Upon further investigation and discussion,
this is actually the opposite direction from what we should be taking,
and this direction wouldn't solve the motivational problem anyway.
Additionally, some more (polly) tests have escaped being updated.
So, let's just take a step back here.
This reverts commit f3190dedee.
This reverts commit 749581d21f.
This reverts commit f3df87d57e.
This reverts commit ab1dbcecd6.
There's precedent for that in `CreateOr()`/`CreateAnd()`.
The motivation here is to avoid bloating the run-time check's IR
in `SCEVExpander::generateOverflowCheck()`.
Refs. https://reviews.llvm.org/D109368#3089809
While we could emit such a tautological `select`,
it will stick around until the next instsimplify invocation,
which may happen after we count the cost of this redundant `select`.
Which is precisely what happens with loop vectorization legality checks,
and that artificially increases the cost of said checks,
which is bad.
There is prior art for this in `IRBuilderBase::CreateAnd()`/`IRBuilderBase::CreateOr()`.
Refs. https://reviews.llvm.org/D109368#3089809
This is a followup to D104662 to generate slightly nicer code for
pointer overflow checks. Bypass expandAddToGEP and instead
explicitly generate i8 GEPs. This saves some bitcasts and negates
the value in a more obvious way. In particular, this prevents SCEV
from looking through the umul.with.overflow, same as in the integer
case.
The wrapping-pointer-ni.ll test deserves a comment: Previously,
this generated a typed GEP which used the umulo argument rather
than the multiplication result. This results in more compact IR in
that case, but effectively does the multiplication twice, the
second one is just hidden in the GEP. Reusing the umulo result
seems pretty reasonable to me.
Differential Revision: https://reviews.llvm.org/D109093
We'd special cased this logic to use pointer types for non-integral pointers, but there's no reason we can't do that for all pointer types. Doing it this was has a few advantages:
a) The code itself becomes more straight forward, and easier to test.
b) We avoid introducing ptrtoint into programs which didn't have them in the source.
c) The resulting codegen is easier to analyze and simplify (mostly due to lack of ptrtoint).
Note that there are some test diffs, but a) running them through instcombine helps a ton, and b) there's enough missing obvious transforms on both before and after IR that it's clear this isn't performance sensitive.
This is mostly motivated by cleaning up mentions of non-integrals to have a clearer idea of what we actually need to support.
Differential Revision: https://reviews.llvm.org/D104662
Currently, InsertNoopCastOfTo() would implicitly insert that cast,
but now that we have SCEVPtrToIntExpr, i'm hoping we could stop
InsertNoopCastOfTo() from doing that. But first all users must be fixed.
The exit blocks of the versioned and non-versioned loops are not dedicated and thus the two loops are not in simplify form.
Insert dummy exit blocks after loop versioning with `formDedicatedExits()` to preserve the simplify form for subsequence passes.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D89569
This reverts commit r365260 which broke the following tests:
Clang :: CodeGenCXX/cfi-mfcall.cpp
Clang :: CodeGenObjC/ubsan-nullability.m
LLVM :: Transforms/LoopVectorize/AArch64/pr36032.ll
llvm-svn: 365284
Without this, we have the unfortunate property that tests are dependent on the order of operads passed the CreateOr and CreateAnd functions. In actual usage, we'd promptly optimize them away, but it made tests slightly more verbose than they should have been.
llvm-svn: 365260
This case is slightly tricky, because loop distribution should be
allowed in some cases, and not others. As long as runtime dependency
checks don't need to be introduced, this should be OK. This is further
complicated by the fact that LoopDistribute partially ignores if LAA
says that vectorization is safe, and then does its own runtime pointer
legality checks.
Note this pass still does not handle noduplicate correctly, as this
should always be forbidden with it. I'm not going to bother trying to
fix it, as it would require more effort and I think noduplicate should
be removed.
https://reviews.llvm.org/D62607
llvm-svn: 363160
Roman Lebedev