DSE would mistakenly remove store (2):
a = calloc(n+1)
for (int i = 0; i < n; i++) {
store 1, a[i+1] // (1)
store 0, a[i] // (2)
}
The fix is to do PHI transaltion while looking for clobbering
instructions between the store and the calloc.
Reviewed By: efriedma, bjope
Differential Revision: https://reviews.llvm.org/D68006
When InstCombine initially populates the worklist, it already
performs constant folding and DCE. However, as the instructions
are initially visited in program order, this DCE can pick up only
the last instruction of a dead chain, the rest would only get
picked up in the main InstCombine run.
To avoid this, we instead perform the DCE in separate pass over the
collected instructions in reverse order, which will allow us to
pick up full dead instruction chains. We already need to do this
reverse iteration anyway to populate the worklist, so this
shouldn't add extra cost.
This by itself only fixes a small part of the problem though:
The same basic issue also applies during the main InstCombine loop.
We generally always want DCE to occur as early as possible,
because it will allow one-use folds to happen. Address this by also
performing DCE while adding deferred instructions to the main worklist.
This drops the number of tests that perform more than 2 InstCombine
iterations from ~80 to ~40. There's some spurious test changes due
to operand order / icmp toggling.
Differential Revision: https://reviews.llvm.org/D75008
Use UnaryOperator::CreateFNeg instead.
Summary:
With the introduction of the native fneg instruction, the
fsub -0.0, %x idiom is obsolete. This patch makes LLVM
emit fneg instead of the idiom in all places.
Reviewed By: cameron.mcinally
Differential Revision: https://reviews.llvm.org/D75130
This tries to improve the accuracy of extract/insert element costs by accounting for subvector extraction/insertion for >128-bit vectors and the shuffling of elements to/from the 0'th index.
It also adds INSERTPS for f32 types and PINSR/PEXTR costs for integer types (at the moment we assume the same cost as MOVD/MOVQ - which isn't always true).
Differential Revision: https://reviews.llvm.org/D74976
Summary:
Currently the dependence analysis in LLVM is unable to compute accurate
dependence vectors for multi-dimensional fixed size arrays.
This is mainly because the delinearization algorithm in scalar evolution
relies on parametric terms to be present in the access functions. In the
case of fixed size arrays such parametric terms are not present, but we
can use the indexes from GEP instructions to recover the subscripts for
each dimension of the arrays. This patch adds this ability under the
existing option `-da-disable-delinearization-checks`.
Authored By: bmahjour
Reviewer: Meinersbur, sebpop, fhahn, dmgreen, grosser, etiotto, bollu
Reviewed By: Meinersbur
Subscribers: hiraditya, arphaman, Whitney, ppc-slack, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72178
-debug-only=inline-cost does not exist in optimized builds without
asserts and therefore the test fails for such configurations.
Related revision: c965fd942f
I added test cases that rely on the availability of the PPC target into
the general directory for the loop vectorizer. This causes failures on
bots that don't build the PPC target. Moving them to the PowerPC directory
to fix this.
A recent commit
(https://reviews.llvm.org/rG66c120f02560ef528a60924104ead66f330190f1) changed
the cost for calls to functions that have a vector version for some
vectorization factor. However, no check is performed for whether the
vectorization factor matches the current one being cost modeled. This leads to
attempts to widen call instructions to a vectorization factor for which such a
function does not exist, which in turn leads to an assertion failure.
This patch adds the check for vectorization factor (i.e. not just that the
called function has a vector version for some VF, but that it has a vector
version for this VF).
Differential revision: https://reviews.llvm.org/D74944
Add extra diagnostics for the inline cost analysis under
-print-instruction-deltas cl option. When enabled along with
-debug-only=inline-cost it prints the IR of inline candidate
annotated with cost and threshold change per every instruction.
Reviewed By: apilipenko, davidxl, mtrofin
Differential Revision: https://reviews.llvm.org/D71501
CVP currently does not simplify cmps with instructions in the same
block, because LVI getPredicateAt() currently does not provide
much useful information for that case (D69686 would change that,
but is stuck.) However, if the instruction is a Phi node, then
LVI can compute the result of the predicate by threading it into
the predecessor blocks, which allows it simplify some conditions
that nothing else can handle. Relevant code:
6d6a4590c5/llvm/lib/Analysis/LazyValueInfo.cpp (L1904-L1927)
Differential Revision: https://reviews.llvm.org/D72169
InstCombine removes pairs of start+end intrinsics that don't
have anything in between them. Currently this is done by starting
at the start intrinsic and scanning forwards. This patch changes
it to start at the end intrinsic and scan backwards.
The motivation here is as follows: When we process the start
intrinsic, we have not yet looked at the following instructions,
which may still get folded/removed. If they do, we will only be
able to remove the start/end pair on the next iteration. When we
process the end intrinsic, all the instructions before it have
already been visited, and we don't run into this problem.
Differential Revision: https://reviews.llvm.org/D75011
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.
Summary:
Loop unswitch hoists branches on loop-invariant conditions. However, if this
condition is poison/undef and the branch wasn't originally reachable, loop
unswitch introduces UB (since the optimized code will branch on poison/undef and
the original one didn't)).
We fix this problem by freezing the condition to ensure we don't introduce UB.
We will now transform the following:
while (...) {
if (C) { A }
else { B }
}
Into:
C' = freeze(C)
if (C') {
while (...) { A }
} else {
while (...) { B }
}
This patch fixes the root cause of the following bug reports (which use the old loop unswitch, but can be reproduced with minor changes in the code and -enable-nontrivial-unswitch):
- https://llvm.org/bugs/show_bug.cgi?id=27506
- https://llvm.org/bugs/show_bug.cgi?id=31652
Reviewers: reames, majnemer, chenli, sanjoy, hfinkel
Reviewed By: reames
Subscribers: hiraditya, jvesely, nhaehnle, filcab, regehr, trentxintong, nlopes, llvm-commits, mzolotukhin
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D29015
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
body
We started seeing cases where ARC optimizer would move retain calls into
loop bodies, causing imbalance in the number of retain and release
calls, after changes were made to delete inert ARC calls since the inert
calls that used to block code motion are gone.
Fix the bug by setting the CFG hazard flag when visiting a loop header.
rdar://problem/56908836
Summary:
Replacing uses of IV outside of the loop is likely generally useful,
but `rewriteLoopExitValues()` is cautious, and if it isn't told to always
perform the replacement, and there are hard uses of IV in loop,
it doesn't replace.
In [[ https://bugs.llvm.org/show_bug.cgi?id=44668 | PR44668 ]],
that prevents `-indvars` from replacing uses of induction variable
after the loop, which might be one of the optimization failures
preventing that code from being vectorized.
Instead, now that the cost model is fixed, i believe we should be
a little bit more optimistic, and also perform replacement
if we believe it is within our budget.
Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=44668 | PR44668 ]].
Reviewers: reames, mkazantsev, asbirlea, fhahn, skatkov
Reviewed By: mkazantsev
Subscribers: nikic, hiraditya, zzheng, javed.absar, dmgreen, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73501
Summary:
Previosly we simply always said that `SCEVMinMaxExpr` is too costly to expand.
But this isn't really true, it expands into just a comparison+swap pair.
And again much like with add/mul, there will be one less such pair
than the number of operands. And we need to count the cost of operands themselves.
This does change a number of testcases, and as far as i can tell,
all of these changes are improvements, in the sense that
we fixed up more latches to do the [in]equality comparison.
This concludes cost-modelling changes, no other SCEV expressions exist as of now.
This is a part of addressing [[ https://bugs.llvm.org/show_bug.cgi?id=44668 | PR44668 ]].
Reviewers: reames, mkazantsev, wmi, sanjoy
Reviewed By: mkazantsev
Subscribers: hiraditya, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73744
Summary:
While this resolves the regression from D73722 in `llvm/test/Transforms/IndVarSimplify/exit_value_test2.ll`,
this now regresses `llvm/test/Transforms/IndVarSimplify/elim-extend.ll` `@nestedIV` test,
we no longer can perform that expansion within default budget of `4`, but require budget of `6`.
That regression is being addressed by D73777.
The basic idea here is simple.
```
Op0, Op1, Op2 ...
| | |
\--+--/ |
| |
\---+---/
```
I.e. given N operands, we will have N-1 operations,
so we have to add cost of an add (mul) for **every** Op processed,
**except** the first one, plus we need to recurse into *every* Op.
I'm guessing there's already canonicalization that ensures we won't
have `1` operand in `scMulExpr`, and no `0` in `scAddExpr`/`scMulExpr`.
Reviewers: reames, mkazantsev, wmi, sanjoy
Reviewed By: mkazantsev
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73728
Summary:
If we don't believe this UDiv is actually a LShr in disguise, things are much worse.
First, we try to see if this UDiv actually originates from user code,
by looking for `S + 1`, and if found considering this UDiv to be free.
But otherwise, we always considered this UDiv to be high-cost.
However that is no longer the case with TTI-driven cost model:
our default budget is 4, which matches the default cost of UDiv,
so now we allow a single UDiv to not be counted as high-cost.
While that is the case, it is evident this is actually a regression
due to the fact that cost-modelling is incomplete - we did not account
for the `add`, `mul` costs yet. That is being addressed in D73728.
Cost-modelling for UDiv also seems pretty straight-forward:
subtract cost of the UDiv itself, and recurse into both the LHS and RHS.
Reviewers: reames, mkazantsev, wmi, sanjoy
Reviewed By: mkazantsev
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73722
This reverts commit 8d22100f66.
