Commit Graph

691 Commits

Author SHA1 Message Date
Michael Kruse 7bf3404c76 [SimplifyCFG] Preserve metadata when unconditionalizing branches (same target).
When replacing a conditional branch by an unconditional one because the targets are identical, transfer the metadata to the new branch instruction.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D101226
2021-04-26 17:23:01 -05:00
Michael Kruse 11f3dcfec5 [SimplifyCFG] Preserve metadata when unconditionalizing branches (constant condition).
When replacing a conditional branch by an unconditional one because the condition is a constant, transfer the metadata to the new branch instruction.

Part of fix for llvm.org/PR50060

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D101141
2021-04-26 10:57:31 -05:00
Stephen Tozer 8b8275b1fc Re-reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands"
Previous build failures were caused by an error in bitcode reading and
writing for DIArgList metadata, which has been fixed in e5d844b587.
There were also some unnecessary asserts that were being triggered on
certain builds, which have been removed.

This reverts commit dad5caa59e6b2bde8d6cf5b64a972c393c526c82.
2021-04-23 10:54:01 +01:00
OCHyams fbe80b0c21 [DebugInfo] Move the findDbg* functions into DebugInfo.cpp
Move the findDbg* functions into lib/IR/DebugInfo.cpp from
lib/Transforms/Utils/Local.cpp.

D99169 adds a call to a function (findDbgUsers) that lives in
lib/Transforms/Utils/Local.cpp (LLVMTransformUtils) from lib/IR/Value.cpp
(LLVMCore). The Core lib doesn't include TransformUtils. The builtbots caught
this here: https://lab.llvm.org/buildbot/#/builders/109/builds/12664. This patch
moves the function, and the 3 similar ones for consistency, into DebugInfo.cpp
which is part of LLVMCore.

Reviewed By: dblaikie, rnk

Differential Revision: https://reviews.llvm.org/D100632
2021-04-19 10:30:25 +01:00
Philip Reames 37583a96a8 Reapply "[InferAttributes] Materialize all infered attributes for declaration"" and follow on patches.
This reverts commit ab98f2c7129a52e216fd7e088b964cf4af27b0f2 and 98eea392cdbcdb7360e58b46e9329573f092cd96.

It includes a fix for the clang test which triggered the revert.  I failed to notice this one because there was another AMDGPU llvm test with a similiar name and the exact same text in the error message.  Odd.  Since only one build bot reported the clang test, I didn't notice that one.
2021-04-14 16:38:07 -07:00
Nico Weber b77d365b9c Revert "[InferAttributes] Materialize all infered attributes for declaration"
Breaks check-clang, see comments on D100400

Also revert follow-up "[NFC] Move a recently added utility into a location to enable reuse"

This reverts commit 3ce61fb6d697d49db471c7077b88b3b9ec9dec66.
This reverts commit 61a85da88235983da565bda0160367461fa0f382.
2021-04-14 18:41:20 -04:00
Philip Reames c14de16461 [NFC] Move a recently added utility into a location to enable reuse
About to refresh a patch that uses this in FunctionAtrrs, doing the move seperately to control build times.
2021-04-14 15:05:16 -07:00
Amy Huang 3d38422040 Revert "Reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands""
This change causes an assert / segmentation fault in LTO builds.

This reverts commit f2e4f3eff3c9135d92840016f8ed4540cdd1313b.
2021-04-12 20:10:17 -07:00
Stephen Tozer 875d444d72 Reapply "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands"
The causes of the previous build errors have been fixed in revisions
aa3e78a59fdf3b211be72f1b3221af831665e67d, and
140757bfaaa00110a92d2247a910c847e6e3bcc8

This reverts commit f40976bd01032f4905dde361e709166704581077.
2021-04-12 16:57:29 +01:00
Roman Lebedev 32907b0f11 [NFCI][Local] MergeBasicBlockIntoOnlyPred(): improve Dominator Tree updating
Same as with TryToSimplifyUncondBranchFromEmptyBlock()/MergeBlockIntoPredecessor() patch.
2021-04-11 23:56:23 +03:00
Roman Lebedev d2b48ac4fd [NFCI][Local] TryToSimplifyUncondBranchFromEmptyBlock(): improve Dominator Tree updating
First, we don't need vector-ness for the predecessor lists.

