This reverts r334428. It incorrectly marks some multiplications as nuw. Tim
Shen is working on a proper fix.
Original commit message:
[SCEV] Add nuw/nsw to mul ops in StrengthenNoWrapFlags where safe.
Summary:
Previously we would add them for adds, but not multiplies.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335016 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Obviates the need for mask/clear/setFlags helpers.
There are some expressions here which can be simplified, but to keep
this easy to review, I have not simplified them in this patch.
No functional change.
Reviewers: sanjoy
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D48237
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334874 91177308-0d34-0410-b5e6-96231b3b80d8
In particular, when asked to print a MemoryAccess, we'll now print where
defs are optimized to, and we'll print optimized access types.
This patch also introduces an operator<< to make printing AliasResults
easier.
Patch by Juneyoung Lee!
Differential Revision: https://reviews.llvm.org/D47860
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334760 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Specifically, we transform
zext(2^K * (trunc X to iN)) to iM ->
2^K * (zext(trunc X to i{N-K}) to iM)<nuw>
This is helpful because pulling the 2^K out of the zext allows further
optimizations.
Reviewers: sanjoy
Subscribers: hiraditya, llvm-commits, timshen
Differential Revision: https://reviews.llvm.org/D48158
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334737 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Previously we would do this simplification only if it did not introduce
any new truncs (excepting new truncs which replace other cast ops).
This change weakens this condition: If the number of truncs stays the
same, but we're able to transform trunc(X + Y) to X + trunc(Y), that's
still simpler, and it may open up additional transformations.
While we're here, also clean up some duplicated code.
Reviewers: sanjoy
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D48160
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334736 91177308-0d34-0410-b5e6-96231b3b80d8
As discussed on PR33744, this patch relaxes ShuffleKind::SK_Alternate which requires shuffle masks to only match an alternating pattern from its 2 sources:
e.g. v4f32: <0,5,2,7> or <4,1,6,3>
This seems far too restrictive as most SIMD hardware which will implement it using a general blend/bit-select instruction, so replaces it with SK_Select, permitting elements from either source as long as they are inline:
e.g. v4f32: <0,5,2,7>, <4,1,6,3>, <0,1,6,7>, <4,1,2,3> etc.
This initial patch just updates the name and cost model shuffle mask analysis, later patch reviews will update SLP to better utilise this - it still limits itself to SK_Alternate style patterns.
Differential Revision: https://reviews.llvm.org/D47985
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334513 91177308-0d34-0410-b5e6-96231b3b80d8
As discussed on D47985, identity shuffle masks should probably be free.
I've limited this to the case where the input and output types all match - but we could probably accept all cases.
Differential Revision: https://reviews.llvm.org/D47986
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334506 91177308-0d34-0410-b5e6-96231b3b80d8
An expression like
(zext i2 {(trunc i32 (1 + %B) to i2),+,1}<%while.body> to i32)
will become zero exactly when the nested value becomes zero in its type.
Strip injective operations from the input value in howFarToZero to make
the value simpler.
Differential Revision: https://reviews.llvm.org/D47951
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334318 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
`%ret = add nuw i8 %x, C`
From [[ https://llvm.org/docs/LangRef.html#add-instruction | langref ]]:
nuw and nsw stand for “No Unsigned Wrap” and “No Signed Wrap”,
respectively. If the nuw and/or nsw keywords are present,
the result value of the add is a poison value if unsigned
and/or signed overflow, respectively, occurs.
So if `C` is `-1`, `%x` can only be `0`, and the result is always `-1`.
I'm not sure we want to use `KnownBits`/`LVI` here, because there is
exactly one possible value (all bits set, `-1`), so some other pass
should take care of replacing the known-all-ones with constant `-1`.
The `test/Transforms/InstCombine/set-lowbits-mask-canonicalize.ll` change *is* confusing.
What happening is, before this: (omitting `nuw` for simplicity)
1. First, InstCombine D47428/rL334127 folds `shl i32 1, %NBits`) to `shl nuw i32 -1, %NBits`
2. Then, InstSimplify D47883/rL334222 folds `shl nuw i32 -1, %NBits` to `-1`,
3. `-1` is inverted to `0`.
But now:
1. *This* InstSimplify fold `%ret = add nuw i32 %setbit, -1` -> `-1` happens first,
before InstCombine D47428/rL334127 fold could happen.