There was a functional regression reported (https://bugs.llvm.org/show_bug.cgi?id=44996). I'm not actually sure the patch is wrong, but I don't have time to investigate currently, and this line of work isn't something I'm likely to get back to quickly.
Much like with reassociateShiftAmtsOfTwoSameDirectionShifts(),
as input, we have the following pattern:
icmp eq/ne (and ((x shift Q), (y oppositeshift K))), 0
We want to rewrite that as:
icmp eq/ne (and (x shift (Q+K)), y), 0 iff (Q+K) u< bitwidth(x)
While we know that originally (Q+K) would not overflow
(because 2 * (N-1) u<= iN -1), we may have looked past extensions of
shift amounts. so it may now overflow in smaller bitwidth.
To ensure that does not happen, we need to ensure that the total maximal
shift amount is still representable in that smaller bitwidth.
If the overflow would happen, (Q+K) u< bitwidth(x) check would be bogus.
https://bugs.llvm.org/show_bug.cgi?id=44802
As input, we have the following pattern:
Sh0 (Sh1 X, Q), K
We want to rewrite that as:
Sh x, (Q+K) iff (Q+K) u< bitwidth(x)
While we know that originally (Q+K) would not overflow
(because 2 * (N-1) u<= iN -1), we may have looked past extensions of
shift amounts. so it may now overflow in smaller bitwidth.
To ensure that does not happen, we need to ensure that the total maximal
shift amount is still representable in that smaller bitwidth.
If the overflow would happen, (Q+K) u< bitwidth(x) check would be bogus.
https://bugs.llvm.org/show_bug.cgi?id=44802
Code duplication (subsequently removed by refactoring) allowed
a logic discrepancy to creep in here.
We were being conservative about creating a vector binop -- but
not a vector cmp -- in the case where a vector op has the same
estimated cost as the scalar op. We want to be more aggressive
here because that can allow other combines based on reduced
instruction count/uses.
We can reverse the transform in DAGCombiner (potentially with a
more accurate cost model) if this causes regressions.
AFAIK, this does not conflict with InstCombine. We have a
scalarize transform there, but it relies on finding a constant
operand or a matching insertelement, so that means it eliminates
an extractelement from the sequence (so we won't have 2 extracts
by the time we get here if InstCombine succeeds).
Differential Revision: https://reviews.llvm.org/D75062
D74976 will handle larger vector types, but since SLM doesn't support AVX+ then we will always be extracting from 128-bit vectors so don't need to scale the cost.
This version fixes a buildbot failure cause by picking the wrong insert
point for XORs. We cannot pick the XOR binary operator as insert point,
as it is not guaranteed that both input operands for the overflow
intrinsic are defined before it.
This reverts the revert commit
c7fc0e5da6.
Add a map from BasicBlocks to overlap intervals. For partial writes, we
can keep track of those in IOLs. We only add candidates that are valid
for eliminations.
Reviewers: dmgreen, bryant, asbirlea, Tyker
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D73757
To unblock the builders this disables a test for which the CHECK lines
need to be updated. The patch causing the failure was not reverted
because it is needed for a different problem we are investigating. Here
we just need to update the CHECK lines which will happen in the
meantime.
This fixes a small mistake from D72944: The worklist add should
happen before assigning the new operand, not after.
In case an actual replacement happens, the old operand needs to
be added for DCE. If no actual replacement happens, then old/new
are the same, so it doesn't matter.
This drops one iteration from the annotated test case.
This changes the SimplifyLibCalls utility to accept an IRBuilderBase,
which allows us to pass through the IRBuilder used by InstCombine.
This will ensure that new instructions get added to the worklist.
The annotated test-case drops from 4 to 2 InstCombine iterations thanks
to this.
To achieve this, I'm adding an IRBuilderBase::OperandBundlesGuard,
which is basically the same as the existing InsertPointGuard and
FastMathFlagsGuard, but for operand bundles. Also add a
setDefaultOperandBundles() method so these can be set outside the
constructor.
Differential Revision: https://reviews.llvm.org/D74792
Can be used like
-debug-counter=dse-memoryssa-skip=10,dse-memoryssa-counter-count=20
Reviewers: dmgreen, rnk, efriedma, bryant, asbirlea
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D72147
For tracked globals that are unknown after solving, we expect all
non-store uses to be replaced.
This is a follow-up to f8045b250d, which removed forcedconstant.
We should not mark unknown loads as overdefined, as they either load
from an unknown pointer or an undef global. Restore the original logic
for loads.
Summary:
As mentioned in D71974, it is useful for must-be-executed-context to explore CFG backwardly.
This patch is ported from parts of D64975. We use a dominator tree to find the previous context if
a dominator tree is available.
Reviewers: jdoerfert, hfinkel, baziotis, sstefan1
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74817
We can look through calls with `returned` argument attributes when we
collect subsuming positions. This allows us to get existing attributes
from more places.
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.
We usually will ask for liveness of an argument anyway so we ended up
lazily creating the attribute anyway. However, that is not always the
case and even if it is we should go the eager route here. Various tests
show how this can improve the outcome. One test exposed a problem with
type mismatches between argument and call site argument, a fix is
included. For liveness various more tests were added as well.
If a function pointer is casted into a different type the resulting
expression can be a constant. If so, it can be used multiple times which
cannot be handled by the AbstractCallSite constructor alone. Instead, we
follow the cast expression uses now explicitly during the call site
traversal.
In builds with assertions enabled (!NDEBUG), IndVarSimplify does an
additional query to ScalarEvolution which may change future SCEV queries
since it fills the internal cache differently. The result is actually
only used with the -verify-indvars command line option. We fix the issue
by only calling SE->getBackedgeTakenCount(L) if -verify-indvars is
enabled such that only -verify-indvars shows the behavior, but not debug
builds themselves. Also add a remark to the description of
-verify-indvars about this behavior.
Fixes llvm.org/PR44815
Differential Revision: https://reviews.llvm.org/D74810
Some IRBuilder methods that were originally defined on
IRBuilderBase do not respect custom IRBuilder inserters/folders,
because those were not accessible prior to D73835. Fix this by
making use of existing (and now accessible) IRBuilder methods,
which will handle inserters/folders correctly.
There are some changes in OpenMP and Instrumentation tests, where
bitcasts now get constant folded. I've also highlighted one
InstCombine test which now finishes in two rather than three
iterations, thanks to new instructions being inserted into the
worklist.
Differential Revision: https://reviews.llvm.org/D74787
Some IRBuilder methods that were originally defined on
IRBuilderBase do not respect custom IRBuilder inserters/folders,
because those were not accessible prior to D73835. Fix this by
making use of existing (and now accessible) IRBuilder methods,
which will handle inserters/folders correctly.
There are some changes in OpenMP tests, where bitcasts now get
constant folded. I've also highlighted one InstCombine test which
now finishes in two rather than three iterations, thanks to new
instructions being inserted into the worklist.
Differential Revision: https://reviews.llvm.org/D74787
Instcombine folds (a + b <u a) to (a ^ -1 <u b) and that does not match
the expected pattern in CodeGenPerpare via UAddWithOverflow.
This causes a regression over Clang 7 on both X86 and AArch64:
https://gcc.godbolt.org/z/juhXYV
This patch extends UAddWithOverflow to also catch the XOR case, if the
XOR is only used in the ICMP. This covers just a single case, but I'd
like to make sure I am not missing anything before tackling the other
cases.
Reviewers: nikic, RKSimon, lebedev.ri, spatel
Reviewed By: nikic, lebedev.ri
Differential Revision: https://reviews.llvm.org/D74228
On some targets, like SPARC, forming overflow ops is only profitable if
the math result is used: https://godbolt.org/z/DxSmdB
This patch adds a new MathUsed parameter to allow the targets
to make the decision and defaults to only allowing it
if the math result is used. That is the conservative choice.
This patch also updates AArch64ISelLowering, X86ISelLowering,
ARMISelLowering.h, SystemZISelLowering.h to allow forming overflow
ops if the math result is not used. On those targets using the
overflow intrinsic for the overflow check only generates better code.
Reviewers: nikic, RKSimon, lebedev.ri, spatel
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D74722
Summary:
Depends on https://reviews.llvm.org/D71901.
The fifth in a series of patches that ports the LLVM coroutines passes
to the new pass manager infrastructure.
The first 4 patches allow users to run coroutine passes by invoking, for
example `opt -passes=coro-early`. However, most of LLVM's tests for
coroutines use an option, `opt -enable-coroutines`, which adds all 4
coroutine passes to the appropriate legacy pass manager extension points.
This patch does the same, but using the new pass manager: when
coroutine features are enabled and the new pass manager is being used,
this adds the new-pass-manager-compliant coroutine passes to the pass
builder's pipeline.
This allows us to run all coroutine tests using the new pass manager
(besides those that use the coroutine retcon ABI used by the Swift
compiler, which is not yet supported in the new pass manager).
Reviewers: GorNishanov, lewissbaker, chandlerc, junparser, wenlei
Subscribers: wenlei, EricWF, Prazek, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71902
Summary:
Depends on https://reviews.llvm.org/D71900.
The fourth in a series of patches that ports the LLVM coroutines passes
to the new pass manager infrastructure. This patch implements
'coro-cleanup'.
No existing regression tests check the behavior of coro-cleanup on its
own, so this patch adds one. (A test named 'coro-cleanup.ll' exists, but
it relies on the entire coroutines pipeline being run. It's updated to
test the new pass manager in the 5th patch of this series.)
