7162 Commits

Author SHA1 Message Date
Craig Topper
a402bd1ba7 [ValueTracking] Remove duplicate call to computeKnownBits for the operands of Select.
We call it unconditionally on the operands of the select. Then decide if its a min/max and call it on the min/max operands or on the select operands again. Either of those second calls will overwrite the results of the initial call so we can just delete the first call.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300256 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-13 20:39:37 +00:00
Craig Topper
e1c6ddcf64 [ValueTracking] Prevent a call to computeKnownBits if we already know the state of the bit we would calculate. Also reuse a temporary APInt instead of creating a new one.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300239 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-13 19:04:45 +00:00
Craig Topper
a7bdbbca61 [ValueTracking] Move a temporary APInt instead of copying it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300233 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-13 18:25:53 +00:00
Brian Gesiak
b2b7c4b1a7 [Analysis] Support bitreverse in -demanded-bits pass
Summary:
* Add a bitreverse case in the demanded bits analysis pass.
* Add tests for the bitreverse (and bswap) intrinsic in the
  demanded bits pass.
* Add a test case to the BDCE tests: that manipulations to
  high-order bits are eliminated once the bits are reversed
  and then right-shifted.

Reviewers: mkuper, jmolloy, hfinkel, trentxintong

Reviewed By: jmolloy

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31857

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300215 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-13 16:44:25 +00:00
Craig Topper
b25869aa9e [InstSimplify] Don't try to constant fold AllocaInsts since it won't do anything.
Should give a small compile time improvement.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300125 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-12 22:54:24 +00:00
Craig Topper
53726fa11a [ValueTracking] Teach GetUnderlyingObject to stop when it reachs an alloca instruction.
Previously it tried to call SimplifyInstruction which doesn't know anything about alloca so defers to constant folding which also doesn't do anything with alloca. This results in wasted cycles making calls that won't do anything. Given the frequency with which this function is called this time adds up.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300118 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-12 22:29:23 +00:00
Jonas Paulsson
43d439da88 [LoopVectorizer, TTI] New method supportsEfficientVectorElementLoadStore()
Since SystemZ supports vector element load/store instructions, there is no
need for extracts/inserts if a vector load/store gets scalarized.

This patch lets Target specify that it supports such instructions by means of
a new TTI hook that defaults to false.

The use for this is in the LoopVectorizer getScalarizationOverhead() method,
which will with this patch produce a smaller sum for a vector load/store on
SystemZ.

New test: test/Transforms/LoopVectorize/SystemZ/load-store-scalarization-cost.ll

Review: Adam Nemet
https://reviews.llvm.org/D30680

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300056 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-12 12:41:37 +00:00
Jonas Paulsson
c33bdfa7b1 [SystemZ] TargetTransformInfo cost functions implemented.
getArithmeticInstrCost(), getShuffleCost(), getCastInstrCost(),
getCmpSelInstrCost(), getVectorInstrCost(), getMemoryOpCost(),
getInterleavedMemoryOpCost() implemented.

Interleaved access vectorization enabled.

BasicTTIImpl::getCastInstrCost() improved to check for legal extending loads,
in which case the cost of the z/sext instruction becomes 0.

Review: Ulrich Weigand, Renato Golin.
https://reviews.llvm.org/D29631

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300052 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-12 11:49:08 +00:00
Chandler Carruth
ddfada260a [IR] Redesign the case iterator in SwitchInst to actually be an iterator
and to expose a handle to represent the actual case rather than having
the iterator return a reference to itself.

All of this allows the iterator to be used with common STL facilities,
standard algorithms, etc.

Doing this exposed some missing facilities in the iterator facade that
I've fixed and required some work to the actual iterator to fully
support the necessary API.

Differential Revision: https://reviews.llvm.org/D31548

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300032 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-12 07:27:28 +00:00
Serguei Katkov
4f5f4e9e2a [BPI] Refactor post domination calculation and simple fix for ColdCall
Collection of PostDominatedByUnreachable and PostDominatedByColdCall have been
split out of heuristics itself. Update of the data happens now for each basic
block (before update for PostDominatedByColdCall might be skipped if
unreachable or matadata heuristic handled this basic block).

This separation allows re-ordering of heuristics without loosing
the post-domination information.

