Summary:
This patch makes GenericDomTreeConstruction use the Semi-NCA algorithm instead of Simple Lengauer-Tarjan.
As described in `RFC: Dynamic dominators`, Semi-NCA offers slightly better performance than SLT. What's more important, it can be extended to perform incremental updates on already constructed dominator trees.
The patch passes check-all, llvm test suite and is able to boostrap clang. I also wasn't able to observe any compilation time regressions.
Reviewers: sanjoy, dberlin, chandlerc, grosser
Reviewed By: dberlin
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34258
llvm-svn: 306437
- DenseMap should be faster than std::map
- Use the `InsertRes = insert() if (!InsertRes.inserted)` pattern rather
than the `if (!X.contains(...)) { X.insert(...); }` to save one map
lookup.
llvm-svn: 306436
This canonicalization was suggested in D33172 as a way to make InstCombine behavior more uniform.
We have this transform for icmp+br, so unless there's some reason that icmp+select should be
treated differently, we should do the same thing here.
The benefit comes from increasing the chances of creating identical instructions. This is shown in
the tests in logical-select.ll (PR32791). InstCombine doesn't fold those directly, but EarlyCSE
can simplify the identical cmps, and then InstCombine can fold the selects together.
The possible regression for the tests in select.ll raises questions about poison/undef:
http://lists.llvm.org/pipermail/llvm-dev/2017-May/113261.html
...but that transform is just as likely to be triggered by this canonicalization as it is to be
missed, so we're just pointing out a commutation deficiency in the pattern matching:
https://reviews.llvm.org/rL228409
Differential Revision: https://reviews.llvm.org/D34242
llvm-svn: 306435
The example code incorrectly invokes ScheduleDAGMI wherein from context
it is clear it intends to invoke ScheduleDAGMILive actually.
Reviewed by: Andrew Trick
Differential Revision: https://reviews.llvm.org/D34675
llvm-svn: 306424
Not sure why this restriction existed, but it seems like we should support any size Constant here.
The particular pattern in the tests is not the only use of this matcher in the tree. There's one in CodeGenPrepare and one in InstSimplify as well.
Differential Revision: https://reviews.llvm.org/D34666
llvm-svn: 306417
•static latency
•number of uOps from which the instructions consists
•all ports used by the instruction
Reviewers:
RKSimon
zvi
aymanmus
m_zuckerman
Differential Revision: https://reviews.llvm.org/D33897
llvm-svn: 306414
Summary:
1. Instruction V_CVT_U32_F32 allow omod operand (see SIInstrInfo.td:1435). In fact this operand shouldn't be allowed here. This fix checks if SDWA pseudo instruction has OMod operand and then copy it.
2. There were several problems with support of VOPC instructions in SDWA peephole pass.
Reviewers: tstellar, arsenm, vpykhtin, airlied, kzhuravl
Subscribers: wdng, nhaehnle, yaxunl, dstuttard, tpr, sarnex, t-tye
Differential Revision: https://reviews.llvm.org/D34626
llvm-svn: 306413
This patch modifies the conditional compares pass so that it keeps successor
probabilities up-to-date after the conversion. Previously, successor
probabilities were being normalized to a uniform distribution, even though they
may have been heavily biased prior to the conversion (e.g., if one of the edges
was the back edge of a loop). This loss of information affected passes later in
the pipeline.
Differential Revision: https://reviews.llvm.org/D34109
llvm-svn: 306412
Instead of getBackEdgeTakenCount, use getExitCount on the latch exiting block
(which is proven to be the only exiting block in the loop to be unrolled).
llvm-svn: 306410
Add the instruction aliases for ds(r|l)l for the two operand alias
of ds(r|l)lv and the aliases ds(r|l)l with the three register operands.
llvm-svn: 306405
When SelectionDAG merges consecutive stores and loads in MergeConsecutiveStores, it does not set dereferenceable flag for a created load instruction. This results in an assertion failure if SelectionDAG commonizes this load instruction with other load instructions, as well as it may miss optimization opportunities.
This patch sat dereferenceable flag for the newly created load instruction if all the load instructions to be merged are dereferenceable.
Differential Revision: https://reviews.llvm.org/D34679
llvm-svn: 306404
[X86][AVX512] Improve lowering of AVX512 compare intrinsics (remove redundant shift left+right instructions).
AVX512 compare instructions return v*i1 types.
In cases where the number of elements in the returned value are less than 8, clang adds zeroes to get a mask of v8i1 type.
Later on it's replaced with CONCAT_VECTORS, which then is lowered to many DAG nodes including insert/extract element and shift right/left nodes.
The fact that AVX512 compare instructions put the result in a k register and zeroes all its upper bits allows us to remove the extra nodes simply by copying the result to the required register class.
When lowering, identify these cases and transform them into an INSERT_SUBVECTOR node (marked legal), then catch this pattern in instructions selection phase and transform it into one avx512 cmp instruction.
Differential Revision: https://reviews.llvm.org/D33188
llvm-svn: 306402
Summary:
After this patch, we finally have test cases that require multiple
instruction emission.
Depends on D33590
Reviewers: ab, qcolombet, t.p.northover, rovka, kristof.beyls
Subscribers: javed.absar, llvm-commits, igorb
Differential Revision: https://reviews.llvm.org/D33596
llvm-svn: 306388
Borrow from the logic for 'jal' in MipsAsmParser::processInstruction
and add the extra condition of bypassing CALL16 if the destination symbol
is an ELF symbol with STB_LOCAL binding.