Thus we now end up with the opposite constant,
and it is all good: https://rise4fun.com/Alive/OA9https://rise4fun.com/Alive/sldC
Was mentioned in D47428 review.
Follow-up for D47883.
Reviewers: spatel, craig.topper
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47908
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334298 91177308-0d34-0410-b5e6-96231b3b80d8
Currently the loop branch heuristic is applied before the invoke heuristic which makes us overestimate the probability of the unwind destination of invokes inside loops. This in turn makes us grossly underestimate the frequencies of loops with invokes.
Reviewed By: skatkov, vsk
Differential Revision: https://reviews.llvm.org/D47371
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334285 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
`%r = shl nuw i8 C, %x`
As per langref:
```
If the nuw keyword is present, then the shift produces
a poison value if it shifts out any non-zero bits.
```
Thus, if the sign bit is set on `C`, then `%x` can only be `0`,
which means that `%r` can only be `C`.
Or in other words, set sign bit means that the signed value
is negative, so the constant is `<= 0`.
https://rise4fun.com/Alive/WMkhttps://rise4fun.com/Alive/udv
Was mentioned in D47428 review.
We already handle the `0` constant, https://godbolt.org/g/UZq1sJ, so this only handles negative constants.
Could use computeKnownBits() / LazyValueInfo,
but the cost-benefit analysis (https://reviews.llvm.org/D47891)
suggests it isn't worth it.
Reviewers: spatel, craig.topper
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47883
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334222 91177308-0d34-0410-b5e6-96231b3b80d8
These weren't included in D19544 - probably just an oversight.
D40044 made it more likely that we'll have LLVM math intrinsics rather
than libcalls, so this bug was more easily exposed.
As the tests/code show, we already have the complete mappings for pow/exp/log.
I don't have any experience with SVML, so I don't know if anything else is
missing. It's also not clear to me that we should be doing this transform in
IR rather than DAG/isel, but that's a separate issue.
Differential Revision: https://reviews.llvm.org/D47610
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334211 91177308-0d34-0410-b5e6-96231b3b80d8
With the upcoming patch to add summary parsing support, IsAnalysis would
be true in contexts where we are not performing module summary analysis.
Rename to the more specific and approprate HaveGVs, which is essentially
what this flag is indicating.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334140 91177308-0d34-0410-b5e6-96231b3b80d8
When checking a select to see if it matches an abs, allow the true/false values
to be a sign-extension of the comparison value instead of requiring that they're
directly the comparison value, as all the comparison cares about is the sign of
the value.
This fixes a regression due to r333702, where we were no longer generating ctlz
due to isKnownNonNegative failing to match such a pattern.
Differential Revision: https://reviews.llvm.org/D47631
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333927 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The isKnownNonZero() function have checks that abort the recursion when
it reaches the specified max depth. However one of the recursive calls
was placed before the max depth check was done, resulting in a endless
recursion that eventually triggered a segmentation fault.
Fixed the problem by moving the max depth check above the first
recursive call.
Reviewers: Prazek, nlopes, spatel, craig.topper, hfinkel
Reviewed By: hfinkel
Subscribers: hfinkel, bjope, llvm-commits
Differential Revision: https://reviews.llvm.org/D47531
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333557 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The atomic variants of the memcpy/memmove/memset intrinsics can be treated
the same was as the regular forms, with respect to aliasing. Update the
AliasSetTracker to treat the atomic forms the same was as the regular forms.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333551 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
A simple change to derive mod/ref info from the atomic memcpy
intrinsic in the same way as from the regular memcpy intrinsic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333454 91177308-0d34-0410-b5e6-96231b3b80d8
Style guide says `else`s after returns are iffy, and I agree. I also
don't know what broke the comments here and in CFLAA, but *shrug*.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333332 91177308-0d34-0410-b5e6-96231b3b80d8
The uint64_ts that we pass around AA to represent MemoryLocation sizes
are logically an Optional<uint64_t>. In D44748, we want to add an extra
'imprecise' bit to this Optional<uint64_t> to represent whether a given
MemoryLocation size is an upper-bound or an exact size. For more context
on why, please see D44748.
That patch is quite large, but reviewers seem to be OK with the
approach. In D45581 (my first attempt to split 'noise' out of D44748),
reames asked that I land a precursor that is solely replacing uint64_t
with LocationSize, which starts out as `using LocationSize = uint64_t;`.