Reviewers: sanjoy, junbuml, vsk, chandlerc, reames

Reviewed By: chandlerc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31701


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300029 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-12 05:42:14 +00:00
Zvi Rackover
f14c498699 InstSimplify: A shuffle of a splat is always the splat itself
Summary:
Fold:
 shuffle (splat-shuffle), undef, M --> splat-shuffle

Reviewers: spatel, RKSimon, craig.topper

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31527

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299990 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-11 21:37:02 +00:00
Daniel Berlin
e0f5ddbc01 MemorySSA: Move to Analysis, from Transforms/Utils. It's used as
Analysis, it has Analysis passes, and once NewGVN is made an Analysis,
this removes the cross dependency from Analysis to Transform/Utils.
NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299980 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-11 20:06:36 +00:00
Vassil Vassilev
afa9824a92 Remove unused functions. Remove static qualifier from functions in header files. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299947 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-11 14:55:32 +00:00
Craig Topper
a0e581d63e [InstSimplify] Use cast instead of dyn_cast after isa<> check. NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299870 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-10 19:37:10 +00:00
Craig Topper
fb99fcdbc9 [ConstantFolding] Use Intrinsic::not_intrinsic instead of 0 for readability. NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299801 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-07 21:36:32 +00:00
Craig Topper
61e26210b1 [InstSimplify] Use Instruction::BinaryOps instead of unsigned for a few function operands to remove some casts. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299745 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-07 05:57:51 +00:00
Daniel Berlin
f634bfbb16 AliasAnalysis: Be less conservative about volatile than atomic.
Summary:
getModRefInfo is meant to answer the question "what impact does this
instruction have on a given memory location" (not even another
instruction).

Long debate on this on IRC comes to the conclusion the answer should be "nothing special".

That is, a noalias volatile store does not affect a memory location
just by being volatile.  Note: DSE and GVN and memdep currently
believe this, because memdep just goes behind AA's back after it says
"modref" right now.

see line 635 of memdep. Prior to this patch we would get modref there, then check aliasing,
and if it said noalias, we would continue.

getModRefInfo *already* has this same AA check, it just wasn't being used because volatile was
lumped in with ordering.

(I am separately testing whether this code in memdep is now dead except for the invariant load case)

Reviewers: jyknight, chandlerc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31726

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299741 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-07 01:28:36 +00:00
Craig Topper
f8e400cffa [InstSimplify] Remove unreachable default from SimplifyBinOp.
We have dedicated handlers for every opcode so nothing can get here anymore. The switch doesn't get detected as fully covered because Opcode is an unsigned. Casting to Instruction::BinaryOps still doesn't detect it because BinaryOpsEnd is in the enum and 1 past the last opcode.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299687 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-06 18:59:08 +00:00
Craig Topper
864291860e [InstSimplify] Teach SimplifyMulInst to recognize vectors of i1 as And. Not just scalar i1.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299665 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-06 17:33:37 +00:00
Craig Topper
1194a001b6 [InstSimplify] Teach SimplifyAddInst and SimplifySubInst that vectors of i1 can be treated as Xor too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299626 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-06 05:28:41 +00:00
James Molloy
3a168569fc [LAA] Correctly return a half-open range in expandBounds
This is a latent bug that's been hanging around for a while. For a loop-invariant
pointer, expandBounds would return the range {Ptr, Ptr}, but this was interpreted
as a half-open range, not a closed range. So we ended up planting incorrect
bounds checks. Even worse, they were tautological, so we ended up incorrectly
executing the optimized loop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299526 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-05 09:24:26 +00:00
Zvi Rackover
07d42b869d InstSimplify: Add a hook for shufflevector
Summary:
Add a hook for simplification of shufflevector's with the following rules:
- Constant folding - NFC, as it was already being done by the default handler.
-  If only one of the operands is constant, constant fold the shuffle if the
    mask does not select elements from the variable operand -  to show the hook is firing and affecting the test-cases.

Reviewers: RKSimon, craig.topper, spatel, sanjoy, nlopes, majnemer

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31525

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299393 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-03 22:05:30 +00:00
Jun Bum Lim
78c95b332b [CodeGenPrep] move aarch64-type-promotion to CGP
Summary:
Move the aarch64-type-promotion pass within the existing type promotion framework in CGP.
This change also support forking sexts when a new sext is required for promotion.
Note that change is based on D27853 and I am submitting this out early to provide a better idea on D27853.