Secondly, like elsewhere, do insertions before deletions.

Lastly, the check that we actually need to insert an edge,
that it doesn't exist already, is backwards. Instead of
looking at successors of every single 'PredOfBB',
just always look at predecessors of the 'Succ'.
The result is always the same, but we avoid *really* inefficient code.
2021-04-11 23:56:22 +03:00
Philip Reames 631f83b6d7 Plumb AssumeInst through operand bundle apis [nfc]
Follow up to a6d2a8d6f5.  This covers all the public interfaces of the bundle related code.  I tried to cleanup the internals where the changes were obvious, but there's definitely more room for improvement.
2021-04-06 12:53:53 -07:00
Roman Lebedev 4def33398a [NFCI][SimplifyCFG] Don't pay for a Small{Map,Set}Vector when plain SmallSet will suffice
This *only* changes the cases where we *really* don't care
about the iteration order of the underlying contained,
namely when we will use the values from it to form DTU updates.
2021-03-25 23:25:40 +03:00
Roman Lebedev a9e5f2d01d [NFCI][SimplifyCFG] Don't form DTU updates if we aren't going to apply them
I think we may want to have a thin wrapper over a vector to deduplicate
those `if(DTU)` predicates, and instead do them in the `insert()` itself.
2021-03-25 00:02:37 +03:00
Stephen Tozer fea97b90a1 Reapply "[DebugInfo] Handle multiple variable location operands in IR"
Fixed section of code that iterated through a SmallDenseMap and added
instructions in each iteration, causing non-deterministic code; replaced
SmallDenseMap with MapVector to prevent non-determinism.

This reverts commit 01ac6d1587e8613ba4278786e8341f8b492ac941.
2021-03-17 16:45:25 +00:00
Hans Wennborg d0e43622c0 Revert "[DebugInfo] Handle multiple variable location operands in IR"
This caused non-deterministic compiler output; see comment on the
code review.

> This patch updates the various IR passes to correctly handle dbg.values with a
> DIArgList location. This patch does not actually allow DIArgLists to be produced
> by salvageDebugInfo, and it does not affect any pass after codegen-prepare.
> Other than that, it should cover every IR pass.
>
> Most of the changes simply extend code that operated on a single debug value to
> operate on the list of debug values in the style of any_of, all_of, for_each,
> etc. Instances of setOperand(0, ...) have been replaced with with
> replaceVariableLocationOp, which takes the value that is being replaced as an
> additional argument. In places where this value isn't readily available, we have
> to track the old value through to the point where it gets replaced.
>
> Differential Revision: https://reviews.llvm.org/D88232

This reverts commit df69c69427dea7f5b3b3a4d4564bc77b0926ec88.
2021-03-17 13:36:48 +01:00
Stephen Tozer 617750cbc9 Revert "[DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands"
This reverts commit c0f3dfb9f119bb5f22dd8846f5502b6abaf026d3.

Reverted due to an error on the clang-x64-windows-msvc buildbot.
2021-03-11 14:48:01 +00:00
gbtozers 3b8eba58df [DebugInfo] Use variadic debug values to salvage BinOps and GEP instrs with non-const operands
This patch improves salvageDebugInfoImpl by allowing it to salvage arithmetic
operations with two or more non-const operands; this includes the GetElementPtr
instruction, and most Binary Operator instructions. These salvages produce
DIArgList locations and are only valid for dbg.values, as currently variadic
DIExpressions must use DW_OP_stack_value. This functionality is also only added
for salvageDebugInfoForDbgValues; other functions that directly call
salvageDebugInfoImpl (such as in ISel or Coroutine frame building) can be
updated in a later patch.

Differential Revision: https://reviews.llvm.org/D91722
2021-03-11 13:33:49 +00:00
gbtozers bed8d760fe [DebugInfo][NFC] Refactor BinOp+GEP salvaging in salvageDebugInfoImpl
This patch refactors out the salvaging of GEP and BinOp instructions into
separate functions, in preparation for further changes to the salvaging of these
instructions coming in another patch; there should be no functional change as a
result of this refactor.

