When checking to see if we can apply IR flags to a SCEV, we need to identify a bound on the defining scope of the SCEV to be produced. We'd previously added support for a couple SCEVExpr types which trivially imply bounds, but hadn't handled types such as umax where the bounds come from the bounds of the operands. This does the obvious thing, and recurses through operands searching for a tighter bound on the defining scope.
I'm honestly surprised by how little this seems to mater on existing tests, but it's worth doing for completeness sake alone.
Differential Revision: https://reviews.llvm.org/D111191
This does for readability of returns within said function as what we do for the caller side when reasoning about what might be poison.
Differential Revision: https://reviews.llvm.org/D111180
This patch removes a compile time restriction from isSCEVExprNeverPoison. We've strengthened our ability to reason about flags on scopes other than addrecs, and this bailout prevents us from using it. The comment is also suspect as well in that we're in the middle of constructing a SCEV for I. As such, we're going to visit all operands *anyways*.
Differential Revision: https://reviews.llvm.org/D111186
Fix copy+pasta that was checking for smul_fix instead of smul_with_overflow to detected signed values.
The LShr is performed on the extended type as we use it to truncate+extract the upper/hi bits of the extended multiply.
More closely matches the default expansion from TargetLowering::expandMULO
BasicAA GEP decomposition currently performs all calculation on the
maximum pointer size, but at least 64-bit, with an option to double
the size. The code comment claims that this improves analysis power
when working with uint64_t indices on 32-bit systems. However, I don't
see how this can be, at least while maintaining correctness:
When working on canonical code, the GEP indices will have GEP index
size. If the original code worked on uint64_t with a 32-bit size_t,
then there will be truncs inserted before use as a GEP index. Linear
expression decomposition does not look through truncs, so this will
be an opaque value as far as GEP decomposition is concerned. Working
on a wider pointer size does not help here (or have any effect at all).
When working on non-canonical code (before first InstCombine), the
GEP indices are implicitly truncated to GEP index size. The BasicAA
code currently just ignores this fact completely, and pretends that
this truncation doesn't happen. This is incorrect and will be
addressed by D110977.
I believe that for correctness reasons, it is important to work on
the actual GEP index size to properly model potential overflow.
BasicAA tries to patch over the fact that it uses the wrong size
(see adjustToPointerSize), but it only does that in limited cases
(only for constant values, and not all of them either). I'd like to
move this code towards always working on the correct size, and
dropping these artificial pointer size adjustments is the first step
towards that.
Differential Revision: https://reviews.llvm.org/D110657
As suggested on D111024, we should treat getCmpSelInstrCost calls without a specific predicate as matching the worst case predicate cost.
These regressions will be addressed with a mixture of D111024 and fixing other specific getCmpSelInstrCost calls to have realistic predicates.
These are meant to check a future patch which recurses through operands of SCEVs, but because all SCEVs are trivially bounded by function entry, we need to arrange the trivial scope not to be valid. (i.e. we specifically need a lower defining scope)
The coverage could have cumulative explosion here,
so i'm adding only the most basic cases,
and hoping it's enough, though more can be added if needed.
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/1jfGddcre - for intels `Block RThroughput: =36.0`; for ryzens, `Block RThroughput: =12.0`
So could pick cost of `36`
For store we have:
https://godbolt.org/z/ao9srMT8r - for intels `Block RThroughput: =30.0`; for ryzens, `Block RThroughput: =12.0`
So we could pick cost of `30`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111094
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/rc8jYxW6M - for intels `Block RThroughput: =18.0`; for ryzens, `Block RThroughput: =6.0`
So could pick cost of `18`.
For store we have:
https://godbolt.org/z/9PhPEr65G - for intels `Block RThroughput: =15.0`; for ryzens, `Block RThroughput: =6.0`
So we could pick cost of `15`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111093
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/onese7rec - for intels `Block RThroughput: =6.0`; for ryzens, `Block RThroughput: =3.0`
So could pick cost of `6`.
For store we have:
https://godbolt.org/z/bMd7dddnT - for intels `Block RThroughput: =8.0`; for ryzens, `Block RThroughput: <=6.0`
So we could pick cost of `8`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111092
This one required quite a bit of an assembly surgery, but i think it's in the right ballpark..
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/na97Kb96o - for intels `Block RThroughput: <=64.0`; for ryzens, `Block RThroughput: <=32.0`
So could pick cost of `64`.
For store we have:
https://godbolt.org/z/GG1WeoKar - for intels `Block RThroughput: =66.0`; for ryzens, `Block RThroughput: <=27.5`
So we could pick cost of `66`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111091
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/jK85GWKaK - for intels `Block RThroughput: =31.0`; for ryzens, `Block RThroughput: <=17.0`
So could pick cost of `31`.
For store we have:
https://godbolt.org/z/hPWWhEEf9 - for intels `Block RThroughput: =33.0`; for ryzens, `Block RThroughput: <=13.8`
So we could pick cost of `33`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111089
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/szEj1ceee - for intels `Block RThroughput: =15.0`; for ryzens, `Block RThroughput: <=8.8`
So could pick cost of `15`.
