Summary:
Expose the internal query structure, start using it.
Note: This is the most minimal change possible i could create. I have
trivial followups, like fixing the one use of const FastMathFlags &,
the renaming of CtxI to be consistent, etc.
This should be NFC.
Reviewers: majnemer, davide
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32448
llvm-svn: 301379
This patch uses various APInt methods to reduce temporary APInt creation.
This should be all of the unrelated cleanups that got buried in D32376(creating a KnownBits struct) as well as some pointed out by Simon during the review of that. Plus a few improvements to use counting instead of masking.
I've left out any places where we do something like (KnownZero & KnownOne) != 0 as I plan to add a helper method to KnownBits to ask that question and didn't want to thrash that code an additional time.
Differential Revision: https://reviews.llvm.org/D32495
llvm-svn: 301338
The code Sanjay Patel moved over from InstCombine doesn't work properly if the 'and' has both inputs as nots because we used a commuted op matcher on the 'and' first. But this will bind to the first 'not' on 'and' when there could be two 'not's. InstCombine could rely on DeMorgan to ensure the 'and' wouldn't have two 'not's eventually, but InstSimplify can't rely on that.
This patch matches the xor first then checks for the ands and allows a not of either operand of the xor.
Differential Revision: https://reviews.llvm.org/D32458
llvm-svn: 301329
This is a pre-commit for a patch I'm working on to turn KnownZero/One into a struct. Once I do that the type here will be less obvious.
llvm-svn: 301324
This is a pre-commit for a patch that I'm working on to merge KnownZero/KnownOne into a KnownBits struct which would have had to touch this line.
llvm-svn: 301323
Summary:
In a previous change I changed SCEV's normalization / denormalization
to work with non-affine add recs. So the bailout in IVUsers can be
removed.
Reviewers: atrick, efriedma
Reviewed By: atrick
Subscribers: davide, mcrosier, llvm-commits
Differential Revision: https://reviews.llvm.org/D32105
llvm-svn: 301298
Summary:
Before this change, SCEV Normalization would incorrectly normalize
non-affine add recurrences. To work around this there was (still is)
a check in place to make sure we only tried to normalize affine add
recurrences.
We recently found a bug in aforementioned check to bail out of
normalizing non-affine add recurrences. However, instead of fixing
the bailout, I have decided to teach SCEV normalization to work
correctly with non-affine add recurrences, making the bailout
unnecessary (I'll remove it in a subsequent change).
I've also added some unit tests (which would have failed before this
change).
Reviewers: atrick, sunfish, efriedma
Reviewed By: atrick
Subscribers: mcrosier, mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D32104
llvm-svn: 301281
We can simplify (and (icmp X, C1), (icmp X, C2)) to one of the icmps in many cases.
I had to check some of these with Alive to prove to myself it's right, but everything
seems to check out. Eg, the code in instcombine was completely ignoring predicates with
mismatched signedness.
Handling or-of-icmps would be a follow-up step.
Differential Revision: https://reviews.llvm.org/D32143
llvm-svn: 301260
Summary:
llvm.invariant.group.barrier returns pointer that mustalias
pointer it takes. It can't be marked with `returned` attribute,
because it would be remove easily. The other reason is that
only Alias Analysis can know about this, because if any other
pass would know it, then the result would be replaced with it's
argument, which would be invalid.
We can think about returned pointer as something that mustalias, but
it doesn't have to be bitwise the same as the argument.
Reviewers: dberlin, chandlerc, hfinkel, sanjoy
Subscribers: reames, nlewycky, rsmith, anna, amharc
Differential Revision: https://reviews.llvm.org/D31585
llvm-svn: 301227
This is a straight cut and paste, but there's a bigger problem: if this
fold exists for simplifyOr, there should be a DeMorganized version for
simplifyAnd. But more than that, we have a patchwork of ad hoc logic
optimizations in InstCombine. There should be some structure to ensure
that we're not missing sibling folds across and/or/xor.
llvm-svn: 301213
This change reboots SCEV's current (off by default) verification logic
to avoid false failures. Instead of stringifying trip counts, it maps
old and new trip counts to the same ScalarEvolution "universe" and
asks ScalarEvolution to compute the difference between them. If the
difference comes out to be a non-zero constant, then (barring some
corner cases) we *know* we messed up.
I've not yet enabled this by default since it hits an exponential time
issue in SCEV, but once I fix that, I'll flip it on by default in
EXPENSIVE_CHECKS builds.
llvm-svn: 301146
- Mark an internal function static
- Remove the llvm namespace (just holding on to the `using namespace
llvm;` Works on My Machine(TM))
llvm-svn: 300947
There have been multiple reports of this causing problems: a
compile-time explosion on the LLVM testsuite, and a stack
overflow for an opencl kernel.
llvm-svn: 300928
getSignBit is a static function that creates an APInt with only the sign bit set. getSignMask seems like a better name to convey its functionality. In fact several places use it and then store in an APInt named SignMask.
Differential Revision: https://reviews.llvm.org/D32108
llvm-svn: 300856
This is preparation for a clang change to improve the [[nodiscard]] warning to not be ignored on methods that return a class marked [[nodiscard]] that are defined in the class itself. See D32207.