Reviewers: GorNishanov, lewissbaker, chandlerc, junparser, deadalnix, wenlei
Reviewed By: wenlei
Subscribers: wenlei, EricWF, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71901
Fixes https://bugs.llvm.org/show_bug.cgi?id=44922 (caused by 4698bf145d)
ThreadThroughTwoBasicBlocks assumes PredBBBranch is conditional. The following code can segfault.
AddPHINodeEntriesForMappedBlock(PredBBBranch->getSuccessor(1), PredBB, NewBB,
ValueMapping);
We can also allow unconditional PredBB, but the produced code is not
better.
Reviewed By: kazu
Differential Revision: https://reviews.llvm.org/D74747
The index of an ExtractElementInst is not guaranteed to be a
ConstantInt. It can be any integer value. Check explicitly for
ConstantInts.
The new test cases illustrate scenarios where we crash without
this patch. I've also added another test case to check the matching
of extractelement vector ops works.
Reviewers: RKSimon, ABataev, dtemirbulatov, vporpo
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D74758
When simplifying demanded bits, we currently only report the
instruction on which SimplifyDemandedBits was called as changed.
However, this is a recursive call, and the actually modified
instruction will usually be further up the chain. Additionally,
all the intermediate instructions should also be revisited,
as additional combines may be possible after the demanded bits
simplification. We fix this by explicitly adding them back to the
worklist.
Differential Revision: https://reviews.llvm.org/D72944
The select-of-cttz transform can currently duplicate cttz intrinsics
and zext/trunc ops. The cause is that it unnecessarily duplicates
the intrinsic and the zext/trunc when setting the "undef_on_zero"
flag to false. However, it's always legal to set the flag from true
to false, so we can make this replacement even if there are extra users.
Differential Revision: https://reviews.llvm.org/D74685
Fix for https://bugs.llvm.org/show_bug.cgi?id=44754. We already have
a fold that converts icmp (and (ashr X, C3), C2), C1 into
icmp (and C2'), C1', but it imposed overly strict requirements on the
transform.
Relax this by checking that both C2 and C1 don't shift out bits
(in a signed sense) when forming the new constants.
Alive proofs (https://rise4fun.com/Alive/PTz0):
Name: ashr_legal
Pre: ((C2 << C3) >> C3) == C2 && ((C1 << C3) >> C3) == C1
%a = ashr i16 %x, C3
%b = and i16 %a, C2
%c = icmp i16 %b, C1
=>
%d = and i16 %x, C2 << C3
%c = icmp i16 %d, C1 << C3
Name: ashr_shiftout_eq
Pre: ((C2 << C3) >> C3) == C2 && ((C1 << C3) >> C3) != C1
%a = ashr i16 %x, C3
%b = and i16 %a, C2
%c = icmp eq i16 %b, C1
=>
%c = false
Note that >> corresponds to ashr here. The case of an equality
comparison has some special handling in this transform, because
it will form to a true/false result if the condition on the comparison
constant it violated.
Differential Revision: https://reviews.llvm.org/D74294
This patch adds a simplification if an OR weakens the overflow condition
for umul.with.overflow by treating any non-zero result as overflow. In that
case, we overflow if both umul.with.overflow operands are != 0, as in that
case the result can only be 0, iff the multiplication overflows.
Code like this is generated by code using __builtin_mul_overflow with
negative integer constants, e.g.
bool test(unsigned long long v, unsigned long long *res) {
return __builtin_mul_overflow(v, -4775807LL, res);
}
```
----------------------------------------
Name: D74141
%res = umul_overflow {i8, i1} %a, %b
%mul = extractvalue {i8, i1} %res, 0
%overflow = extractvalue {i8, i1} %res, 1
%cmp = icmp ne %mul, 0
%ret = or i1 %overflow, %cmp
ret i1 %ret
=>
%t0 = icmp ne i8 %a, 0
%t1 = icmp ne i8 %b, 0
%ret = and i1 %t0, %t1
ret i1 %ret
%res = umul_overflow {i8, i1} %a, %b
%mul = extractvalue {i8, i1} %res, 0
%cmp = icmp ne %mul, 0
%overflow = extractvalue {i8, i1} %res, 1
Done: 1
Optimization is correct!
```
Reviewers: nikic, lebedev.ri, spatel, Bigcheese, dexonsmith, aemerson
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D74141
Summary:
Depends on https://reviews.llvm.org/D71899.
The third in a series of patches that ports the LLVM coroutines passes
to the new pass manager infrastructure. This patch implements 'coro-elide'.
The new pass manager infrastructure does not implicitly repeat CGSCC
pass pipelines when a function is devirtualized, and so the tests
for the new pass manager that rely on that behavior now explicitly
specify `repeat<2>`.
Reviewers: GorNishanov, lewissbaker, chandlerc, jdoerfert, junparser, deadalnix, wenlei
Reviewed By: wenlei
Subscribers: wenlei, EricWF, Prazek, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71900
Summary:
This patch has four dependencies:
1. The first in this series of patches that implement coroutine passes in the
new pass manager: https://reviews.llvm.org/D71898.
2. A patch that introduces an API for CGSCC passes to add new reference
edges to a `LazyCallGraph`, `updateCGAndAnalysisManagerForCGSCCPass`:
https://reviews.llvm.org/D72025.
3. A patch that introduces a `CallGraphUpdater` helper class that is
capable of mutating internal `LazyCallGraph` state in order to insert
new function nodes into a specific SCC: https://reviews.llvm.org/D70927.
4. And finally, a small edge case fix for updating `LazyCallGraph` that
patch 3 above happens to run into: https://reviews.llvm.org/D72226.
This is the second in a series of patches that ports the LLVM coroutines
passes to the new pass manager infrastructure. This patch implements
'coro-split'.
Some notes:
* Using the new CGSCC pass manager resulted in IR being printed in the
reverse order in some tests. To prevent FileCheck checks from failing due
to these reversed orders, this patch splits up test files that test
multiple different coroutine functions: specifically
coro-alloc-with-param.ll, coro-split-eh.ll, and coro-eh-aware-edge-split.ll.
* CoroSplit.cpp contained 2 overloads of `splitCoroutine`, one of which
dispatched to the other based on the coroutine ABI being used (C++20
switch-based versus Swift returned-continuation-based). I found this
confusing, especially with the additional branching based on `CallGraph`
vs. `LazyCallGraph`, so I removed the ABI-checking overload of
`splitCoroutine`.
Reviewers: GorNishanov, lewissbaker, chandlerc, jdoerfert, junparser, deadalnix, wenlei
Reviewed By: wenlei
Subscribers: wenlei, qcolombet, EricWF, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71899
Summary:
The first in a series of patches that ports the LLVM coroutines passes
to the new pass manager infrastructure. This patch implements
'coro-early'.
NB: All coroutines passes begin by checking that coroutine intrinsics are
declared within the LLVM IR module they're operating on. To do so, they call
`coro::declaresIntrinsics`. The next 3 patches in this series, which add new
pass manager implementations of the 'coro-split', 'coro-elide', and
'coro-cleanup' passes, use a similar pattern as the one used here: a static
function is shared across both old and new passes to detect if relevant
coroutine intrinsics are delcared. To make this pattern easier to read, this
patch adds `const` keywords to the parameters of `coro::declaresIntrinsics`.
Reviewers: GorNishanov, lewissbaker, junparser, chandlerc, deadalnix, wenlei
Reviewed By: wenlei
Subscribers: ychen, wenlei, EricWF, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71898
getOperationCost() is not the cost we wanted; that's not the
throughput value that the rest of the calculation uses.
We may want to switch everything in this code to use the
getInstructionThroughput() wrapper to avoid these kinds of
problems, but I'll look at that as a follow-up because that
can create other logical diffs via using optional parameters
(we'd need to speculatively create the vector instruction to
make a fair(er) comparison).
This includes a fix for cases where things get marked as overdefined in
ResolvedUndefsIn, but we later discover a constant. To avoid crashing,
we consistently bail out on overdefined values in the visitors. This is
similar to the previous behavior with forcedconstant.
This reverts the revert commit 02b72f564c.
In addition to a single bit per memory locations, e.g., globals and
arguments, we now collect more information about the actual accesses,
e.g., what instruction caused it, was it a read/write/read+write, and
what the underlying base pointer was. Follow up patches will make
explicit use of this.
Reviewed By: uenoku
Differential Revision: https://reviews.llvm.org/D73527
While the function return updateImpl did only look at call sites the
manifest method looked at return values. If we don't do this during the
updateImpl we might create new abstract attributes during manifest. This
is a problem when it comes to liveness information.
In addition to memory behavior attributes (readonly/writeonly) we now
derive memory location attributes (argmemonly/inaccessiblememonly/...).
The former is part of AAMemoryBehavior and the latter part of
AAMemoryLocation. While they are similar in nature it got messy when
they were put in a single AA. Location attributes for arguments and
floating values will follow later.
Note that both memory attributes kinds can derive readnone. If there are
no accesses AAMemoryBehavior will derive readnone. If there are accesses
but only to stack (=local) locations AAMemoryLocation will derive
readnone.
Reviewed By: uenoku
Differential Revision: https://reviews.llvm.org/D73426
Due to the genericValueTraversal we might visit values for which we did
not create an AAValueConstantRange object, e.g., as they are behind a
PHI or select or call with `returned` argument. As a consequence we need
to validate the types as we are about to query AAValueConstantRange for
operands.
replaceDbgDeclare is used to update the descriptions of stack variables
when they are moved (e.g. by ASan or SafeStack). A side effect of
replaceDbgDeclare is that it moves dbg.declares around in the
instruction stream (typically by hoisting them into the entry block).