Reviewers: jmolloy, mcrosier, javed.absar, qcolombet

Reviewed By: qcolombet

Subscribers: llvm-commits, aemerson, rengolin, mcrosier

Differential Revision: https://reviews.llvm.org/D28680

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299379 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-03 19:20:07 +00:00
Craig Topper
68149f546e [APInt] Move isMask and isShiftedMask out of APIntOps and into the APInt class. Implement them without memory allocation for multiword
This moves the isMask and isShiftedMask functions to be class methods. They now use the MathExtras.h function for single word size and leading/trailing zeros/ones or countPopulation for the multiword size. The previous implementation made multiple temorary memory allocations to do the bitwise arithmetic operations to match the MathExtras.h implementation.

Differential Revision: https://reviews.llvm.org/D31565




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299362 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-03 16:34:59 +00:00
Sanjay Patel
6d5ad7b563 [InstSimplify] add constant folding for fdiv/frem
Also, add a helper function so we don't have to repeat this code for each binop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299309 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-01 19:05:11 +00:00
Sanjay Patel
c1440de334 fix formatting; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299307 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-01 18:40:30 +00:00
Craig Topper
fa958b2284 [APInt] Remove the mul/urem/srem/udiv/sdiv functions from the APIntOps namespace. Replace the few usages with calls to the class methods. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299292 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-01 05:08:57 +00:00
Craig Topper
38017a1fee [APInt] Remove shift functions from APIntOps namespace. Replace the few users with the APInt class methods. NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299248 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-31 20:01:16 +00:00
Max Kazantsev
85ae85b821 [ScalarEvolution] Re-enable Predicate implication from operations
The patch rL298481 was reverted due to crash on clang-with-lto-ubuntu build.
The reason of the crash was type mismatch between either a or b and RHS in the following situation:

  LHS = sext(a +nsw b) > RHS.

This is quite rare, but still possible situation. Normally we need to cast all {a, b, RHS} to their widest type.
But we try to avoid creation of new SCEV that are not constants to avoid initiating recursive analysis that
can take a lot of time and/or cache a bad value for iterations number. To deal with this, in this patch we
reject this case and will not try to analyze it if the type of sum doesn't match with the type of RHS. In this
situation we don't need to create any non-constant SCEVs.

This patch also adds an assertion to the method IsProvedViaContext so that we could fail on it and not
go further into range analysis etc (because in some situations these analyzes succeed even when the passed
arguments have wrong types, what should not normally happen).

The patch also contains a fix for a problem with too narrow scope of the analysis caused by wrong
usage of predicates in recursive invocations.

The regression test on the said failure: test/Analysis/ScalarEvolution/implied-via-addition.ll

Reviewers: reames, apilipenko, anna, sanjoy

Reviewed By: sanjoy

Subscribers: mzolotukhin, mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D31238


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299205 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-31 12:05:30 +00:00
Simon Pilgrim
8d28e34276 Spelling mistakes in comments. NFCI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299197 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-31 10:59:37 +00:00
Peter Collingbourne
2dee6275de ModuleSummaryAnalysis: Use a more precise #include. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299142 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-31 00:08:24 +00:00
Craig Topper
83c5596f48 [InstSimplify] Use m_SignBit instead of calling getSignBit and using m_Specific. NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299121 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-30 22:21:16 +00:00
Craig Topper
3361f1d2d7 [InstSimplify] Use APInt::isMaxSignedValue() instead of comparing with ~APInt::getSignBit. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299120 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-30 22:10:54 +00:00
Craig Topper
7ebd1797a3 Revert r298711 "[InstCombine] Provide a way to calculate KnownZero/One for Add/Sub in SimplifyDemandedUseBits without recursing into ComputeKnownBits"
Tsan bot is failing.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298745 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-24 22:12:10 +00:00
Craig Topper
bab6d5ee26 [InstCombine] Provide a way to calculate KnownZero/One for Add/Sub in SimplifyDemandedUseBits without recursing into ComputeKnownBits
SimplifyDemandedUseBits for Add/Sub already recursed down LHS and RHS for simplifying bits. If that didn't provide any simplifications we fall back to calling computeKnownBits which will recurse again. Instead just take the known bits for LHS and RHS we already have and call into a new function in ValueTracking that can calculate the known bits given the LHS/RHS bits.





git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298711 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-24 16:56:51 +00:00
Max Kazantsev
a7af2e0acb Revert "[ScalarEvolution] Re-enable Predicate implication from operations"
This reverts commit rL298690

Causes failures on clang.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298693 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-24 07:04:31 +00:00
Max Kazantsev
8229f1dfef [ScalarEvolution] Re-enable Predicate implication from operations
The patch rL298481 was reverted due to crash on clang-with-lto-ubuntu build.
The reason of the crash was type mismatch between either a or b and RHS in the following situation:

  LHS = sext(a +nsw b) > RHS.