We should consider adding wrapper methods to APInt that return the overflow flag directly and discard the APInt result. This would eliminate the void casts and the need to create a bool before the call to pass to the out param.
llvm-svn: 300758
Use haveNoCommonBitsSet to figure out whether an "or" instruction
is equivalent to addition. This handles more cases than just
checking for a constant on the RHS.
Differential Revision: https://reviews.llvm.org/D32239
llvm-svn: 300746
This patch simplifies the examples from D31509 and D31927 (PR30630) and catches
the basic identity shuffle tests that Zvi recently added.
I'm not sure if we have something like this in DAGCombiner, but we should?
It's worth noting that "MaxRecurse / RecursionLimit" is only 3 on entry at the moment.
We might want to bump that up if there are longer shuffle chains like this in the wild.
For now, we're ignoring shuffles that have undef mask elements because it's not
clear how those should be handled.
Differential Revision: https://reviews.llvm.org/D31960
llvm-svn: 300714
InstSimplify returned the wrong type when simplifying a vector GEP
and we ended up crashing when trying to replace all uses with the
new value. Fixes PR32697.
Differential Revision: https://reviews.llvm.org/D32180
llvm-svn: 300693
BasicAA wants to know if a function is either a malloc or calloc like function. Currently we have to check both separately. This means both calls check if its an intrinsic, query TLI, check the nobuiltin attribute, scan the AllocationFnData, etc.
This patch adds a isMallocOrCallocLikeFn so we can go through all of the checks once per call.
This also changes the one other location I saw that called both together.
Differential Revision: https://reviews.llvm.org/D32188
llvm-svn: 300608
This patch uses lshrInPlace to replace code where the object that lshr is called on is being overwritten with the result.
This adds an lshrInPlace(const APInt &) version as well.
Differential Revision: https://reviews.llvm.org/D32155
llvm-svn: 300566
the exponential behavior.
The patch is to fix PR32043. Functions getZeroExtendExpr and getSignExtendExpr
may call themselves recursively more than once. This is potentially a 2^N
complexity behavior. The exponential behavior was not commonly exposed before
because of existing global cache mechnism like UniqueSCEVs or some early return
mechanism when flags FlagNSW or FlagNUW are seen. However, we still have case
which can expose the exponential behavior, like the case in PR32043, so we add
a local cache in getZeroExtendExpr and getSignExtendExpr. If the input of the
functions -- SCEV and type pair have been seen before, we can find the extended
expression directly in the local cache.
Differential Revision: https://reviews.llvm.org/D30350
llvm-svn: 300494
This is non-functional change to re-order if statements to bail out earlier
from unreachable and ColdCall heuristics.
Reviewers: sanjoy, reames, junbuml, vsk, chandlerc
Reviewed By: chandlerc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31704
llvm-svn: 300442
Metadata potentially is more precise than any heuristics we use, so
it makes sense to use first metadata info if it is available. However it makes
sense to examine it against other strong heuristics like unreachable one.
If edge coming to unreachable block has higher probability then it is expected
by unreachable heuristic then we use heuristic and remaining probability is
distributed among other reachable blocks equally.
An example where metadata might be more strong then unreachable heuristic is
as follows: it is possible that there are two branches and for the branch A
metadata says that its probability is (0, 2^25). For the branch B
the probability is (1, 2^25).
So the expectation is that first edge of B is hotter than first edge of A
because first edge of A did not executed at least once.
If first edge of A points to the unreachable block then using the unreachable
heuristics we'll set the probability for A to (1, 2^20) and now edge of A
becomes hotter than edge of B.
This is unexpected behavior.
This fixed the biggest part of https://bugs.llvm.org/show_bug.cgi?id=32214
Reviewers: sanjoy, junbuml, vsk, chandlerc
Reviewed By: chandlerc
Subscribers: llvm-commits, reames, davidxl
Differential Revision: https://reviews.llvm.org/D30631
llvm-svn: 300440
If we already called computeKnownBits for the RHS being a constant power of 2, we've already computed everything we can and should just stop. I think previously we would still recurse if we had determined the result was negative or had not determined the sign bit at all.
llvm-svn: 300432
The ConstantInt version has the same assert, and using null/allOnes is likely less efficient.
The only advantage of these local variants (and there's probably a better way to achieve this?)
is to save typing "ConstantInt::" over and over.
llvm-svn: 300426
This avoids the confusing 'CS.paramHasAttr(ArgNo + 1, Foo)' pattern.
Previously we were testing return value attributes with index 0, so I
introduced hasReturnAttr() for that use case.
llvm-svn: 300367
It won't compile after the recent changes I've made, and I think
keeping it in provides very little value.
Instead I've added (in an earlier commit) a C++ unit test to check the
Denormalize(Normalized(X)) == X property for specific instances of X,
which is what the assert was trying to do anyway.
llvm-svn: 300339
The PostIncTransform class was not pulling its weight, so delete it
and use free functions instead.
This also makes the use of `function_ref` more idiomatic. We were
storing an instance of function_ref in the PostIncTransform class
before, which was fine in that specific case, but the usage after this
change is more obviously okay.
llvm-svn: 300338
Daniel Berlin