This behavior was introduced in llvm/r227544 to fix an assertion failure
(llvm.org/PR22386), but no longer appears to be necessary.
Hoisting a dbg.declare generally does not create problems. Usually,
dbg.declare either describes an argument or an alloca in the entry
block, and backends have special handling to emit locations for these.
In optimized builds, LowerDbgDeclare places dbg.values in the right
spots regardless of where the dbg.declare is. And no one uses
replaceDbgDeclare to handle things like VLAs.
However, there doesn't seem to be a positive case for moving
dbg.declares around anymore, and this reordering can get in the way of
understanding other bugs. I propose getting rid of it.
Testing: stage2 RelWithDebInfo sanitized build, check-llvm
rdar://59397340
Differential Revision: https://reviews.llvm.org/D74517
binop (extelt X, C), (extelt Y, C) --> extelt (binop X, Y), C
This is a transform that has been considered for canonicalization (instcombine)
in the past because it reduces instruction count. But as shown in the x86 tests,
it's impossible to know if it's profitable without a cost model. There are many
potential target constraints to consider.
We have implemented similar transforms in the backend (DAGCombiner and
target-specific), but I don't think we have this exact fold there either (and if
we did it in SDAG, it wouldn't work across blocks).
Note: this patch was intended to handle the more general case where the extract
indexes do not match, but it got too big, so I scaled it back to this pattern
for now.
Differential Revision: https://reviews.llvm.org/D74495
This reverts commit 80a34ae311 with fixes.
Previously, since bots turning on EXPENSIVE_CHECKS are essentially turning on
MachineVerifierPass by default on X86 and the fact that
inline-asm-avx-v-constraint-32bit.ll and inline-asm-avx512vl-v-constraint-32bit.ll
are not expected to generate functioning machine code, this would go
down to `report_fatal_error` in MachineVerifierPass. Here passing
`-verify-machineinstrs=0` to make the intent explicit.
This reverts commit 80a34ae311 with fixes.
On bots llvm-clang-x86_64-expensive-checks-ubuntu and
llvm-clang-x86_64-expensive-checks-debian only,
llc returns 0 for these two tests unexpectedly. I tweaked the RUN line a little
bit in the hope that LIT is the culprit since this change is not in the
codepath these tests are testing.
llvm\test\CodeGen\X86\inline-asm-avx-v-constraint-32bit.ll
llvm\test\CodeGen\X86\inline-asm-avx512vl-v-constraint-32bit.ll
We want the extra-use tests to be consistent with the
earlier single-use tests and be as cheap as possible
in vector form to show cost model edge cases. So use
i8 and extract from element 0 since that should be
cheap for all x86 targets.
This reverts commit 61b35e4111.
This commit causes a timeout in chromium builds; likely to have a
similar cause to the previous timeout issue caused by this commit (see
6ded69f294 for more details). It is possible that there is no way to
fix this bug that will not cause this issue; further investigations as
to the efficiency of handling large amounts of debug info will be
necessary.
We used coarse-grained liveness before, thus we looked if the
instruction was executed, but we did not use fine-grained liveness,
hence if the instruction was needed or could be deleted even if the
surrounding ones are live. This patches introduces this level of
liveness checks together with other liveness queries, e.g., for uses.
For more control we enforce that all liveness queries go through the
Attributor.
Test have been adjusted to reflect the changes or augmented to prevent
deletion of the parts we want to check.
Reviewed By: sstefan1
Differential Revision: https://reviews.llvm.org/D73313
If we have a replacement for a value, via AAValueSimplify, the original
value will lose all its uses. Thus, as long as a value is simplified we
can skip the uses in checkForAllUses, given that these uses are
transitive uses for the simplified version and will therefore affect the
simplified version as necessary.
Since this allowed us to remove calls without side-effects and a known
return value, we need to make sure not to eliminate `musttail` calls.
Those we keep around, or later remove the entire `musttail` call chain.
We relied on wouldInstructionBeTriviallyDead before but that functions
does not take assumed information, especially for calls, into account.
The replacement, AAIsDead::isAssumeSideEffectFree, does.
This change makes AAIsDeadCallSiteReturn more complex as we can have
a dead call or only dead users.
The test have been modified to include a side effect where there was
none in order to keep the coverage.
Reviewed By: sstefan1
Differential Revision: https://reviews.llvm.org/D73311
This version includes a fix for a set of crashes caused by marking
values depending on a yet unknown & tracked call as overdefined.
In some cases, we would later discover that the call has a constant
result and try to mark a user of it as constant, although it was already
marked as overdefined. Most instruction handlers bail out early if the
instruction is already overdefined. But that is not necessary for
CastInsts for example. By skipping values that depend on skipped
calls, we resolve the crashes and also improve the precision in some
cases (see resolvedundefsin-tracked-fn.ll).
Note that we may not skip PHI nodes that may depend on a skipped call,
but they can be safely marked as overdefined, as we bail out early if
the PHI node is overdefined.
This reverts the revert commit
a74b31a3e9cd844c7ce2087978568e3f5ec8519.
This reverts commit 636c93ed11.
The original patch caused build failures on TSan buildbots. Commit 6ded69f294
fixes this issue by reducing the rate at which empty debug intrinsics
propagate, reducing the memory footprint and preventing a fatal spike.
This patch is a fix following the revert of 72ce759
(https://reviews.llvm.org/rG72ce759928e6dfee6a9efa310b966c19722352ba)
and fixes the failure that it caused.
The above patch failed on the Thread Sanitizer buildbot with an out of
memory error. After an investigation, the cause was identified as an
explosion in debug intrinsics while running the Jump Threading pass on
ModuleMap.ll. The above patched prevented debug intrinsics from being
dropped when their Basic Block was deleted due to being "empty". In this
case, one of the functions in ModuleMap.ll had (after many optimization
passes) a very large number of debug intrinsics representing a set of
repeatedly inlined variables. Previously the vast majority of these were
silently dropped during Jump Threading when their blocks were deleted,
but as of the above patch they survived for longer, causing a large
increase in the number of debug intrinsics. These intrinsics were then
repeatedly cloned by the Jump Threading pass as edges were threaded,
multiplying the intrinsic count further. The memory consumed by this
process spiralled out of control, crashing the buildbot that uses TSan
(which has an estimated 5-10x memory overhead compared to non-sanitized
builds).
This patch adds RemoveRedundantDbgInstrs to the Jump Threading pass, in
order to reduce the number of debug intrinsics down to a manageable
amount in cases where many intrinsics for the same variable end up
bunched together contiguously, as in this case.
Differential Revision: https://reviews.llvm.org/D73054
This causes a crash for the reproducer below
enum { a };
enum b { c, d };
e;
static _Bool g(struct f *h, enum b i) {
i &&j();
return a;
}
static k(char h, enum b i) {
_Bool l = g(e, i);
l;
}
m(h) {
k(h, c);
g(h, d);
}
This reverts commit aadb635e04.
Summary:
Right now the alignment of the lower half of a store is computed as
align/2, which fails for unaligned stores (align = 1), and is overly
pessimitic for, e.g. a 8 byte store aligned to 4 bytes.
Fixes PR44851
Fixes PR44877
Reviewers: gchatelet, spatel, lebedev.ri
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74311
Summary:
Currently, `SCEVExpander::isHighCostExpansionHelper()` has the following logic:
```
if (auto *UDivExpr = dyn_cast<SCEVUDivExpr>(S)) {
// If the divisor is a power of two and the SCEV type fits in a native
// integer (and the LHS not expensive), consider the division cheap
// irrespective of whether it occurs in the user code since it can be
// lowered into a right shift.
if (auto *SC = dyn_cast<SCEVConstant>(UDivExpr->getRHS()))
if (SC->getAPInt().isPowerOf2()) {
if (isHighCostExpansionHelper(UDivExpr->getLHS(), L, At,
BudgetRemaining, TTI, Processed))
return true;
const DataLayout &DL =
L->getHeader()->getParent()->getParent()->getDataLayout();
unsigned Width = cast<IntegerType>(UDivExpr->getType())->getBitWidth();
return DL.isIllegalInteger(Width);
}
```
Since this test does not have a datalayout specified,
`SCEVExpander::isHighCostExpansionHelper()` says that
`[[TMP2:%.*]] = lshr exact i64 [[TMP1]], 5` is high-cost, and didn't perform it.
But future patches will change that logic to solely rely on cost-model,
without any such datalayout checks, so i think it is best to show
that that change is ephemeral, and can already happen without costmodel changes.
Reviewers: reames, fhahn, sanjoy, craig.topper, RKSimon
Reviewed By: RKSimon
Subscribers: javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73717
This reverts commit rGcd5b308b828e, rGcd5b308b828e, rG8cedf0e2994c.
There are issues to be investigated for polly bots and bots turning on
EXPENSIVE_CHECKS.
This is apparently worse than 1-byte alignment. This does not attempt
to decompose 2-byte aligned wide stores, but will stop trying to
produce them.
Also fix bug in LoadStoreVectorizer which was decreasing the alignment
and vectorizing stack accesses. It was assuming a stack object was an
alloca that could have its base alignment changed, which is not true
if the pointer is derived from a function argument.
Update test scripts were limited because they performed a single action
on the entire file and if that action was controlled by arguments, like
the one introduced in D68819, there was no record of it.
