Commit Graph

3928 Commits

Author SHA1 Message Date
Johannes Doerfert
bcd8009369 [Attributor] Use the proper context instruction in genericValueTraversal
There was a TODO in genericValueTraversal to provide the context
instruction and due to the lack of it users that wanted one just used
something available. Unfortunately, using a fixed instruction is wrong
in the presence of PHIs so we need to update the context instruction
properly.

Reviewed By: uenoku

Differential Revision: https://reviews.llvm.org/D76870
2020-04-01 22:20:47 -05:00
Johannes Doerfert
ac96c8fd85 [Attributor][FIX] Do not compute ranges for arguments of declarations
This cannot be triggered right now, as far as I know, but it doesn't
make sense to deduce a constant range on arguments of declarations.
Exposed during testing of AAValueSimplify extensions.
2020-04-01 22:05:30 -05:00
Johannes Doerfert
54d6a608bf [Attributor][NFC] Predetermine the module
It could happen that we delete the first function in the SCC in the
future so we should be careful accessing `Functions` after the manifest
stage.
2020-04-01 21:56:17 -05:00
Johannes Doerfert
9e19693994 [Attributor] Derive better alignment for accessed pointers
Use DL & ABI information for better alignment deduction, e.g., if a type
is accessed and the ABI specifies an alignment requirement for such an
access we can use it. This is based on a patch by @lebedev.ri and
inspired by getBaseAlign in Loads.cpp.

Depends on D76673.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D76674
2020-04-01 21:49:57 -05:00
Johannes Doerfert
b1c788d051 [Attributor][FIX] Prevent alignment breakage wrt. must-tail calls
If we have a must-tail call the callee and caller need to have matching
ABIs. Part of that is alignment which we might modify when we deduce
alignment of arguments of either. Since we would need to keep them in
sync, which is not as simple, we simply avoid deducing alignment for
arguments of the must-tail caller or callee.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D76673
2020-04-01 21:40:07 -05:00
Johannes Doerfert
41f2a57d0b [Attributor][NFC] Use a BumpPtrAllocator to allocate AbstractAttributes
We create a lot of AbstractAttributes and they live as long as
the Attributor does. It seems reasonable to allocate them via a
BumpPtrAllocator owned by the Attributor.

Reviewed By: baziotis

Differential Revision: https://reviews.llvm.org/D76589
2020-04-01 20:53:28 -05:00
Uday Bondhugula
c4499e3333 [Attributor] Make attributor aware of aligned_alloc for heap to stack conversion
Make the attributor pass aware of aligned_alloc for converting heap
allocations to stack ones.

Depends on D76971.

Differential Revision: https://reviews.llvm.org/D76974
2020-04-01 23:26:50 +05:30
Wei Mi
ebad678857 [SampleFDO] Port MD5 name table support to extbinary format.
Compbinary format uses MD5 to represent strings in name table. That gives smaller profile without the need of compression/decompression when writing/reading the profile. The patch adds the support in extbinary format. It is off by default but user can choose to enable it.

Note the feature of using MD5 in name table can bring very small chance of name conflict leading to profile mismatch. Besides, profile using the feature won't have the profile remapping support.

Differential Revision: https://reviews.llvm.org/D76255
2020-03-30 22:07:08 -07:00
Uday Bondhugula
06066c4003 [NFC] Attributor comment updates / cast cleanup
Minor update/fixes to comments for the Attributor pass, and dyn_cast -> cast.

Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>

Differential Revision: https://reviews.llvm.org/D76972
2020-03-28 13:36:43 +05:30
Johannes Doerfert
5699d08b79 [Attributor] Use knowledge retained in llvm.assume (operand bundles)
This patch integrates operand bundle llvm.assumes [0] with the
Attributor. Most IRAttributes will now look at uses of the associated
value and if there are llvm.assume operand bundle uses with the right
tag we will check if they are in the must-be-executed-context (around
the context instruction). Droppable users, which is currently only
llvm::assume, are handled special in some places now as well.