For store we have:
https://godbolt.org/z/81bq4fTo1 - for intels `Block RThroughput: =12.0`; for ryzens, `Block RThroughput: <=10.0`
So we could pick cost of `12`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111087
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/aec96Thee - for intels `Block RThroughput: =6.0`; for ryzens, `Block RThroughput: <=3.3`
So could pick cost of `6`.
For store we have:
https://godbolt.org/z/aec96Thee - for intels `Block RThroughput: =9.0`; for ryzens, `Block RThroughput: <=3.0`
So we could pick cost of `9`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111083
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/3M3hbq7n8 - for intels `Block RThroughput: =20.0`; for ryzens, `Block RThroughput: =8.0`
So could pick cost of `20`.
For store we have:
https://godbolt.org/z/zvnPYWTx7 - for intels `Block RThroughput: =20.0`; for ryzens, `Block RThroughput: =8.0`
So we could pick cost of `20`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111076
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/MTKdzjvnr - for intels `Block RThroughput: =8.0`; for ryzens, `Block RThroughput: <=4.0`
So could pick cost of `8`.
For store we have:
https://godbolt.org/z/cMYEvqoah - for intels `Block RThroughput: =8.0`; for ryzens, `Block RThroughput: <=4.0`
So we could pick cost of `8`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111075
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/z197317d1 - for intels `Block RThroughput: =6.0`; for ryzens, `Block RThroughput: =2.0`
So could pick cost of `6`.
For store we have:
https://godbolt.org/z/8dzszjf9q - for intels `Block RThroughput: =6.0`; for ryzens, `Block RThroughput: <=4.0`
So we could pick cost of `6`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111073
This one required quite a bit of assembly surgery, but the trend continues, so i think this is right.
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/EKWdj8cKT - for intels `Block RThroughput: <=32.0`; for ryzens, `Block RThroughput: <=24.0`
So could pick cost of `32`.
For store we have:
https://godbolt.org/z/zj4bb9P75 - for intels `Block RThroughput: =32.0`; for ryzens, `Block RThroughput: <=16.0`
So we could pick cost of `32`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111064
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/a6rxMG6ec - for intels `Block RThroughput: =16.0`; for ryzens, `Block RThroughput: <=12.0`
So could pick cost of `16`.
For store we have:
https://godbolt.org/z/ced1bdqc9 - for intels `Block RThroughput: =16.0`; for ryzens, `Block RThroughput: <=8.0`
So we could pick cost of `16`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111063
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/avq1oz98W - for intels `Block RThroughput: =8.0`; for ryzens, `Block RThroughput: =4.0`
So could pick cost of `8`.
For store we have:
https://godbolt.org/z/89PGMc1qs - for intels `Block RThroughput: =6.0`; for ryzens, `Block RThroughput: <=6.0`
So we could pick cost of `6`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111061
Finally, we are getting to the heavy-hitter stuff!
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/7crGWoar6 - for intels `Block RThroughput: =4.0`; for ryzens, `Block RThroughput: <=2.0`
So could pick cost of `4`.
For store we have:
https://godbolt.org/z/T8aq3MszM - for intels `Block RThroughput: =5.0`; for ryzens, `Block RThroughput: <=2.0`
So we could pick cost of `5`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111060
When determining NoAlias based on object size and dereferenceability
information, we can ignore frees for the same reason we can ignore
possible null pointers (if null is not a valid pointer): Actually
accessing the null pointer / freed pointer would be immediate UB,
and AA results are only valid under the assumption of an access.
This addresses a minor regression from D110745.
Differential Revision: https://reviews.llvm.org/D111028
This required huge amount of assembly surgery, but i think this is about right.
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/z11crMEcj - for intels `Block RThroughput: =20.0`; for ryzens, `Block RThroughput: <=18.0`
So could pick cost of `25`.
For store we have:
https://godbolt.org/z/eqT4ze3j4 - for intels `Block RThroughput: =24.0`; for ryzens, `Block RThroughput: <=16.0`
So we could pick cost of `24`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111031
This one required quite a bit of assembly surgery.
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/oYWv4cTnK - for intels `Block RThroughput: =10.0`; for ryzens, `Block RThroughput: <=8.0`
So pick cost of `10`.
For store we have:
https://godbolt.org/z/33GMhrsG9 - for intels `Block RThroughput: =12.0`; for ryzens, `Block RThroughput: <=8.0`
So pick cost of `12`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111027
This one required quite a bit of assembly surgery.
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/Tce3osvcz - for intels `Block RThroughput: =5.0`; for ryzens, `Block RThroughput: <=4.0`
So pick cost of `5`.