This patch introduces the capability of changing the arguments passed to
the script "on-the-fly" while processing a test file. In addition, an
"on/off" switch was added so that processing can be disabled for parts
of the file where the content is simply copied. The last extension is a
record of the invocation arguments in the auto generated NOTE. These
arguments are also picked up in a subsequent invocation, allowing
updates with special options enabled without user interaction.
To change the arguments the string `UTC_ARGS:` has to be present in a
line, followed by "additional command line arguments". That is
everything that follows `UTC_ARGS:` will be added to a growing list
of "command line arguments" which is reparsed after every update.
Reviewed By: arichardson
Differential Revision: https://reviews.llvm.org/D69701
This restores commit 748bb5a0f1, along
with a fix for a Chromium test suite build issue (and a new test for
that case).
Differential Revision: https://reviews.llvm.org/D73242
The changeXXXAfterManifest functions are better suited to deal with
changes so we should prefer them. These functions also recursively
delete dead instructions which is why we see test changes.
This patch removes forcedconstant to simplify things for the
move to ValueLattice, which includes constant ranges, but no
forced constants.
This patch removes forcedconstant and changes ResolvedUndefsIn
to mark instructions with unknown operands as overdefined. This
means we do not do simplifications based on undef directly in SCCP
any longer, but this seems to hardly come up in practice (see stats
below), presumably because InstCombine & others take care
of most of the relevant folds already.
It is still beneficial to keep ResolvedUndefIn, as it allows us delaying
going to overdefined until we propagated all known information.
I also built MultiSource, SPEC2000 and SPEC2006 and compared
sccp.IPNumInstRemoved and sccp.NumInstRemoved. It looks like the impact
is quite low:
Tests: 244
Same hash: 238 (filtered out)
Remaining: 6
Metric: sccp.IPNumInstRemoved
Program base patch diff
test-suite...arks/VersaBench/dbms/dbms.test 4.00 3.00 -25.0%
test-suite...TimberWolfMC/timberwolfmc.test 38.00 34.00 -10.5%
test-suite...006/453.povray/453.povray.test 158.00 155.00 -1.9%
test-suite.../CINT2000/176.gcc/176.gcc.test 668.00 668.00 0.0%
test-suite.../CINT2006/403.gcc/403.gcc.test 1209.00 1209.00 0.0%
test-suite...arks/mafft/pairlocalalign.test 76.00 76.00 0.0%
Tests: 244
Same hash: 238 (filtered out)
Remaining: 6
Metric: sccp.NumInstRemoved
Program base patch diff
test-suite...arks/mafft/pairlocalalign.test 185.00 175.00 -5.4%
test-suite.../CINT2006/403.gcc/403.gcc.test 2059.00 2056.00 -0.1%
test-suite.../CINT2000/176.gcc/176.gcc.test 2358.00 2357.00 -0.0%
test-suite...006/453.povray/453.povray.test 317.00 317.00 0.0%
test-suite...TimberWolfMC/timberwolfmc.test 12.00 12.00 0.0%
Reviewers: davide, efriedma, mssimpso
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D61314
This reverts commit d0c4d4fe09.
Revert "[DSE,MSSA] Move more passing test cases from todo to simple.ll."
This reverts commit 02266e64bb.
Revert "[DSE,MSSA] Adjust mda-with-dbg-values.ll to MSSA backed DSE."
This reverts commit 74f03e4ff0.
As discussed in PR41083:
https://bugs.llvm.org/show_bug.cgi?id=41083
...we can assert/crash in EarlyCSE using the current hashing scheme and
instructions with flags.
ValueTracking's matchSelectPattern() may rely on overflow (nsw, etc) or
other flags when detecting patterns such as min/max/abs composed of
compare+select. But the value numbering / hashing mechanism used by
EarlyCSE intersects those flags to allow more CSE.
Several alternatives to solve this are discussed in the bug report.
This patch avoids the issue by doing simple matching of min/max/abs
patterns that never requires instruction flags. We give up some CSE
power because of that, but that is not expected to result in much
actual performance difference because InstCombine will canonicalize
these patterns when possible. It even has this comment for abs/nabs:
/// Canonicalize all these variants to 1 pattern.
/// This makes CSE more likely.
(And this patch adds PhaseOrdering tests to verify that the expected
transforms are still happening in the standard optimization pipelines.
I left this code to use ValueTracking's "flavor" enum values, so we
don't have to change the callers' code. If we decide to go back to
using the ValueTracking call (by changing the hashing algorithm
instead), it should be obvious how to replace this chunk.
Differential Revision: https://reviews.llvm.org/D74285
Test that instcombine and early-cse can cooperate
to reduce sequences of select patterns that are not
composed of the same underlying instructions.
There's a bug in EarlyCSE (PR41083), and we can test
how much a possible fix (D74285) may affect optimization.
We were checking for extra uses of the negated operand even
if we were not going to create it as part of this canonicalization.
This was showing up as a regression when we limit EarlyCSE as
proposed in D74285.
This reverts commit b54a8ec1bc.
The commit triggered debug invariance (different output with/without
-g). The patch seems to have exposed a pre-existing invariance problem
in GlobalOpt, which I'll write a bug report for.
This patch adds a first version of a MemorySSA based DSE. It is missing
a lot of features, which will get added as follow-ups, to help to keep
the review manageable.
The patch uses the following general approach: given a MemoryDef, walk
upwards to find clobbering MemoryDefs that may be killed by the
starting def. Then check that there are no uses that may read the
location of the original MemoryDef in between both MemoryDefs. A bit
more concretely:
For all MemoryDefs StartDef:
1. Get the next dominating clobbering MemoryDef (DomAccess) by walking upwards.
2. Check that there no reads between DomAccess and the StartDef by checking
all uses starting at DomAccess and walking until we see StartDef.
3. For each found DomDef, check that:
1. There are no barrier instructions between DomDef and StartDef (like
throws or stores with ordering constraints).
2. StartDef is executed whenever DomDef is executed.
3. StartDef completely overwrites DomDef.
4. Erase DomDef from the function and MemorySSA.
The patch uses a very simple approach to guarantee that no throwing
instructions are between 2 stores: We only allow accesses to stack
objects, access that are in the same basic block if the block does not
contain any throwing instructions or accesses in functions that do
not contain any throwing instructions. This will get lifted later.
Besides adding support for the missing cases, there is plenty of additional
potential for improvements as follow-up work, e.g. the way we visit stores
(could be just a traversal of the MemorySSA, rather than collecting them
up-front), using the alias information discovered during walking to optimize
the MemorySSA.
This is loosely based on D40480 by Dave Green.
Reviewers: dmgreen, rnk, efriedma, bryant, asbirlea, Tyker
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D72700
This copies the DSE tests into a MSSA subdirectory to test the MemorySSA
backed DSE implementation, without disturbing the original tests.
Differential Revision: https://reviews.llvm.org/D72145
This is a minimal but important advancement over the existing code. A
cast with an operand that is only used in the cast retains the no-alias
property of the operand.
Traversing PHI nodes is natural with the genericValueTraversal but also
a bit tricky. The problem is similar to the ones we have seen in AAAlign
and AADereferenceable, namely that we continue to increase the range in
each iteration. We use a pessimistic approach here to stop the
iterations. Nevertheless, optimistic information can now be propagated
through a PHI node.
The change is performed as stated by the FIXME and the tests are
adjusted. All changes look fine to me and values can be inferred as
undef without it being an error.
Casts can be handled natively by the ConstantRange class. We do limit it
to extends for now as we assume an integer type in different locations.
A TODO and a test case with a FIXME was added to remove that restriction
in the future.
We have several bug reports that could be characterized as "reducing scalarization",
and this topic was also raised on llvm-dev recently:
http://lists.llvm.org/pipermail/llvm-dev/2020-January/138157.html
...so I'm proposing that we deal with these patterns in a new, lightweight IR vector
pass that runs before/after other vectorization passes.
There are 4 alternate options that I can think of to deal with this kind of problem
(and we've seen various attempts at all of these), but they all have flaws:
InstCombine - can't happen without TTI, but we don't want target-specific
folds there.
SDAG - too late to assist other vectorization passes; TLI is not equipped
for these kind of cost queries; limited to a single basic block.
CGP - too late to assist other vectorization passes; would need to re-implement
basic cleanups like CSE/instcombine.
SLP - doesn't fit with existing transforms; limited to a single basic block.
This initial patch/transform is based on existing code in AggressiveInstCombine:
we walk backwards through the function looking for a pattern match. But we diverge
from that cost-independent IR canonicalization pass by using TTI to decide if the
vector alternative is profitable.
We probably have at least 10 similar bug reports/patterns (binops, constants,
inserts, cheap shuffles, etc) that would fit in this pass as follow-up enhancements.
It's possible that we could iterate on a worklist to fix-point like InstCombine does,
but it's safer to start with a most basic case and evolve from there, so I didn't
try to do anything fancy with this initial implementation.
Differential Revision: https://reviews.llvm.org/D73480
The LoopExtractor created new functions (by definition), which violates
the restrictions of a LoopPass.
The correct implementation of this pass should be as a ModulePass.
Includes reverting rL82990 implications on the LoopExtractor.
Fixes PR3082 and PR8929.
Differential Revision: https://reviews.llvm.org/D69069
In addition to the module pass, this patch introduces a CGSCC pass that
runs the Attributor on a strongly connected component of the call graph
(both old and new PM). The Attributor was always design to be used on a
subset of functions which makes this patch mostly mechanical.