Patch by: John Baldwin
Reviewers: sdardis
Differential Revision: https://reviews.llvm.org/D33999
llvm-svn: 306387
* Mark as legal for (s32, i1, s32, s32)
* Map everything into GPRs
* Select to two instructions: a CMP of the condition against 0, to set
the flags, and a MOVCCr to select between the two inputs based on the
flags that we've just set
llvm-svn: 306382
Undoing revert 306338 after fixed bug: add metadata to the load instead of the
reverse shuffle added to it, retaining the original ValueMap implementation.
llvm-svn: 306381
This is based heavily on the work done ni D34285. I mostly wanted to do
test cleanup for the author to save them some time, but I had a really
hard time understanding why it was so hard to write better test cases
for these issues.
The problem is that because SROA does a second rewrite of the loads and
because we *don't* propagate !nonnull for non-pointer loads, we first
introduced invalid !nonnull metadata and then stripped it back off just
in time to avoid most ways of this PR manifesting. Moving to the more
careful utility only fixes this by changing the predicate to look at the
new load's type rather than the target type. However, that *does* fix
the bug, and the utility is much nicer including adding range metadata
to model the nonnull property after a conversion to an integer.
However, we have bigger problems because we don't actually propagate
*range* metadata, and the utility to do this extracted from instcombine
isn't really in good shape to do this currently. It *only* handles the
case of copying range metadata from an integer load to a pointer load.
It doesn't even handle the trivial cases of propagating from one integer
load to another when they are the same width! This utility will need to
be beefed up prior to using in this location to get the metadata to
fully survive.
And even then, we need to go and teach things to turn the range metadata
into an assume the way we do with nonnull so that when we *promote* an
integer we don't lose the information.
All of this will require a new test case that looks kind-of like
`preserve-nonnull.ll` does here but focuses on range metadata. It will
also likely require more testing because it needs to correctly handle
changes to the integer width, especially as SROA actively tries to
change the integer width!
Last but not least, I'm a little worried about hooking the range
metadata up here because the instcombine logic for converting from
a range metadata *to* a nonnull metadata node seems broken in the face
of non-zero address spaces where null is not mapped to the integer `0`.
So that probably needs to get fixed with test cases both in SROA and in
instcombine to cover it.
But this *does* extract the core PR fix from D34285 of preventing the
!nonnull metadata from being propagated in a broken state just long
enough to feed into promotion and crash value tracking.
On D34285 there is some discussion of zero-extend handling because it
isn't necessary. First, the new load size covers all of the non-undef
(ie, possibly initialized) bits. This may even extend past the original
alloca if loading those bits could produce valid data. The only way its
valid for us to zero-extend an integer load in SROA is if the original
code had a zero extend or those bits were undef. And we get to assume
things like undef *never* satifies nonnull, so non undef bits can
participate here. No need to special case the zero-extend handling, it
just falls out correctly.
The original credit goes to Ariel Ben-Yehuda! I'm mostly landing this to
save a few rounds of trivial edits fixing style issues and test case
formulation.
Differental Revision: D34285
llvm-svn: 306379
Summary:
With scalar stores, M0 is clobbered and therefore marked as implicitly
defined. However, it is also dead.
This fixes an assertion when the Greedy Register Allocator decides to
optimize a spill/restore pair away again (via tryHintsRecoloring).
Reviewers: arsenm
Subscribers: qcolombet, kzhuravl, wdng, yaxunl, dstuttard, tpr, t-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D33319
llvm-svn: 306375
All patterns reside in a std::vector container, where new variants are added to it using the standard library's emplace_back function.
When calling this with a new element while there is no enough allocated space, a bigger space is allocated and all the old info in the small vector is copied to the newly allocated vector, then the old vector is freed.
The problem is that before doing this "copying", we take a reference of one of the elements in the old vector, and after the "copying" we add it to the new vector.
As the old vector is freed after the copying, the reference now does not point to a valid element.
Added new function to the API of CodeGenDAGPatterns class to return the same information as a copy in order to avoid this issue.
This was revealed in rL305465 that added many patterns and forced the reallocation of the vector which caused crashes in windows bots.
Differential Revision: https://reviews.llvm.org/D34341
llvm-svn: 306371
Summary:
EraseInst didn't report that it made IR changes through MadeChange.
It is essential that changes to the IR are reported correctly,
since for example ReassociatePass::run() will indicate that all
analyses are preserved otherwise.
And the CGPassManager determines if the CallGraph is up-to-date
based on status from InstructionCombiningPass::runOnFunction().
Reviewers: craig.topper, rnk, davide
Reviewed By: rnk, davide
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34616
llvm-svn: 306368
PowerPC backend does not pass the current optimization level to SelectionDAGISel and so SelectionDAGISel works with the default optimization level regardless of the current optimization level.
This patch makes the PowerPC backend set the optimization level correctly.
Differential Revision: https://reviews.llvm.org/D34615
llvm-svn: 306367
Remove invalid shortcut in fixupKills(): A register needs to be marked
live even when we are not adding a kill flag. This is because a
partially live register must not get a kill flags, but it still needs to
be fully marked live when walking backwards.
llvm-svn: 306352
Using Optional<> here doesn't seem to be terribly valuable, but
this is not the main point of this change. The change enables
us to merge the (now) two identical copies of parentFunctionOfValue()
that Steensgaard's and Andersens' provide.
llvm-svn: 306351
