lack of IR Matcher support for constrained intrinsics.
While I'm here, remove some TODO notices since the work is no longer
planned.
Differential Revision: https://reviews.llvm.org/D131607
From the opengroup specifications, atan2 may fail if the result
underflows and atan may fail if the argument is subnormal, but
we assume that does not happen and eliminate the calls if we
can constant fold the result at compile-time.
Differential Revision: https://reviews.llvm.org/D127964
After D121595 was commited, I noticed regressions assosicated with small trip
count numbersvectorisation by tail folding with scalable vectors. As a solution
for those issues I propose to introduce the minimal trip count threshold value.
Differential Revision: https://reviews.llvm.org/D130755
To move from TF C API to TFLite, we found that the argmax op in TFLite does not work for int64 inputs, so cast the int64 inputs to int32 inputs to make TFLite argmax op work
Differential Revision: https://reviews.llvm.org/D131462
We get a couple of improvements from recognizing swapped
operand patterns that were not handled by the replicated
code.
This should also enable simplifying larger patterns as
seen in issue #56653 and issue #56654, but that requires
enhancements to isImpliedCondition() itself.
Given a poison constant as input, the dyn_cast to a ConstantInt would
fail so we would fall through to the generic code that attempts to fold
each element of the input vectors. The inputs to these intrinsics are
not vectors though, leading to a compile time crash. Instead bail out
properly for poison values by returning nullptr. This doesn't try to
define what poison means for these intrinsics.
Fixes#56945
A const reference is preferred over a non-null const pointer.
`Type *` is kept as is to match the other overload.
Reviewed By: davidxl
Differential Revision: https://reviews.llvm.org/D131197
1) Overloaded (instruction-based) method is a wrapper around the current (opcode-based) method.
2) This patch also changes a few callsites (VectorCombine.cpp,
SLPVectorizer.cpp, CodeGenPrepare.cpp) to call the overloaded method.
3) This is a split of D128302.
Differential Revision: https://reviews.llvm.org/D131114
BoundsChecking uses ObjectSizeOffsetEvaluator to keep track of the
underlying size/offset of pointers in allocations. However,
ObjectSizeOffsetVisitor (something ObjectSizeOffsetEvaluator
uses to check for constant sizes/offsets)
doesn't quite treat sizes and offsets the same way as
BoundsChecking. BoundsChecking wants to know the size of the
underlying allocation and the current pointer's offset within
it, but ObjectSizeOffsetVisitor only cares about the size
from the pointer to the end of the underlying allocation.
This only comes up when merging two size/offset pairs. Add a new mode to
ObjectSizeOffsetVisitor which cares about the underlying size/offset
rather than the size from the current pointer to the end of the
allocation.
Fixes a false positive with -fsanitize=bounds.
Reviewed By: vitalybuka, asbirlea
Differential Revision: https://reviews.llvm.org/D131001
This patch is the first of the two-patch series (D130188, D130179) that
resolve PR56275 (https://github.com/llvm/llvm-project/issues/56275)
which is a missed opportunity, where a perfrectly valid case for loop
interchange failed interchange legality.
If the distance/direction vector produced by dependence analysis (DA) is
negative, it needs to be normalized (reversed). This patch provides helper
functions `isDirectionNegative()` and `normalize()` in DA that does the
normalization, and clients can query DA to do normalization if needed.
A pass option `<normalized-results>` is added to DependenceAnalysisPrinterPass,
and we leverage it to update DA test cases to make sure of test coverage. The
test cases added in `Banerjee.ll` shows that negative vectors are normalized
with `print<da><normalized-results>`.
Reviewed By: bmahjour, Meinersbur, #loopoptwg
Differential Revision: https://reviews.llvm.org/D130188
This just shuffles implementations and declarations around. Now the
logger and the TF C API-based model evaluator are separate.
Differential Revision: https://reviews.llvm.org/D131116
Unfortunately, this overflow is extremely hard to reproduce reliably (in fact, I was unable to do so). The issue is that:
- getOperandsToCreate sometimes skips creating an SCEV for the LHS
- then, createSCEV is called for the BinaryOp
- ... which calls getNoWrapFlagsFromUB
- ... which under certain circumstances calls isSCEVExprNeverPoison
- ... which under certain circumstances requires the SCEVs of all operands
For certain deep dependency trees, this causes a stack overflow.
Reviewed By: bkramer, fhahn
Differential Revision: https://reviews.llvm.org/D129745
Mark ModRefInfo as a bitmask enum, which allows using normal
& and | operators on it. This supersedes various functions like
unionModRef() and intersectModRef(). I think this makes the code
cleaner than going through helper functions...
Differential Revision: https://reviews.llvm.org/D130870
Sometimes SCEV cannot infer nuw/nsw from something as simple as
```
len in [0, MAX_INT]
...
iv = phi(0, iv.next)
guard(iv <s len)
guard(iv <u len)
iv.next = iv + 1
```
just because flag strenthening only relies on definition and does not use local facts.
This patch adds support for the simplest case: inference of flags of `add(x, constant)`
if we can contextually prove that `x <= max_int - constant`.
In case if it has negative CT impact, we can add an option to switch it off. I woudln't
expect that though.
Differential Revision: https://reviews.llvm.org/D129643
Reviewed By: apilipenko
In this patch we replace common code patterns with the use of utility
functions for dealing with profiling metadata. There should be no change
in functionality, as the existing checks should be preserved in all
cases.
Reviewed By: bogner, davidxl
Differential Revision: https://reviews.llvm.org/D128860
If we have interleave groups in the loop we want to vectorise then
we should fall back on normal vectorisation with a scalar epilogue. In
such cases when tail-folding is enabled we'll almost certainly go on to
create vplans with very high costs for all vector VFs and fall back on
VF=1 anyway. This is likely to be worse than if we'd just used an
unpredicated vector loop in the first place.
Once the vectoriser has proper support for analysing all the costs
for each combination of VF and vectorisation style, then we should
be able to remove this.
Added an extra test here:
Transforms/LoopVectorize/AArch64/sve-tail-folding-option.ll
Differential Revision: https://reviews.llvm.org/D128342
Now the API getExtendedAddReductionCost is used to determine the cost of extended Add reduction with optional Mul. For Arm, it could cover the cases. But for other target, for example: RISCV, they support other kinds of extended recution, such as FAdd.
This patch does the following changes:
1, Split getExtendedAddReductionCost into 2 new API: getExtendedReductionCost which handles the extended reduction with addtional input of Opcode; getMulAccReductionCost which handle the MLA cases the getExtendedAddReductionCost.
2, Refactor getReductionPatternCost, add some contraint condition to make sure the getMulAccReductionCost should only handle the reuction of Add + Mul.
Differential Revision: https://reviews.llvm.org/D130868
getModRefInfo() queries currently track whether the result is a
MustAlias on a best-effort basis. The only user of this functionality
is the optimized memory access type in MemorySSA -- which in turn
has no users. Given that this functionality has not found a user
since it was introduced five years ago (in D38862), I think we
should drop it again.
The context is that I'm working to separate FunctionModRefBehavior
to track mod/ref for different location kinds (like argmem or
inaccessiblemem) separately, and the fact that ModRefInfo also has
an unrelated Must flag makes this quite awkward, especially as this
means that NoModRef is not a zero value. If we want to retain the
functionality, I would probably split getModRefInfo() results into
a part that just contains the ModRef information, and a separate
part containing a (best-effort) AliasResult.
Differential Revision: https://reviews.llvm.org/D130713
Simon Pilgrim