The one change is that we give up `norecurse` deduction in the module
pass in favor of doing it during the CGSCC pass. This makes the
interfaces simpler but can be revisited if needed.
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D70767
Parallel regions known to be read-only, e.g., after we removed all dead
write accesses, and terminating (`willreturn`) can be removed.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D69954
The OpenMPOpt pass is a CGSCC pass in which OpenMP specific
optimizations can reside.
The OpenMPOpt pass uses the OpenMPKinds.def file to identify runtime
calls and their uses. This allows targeted transformations and eases
their implementation.
This initial patch deduplicates `__kmpc_global_thread_num` and
`omp_get_thread_num` calls. We can also identify arguments that are
equivalent to such a call result and use it instead. Later we can
determine "gtid" arguments based on the use in kernel functions etc.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D69930
Bionic has had `__strlen_chk` for a while. Optimizing that into a
constant is quite profitable, when possible.
Differential Revision: https://reviews.llvm.org/D74079
While D72944 also fixes https://bugs.llvm.org/show_bug.cgi?id=44541,
it does so in a more roundabout manner and there might be other
loopholes to trigger the same issue. This is a more direct fix,
that prevents the transform if the min/max is based on a
non-canonical sub X, 0 instruction.
Differential Revision: https://reviews.llvm.org/D73849
As discussed on D73919, this replaces a few cases where we were
modifying multiple operands of instructions in-place with the
creation of a new instruction, which we generally prefer nowadays.
This tends to be more readable and less prone to worklist management
bugs.
Test changes are only superficial (instruction naming and order).
Fixes https://bugs.llvm.org/show_bug.cgi?id=44835. Skip the transform
if it wouldn't actually do anything (apart from removing and reinserting
the same instructions).
Note that the test case doesn't loop on current master anymore, only
on the LLVM 10 release branch. The issue is already mitigated on master
due to worklist order fixes, but we should fix the root cause there as well.
As a side note, we should probably assert in combineLoadToNewType()
that it does not combine to the same type. Not doing this here, because
this assertion would also be triggered in another place right now.
Differential Revision: https://reviews.llvm.org/D74278
This improves on the following patch, which removed ARC runtime calls
taking inert global variables:
https://reviews.llvm.org/D62433
rdar://problem/59137105
If we know that a >= b (unsigned), usub.with.overflow(a, b) cannot
overflow. Similarly, if b > a, the same expression overflows.
Reviewers: nikic, RKSimon, lebedev.ri, spatel
Reviewed By: nikic, Gerolf
Differential Revision: https://reviews.llvm.org/D74066
IRCE pass checks that it can calculate loop bounds by checking
SCEV availability at loop entry. However it is possible that loop
bound SCEV is loop invariant, but instruction used to compute it
resides within loop. In such case adjusting loop bound in preheader
using IRBuilder leads to malformed SSA.
Use SCEVExpander instead to generate proper instructions.
Reviewed-by: mkazantsev
Differential Revision: https://reviews.llvm.org/D73496
Summary: This patch fixes https://bugs.llvm.org/show_bug.cgi?id=44388 which incorrectly assigns an ABI alignment to memset when there was no explicit alignment given.
Reviewers: gchatelet, lenary, nikic
Reviewed By: nikic
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74083
This reverts commit 41784bed01.
Since the original revision ead815924e,
this revision fixes three issues:
- This revision fixes the Windows build. My original patch improperly
copied EH pads on Windows. This patch disregards jump threading
opportunities having to do with EH pads.
- This revision fixes jump threading to a wrong destination.
Specifically, my original patch treated any Constant other than 0 as 1
while evaluating the branch condition. This bug led to treating
constant expressions like:
icmp ugt i8* null, inttoptr (i64 4 to i8*)
to "true". This patch fixes the bug by calling isOneValue.
- This revision fixes the cost calculation of two basic blocks being
threaded through. Note that getJumpThreadDuplicationCost returns
"(unsigned)~0" for those basic blocks that cannot be duplicated. If
we sum of two return values from getJumpThreadDuplicationCost, we
could have an unsigned overflow like:
(unsigned)~0 + 5 = 4
and mistakenly determine that it's safe and profitable to proceed
with the jump threading opportunity. The patch fixes the bug by
checking each return value before summing them up.
[JumpThreading] Thread jumps through two basic blocks
Summary:
This patch teaches JumpThreading.cpp to thread through two basic
blocks like:
bb3:
%var = phi i32* [ null, %bb1 ], [ @a, %bb2 ]
%tobool = icmp eq i32 %cond, 0
br i1 %tobool, label %bb4, label ...
bb4:
%cmp = icmp eq i32* %var, null
br i1 %cmp, label bb5, label bb6
by duplicating basic blocks like bb3 above. Once we duplicate bb3 as
bb3.dup and redirect edge bb2->bb3 to bb2->bb3.dup, we have:
bb3:
%var = phi i32* [ @a, %bb2 ]
%tobool = icmp eq i32 %cond, 0
br i1 %tobool, label %bb4, label ...
bb3.dup:
%var = phi i32* [ null, %bb1 ]
%tobool = icmp eq i32 %cond, 0
br i1 %tobool, label %bb4, label ...
bb4:
%cmp = icmp eq i32* %var, null
br i1 %cmp, label bb5, label bb6
Then the existing code in JumpThreading.cpp can thread edge
bb3.dup->bb4 through bb4 and eventually create bb3.dup->bb5.
Reviewers: wmi
Subscribers: hiraditya, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70247
Summary:
Currently type test assume sequences inserted for devirtualization are
removed during WPD. This patch delays their removal until later in the
optimization pipeline. This is an enabler for upcoming enhancements to
indirect call promotion, for example streamlined promotion guard
sequences that compare against vtable address instead of the target
function, when there are small number of possible vtables (either
determined via WPD or by in-progress type profiling). We need the type
tests to correlate the callsites with the address point offset needed in
the compare sequence, and optionally to associated type summary info
computed during WPD.
This depends on work in D71913 to enable invocation of LowerTypeTests to
drop type test assume sequences, which will now be invoked following ICP
in the ThinLTO post-LTO link pipelines, and also after the existing
export phase LowerTypeTests invocation in regular LTO (which is already
after ICP). We cannot simply move the existing import phase
LowerTypeTests pass later in the ThinLTO post link pipelines, as the
comment in PassBuilder.cpp notes (it must run early because when
performing CFI other passes may disturb the sequences it looks for).
This necessitated adding a new type test resolution "Unknown" that we
can use on the type test assume sequences previously removed by WPD,
that we now want LTT to ignore.
Depends on D71913.
Reviewers: pcc, evgeny777
Subscribers: mehdi_amini, Prazek, hiraditya, steven_wu, dexonsmith, arphaman, davidxl, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D73242
Summary:
It can be useful to tune the default inline threshold without overriding other inlining thresholds (e.g. in code compiled for size).
The existing `-inline-threshold` flag overrides other thresholds, so it is insufficient in codebases where there is a mix of code compiled for size and speed.
Patch by Michael Holman <michael.holman@microsoft.com>
Reviewers: eraman, tejohnson
Reviewed By: tejohnson
Subscribers: tejohnson, mtrofin, davidxl, hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73217
This is a bug noted in the recent D72733 and seen
in the similar transform just above the changed source code.
I added tests with illegal types and zexts to show the bug -
we could transform legal phi ops to illegal, etc. I did not add
tests with trunc because we won't see any diffs on those patterns.
That is because InstCombiner::SliceUpIllegalIntegerPHI() appears to
do those transforms independently of datalayout. It can also create
more casts than are present in existing code.
There are some existing regression tests that do not include a
datalayout that would be altered by this fix. I assumed that the
lack of a datalayout in those regression files is an oversight, so
I added the minimal layout (make i32 legal) necessary to preserve
behavior on those tests.
Differential Revision: https://reviews.llvm.org/D73907
Adds the global (cl::opt) GVNOption enable-load-in-loop-pre in order
to control whether the optimization will be performed if the load
is part of a loop.
Patch by Hendrik Greving!
Differential Revision: https://reviews.llvm.org/D73804
bo (splat X), (bo Y, OtherOp) --> bo (splat (bo X, Y)), OtherOp
This patch depends on the splat analysis enhancement in D73549.
See the test with comment:
; Negative test - mismatched splat elements
...as the motivation for that first patch.
The motivating case for reassociating splatted ops is shown in PR42174:
https://bugs.llvm.org/show_bug.cgi?id=42174
In that example, a slight change in order-of-associative math results
in a big difference in IR and codegen. This patch gets all of the
unnecessary shuffles out of the way, but doesn't address the potential
scalarization (see D50992 or D73480 for that).
Differential Revision: https://reviews.llvm.org/D73703
Duplicating instructions can lead to code size increases but using
a threshold of 3 is good for reducing code size.
Differential Revision: https://reviews.llvm.org/D72916
There seems to be another instance of non-determinism which causes the
number of iterations to be either 1 or 3 for one benchmark, depending
on the system. This needs to be investigated and resolved. In the
meantime we do not verify the number of iterations for this benchmark.
If all call sites are in `norecurse` functions we can derive `norecurse`
as the ReversePostOrderFunctionAttrsPass does. This should make
ReversePostOrderFunctionAttrsLegacyPass obsolete once the Attributor is
enabled.
Reviewed By: uenoku
Differential Revision: https://reviews.llvm.org/D72017
If we had `noalias` on an argument the inliner created alias scope
metadata already. However, the call site `noalias` annotation was not
considered. Since the Attributor can derive such call site `noalias`
annotation we should treat them the same as argument annotations.