[0] http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

Reviewed By: uenoku

Differential Revision: https://reviews.llvm.org/D74888
2020-03-24 15:33:40 -05:00
Vedant Kumar
b7cd291c15 [GlobalOpt] Treat null-check of loaded value as use of global (PR35760)
PR35760 shows an example program which, when compiled with `clang -O0`
or gcc at any optimization level, prints '0'. However, llvm transforms
the program in a way that causes it to print '1'.

Fix the issue by having `AllUsesOfValueWillTrapIfNull` return false when
analyzing a load from a global which is used by an `icmp`. This special
case was untested [0] so this is just deleting dead code.

An alternative fix might be to change the GlobalStatus analysis for the
global to report "Stored" instead of "StoredOnce". However, "StoredOnce"
is appropriate when only one value other than the initializer is stored
to the global.

[0]
http://lab.llvm.org:8080/coverage/coverage-reports/coverage/Users/buildslave/jenkins/workspace/coverage/llvm-project/llvm/lib/Transforms/IPO/GlobalOpt.cpp.html#L662

Differential Revision: https://reviews.llvm.org/D76645
2020-03-23 22:36:09 -07:00
Johannes Doerfert
f09f4b2676 [OpenMPOpt] Initialize value to avoid use of uninitialized memory
This should fix the issue reported here:
  https://reviews.llvm.org/D76058#1937554
2020-03-23 19:17:19 -05:00
Stefanos Baziotis
a650d555fc [Attributor][NFC] Refactorings and typos in doc
Reviewed By: sstefan1, uenoku

Differential Revision: https://reviews.llvm.org/D76175
2020-03-23 22:44:10 +02:00
Johannes Doerfert
9d38f98dc3 [OpenMPOpt] Validate declaration types against the expected types
Validation of the found runtime library functions declarations types
(return and argument types) with the expected types.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D76058
2020-03-23 11:43:36 -05:00
Benjamin Kramer
ff2f5097ed [Attributor] Fold single-use variable into assert
Fixes unused variable warning in Release builds.
2020-03-23 17:41:52 +01:00
Johannes Doerfert
c57689bef2 [Attributor][NFC] Copy llvm::function_ref, don't use references
On IRC this was called a "code smell" so we get rid of it.
2020-03-23 10:45:24 -05:00
Johannes Doerfert
68fed27067 [Attributor] Handle calls in AAValueConstantRange properly
We did handle calls that were operands of certain instructions but not
standalone calls we visit via indirection, e.g., selects.
2020-03-23 10:45:24 -05:00
Johannes Doerfert
54ec9b54f6 [Attributor] Unify handling of must-tail calls
We special cased must-tail calls all over the place because they cannot
be modified as other calls can be. However, we already centralized the
modification API so we can centralize the handling as well. This
simplifies the code and allows to remove must-tail calls completely.
2020-03-23 10:45:24 -05:00
Johannes Doerfert
0995001ce5 [Attributor][NFC] Predetermine the module before verification
It could happen that we delete the first function in the SCC in the
future so we should be careful accessing `Functions` after the manifest
stage.
2020-03-23 10:45:23 -05:00
Johannes Doerfert
f3bf4b05c2 [Attributor][NFC] clang-format Attributor.{h,cpp} 2020-03-23 10:45:23 -05:00
Nikita Popov
dc81923659 [InstCombine] Remove ExpensiveCombines option
D75801 removed the last and only user of this option, so we can
drop it now. The original idea behind this was to only run expensive
transforms under -O3, but apart from the one known bits transform,
this has never really taken off. I believe nowadays the recommendation
is to put expensive transforms in AggressiveInstCombine instead,
though that isn't terribly popular either :)

Differential Revision: https://reviews.llvm.org/D76540
2020-03-22 16:56:28 +01:00
Eli Friedman
e24e95fe90 Remove CompositeType class.
The existence of the class is more confusing than helpful, I think; the
commonality is mostly just "GEP is legal", which can be queried using
APIs on GetElementPtrInst.

