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[Attributor] Do not derive norecurse without looking at all call sites #53884

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jdoerfert opened this issue Feb 16, 2022 · 8 comments
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[Attributor] Do not derive norecurse without looking at all call sites #53884

jdoerfert opened this issue Feb 16, 2022 · 8 comments
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@jdoerfert
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ipo Interprocedural optimizations release:backport release:cherry-pick-failed release:merged release:reviewed
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LLVM 14.0.0 Release

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@jdoerfert
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Since we did not track the fact that we might have skipped call sites assumed dead in checkForAllCallSites we accidentally derive norecurse in certain situations.
An example (https://godbolt.org/z/oxvcjsaGf):

declare void @extern()

define i1 @test_rec_neg(i1 %c) norecurse {
    %rc1 = call i1 @rec(i1 true)
    br i1 %rc1, label %t, label %f
t:
    %rc2 = call i1 @rec(i1 %c)
    ret i1 %rc2
f:
    ret i1 %rc1
}

define internal i1 @rec(i1 %c1) {
    br i1 %c1, label %t, label %f
t:
    ret i1 true
f:
    %r = call i1 @rec(i1 true)
    call void @extern()
    ret i1 false
}
@jdoerfert jdoerfert added the ipo Interprocedural optimizations label Feb 16, 2022
@jdoerfert jdoerfert added this to the LLVM 14.0.0 Release milestone Feb 16, 2022
@jdoerfert jdoerfert self-assigned this Feb 16, 2022
@jdoerfert
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/cherry-pick 6ed1ef0

@llvmbot
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llvmbot commented Feb 16, 2022

Failed to cherry-pick: 6ed1ef0

https://github.com/llvm/llvm-project/actions/runs/1855580229

Please manually backport the fix and push it to your github fork. Once this is done, please add a comment like this:

/branch <user>/<repo>/<branch>

@jdoerfert
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/cherry-pick 6ed1ef0

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llvmbot commented Feb 16, 2022

Failed to cherry-pick: 6ed1ef0

https://github.com/llvm/llvm-project/actions/runs/1855716837

Please manually backport the fix and push it to your github fork. Once this is done, please add a comment like this:

/branch <user>/<repo>/<branch>

@jdoerfert
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/branch jdoerfert/llvm-projects/issue53884

@llvmbot llvmbot mentioned this issue Feb 18, 2022
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llvmbot commented Feb 18, 2022

/pull-request llvmbot#80

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tstellar commented Mar 1, 2022

@jdoerfert Can you rebase the issue53884 branch? The patches no longer apply.

jdoerfert added a commit to jdoerfert/llvm-project that referenced this issue Mar 1, 2022
@jdoerfert
[Attributor][FIX] Pipe UsedAssumedInformation through more interfaces
cbbc822 
`UsedAssumedInformation` is a return argument utilized to determine what
information is known. Most APIs used it already but
`genericValueTraversal` did not. This adds it to `genericValueTraversal`
and replaces `AllCallSitesKnown` of `checkForAllCallSites` with the
commonly used `UsedAssumedInformation`.

This was supposed to be a NFC commit, then the test change appeared.
Turns out, we had one user of `AllCallSitesKnown` (AANoReturn) and the
way we set `AllCallSitesKnown` was wrong as we ignored the fact some
call sites were optimistically assumed dead. Included a dedicated test
for this as well now.

Fixes llvm#53884
tstellar pushed a commit to llvmbot/llvm-project that referenced this issue Mar 1, 2022
@jdoerfert @tstellar
[Attributor][FIX] Pipe UsedAssumedInformation through more interfaces
f58ab32 
`UsedAssumedInformation` is a return argument utilized to determine what
information is known. Most APIs used it already but
`genericValueTraversal` did not. This adds it to `genericValueTraversal`
and replaces `AllCallSitesKnown` of `checkForAllCallSites` with the
commonly used `UsedAssumedInformation`.

This was supposed to be a NFC commit, then the test change appeared.
Turns out, we had one user of `AllCallSitesKnown` (AANoReturn) and the
way we set `AllCallSitesKnown` was wrong as we ignored the fact some
call sites were optimistically assumed dead. Included a dedicated test
for this as well now.

Fixes llvm#53884
@tstellar
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tstellar commented Mar 1, 2022

Merged: f58ab32

jdoerfert added a commit to jdoerfert/llvm-project that referenced this issue Mar 25, 2022
@jdoerfert
[Attributor][FIX] Pipe UsedAssumedInformation through more interfaces
38d8289 
`UsedAssumedInformation` is a return argument utilized to determine what
information is known. Most APIs used it already but
`genericValueTraversal` did not. This adds it to `genericValueTraversal`
and replaces `AllCallSitesKnown` of `checkForAllCallSites` with the
commonly used `UsedAssumedInformation`.

This was supposed to be a NFC commit, then the test change appeared.
Turns out, we had one user of `AllCallSitesKnown` (AANoReturn) and the
way we set `AllCallSitesKnown` was wrong as we ignored the fact some
call sites were optimistically assumed dead. Included a dedicated test
for this as well now.

Fixes llvm#53884
mem-frob pushed a commit to draperlaboratory/hope-llvm-project that referenced this issue Oct 7, 2022
@jdoerfert
[Attributor][FIX] Pipe UsedAssumedInformation through more interfaces
5b9453b 
`UsedAssumedInformation` is a return argument utilized to determine what
information is known. Most APIs used it already but
`genericValueTraversal` did not. This adds it to `genericValueTraversal`
and replaces `AllCallSitesKnown` of `checkForAllCallSites` with the
commonly used `UsedAssumedInformation`.

This was supposed to be a NFC commit, then the test change appeared.
Turns out, we had one user of `AllCallSitesKnown` (AANoReturn) and the
way we set `AllCallSitesKnown` was wrong as we ignored the fact some
call sites were optimistically assumed dead. Included a dedicated test
for this as well now.

Fixes llvm/llvm-project#53884
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