Reviewed By: hfinkel
Differential Revision: https://reviews.llvm.org/D73528
Fix attempt
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
The code paths in the absence of TargetMachine, TargetLowering or
TargetRegisterInfo are poorly tested. As rL285987 said, requiring
TargetPassConfig allows us to delete many (untested) checks littered
everywhere.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D73754
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
Summary:
this is part of the implementation of http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html
this patch gives the basis of building an assume to preserve all information from an instruction and add support for building an assume that preserve the information from a call.
Reviewers: jdoerfert
Reviewed By: jdoerfert
Subscribers: mgrang, fhahn, mgorny, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72475
This patch adds initial support for a DemandedElts mask to the internal computeKnownBits/ComputeNumSignBits methods, matching the SelectionDAG and GlobalISel equivalents.
So far only a couple of instructions have been setup to handle the DemandedElts, the remainder still using the existing 'all elements' default. The plan is to extend support as we have test coverage.
Differential Revision: https://reviews.llvm.org/D73435
We may calculate reassociable math ops in arbitrary order when creating a shuffle reduction,
so there's no guarantee that things like 'nsw' hold on those intermediate values. Drop all
poison-generating flags for safety.
This change is limited to shuffle reductions because I don't think we have a problem in the
general case (where we intersect flags of each scalar op that goes into a vector op), but if
there's evidence of other cases being wrong, we can extend this fix to cover those cases.
https://bugs.llvm.org/show_bug.cgi?id=44536
Differential Revision: https://reviews.llvm.org/D73727
First attempt at implementing -fsemantic-interposition.
Rely on GlobalValue::isInterposable that already captures most of the expected
behavior.
Rely on a ModuleFlag to state whether we should respect SemanticInterposition or
not. The default remains no.
So this should be a no-op if -fsemantic-interposition isn't used, and if it is,
isInterposable being already used in most optimisation, they should honor it
properly.
Note that it only impacts architecture compiled with -fPIC and no pie.
Differential Revision: https://reviews.llvm.org/D72829
from FC0.ExitBlock to FC1.ExitBlock when proven safe.
Summary:
Currently LoopFusion give up when the second loop nest guard
block or the first loop nest exit block is not empty. For example:
if (0 < N) {
for (int i = 0; i < N; ++i) {}
x+=1;
}
y+=1;
if (0 < N) {
for (int i = 0; i < N; ++i) {}
}
The above example should be safe to fuse.
This PR moves instructions in FC1 guard block (e.g. y+=1;) to
FC0 guard block, or instructions in FC0 exit block (e.g. x+=1;) to
FC1 exit block, which then LoopFusion is able to fuse them.
Reviewer: kbarton, jdoerfert, Meinersbur, dmgreen, fhahn, hfinkel,
bmahjour, etiotto
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D73641
Summary:
When constant folding, constants that are wrapped in metadata were not
folded. This could lead to dbg.values being the only user of a constant
expression, due to the non-dbg uses having been rewritten, resulting in
the constant later on being removed by some other pass. This occurred
with the attached test case, in which the non-rewritten GEP in the
dbg.value intrinsic was later on removed by globalopt.
This patch makes the code look through metadata and fold such constants.
I guess that we in the future may want to allow dbg.values using GEPs and
other constant expressions to be emittable even if there are no non-dbg
uses, but for example SelectionDAG does not support that.
Reviewers: jmorse, aprantl, vsk, davide
Reviewed By: aprantl, vsk, davide
Subscribers: hiraditya, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D73630
Summary:
Add trimming of unused components of s_buffer_load.
For s_buffer_load and unformatted buffer_load also trim unused
components at the beginning of vector and update offset accordingly.
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71785
InstCombine operates on the basic premise that the operands of the
currently processed instruction have already been simplified. It
achieves this by pushing instructions to the worklist in reverse
program order, so that instructions are popped off in program order.
The worklist management in the main combining loop also makes sure
to uphold this invariant.
However, the same is not true for all the code that is performing
manual worklist management. The largest problem (addressed in this
patch) are instructions inserted by InstCombine's IRBuilder. These
will be pushed onto the worklist in order of insertion (generally
matching program order), which means that a) the users of the
original instruction will be visited first, as they are pushed later
in the main loop and b) the newly inserted instructions will be
visited in reverse program order.
This causes a number of problems: First, folds operate on instructions
that have not had their operands simplified, which may result in
optimizations being missed (ran into this in
https://reviews.llvm.org/D72048#1800424, which was the original
motivation for this patch). Additionally, this increases the amount
of folds InstCombine has to perform, both within one iteration, and
by increasing the number of total iterations.
This patch addresses the issue by adding a Worklist.AddDeferred()
method, which is used for instructions inserted by IRBuilder. These
will only be added to the real worklist after the combine finished,
and in reverse order, so they will end up processed in program order.
I should note that the same should also be done to nearly all other
uses of Worklist.Add(), but I'm starting with just this occurrence,
which has by far the largest test fallout.
Most of the test changes are due to
https://bugs.llvm.org/show_bug.cgi?id=44521 or other cases where
we don't canonicalize something. These are neutral. One regression
has been addressed in D73575 and D73647. The remaining regression
in an shl+sdiv fold can't really be fixed without dropping another
transform, but does not seem particularly problematic in the first
place.
Differential Revision: https://reviews.llvm.org/D73411
A pointer is privatizeable if it can be replaced by a new, private one.
Privatizing pointer reduces the use count, interaction between unrelated
code parts. This is a first step towards replacing argument promotion.
While we can already handle recursion (unlike argument promotion!) we
are restricted to stack allocations for now because we do not analyze
the uses in the callee.
Reviewed By: uenoku
Differential Revision: https://reviews.llvm.org/D68852
For the
icmp eq (add X, C1), C2 => icmp eq X, C2-C1
icmp eq (sub C1, X), C2 => icmp eq X, C1-C2
folds, this allows C1 to be non-splat and contain undefs.
C2 is still splat, due to the structure of the code.
This is to address the remaining part of the regression in D73411,
where demanded element analysis replaces some elements with undef.
Differential Revision: https://reviews.llvm.org/D73647
proven safe.
Summary:
Currently LoopFusion give up when the second loop nest preheader is
not empty. For example:
for (int i = 0; i < 100; ++i) {}
x+=1;
for (int i = 0; i < 100; ++i) {}
The above example should be safe to fuse.
This PR moves instructions in FC1 preheader (e.g. x+=1; ) to
FC0 preheader, which then LoopFusion is able to fuse them.
Reviewer: kbarton, Meinersbur, jdoerfert, dmgreen, fhahn, hfinkel,
bmahjour, etiotto
Reviewed By: jdoerfert
Subscribers: hiraditya, llvm-commits
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D71821
cmp (splat V1, M), SplatC --> splat (cmp V1, SplatC'), M
As discussed in PR44588:
https://bugs.llvm.org/show_bug.cgi?id=44588
...we try harder to push shuffles after binops than after compares.
This patch handles the special (but presumably most common case) of
splat shuffles. If both operands are splats, then we can do the
comparison on the non-splat inputs followed by splat of the compare.
That should take care of the regression noted in D73411.
There's another potential fold requested in PR37463 to scalarize the
compare, but that's another patch (and it's not clear if we can do
that without the ability to undo it later):
https://bugs.llvm.org/show_bug.cgi?id=37463
Differential Revision: https://reviews.llvm.org/D73575
If we invalidate an attribute we need to inform all dependent ones even
if the fixpoint state is not invalid. Before we only continued
invalidation if the fixpoint state was invalid, now we signal a change
in case the fixpoint state is valid.
The test case was already included in D71620 but the problem was hiding
because it only manifested with the old PM (for that input).
This patch modularizes the way we check for no-alias call site arguments
by putting the existing logic into helper functions. The reasoning was
not changed but special cases for readonly/readnone were added.
If `null` is not defined we cannot access it, hence the pointer is
`noalias`. While this is not helpful on it's own it simplifies later
deductions that can skip over already known `noalias` pointers in
certain situations.
During extraction, stale llvm.assume handles may be retained in the
original function. The setup is:
1) CodeExtractor unregisters assumptions in the blocks that are to be
extracted.
2) Extraction happens. There are now two functions: f1 and f1.extracted.
3) Leftover assumptions in f1 (/not/ removed as they were not in the set of
blocks to be extracted) now have affected-value llvm.assume handles in
f1.extracted.
When assumptions for a value used in f1 are looked up, ValueTracking can assert
as some of the handles are in the wrong function. To fix this, simply erase the
llvm.assume calls in the extracted function.
Alternatives include flushing the assumption cache in the original function, or
walking all values used in the original function to prune stale affected-value
handles. Both seem more expensive.