Differential Revision: https://reviews.llvm.org/D75660
2020-03-18 13:53:17 -07:00
omarahmed1111
b285b333dc [Attributor] Detect possibly unbounded cycles in functions
This patch add mayContainUnboundedCycle helper function which checks whether a function has any cycle which we don't know if it is bounded or not.
Loops with maximum trip count are considered bounded, any other cycle not.
It also contains some fixed tests and some added tests contain bounded and
unbounded loops and non-loop cycles.

Reviewed By: jdoerfert, uenoku, baziotis

Differential Revision: https://reviews.llvm.org/D74691
2020-03-13 11:17:33 -05:00
Pankaj Gode
bf990530ae [Attributor] Improve noalias preservation using reachability
Resolution for below fixme:
(ii) Check whether the value is captured in the scope using AANoCapture.
FIXME: This is conservative though, it is better to look at CFG and
             check only uses possibly executed before this callsite.

Propagates caller argument's noalias attribute to callee.

Reviewed by: jdoerfert, uenoku

Reviewers: jdoerfert, sstefan1, uenoku

Subscribers: uenoku, sstefan1, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D71617
2020-03-13 21:09:08 +05:30
Johannes Doerfert
a198adb490 [Attributor] IPO across definition boundary of a function marked alwaysinline
Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D75590
2020-03-13 01:06:12 -05:00
rathod-sahaab
263c4a3c75 Fix compiler warning when compiling without asserts
This patch aims to prevent warning-as-error failures in release build.
As suggested in this comment
https://reviews.llvm.org/D69930#1910922

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D75970
2020-03-13 00:26:49 -05:00
Hideto Ueno
d9bf79f4e9 [Attributor][FIX] Add a missing dependence track in noalias deduction 2020-03-12 15:27:35 +00:00
evgeny
6d2032e259 [WPD] Provide a way to prevent functions from being devirtualized
Differential revision: https://reviews.llvm.org/D75617
2020-03-09 14:05:15 +03:00
Hideto Ueno
bdcbdb4848 [Attributor] Deduction based on path exploration
This patch introduces the propagation of known information based on path exploration.
For example,
```
int u(int c, int *p){
  if(c) {
     return *p;
  } else {
     return *p + 1;
  }
}
```
An argument `p` is dereferenced whatever c's value is.

For an instruction `CtxI`, we accumulate branch instructions in the must-be-executed-context of `CtxI` and then, we take the conjunction of the successors' known state.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D65593
2020-03-09 14:29:26 +09:00
Stefanos Baziotis
01c48d7d11 [Attributor] Fold terminators before changing instructions to unreachable
It is possible that an instruction to be changed to unreachable is
in the same block with a terminator that can be constant-folded.
In this case, as of now, the instruction will be changed to
unreachable before the terminator is folded. But, then the
whole BB becomes invalidated and so when we go ahead to fold
the terminator, we trap.

Change the order of these two.

Differential Revision: https://reviews.llvm.org/D75780
2020-03-07 12:38:44 +02:00
Fangrui Song
952ee0df9e ThinLTOBitcodeWriter: drop dso_local when a GlobalVariable is converted to a declaration
If we infer the dso_local flag for -fpic, dso_local should be dropped
when we convert a GlobalVariable a declaration. dso_local causes the
generation of direct access (e.g. R_X86_64_PC32). Such relocations referencing
STB_GLOBAL STV_DEFAULT objects are not allowed in a -shared link.

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D74749
2020-03-05 18:09:33 -08:00
Nikita Popov
0e890cd4d4 [ConstantFolding] Always return something from ConstantFoldConstant
Spin-off from D75407. As described there, ConstantFoldConstant()
currently returns null for non-ConstantExpr/ConstantVector inputs,
but otherwise always returns non-null, independently of whether
any folding has happened or not.

This is confusing and makes consumer code more complicated.
I would expect either that ConstantFoldConstant() returns only if
it actually folded something, or that it always returns non-null.
I'm going to the latter possibility here, which appears to be more
useful considering existing usage.

