Continue in the spirit of D63618, and use exit count reasoning to prove away loop exits which can not be taken since the backedge taken count of the loop as a whole is provably less than the minimal BE count required to take this particular loop exit.
As demonstrated in the newly added tests, this triggers in a number of cases where IndVars was previously unable to discharge obviously redundant exit tests. And some not so obvious ones.
Differential Revision: https://reviews.llvm.org/D63733
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365920 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce and deduce "nosync" function attribute to indicate that a function
does not synchronize with another thread in a way that other thread might free memory.
Reviewers: jdoerfert, jfb, nhaehnle, arsenm
Subscribers: wdng, hfinkel, nhaenhle, mehdi_amini, steven_wu,
dexonsmith, arsenm, uenoku, hiraditya, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D62766
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365830 91177308-0d34-0410-b5e6-96231b3b80d8
This patch replaces the three almost identical "strip & accumulate"
implementations for constant pointer offsets with a single one,
combining the respective functionalities. The old interfaces are kept
for now.
Differential Revision: https://reviews.llvm.org/D64468
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365723 91177308-0d34-0410-b5e6-96231b3b80d8
An alloca which can be sunk into the extraction region may have more
than one bitcast use. Move these uses along with the alloca to prevent
use-before-def.
Testing: check-llvm, stage2 build of clang
Fixes llvm.org/PR42451.
Differential Revision: https://reviews.llvm.org/D64463
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alive proofs:
a,b: https://rise4fun.com/Alive/4zsf
c,d,e,f: https://rise4fun.com/Alive/RC49
Indeed, not all of these patterns are canonical.
But since this fold will only produce a single instruction
i'm really interested in handling even uncanonical patterns.
Other than these 6 patterns, i can't think of any other
reasonable variants right now, although i'm sure they exist.
For now let's start with patterns where both shift amounts are variable,
with trivial constant "offset" between them, since i believe this is
both simplest to handle and i think this is most common.
But again, there are likely other variants where we could use
ValueTracking/ConstantRange to handle more cases.
https://bugs.llvm.org/show_bug.cgi?id=42563
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365641 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Transform
pow(C,x)
To
exp2(log2(C)*x)
if C > 0, C != inf, C != NaN (and C is not power of 2, since we have some fold for such case already).
log(C) is folded by the compiler and exp2 is much faster to compute than pow.
Reviewers: spatel, efriedma, evandro
Reviewed By: evandro
Subscribers: lebedev.ri, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64099
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Only instructions with two or more unique successors should be considered for unswitching.
Patch Author: Daniil Suchkov.
Reviewers: reames, asbirlea, skatkov
Reviewed By: skatkov
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D64404
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365611 91177308-0d34-0410-b5e6-96231b3b80d8
This test exposes a bug in SimpleLoopUnswitch that leads to a crash on
assert(SuccessorsCount > 1 && "Cannot unswitch a condition without multiple distinct successors!");
when SimpleLoopUnswitch considers unswitching of a loop by a switch with one successor.
Fix will be submitted soon.
Patch Author: Daniil Suchkov.
Reviewers: reames, asbirlea, skatkov
Reviewed By: skatkov
Subscribers: zzheng, llvm-commits
Differential Revision: https://reviews.llvm.org/D64403
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365600 91177308-0d34-0410-b5e6-96231b3b80d8
I'm not sure if transforming any of these is valid as
a target-independent fold, but we might as well have
a few tests here to confirm or deny our position.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365523 91177308-0d34-0410-b5e6-96231b3b80d8
APInt::getSExtValue will assert if getMinSignedBits() > 64. This can happen,
for instance, if examining an i128. Avoid this assertion by checking
Imm.getMinSignedBits() <= 64 before doing
getTLI()->isLegalAddImmediate(Imm.getSExtValue()). We could directly check
getMinSignedBits() <= 12 but it seems better to reuse the isLegalAddImmediate
helper for this.