Testing: check-llvm, LNT run with -mllvm -hot-cold-split enabled
rdar://58460728
This patch adds support for explicitly highlighting sub-expressions
shared by multiple leaf nodes. For example consider the following
code
%shared.load = tail call <8 x double> @llvm.matrix.columnwise.load.v8f64.p0f64(double* %arg1, i32 %stride, i32 2, i32 4), !dbg !10, !noalias !10
%trans = tail call <8 x double> @llvm.matrix.transpose.v8f64(<8 x double> %shared.load, i32 2, i32 4), !dbg !10
tail call void @llvm.matrix.columnwise.store.v8f64.p0f64(<8 x double> %trans, double* %arg3, i32 10, i32 4, i32 2), !dbg !10
%load.2 = tail call <30 x double> @llvm.matrix.columnwise.load.v30f64.p0f64(double* %arg3, i32 %stride, i32 2, i32 15), !dbg !10, !noalias !10
%mult = tail call <60 x double> @llvm.matrix.multiply.v60f64.v8f64.v30f64(<8 x double> %trans, <30 x double> %load.2, i32 4, i32 2, i32 15), !dbg !11
tail call void @llvm.matrix.columnwise.store.v60f64.p0f64(<60 x double> %mult, double* %arg2, i32 10, i32 4, i32 15), !dbg !11
We have two leaf nodes (the 2 stores) and the first store stores %trans
which is also used by the matrix multiply %mult. We generate separate
remarks for each leaf (stores). To denote that parts are shared, the
shared expressions are marked as shared (), with a reference to the
other remark that shares it. The operation summary also denotes the
shared operations separately.
Reviewers: anemet, Gerolf, thegameg, hfinkel, andrew.w.kaylor, LuoYuanke
Reviewed By: anemet
Differential Revision: https://reviews.llvm.org/D72526
Dead instructions do not need to be sunk. Currently we try and record
the recipies for them, but there are no recipes emitted for them and
there's nothing to sink. They can be removed from SinkAfter while
marking them for recording.
Fixes PR44634.
Reviewers: rengolin, hsaito, fhahn, Ayal, gilr
Reviewed By: gilr
Differential Revision: https://reviews.llvm.org/D73423
This patch updates the remark to also include a summary of the number of
vector operations generated for each matrix expression.
Reviewers: anemet, Gerolf, thegameg, hfinkel, andrew.w.kaylor, LuoYuanke
Reviewed By: anemet
Differential Revision: https://reviews.llvm.org/D72480
from DenseMap to MapVector
The iteration order of LoopVectorizationLegality::Reductions matters for the
final code generation, so we better use MapVector instead of DenseMap for it
to remove the nondeterminacy. reduction-order.ll in the patch is an example
reduced from the case we saw. In the output of opt command, the order of the
select instructions in the vector.body block keeps changing from run to run
currently.
Differential Revision: https://reviews.llvm.org/D73490
Generate remarks for matrix operations in a function. To generate remarks
for matrix expressions, the following approach is used:
1. Collect leafs of matrix expressions (done in
RemarkGenerator::getExpressionLeafs). Leafs are lowered matrix
instructions without other matrix users (like stores).
2. For each leaf, create a remark containing a linearizied version of the
matrix expression.
The following improvements will be submitted as follow-ups:
* Summarize number of vector instructions generated for each expression.
* Account for shared sub-expressions.
* Propagate matrix remarks up the inlining chain.
The information provided by the matrix remarks helps users to spot cases
where matrix expression got split up, e.g. due to inlining not
happening. The remarks allow users to address those issues, ensuring
best performance.
Reviewers: anemet, Gerolf, thegameg, hfinkel, andrew.w.kaylor, LuoYuanke
Reviewed By: anemet
Differential Revision: https://reviews.llvm.org/D72453
D47163 created a rule that we should not change the casted
type of a select when we have matching types in its compare condition.
That was intended to help vector codegen, but it also could create
situations where we miss subsequent folds as shown in PR44545:
https://bugs.llvm.org/show_bug.cgi?id=44545
By using shouldChangeType(), we can continue to get the vector folds
(because we always return false for vector types). But we also solve
the motivating bug because it's ok to narrow the scalar select in that
example.
Our canonicalization rules around select are a mess, but AFAICT, this
will not induce any infinite looping from the reverse transform (but
we'll need to watch for that possibility if committed).
Side note: there's a similar use of shouldChangeType() for phi ops
just below this diff, and the source and destination types appear to
be reversed.
Differential Revision: https://reviews.llvm.org/D72733
Followup to D72978. This moves existing negation handling in
InstCombine into freelyNegateValue(), which make it composable.
In particular, root negations of div/zext/sext/ashr/lshr/sub can
now always be performed through a shl/trunc as well.
Differential Revision: https://reviews.llvm.org/D73288
This restores 59733525d3 (D71913), along
with bot fix 19c76989bb.
The bot failure should be fixed by D73418, committed as
af954e441a.
I also added a fix for non-x86 bot failures by requiring x86 in new test
lld/test/ELF/lto/devirt_vcall_vis_public.ll.
Summary: masked_load and masked_store instructions require the alignment to be specified and a power of two. It seems to me that this requirement applies to masked_gather and masked_scatter as well.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73179
Patch by Chris Chrulski
When generating value profiling instrumentation, ensure the call gets the
correct funclet token, otherwise WinEHPrepare will turn the call (and all
subsequent instructions) into unreachable.
Differential Revision: https://reviews.llvm.org/D73221
Patch by Chris Chrulski
This fixes a problem with the current behavior when assertions are enabled.
A loop that exits to a catchswitch instruction is skipped for the counter
promotion, however this check was being done after the PGOCounterPromoter
tried to collect an insertion point for the exit block. A call to
getFirstInsertionPt() on a block that begins with a catchswitch instruction
triggers an assertion. This change performs a check whether the counter
promotion is possible prior to collecting the ExitBlocks and InsertPts.
Differential Revision: https://reviews.llvm.org/D73222
The codegen for splitting a llvm.vector.reduction intrinsic into parts
will be better than the codegen for the generic reductions. This will
only directly effect when vectorization factors are specified by the
user.
Also added tests to make sure the codegen for larger reductions is OK.
Differential Revision: https://reviews.llvm.org/D72257
This fixes a bug where a PHI node that is only referenced by a lifetime.end intrinsic in an otherwise empty cleanuppad can cause SimplyCFG to create an SSA violation while removing the empty cleanuppad. Theoretically the same problem can occur with debug intrinsics.
Differential Revision: https://reviews.llvm.org/D72540
When we use information only to short-cut deduction or improve it, we
can use OPTIONAL dependences instead of REQUIRED ones to avoid cascading
pessimistic fixpoints.
We also need to track dependences only when we use assumed information,
e.g., we act on assumed liveness information.
When we follow uses, e.g., in AAMemoryBehavior or AANoCapture, we need
to make sure the value is a pointer before we ask for abstract
attributes only valid for pointers. This happens because we follow
pointers through calls that do not capture but may return the value.
Summary:
Third part in series to support Safe Whole Program Devirtualization
Enablement, see RFC here:
http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html
This patch adds type test metadata under -fwhole-program-vtables,
even for classes without hidden visibility. It then changes WPD to skip
devirtualization for a virtual function call when any of the compatible
vtables has public vcall visibility.
Additionally, internal LLVM options as well as lld and gold-plugin
options are added which enable upgrading all public vcall visibility
to linkage unit (hidden) visibility during LTO. This enables the more
aggressive WPD to kick in based on LTO time knowledge of the visibility
guarantees.
Support was added to all flavors of LTO WPD (regular, hybrid and
index-only), and to both the new and old LTO APIs.
Unfortunately it was not simple to split the first and second parts of
this part of the change (the unconditional emission of type tests and
the upgrading of the vcall visiblity) as I needed a way to upgrade the
public visibility on legacy WPD llvm assembly tests that don't include
linkage unit vcall visibility specifiers, to avoid a lot of test churn.
I also added a mechanism to LowerTypeTests that allows dropping type
test assume sequences we now aggressively insert when we invoke
distributed ThinLTO backends with null indexes, which is used in testing
mode, and which doesn't invoke the normal ThinLTO backend pipeline.
Depends on D71907 and D71911.
Reviewers: pcc, evgeny777, steven_wu, espindola
Subscribers: emaste, Prazek, inglorion, arichardson, hiraditya, MaskRay, dexonsmith, dang, davidxl, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D71913
We currently use integer ranges to merge concrete function arguments.
We use the ParamState range for those, but we only look up concrete
values in the regular state. For concrete function arguments that are
themselves arguments of the containing function, we can use the param
state directly and improve the precision in some cases.
Besides improving the results in some cases, this is also a small step towards
switching to ValueLatticeElement, by allowing D60582 to be a NFC.
Reviewers: efriedma, davide
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D71836
Summary:
First patch to support Safe Whole Program Devirtualization Enablement,
see RFC here: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html
Always emit !vcall_visibility metadata under -fwhole-program-vtables,
and not just for -fvirtual-function-elimination. The vcall visibility
metadata will (in a subsequent patch) be used to communicate to WPD
which vtables are safe to devirtualize, and we will optionally convert
the metadata to hidden visibility at link time. Subsequent follow on
patches will help enable this by adding vcall_visibility metadata to the
ThinLTO summaries, and always emit type test intrinsics under
-fwhole-program-vtables (and not just for vtables with hidden
visibility).
In order to do this safely with VFE, since for VFE all vtable loads must
be type checked loads which will no longer be the case, this patch adds
a new "Virtual Function Elim" module flag to communicate to GlobalDCE
whether to perform VFE using the vcall_visibility metadata.
One additional advantage of using the vcall_visibility metadata to drive
more WPD at LTO link time is that we can use the same mechanism to
enable more aggressive VFE at LTO link time as well. The link time
option proposed in the RFC will convert vcall_visibility metadata to
hidden (aka linkage unit visibility), which combined with
-fvirtual-function-elimination will allow it to be done more
aggressively at LTO link time under the same conditions.
Reviewers: pcc, ostannard, evgeny777, steven_wu
Subscribers: mehdi_amini, Prazek, hiraditya, dexonsmith, davidxl, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D71907
Juneyoung Lee