Commit Graph

24 Commits

Author SHA1 Message Date
Nikita Popov ff8b1b1b9c Reapply [IR] Don't mark mustprogress as type attribute
Reapply with fixes for clang tests.

-----

This is a simple enum attribute. Test changes are because enum
attributes are sorted before type attributes, so mustprogress is
now in a different position.
2021-07-09 20:57:44 +02:00
Nikita Popov 23dd750279 Revert "[IR] Don't mark mustprogress as type attribute"
This reverts commit 84ed3a794b.

A number of clang tests are also affected by this change. Revert
until I can update them.
2021-07-09 18:46:00 +02:00
Nikita Popov 84ed3a794b [IR] Don't mark mustprogress as type attribute
This is a simple enum attribute.

Test changes are because enum attributes are sorted before type
attributes.
2021-07-09 18:24:16 +02:00
Philip Reames f549176ad9 [funcattrs] Add the maximal set of implied attributes to definitions
Have funcattrs expand all implied attributes into the IR. This expands the infrastructure from D100400, but for definitions not declarations this time.

Somewhat subtly, this mostly isn't semantic. Because the accessors did the inference, any client which used the accessor was already getting the stronger result. Clients that directly checked presence of attributes (there are some), will see a stronger result now.

The old behavior can end up quite confusing for two reasons:
* Without this change, we have situations where function-attrs appears to fail when inferring an attribute (as seen by a human reading IR), but that consuming code will see that it should have been implied. As a human trying to sanity check test results and study IR for optimization possibilities, this is exceeding error prone and confusing. (I'll note that I wasted several hours recently because of this.)
* We can have transforms which trigger without the IR appearing (on inspection) to meet the preconditions. This change doesn't prevent this from happening (as the accessors still involve multiple checks), but it should make it less frequent.

I'd argue in favor of deleting the extra checks out of the accessors after this lands, but I want that in it's own review as a) it's purely stylistic, and b) I already know there's some disagreement.

Once this lands, I'm also going to do a cleanup change which will delete some now redundant duplicate predicates in the inference code, but again, that deserves to be a change of it's own.

Differential Revision: https://reviews.llvm.org/D100226
2021-04-16 14:22:19 -07:00
Philip Reames 8c95f995db Speculative attempt to stablize a test
New pass manager and old pass manager appear to differ on whether declarations are included in SCCs.  For some reason, which you get appears to depend on build configuration.
2021-04-03 09:46:02 -07:00
Philip Reames 6ef4505298 [funcattrs] Infer nosync from readnone and non-convergent
This implements the most basic possible nosync inference. The choice of inference rule is taken from the comments in attributor and the discussion on the review of the change which introduced the nosync attribute (0626367202).

This is deliberately minimal. As noted in code comments, I do plan to add a more robust inference which actually scans the function IR directly, but a) I need to do some refactoring of the attributor code to use common interfaces, and b) I wanted to get something in. I also wanted to minimize the "interesting" analysis discussion since that's time intensive.

Context: This combines with existing nofree attribute inference to help prove dereferenceability in the ongoing deref-at-point semantics work.

Differential Revision: https://reviews.llvm.org/D99749
2021-04-01 11:37:34 -07:00
Arthur Eubanks 2ca6c422d2 [FunctionAttrs] Rename functionattrs -> function-attrs
To match NewPM pass name, and also for readability.
Also rename rpo-functionattrs -> rpo-function-attrs while we're here.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D84694
2020-07-28 09:09:13 -07:00
Hideto Ueno 96552036e3 [Attributor] Copy or port test cases related to Attributor to` Attributor` test folder
Summary:
This patch moves the test cases related to Attributor to `Transforms/Attributor` folder.
We have used `Transforms/FunctionAttrs` as the primary folder for Attributor test but we need to change testing way now.

For the test cases which I think functionattrs doesn't infer anything something like (willreturn, nosync, value-simplify, h2s ..etc), I moved them with the command `git mv`.

For the test cases in which functoinattrs and attributor are tested, I copied the test to the folder and remove the check only used by functoinattrs.

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70843
2019-12-02 15:36:29 +00:00
Hideto Ueno 88b04ef832 [Attributor] Use must-be-executed-context in align deduction
Summary:
This patch introduces align attribute deduction for callsite argument, function argument, function returned and floating value based on must-be-executed-context.

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: hiraditya, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69797
2019-11-12 06:41:19 +00:00
Johannes Doerfert 680f638027 [Attributor][NFCI] Distinguish optional and required dependences
Dependences between two abstract attributes SRC and TRG come naturally in
two flavors:
  Either (1) "some" information of SRC is *required* for TRG to derive
  information, or (2) SRC is just an *optional* way for TRG to derive
  information.

While it is not strictly necessary to distinguish these types
explicitly, it can help us to converge faster, in terms of iterations,
and also cut down the number of `AbstractAttribute::update` calls.

As far as I can tell, we only use optional dependences for liveness so
far but that might change in the future. With this change the Attributor
can be informed about the "dependence class" and it will perform
appropriate actions when an Attribute is set to an invalid state, thus
one that cannot be used by others to derive information from.
2019-11-02 15:26:22 -05:00
Stefan Stipanovic f35740d6e9 NoFree argument attribute.
Summary: Deducing nofree atrribute for function arguments.