Differential Revision: https://reviews.llvm.org/D75543
2020-03-04 18:24:47 +01:00
Sanjay Patel
71a316883d [PassManager] adjust VectorCombine placement
The initial placement of vector-combine in the opt pipeline revealed phase ordering bugs:
https://bugs.llvm.org/show_bug.cgi?id=45015
https://bugs.llvm.org/show_bug.cgi?id=42022

This patch contains a few independent changes:

1. Move the pass up in the pipeline, so it happens just after loop-vectorization.
   This is only to keep vectorization passes together in the pipeline at the moment.
   I don't have evidence of interaction between these yet.
2. Add an -early-cse pass after -vector-combine to clean up redundant ops. This was
   partly proposed as far back as rL219644 (which is why it's effectively being moved
   in the old PM code). This is important because the subsequent -instcombine doesn't
   work as well without EarlyCSE. With the CSE, -instcombine is able to squash
   shuffles together in 1 of the tests (because those are simple "select" shuffles).
3. Remove the -vector-combine pass that was running after SLP. We may want to do that
   eventually, but I don't have a test case to support it yet.

Differential Revision: https://reviews.llvm.org/D75145
2020-03-04 11:10:49 -05:00
Teresa Johnson
80bf137fa1 Revert "Restore "[WPD/LowerTypeTests] Delay lowering/removal of type tests until after ICP""
This reverts commit 80d0a137a5, and the
follow on fix in 873c0d0786. It is
causing test failures after a multi-stage clang bootstrap. See
discussion on D73242 and D75201.
2020-03-02 14:02:13 -08:00
Teresa Johnson
873c0d0786 [ThinLTO/LowerTypeTests] Handle unpromoted local type ids
Summary:
Fixes an issue that cropped up after the changes in D73242 to delay
the lowering of type tests. LTT couldn't handle any type tests with
non-string type id (which happens for local vtables, which we try to
promote during the compile step but cannot always when there are no
exported symbols).

We can simply treat the same as having an Unknown resolution, which
delays their lowering, still allowing such type tests to be used in
subsequent optimization (e.g. planned usage during ICP). The final
lowering which simply removes these handles them fine.

Beefed up an existing ThinLTO test for such unpromoted type ids so that
the internal vtable isn't removed before lower type tests, which hides
the problem.

Reviewers: evgeny777, pcc

Subscribers: inglorion, hiraditya, steven_wu, dexonsmith, aganea, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75201
2020-03-02 09:31:44 -08:00
Hiroshi Yamauchi
f16d2bec40 Devirtualize a call on alloca without waiting for post inline cleanup and next DevirtSCCRepeatedPass iteration.
This aims to fix a missed inlining case.

If there's a virtual call in the callee on an alloca (stack allocated object) in
the caller, and the callee is inlined into the caller, the post-inline cleanup
would devirtualize the virtual call, but if the next iteration of
DevirtSCCRepeatedPass doesn't happen (under the new pass manager), which is
based on a heuristic to determine whether to reiterate, we may miss inlining the
devirtualized call.

This enables inlining in clang/test/CodeGenCXX/member-function-pointer-calls.cpp.

This is a second commit after a revert
https://reviews.llvm.org/rG4569b3a86f8a4b1b8ad28fe2321f936f9d7ffd43 and a fix
https://reviews.llvm.org/rG41e06ae7ba91.

Differential Revision: https://reviews.llvm.org/D69591
2020-02-28 09:43:32 -08:00
Teresa Johnson
f9ca75f19b [Inliner] Inlining should honor nobuiltin attributes
Summary:
Final patch in series to fix inlining between functions with different
nobuiltin attributes/options, which was specifically an issue in LTO.
See discussion on D61634 for background.

The prior patch in this series (D67923) enabled per-Function TLI
construction that identified the nobuiltin attributes.

Here I have allowed inlining to proceed if the callee's nobuiltins are a
subset of the caller's nobuiltins, but not in the reverse case, which
should be conservatively correct. This is controlled by a new option,
-inline-caller-superset-nobuiltin, which is enabled by default.