Differential Revision: https://reviews.llvm.org/D64390
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365462 91177308-0d34-0410-b5e6-96231b3b80d8
A while back, I added support for NE latches formed by LFTR. I didn't think that quite through, as LFTR will also produce the inverse EQ form for some loops and I hadn't handled that. This change just adds handling for that case as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365419 91177308-0d34-0410-b5e6-96231b3b80d8
Deduce the "returned" argument attribute by collecting all potentially
returned values.
Not only the unique return value, if any, can be used by subsequent
attributes but also the set of all potentially returned values as well
as the mapping from returned values to return instructions that they
originate from (see AAReturnedValues::checkForallReturnedValues).
Change in statistics (-stats) for LLVM-TS + Spec2006, totaling ~19% more "returned" arguments.
ADDED: attributor NumAttributesManifested n/a -> 637
ADDED: attributor NumAttributesValidFixpoint n/a -> 25545
ADDED: attributor NumFnArgumentReturned n/a -> 637
ADDED: attributor NumFnKnownReturns n/a -> 25545
ADDED: attributor NumFnUniqueReturned n/a -> 14118
CHANGED: deadargelim NumRetValsEliminated 470 -> 449 ( -4.468%)
REMOVED: functionattrs NumReturned 535 -> n/a
CHANGED: indvars NumElimIdentity 138 -> 164 ( +18.841%)
Reviewers: homerdin, hfinkel, fedor.sergeev, sanjoy, spatel, nlopes, nicholas, reames, efriedma, chandlerc
Subscribers: hiraditya, bollu, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D59919
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Forming the canonical splat shuffle improves analysis and
may allow follow-on transforms (although some possibilities
are missing as shown in the test diffs).
The backend generically turns these patterns into build_vector,
so there should be no codegen regressions. All targets are
expected to be able to lower splats efficiently.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365379 91177308-0d34-0410-b5e6-96231b3b80d8
We recognize a splat from element 0 in (VectorUtils) llvm::getSplatValue()
and also in ShuffleVectorInst::isZeroEltSplatMask(), so this converts
to that form for better matching.
The backend generically turns these patterns into build_vector,
so there should be no codegen difference.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365342 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds a function attribute, nofree, to indicate that a function does
not, directly or indirectly, call a memory-deallocation function (e.g., free,
C++'s operator delete).
Reviewers: jdoerfert
Differential Revision: https://reviews.llvm.org/D49165
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Without this, we have the unfortunate property that tests are dependent on the order of operads passed the CreateOr and CreateAnd functions. In actual usage, we'd promptly optimize them away, but it made tests slightly more verbose than they should have been.
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If the block being cloned contains a PHI node, in general, we need to
clone that PHI node, even though it's trivial. If the operand of the PHI
is an instruction in the block being cloned, the correct value for the
operand doesn't exist until SSAUpdater constructs it.
We usually don't hit this issue because we try to avoid threading across
loop headers, but it's possible to hit this in some cases involving
irreducible CFGs. I added a flag to allow threading across loop headers
to make the testcase easier to understand.
Thanks to Brian Rzycki for reducing the testcase.
Fixes https://bugs.llvm.org/show_bug.cgi?id=42085.
Differential Revision: https://reviews.llvm.org/D63913
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As noted in the test change, this is not trivially NFC, but all of the changes in output are cases where the SCEVExpander form is more canonical/optimal than the hand generation.
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The motivation for this is two fold:
1) Make the output (and thus tests) a bit more readable to a human trying to understand the result of the transform
2) Reduce spurious diffs in a potential future change to restructure all of this logic to use SCEVExpander (which hoists by default)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365066 91177308-0d34-0410-b5e6-96231b3b80d8
I'm not sure if this falls within the scope of SLP,
but we could create vector loads for some of these
patterns.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365055 91177308-0d34-0410-b5e6-96231b3b80d8
On some occasions ReuseOrCreateCast may convert previously
expanded value to undefined. That value may be passed by
SCEVExpander as an argument to InsertBinop making IV chain
undefined.
Differential revision: https://reviews.llvm.org/D63928
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This reverts r364422 (git commit 1a3dc761860d620ac8ed7e32a4285952142f780b)
The inlining cost calculation is incorrect, leading to stack overflow due to large stack frames from heavy inlining.
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