Reviewers: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67886
2019-11-02 19:40:48 +01:00
Stefan Stipanovic 5fb1782918 Revert "NoFree argument attribute."
This reverts commit c12efa2ed0.
2019-11-02 17:31:02 +01:00
Stefan Stipanovic c12efa2ed0 NoFree argument attribute.
Summary: Deducing nofree atrribute for function arguments.

Reviewers: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67886
2019-11-02 16:35:38 +01:00
Johannes Doerfert c36e2ebf9f [Attributor][NFCI] Avoid unnecessary work except for testing
Trying to deduce information for declarations and calls sites of
declarations is not useful in practice but only for testing. Add a flag
that disables this by default but also enable it in the tests.

The misc.ll test will verify the flag "works" as expected.
2019-11-02 00:28:24 -05:00
Johannes Doerfert 1097fab1cf [Attributor] Deduce memory behavior of functions and arguments
Deduce the memory behavior, aka "read-none", "read-only", or
"write-only", for functions and arguments.

Reviewers: sstefan1, uenoku

Subscribers: hiraditya, bollu, jfb, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67384

llvm-svn: 373965
2019-10-07 21:07:57 +00:00
Johannes Doerfert 3ab9e8b818 [Attributor][Fix] Initialize the cache prior to using it
Summary:
There were segfaults as we modified and iterated the instruction maps in
the cache at the same time. This was happening because we created new
instructions while we populated the cache. This fix changes the order
in which we perform these actions. First, the caches for the whole
module are created, then we start to create abstract attributes.

I don't have a unit test but the LLVM test suite exposes this problem.

Reviewers: uenoku, sstefan1

Subscribers: hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67232

llvm-svn: 372105
2019-09-17 10:52:41 +00:00
Johannes Doerfert 97fd582b91 [Attributor] Use the white list for attributes consistently
Summary:
We create attributes on-demand so we need to check the white list
on-demand. This also unifies the location at which we create,
initialize, and eventually invalidate new abstract attributes.

The tests show mixed results, a few more call site attributes are
determined which can cause more iterations.

Reviewers: uenoku, sstefan1

Subscribers: hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66913

llvm-svn: 370922
2019-09-04 16:26:20 +00:00
Johannes Doerfert 3fac668d83 [Attributor] Use existing function information for the call site
Summary:
Instead of recomputing information for call sites we now use the
function information directly. This is always valid and once we have
call site specific information we can improve here.

This patch also bootstraps attributes that are created on-demand through
an initial update call. Information that is known will then directly be
available in the new attribute without causing an iteration delay.

The tests show how this improves the iteration count.

Reviewers: sstefan1, uenoku

Subscribers: hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66781

llvm-svn: 370480
2019-08-30 15:24:52 +00:00
Johannes Doerfert b504eb8bb5 [Attributor] Adjust and test the iteration bound of tests
Summary:
Try to verify how many iterations we need for a fixpoint in our tests.
This patch adjust the way we count to make it easier to follow. It also
adjusts the bounds to actually account for a fixpoint and not only the
minimum number to pass all checks.

Reviewers: uenoku, sstefan1

Subscribers: hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66757

llvm-svn: 369945
2019-08-26 18:55:47 +00:00
Johannes Doerfert a41b239081 [Attributor][NFCI] Introduce tight iteration bounds in the tests
Summary:
To be able to track how many iterations we need to manifest all
information we check for we now make the maximum iteration count
explicit. The count is set tightly now and should be kept that way.

Reviewers: uenoku, sstefan1

Subscribers: bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66554

llvm-svn: 369586
2019-08-21 21:42:46 +00:00
Johannes Doerfert e83f303938 [Attributor] Deduce the "no-return" attribute for functions
A function is "no-return" if we never reach a return instruction, either
because there are none or the ones that exist are dead.

Test have been adjusted:
  - either noreturn was added, or
  - noreturn was avoided by modifying the code.

The new noreturn_{sync,async} test make sure we do handle invoke
instructions with a noreturn (and potentially nowunwind) callee
correctly, even in the presence of potential asynchronous exceptions.

llvm-svn: 367948
2019-08-05 23:22:05 +00:00
Tim Northover a009a60a91 IR: print value numbers for unnamed function arguments
For consistency with normal instructions and clarity when reading IR,
it's best to print the %0, %1, ... names of function arguments in
definitions.

Also modifies the parser to accept IR in that form for obvious reasons.

llvm-svn: 367755
2019-08-03 14:28:34 +00:00
Hideto Ueno 65bbaf9ece [Attributor] Deduce "nofree" function attribute
Summary: Deduce "nofree" function attribute. A more concise description of "nofree" is on D49165.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: homerdin, hfinkel, lebedev.ri, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62687

llvm-svn: 365924
2019-07-12 17:38:51 +00:00
Hideto Ueno 8ea7326b7f [FunctionAttrs] Add a test for "nofree" function attribute
This patch adds a test for nofree function attribute.

llvm-svn: 365916
2019-07-12 16:29:14 +00:00