This is quite rare, but still possible situation. Normally we need to cast all {a, b, RHS} to their widest type.
But we try to avoid creation of new SCEV that are not constants to avoid initiating recursive analysis that
can take a lot of time and/or cache a bad value for iterations number. To deal with this, in this patch we
reject this case and will not try to analyze it if the type of sum doesn't match with the type of RHS. In this
situation we don't need to create any non-constant SCEVs.

This patch also adds an assertion to the method IsProvedViaContext so that we could fail on it and not
go further into range analysis etc (because in some situations these analyzes succeed even when the passed
arguments have wrong types, what should not normally happen).

The patch also contains a fix for a problem with too narrow scope of the analysis caused by wrong
usage of predicates in recursive invocations.

The regression test on the said failure: test/Analysis/ScalarEvolution/implied-via-addition.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298690 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-24 06:19:00 +00:00
Craig Topper
8a6bd3fdda [ValueTracking] Use uint64_t for CarryIn in computeKnownBitsAddSub instead of a creating a temporary APInt. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298688 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-24 05:38:09 +00:00
Craig Topper
d738e6a7b3 [ValueTracking] Convert more places to use setHighBits/setLowBits/setSignBit. NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298683 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-24 03:57:24 +00:00
Dehao Chen
261eb1f850 Use isFunctionHotInCallGraph to set the function section prefix.
Summary: The current prefix based function layout algorithm only looks at function's entry count, which is not sufficient. A function should be grouped together if its entry count or any call edge count is hot.

Reviewers: davidxl, eraman

Reviewed By: eraman

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31225

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298656 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-23 23:14:11 +00:00
Anna Thomas
3ae0a79c0d [LVIPrinterPass] Print LVI info for function arguments
Using AssemblyAnnotationWriter for LVI printer prints
for instructions and basic blocks.
So, we explicitly need to print LVI info for the arguments of the function (these
are values and not instructions).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298640 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-23 20:00:54 +00:00
Zhaoshi Zheng
d59827deef Model ashr(shl(x, n), m) as mul(x, 2^(n-m)) when n > m
Given below case:

  %y = shl %x, n
  %z = ashr %y, m

when n = m, SCEV models it as sext(trunc(x)). This patch tries to handle
the case where n > m by using sext(mul(trunc(x), 2^(n-m)))) as the SCEV
expression.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298631 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-23 18:06:09 +00:00
Zhaoshi Zheng
c4fa083a1d revert test commit r298629
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298630 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-23 17:52:20 +00:00
Zhaoshi Zheng
dca48688fd test commit
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298629 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-23 17:38:47 +00:00
Craig Topper
31f7be5e2b [ValueTracking] Use APInt::isNegative instead of using operator[BitWidth-1]. NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298584 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-23 07:06:42 +00:00
Craig Topper
fe5b80b4c9 [ValueTracking] Use setAllBits/setSignBit/setLowBits/setHighBits. NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298583 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-23 07:06:39 +00:00
Anna Thomas
6cde87723e [LVI] Add an LVI printer pass to capture test LVI cache after transformations
Summary:
Adding a printer pass for printing the LVI cache values after transformations
that use LVI.
This will help us in identifying cases where LVI
invariants are violated, or transforms that leave LVI in an incorrect state.
Right now, I have added two test cases to show that the printer pass is working.
I will be adding more test cases in a later change, once this change is
checked in upstream.

Reviewers: reames, dberlin, sanjoy, apilipenko

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D30790

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298542 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-22 19:27:12 +00:00
Max Kazantsev
84c3daf081 Revert "[ScalarEvolution] Predicate implication from operations"
This reverts commit rL298481

Fails clang-with-lto-ubuntu build.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298489 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-22 07:50:33 +00:00
Craig Topper
f448321cdd [ValueTracking] Make sure we keep range metadata information when calculating known bits for calls to bitreverse intrinsic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298488 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-22 07:22:49 +00:00
Craig Topper
5b64d78c22 [ValueTracking] use setLowBits/setHighBits/setBitsFrom to replace |= getHighBits/getLowBits. NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298486 91177308-0d34-0410-b5e6-96231b3b80d8
2017-03-22 06:19:37 +00:00