For store we have:
https://godbolt.org/z/oc3arEcnE - for intels `Block RThroughput: =6.0`; for ryzens, `Block RThroughput: <=4.0`
So pick cost of `6`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111026
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/sz5qdKnr4 - for intels `Block RThroughput: =1.0`; for ryzens, `Block RThroughput: <=1.0`
So pick cost of `1`.
For store we have:
https://godbolt.org/z/Kzdjff63v - for intels `Block RThroughput: =4.0`; for ryzens, `Block RThroughput: <=3.0`
So pick cost of `4`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111025
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/5fqrh4qqo - for intels `Block RThroughput: =14.0`; for ryzens, `Block RThroughput: <=12.0`
So pick cost of `14`.
For store we have:
https://godbolt.org/z/5fqrh4qqo - for intels `Block RThroughput: =22.0`; for ryzens, `Block RThroughput: <=16.0`
So pick cost of `22`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111022
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/zdz5Ga6fs - for intels `Block RThroughput: =7.0`; for ryzens, `Block RThroughput: <=6.0`
So pick cost of `7`.
For store we have:
https://godbolt.org/z/qn71513ac - for intels `Block RThroughput: =11.0`; for ryzens, `Block RThroughput: <=8.0`
So pick cost of `11`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111021
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/d8PdhEszo - for intels `Block RThroughput: =3.0`; for ryzens, `Block RThroughput: <=3.0`
So pick cost of `3`.
For store we have:
https://godbolt.org/z/WojonfG5n - for intels `Block RThroughput: =5.0`; for ryzens, `Block RThroughput: <=3.0`
So pick cost of `5`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111020
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/z8qa14bs3 - for intels `Block RThroughput: =3.0`; for ryzens, `Block RThroughput: =1.5`
So pick cost of `3`.
For store we have:
https://godbolt.org/z/GYGajoc4K - for intels `Block RThroughput: <=4.0`; for ryzens, `Block RThroughput: <=2.0`
So pick cost of `4`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111019
This addresses a comment from review on D109845. Even for SCEVs which we can't find true bounds without recursing through operands, entry to the function forms a trivial upper bound. In some cases, this trivial bound is enough to prove safety of flag inference.
This is a followon to D109845. With that landed, we will have fixed all known instances of pr51817, and can thus start inferring flags more aggressively with greatly reduced risk of miscompiles. This patch simply applies the same inference logic used in that patch to our other major flag inference path.
We can still do much better here (on both paths), but this is our first step.
Differential Revision: https://reviews.llvm.org/D111003
This fixes a violation of the wrap flag rules introduced in c4048d8f. This is an alternate fix to D106852.
The basic problem being fixed is that we infer a set of flags which is valid at some inner scope S1 (usually by correctly propagating them from IR), and then (incorrectly) extend them to a SCEV in scope S2 where S1 != S2. This is not in general safe per the wrap flags semantics recently defined.
In this patch, I include a simple inference step to handle the case where we can prove that S2 is the preheader of the loop S1, and that entry into S2 implies execution of S1. See the code for a more detailed explanation.
One worry I have with this patch is that I might be over-fitting what shows up in tests - and thus hiding negative impact we'd see in the real world. My best defense is that the rule used here very closely follows the one used to propagate the flags from IR to the inner add to start with, and thus if one is reasonable, so probably is the other. Curious what others think about that piece.
The test diffs are roughly as expected. Mostly analysis only, with two transform changes. Oddly, the result looks better in the loop-idiom test, and I don't understand the PPC output enough to have tell. Nothing terrible looking though. (For context, without the scope inference peephole, the test delta includes a couple of vectorization tests. Again, not super concerning, but slightly more so.)
Differential Revision: https://reviews.llvm.org/D109845
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/rMaYr67hz - for intels `Block RThroughput: =56.0`; for ryzens, `Block RThroughput: <=17.8`
So pick cost of `56`.
For store we have:
https://godbolt.org/z/eMsbKqnvv - for intels `Block RThroughput: <=54.0`; for ryzens, `Block RThroughput: <=15.0`
So pick cost of `54`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111018
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/1T6MMzeh3 - for intels `Block RThroughput: =28.0`; for ryzens, `Block RThroughput: <=8.5`
So pick cost of `28`.
For store we have:
https://godbolt.org/z/1T6MMzeh3 - for intels `Block RThroughput: <=27.0`; for ryzens, `Block RThroughput: <=7.0`
So pick cost of `27`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111017
The only sched models that for cpu's that support avx2
but not avx512 are: haswell, broadwell, skylake, zen1-3
For load we have:
https://godbolt.org/z/Mh9MnnT8W - for intels `Block RThroughput: =9.0`; for ryzens, `Block RThroughput: <=2.3`
So pick cost of `9`.
For store we have:
https://godbolt.org/z/Mh9MnnT8W - for intels `Block RThroughput: <=12.0`; for ryzens, `Block RThroughput: <=3.3`
So pick cost of `12`.
I'm directly using the shuffling asm the llc produced,
without any manual fixups that may be needed
to ensure sequential execution.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D111016