Differential Revision: https://reviews.llvm.org/D92851
2021-03-10 18:03:12 +00:00
gbtozers 9b334d3086 [DebugInfo] Handle multiple variable location operands in IR
This patch updates the various IR passes to correctly handle dbg.values with a
DIArgList location. This patch does not actually allow DIArgLists to be produced
by salvageDebugInfo, and it does not affect any pass after codegen-prepare.
Other than that, it should cover every IR pass.

Most of the changes simply extend code that operated on a single debug value to
operate on the list of debug values in the style of any_of, all_of, for_each,
etc. Instances of setOperand(0, ...) have been replaced with with
replaceVariableLocationOp, which takes the value that is being replaced as an
additional argument. In places where this value isn't readily available, we have
to track the old value through to the point where it gets replaced.

Differential Revision: https://reviews.llvm.org/D88232
2021-03-09 16:44:38 +00:00
Philip Reames fec6c4d338 [gvn] Precisely propagate equalities to phi operands
The code used for propagating equalities (e.g. assume facts) was conservative in two ways - one of which this patch fixes. Specifically, it shifts the code reasoning about whether a use is dominated by the end of the assume block to consider phi uses to exist on the predecessor edge. This matches the dominator tree handling for dominates(Edge, Use), and simply extends it to dominates(BB, Use).

Note that the decision to use the end of the block is itself a conservative choice. The more precise option would be to use the later of the assume and the value, and replace all uses after that. GVN handles that case separately (with the replace operand mechanism) because it used to be expensive to ask dominator questions within blocks. With the new instruction ordering support, we should probably rewrite this code at some point to simplify.

Differential Revision: https://reviews.llvm.org/D98082
2021-03-08 08:59:00 -08:00
gbtozers bfb6dad2ae [DebugInfo] Support DIArgList in DbgVariableIntrinsic
This patch updates DbgVariableIntrinsics to support use of a DIArgList for the
location operand, resulting in a significant change to its interface. This patch
does not update all IR passes to support multiple location operands in a
dbg.value; the only change is to update the DbgVariableIntrinsic interface and
its uses. All code outside of the intrinsic classes assumes that an intrinsic
will always have exactly one location operand; they will still support
DIArgLists, but only if they contain exactly one Value.

Among other changes, the setOperand and setArgOperand functions in
DbgVariableIntrinsic have been made private. This is to prevent code from
setting the operands of these intrinsics directly, which could easily result in
incorrect/invalid operands being set. This does not prevent these functions from
being called on a debug intrinsic at all, as they can still be called on any
CallInst pointer; it is assumed that any code directly setting the operands on a
generic call instruction is doing so safely. The intention for making these
functions private is to prevent DIArgLists from being overwritten by code that's
naively trying to replace one of the Values it points to, and also to fail fast
if a DbgVariableIntrinsic is updated to use a DIArgList without a valid
corresponding DIExpression.
2021-03-08 14:36:13 +00:00
Hongtao Yu f2b87eabed [CSSPGO] Unblocking optimizations by dangling pseudo probes.
This change fixes a couple places where the pseudo probe intrinsic blocks optimizations because they are not naturally removable. To unblock those optimizations, the blocking pseudo probes are moved out of the original blocks and tagged dangling, instead of allowing pseudo probes to be literally removed. The reason is that when the original block is removed, we won't be able to sample it. Instead of assigning it a zero weight, moving all its pseudo probes into another block and marking them dangling should allow the counts inference a chance to assign them a more reasonable weight. We have not seen counts quality degradation from our experiments.

The optimizations being unblocked are:

	1. Removing conditional probes for if-converted branches. Conditional probes are tagged dangling when their homing branch arms are folded so that they will not be over-counted.
	2. Unblocking jump threading from removing empty blocks. Pseudo probe prevents jump threading from removing logically empty blocks that only has one unconditional jump instructions.
	3. Unblocking SimplifyCFG and MIR tail duplicate to thread empty blocks and blocks with redundant branch checks.

Since dangling probes are logically deleted, they should not consume any samples in LTO postLink. This can be achieved by setting their distribution factors to zero when dangled.

Reviewed By: wmi

Differential Revision: https://reviews.llvm.org/D97481
2021-03-03 22:44:42 -08:00
Sanjay Patel c42cc1f879 [SimplifyCFG] avoid illegal phi with both poison and undef
In the example based on:
https://llvm.org/PR49218
...we are crashing because poison is a subclass of undef, so we merge blocks and create:

PHI node has multiple entries for the same basic block with different incoming values!
  %k3 = phi i64 [ poison, %entry ], [ %k3, %g ], [ undef, %entry ]

If both poison and undef values are incoming, we soften the poison values to undef.