Reviewers: hfinkel, gchatelet, chandlerc, davidxl

Subscribers: arsenm, jvesely, nhaehnle, mehdi_amini, eraman, hiraditya, haicheng, dexonsmith, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74162
2020-02-28 07:34:14 -08:00
Kirill Bobyrev
4569b3a86f Revert "Devirtualize a call on alloca without waiting for post inline cleanup and next"
This reverts commit 59fb9cde7a.

The patch caused internal miscompilations.
2020-02-27 15:58:39 +01:00
Hiroshi Yamauchi
59fb9cde7a Devirtualize a call on alloca without waiting for post inline cleanup and next
DevirtSCCRepeatedPass iteration.  Needs ReviewPublic

This aims to fix a missed inlining case.

If there's a virtual call in the callee on an alloca (stack allocated object) in
the caller, and the callee is inlined into the caller, the post-inline cleanup
would devirtualize the virtual call, but if the next iteration of
DevirtSCCRepeatedPass doesn't happen (under the new pass manager), which is
based on a heuristic to determine whether to reiterate, we may miss inlining the
devirtualized call.

This enables inlining in clang/test/CodeGenCXX/member-function-pointer-calls.cpp.
2020-02-26 09:51:24 -08:00
Johannes Doerfert
396b725394 [OpenMP][Opt] Combine struct ident_t* during deduplication
If we deduplicate OpenMP runtime calls we have multiple `ident_t*` that
represent information like source location. So far, we simply kept the
one used by the replacement call. However, as exposed by PR44893, that
can cause problems if we have stack allocated `ident_t` objects. While
we need to revisit the use of these as well, it is clear that we
eventually want to merge source location information in some way. With
this patch we add the infrastructure to do so but without doing the
actual merge. Instead we pick a global `ident_t` from the replaced
calls, if possible, or create a new one with an unknown location
instead.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D74925
2020-02-25 14:07:14 -08:00
Hideto Ueno
2c0edbf19c [Attributor] Use AssumptionCache in AANonNullFloating::initialize 2020-02-25 13:00:03 +09:00
Ayke van Laethem
2a7a989c3e [LLVM-C] Add bindings for addCoroutinePassesToExtensionPoints
This patch adds bindings to C and Go for
addCoroutinePassesToExtensionPoints, which is used to add coroutine
passes to the correct locations in PassManagerBuilder.

Differential Revision: https://reviews.llvm.org/D51642
2020-02-24 20:15:51 +01:00
Johannes Doerfert
9708279c72 [Attributor][FIX] Undo 16188f9 until SCC iterator bug is fixed
The buildbot
  http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win
shows some strange SCC iterator bug since 16188f9 which we need to
investigate. This patch should remove the part of 16188f9 that could
have exposed the problem.
2020-02-21 14:20:42 -08:00
Johannes Doerfert
d95cb56649 [Attributor] Make sure abstract attributes are properly initialized 2020-02-20 02:46:40 -06:00
Johannes Doerfert
6185fb13d6 [Attributor][NFC] Refactor interface 2020-02-20 02:46:40 -06:00
Johannes Doerfert
8e76fec0ae [Attributor][NFC] Improve the debug output & add a TODO 2020-02-19 23:46:08 -06:00
Johannes Doerfert
f8ad735729 [Attributor] Use existing returned information better
We can look through calls with `returned` argument attributes when we
collect subsuming positions. This allows us to get existing attributes
from more places.
2020-02-19 23:46:07 -06:00
Johannes Doerfert
a801ee869d [Attributor][FIX] Avoid setting wrong load/store alignments 2020-02-19 23:46:07 -06:00
Johannes Doerfert
e1eed6c5b9 [Attributor] Generalize getAssumedConstantInt interface
We are often interested in an assumed constant and sometimes it has to
be an integer constant. Before we only looked for the latter, now we can
ask for either.
2020-02-19 22:33:51 -06:00
Johannes Doerfert
16188f9d70 [Attributor][FIX] Do not create new calls edge we cannot handle
If we propagate function pointers across function boundaries we can
create new call edges. These need to be represented in the CG if we run
as a CGSCC pass. In the new pass manager that is currently not handled
by the CallGraphUpdater so we need to prevent the situation for now.
2020-02-19 22:33:51 -06:00