He also gave me the OK to submit this rename without further review.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333314 91177308-0d34-0410-b5e6-96231b3b80d8
Libfuzzer tests have been fixed to prevent being optimized.
Original commit message:
If the nsw flag is used in the absolute value then it is undefined for INT_MIN. For all other value it will produce a positive number. So we can assume the result is positive.
This breaks some InstCombine abs/nabs combining tests because we simplify the second compare from known bits rather than as the whole pattern. Looks like we can probably fix it by adding a neg+abs/nabs combine to just swap the select operands. N
Differential Revision: https://reviews.llvm.org/D47041
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333300 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Look past debug intrinsics when querying whether an instruction is the
first instruction in the header block. The commit includes a reproducer
for a case where LICM would not hoist an instruction, due to the presence
of the intrinsic.
A caveat with this commit is that the check will not work properly if
the instruction at hand is a debug intrinsic. I assume that no one
depends on isGuaranteedToExecute() to return true for debug intrinsics
for these cases (and that this might be an indication of another debug
invariant issue), so I thought that it was not worth adding that extra
bit of complexity.
Reviewers: reames, anna
Reviewed By: anna
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47197
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333274 91177308-0d34-0410-b5e6-96231b3b80d8
If the nsw flag is used in the absolute value then it is undefined for INT_MIN. For all other value it will produce a positive number. So we can assume the result is positive.
This breaks some InstCombine abs/nabs combining tests because we simplify the second compare from known bits rather than as the whole pattern. Looks like we can probably fix it by adding a neg+abs/nabs combine to just swap the select operands. Need to check alive to make sure there are no corner cases.
Differential Revision: https://reviews.llvm.org/D47041
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333226 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: This patch adds a PDT constructor from Function and lets codes previously using a local class to do this use PostDominatorTree class directly.
Reviewers: davide, kuhar, grosser, dberlin
Reviewed By: kuhar
Author: NutshellySima
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D46709
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333102 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Patch for capture tracking broke
bootstrap of clang with -fstict-vtable-pointers
which resulted in debbugging nightmare. It was fixed
https://reviews.llvm.org/D46900 but as it turned
out, there were other parts like inliner (computing of
noalias metadata) that I found after bootstraping with enabled
assertions.
Reviewers: hfinkel, rsmith, chandlerc, amharc, kuhar
Subscribers: JDevlieghere, eraman, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D47088
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333070 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: Previous patch does not care if a value is changed between calloc and strlen. This needs to be removed from InstCombine and maybe moved to DSE later after some rework.
Reviewers: efriedma
Reviewed By: efriedma
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47218
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333022 91177308-0d34-0410-b5e6-96231b3b80d8
This enables us to detect more fast path sdiv cases under cost analysis.
This patch also enables us to handle non-uniform-constant pow2 cases for X86 SDIV costs.
Found while working on D46276
Future patches can then extend the vectorizers to more fully support non-uniform pow2 cases.
Differential Revision: https://reviews.llvm.org/D46637
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332969 91177308-0d34-0410-b5e6-96231b3b80d8
Change matchSelectPattern to return X and -X for ABS/NABS in a well defined order. Adjust EarlyCSE to account for this. Ensure the SPF result is some kind of min/max and not abs/nabs in one place in InstCombine that made me nervous.
Prevously we returned the two operands of the compare part of the abs pattern. The RHS is always going to be a 0i, 1 or -1 constant. This isn't a very meaningful thing to return for any one. There's also some freedom in the abs pattern as to what happens when the value is equal to 0. This freedom led to early cse failing to match when different constants were used in otherwise equivalent operations. By returning the input and its negation in a defined order we can ensure an exact match. This also makes sure both patterns use the exact same subtract instruction for the negation. I believe CSE should evebntually make this happen and properly merge the nsw/nuw flags. But I'm not familiar with CSE and what order it does things in so it seemed like it might be good to really enforce that they were the same.
Differential Revision: https://reviews.llvm.org/D47037
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332865 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
invariant.group.launder should not stop propagation
of nonnull and dereferenceable, because e.g. we would not be
able to hoist loads speculatively.
Reviewers: rsmith, amharc, kuhar, xbolva00, hfinkel
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D46972
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332788 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This feature is not needed, but it might be usefull in the future
to use metadata to mark what which function should support it
(and strip it when not).
Reviewers: rsmith, sanjoy, amharc, kuhar
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D45419
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332787 91177308-0d34-0410-b5e6-96231b3b80d8