Differential Revision: https://reviews.llvm.org/D97495
2021-02-27 09:10:32 -05:00
Kazu Hirata ca656eb6e9 [Transforms/Utils] Use range-based for loops (NFC) 2021-02-26 22:36:40 -08:00
Simon Pilgrim e298ce89c1 [Utils] collectBitParts - bail for integers > 128-bits
collectBitParts uses int8_t for the bit indices, leaving a 128-bit limit.

We already test for this before calling collectBitParts, but rGb94c215592bd added truncate handling which meant we could end up processing wider integers.

Thanks to @manojgupta for the repro.
2021-02-26 14:58:01 +00:00
Simon Pilgrim 4081766ef3 [Utils] collectBitParts - add truncate() handling 2021-02-24 11:48:34 +00:00
Nikita Popov 56e22ed4c5 [IR] Move willReturn() to Instruction
This moves the willReturn() helper from CallBase to Instruction,
so that it can be used in a more generic manner. This will make
it easier to fix additional passes (ADCE and BDCE), and will give
us one place to change if additional instructions should become
non-willreturn (e.g. there has been talk about handling volatile
operations this way).

I have also included the IntrinsicInst workaround directly in
here, so that it gets applied consistently. (As such this change
is not entirely NFC -- FuncAttrs will now use this as well.)

Differential Revision: https://reviews.llvm.org/D96992
2021-02-19 11:56:01 +01:00
Kazu Hirata 5ccf86fedd [Transforms/Utils] Use range-based for loops (NFC) 2021-02-07 09:49:36 -08:00
Roman Lebedev e695f6dc77 [ShadowStackGCLowering] Preserve Dominator Tree, if avaliable
This doesn't help avoid any Dominator Tree recalculations just yet,
there's one more pass to go..
2021-01-30 01:14:51 +03:00
Florian Hahn 283961f4c8 [Local] Treat calls that may not return as being alive.
With the addition of the `willreturn` attribute, functions that may
not return (e.g. due to an infinite loop) are well defined, if they are
not marked as `willreturn`.

This patch updates `wouldInstructionBeTriviallyDead` to not consider
calls that may not return as dead.

This patch still provides an escape hatch for intrinsics, which are
still assumed as willreturn unconditionally. It will be removed once
all intrinsics definitions have been reviewed and updated.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D94106
2021-01-23 16:05:14 +00:00
Roman Lebedev 39927e70ac [SimplifyCFG] markAliveBlocks(): catchswitch: preserve PostDomTree
When removing catchpad's from catchswitch, if that removes a successor,
we need to record that in DomTreeUpdater.

This fixes PostDomTree preservation failure in an existing test.
This appears to be the single issue that i see in my current test coverage.
2021-01-17 01:21:05 +03:00
Roman Lebedev ef53c50f1a [NFCI][Utils/Local] removeUnreachableBlocks(): cleanup support for lazy DomTreeUpdater
When DomTreeUpdater is in lazy update mode, the blocks
that were scheduled to be removed, won't be removed
until the updates are flushed, e.g. by asking
DomTreeUpdater for a up-to-date DomTree.

From the function's current code, it is pretty evident
that the support for the lazy mode is an afterthought,
see e.g. how we roll-back NumRemoved statistic..

So instead of considering all the unreachable blocks
as the blocks-to-be-removed, simply additionally skip
all the blocks that are already scheduled to be removed
2021-01-12 02:09:47 +03:00
Roman Lebedev 3730886cb5 [NFCI][SimplifyCFG] Prefer to add Insert edges before Delete edges into DomTreeUpdater, if reasonable
This has a measurable impact on the number of DomTree recalculations.
While this doesn't handle all the cases,
it deals with the most obvious ones.
2021-01-11 00:30:44 +03:00
Roman Lebedev 56d34ce62d [SimplifyCFG] markAliveBlocks(): switch to non-permissive DomTree updates
No actual changes needed, invoke can't have the same block as an unwind
destination and a normal destination.
2021-01-08 02:15:27 +03:00
Roman Lebedev b2fa375285 [SimplifyCFG] removeUnwindEdge(): switch to non-permissive DomTree updates
No actual changes needed, Catchswitch cannot unwind to one of its catchpads.
2021-01-08 02:15:27 +03:00
Roman Lebedev 033a378324 [SimplifyCFG] changeToCall(): switch to non-permissive DomTree updates
No actual changes needed, normal and unwind destinations of an invoke
can never be identical.
2021-01-08 02:15:27 +03:00
Roman Lebedev 561c5ece8e [SimplifyCFG] changeToUnreachable(): switch to non-permissive DomTree updates
... which requires not deleting edges that were just deleted already,
    by not processing the same predecessor more than once.
2021-01-08 02:15:26 +03:00
Roman Lebedev f6303c71bb [SimplifyCFG] removeUnreachableBlocks(): switch to non-permissive DomTree updates
... which requires not deleting edges that were just deleted already,
    by not processing the same predecessor more than once.
2021-01-08 02:15:26 +03:00
Roman Lebedev 5bb87e1419 [SimplifyCFG] TryToSimplifyUncondBranchFromEmptyBlock(): switch to non-permissive DomTree updates
... which requires not deleting edges that were just deleted already,
    by not processing the same predecessor more than once.
2021-01-08 02:15:25 +03:00
Roman Lebedev 8cb44d8699 [SimplifyCFG] ConstantFoldTerminator(): switch to non-permissive DomTree updates in indirectbr handling
... which requires not deleting edges that were just deleted already.
2021-01-08 02:15:25 +03:00
Roman Lebedev 9972af1139 [SimplifyCFG] ConstantFoldTerminator(): switch to non-permissive DomTree updates in SwitchInst handling
... which requires not deleting edges that will still be present.
2021-01-08 02:15:24 +03:00
Roman Lebedev 3be56d0764 [SimplifyCFG] ConstantFoldTerminator(): handle matching destinations of condbr earlier
We need to handle this case before dealing with the case of constant
branch condition, because if the destinations match, latter fold
would try to remove the DomTree edge that would still be present.

This allows to make that particular DomTree update non-permissive
2021-01-08 02:15:24 +03:00
Francesco Petrogalli 85e110e6e7 [InstCombine] Update valueCoversEntireFragment to use TypeSize
* Update valueCoversEntireFragment to use TypeSize.
* Add a regression test.
* Assertions have been added to protect untested codepaths.

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D91806
2021-01-06 17:14:59 +00:00
Kazu Hirata db085a4bfd [Transforms/Utils] Construct SmallVector with iterator ranges (NFC) 2020-12-29 19:23:23 -08:00
Kazu Hirata 950b351780 [Local] Remove unused function RemovePredecessorAndSimplify (NFC)
The last use of the function was removed on Sep 29, 2010 in commit
99c985c37dd45dd0fbd03863037d8e93153783e6.
2020-12-25 09:35:20 -08:00
Fangrui Song 0140db71cc Migrate deprecated DebugLoc::get to DILocation::get
This migrates all LLVM (except Kaleidoscope and
CodeGen/StackProtector.cpp) DebugLoc::get to DILocation::get.

The CodeGen/StackProtector.cpp usage may have a nullptr Scope
and can trigger an assertion failure, so I don't migrate it.

Reviewed By: #debug-info, dblaikie

Differential Revision: https://reviews.llvm.org/D93087
2020-12-11 12:45:22 -08:00
Kazu Hirata 0fce5c3fd1 [Transforms] Use llvm::is_contained (NFC) 2020-11-18 20:42:22 -08:00
Arthur Eubanks bb84082e59 Revert "Use uint64_t for branch weights instead of uint32_t"
This reverts commit 10f2a0d662d8d72eaac48d3e9b31ca8dc90df5a4.

More uint64_t overflows.
2020-10-31 00:25:32 -07:00
Arthur Eubanks f52f1e83f5 Use uint64_t for branch weights instead of uint32_t
CallInst::updateProfWeight() creates branch_weights with i64 instead of i32.
To be more consistent everywhere and remove lots of casts from uint64_t
to uint32_t, use i64 for branch_weights.

Reviewed By: davidxl

Differential Revision: https://reviews.llvm.org/D88609
2020-10-30 10:03:46 -07:00