Commit Graph

524 Commits

Author SHA1 Message Date
Nikolai Bozhenov bde9b14c6f Revert of r306525: "Canonicalize clamp of float types to minmax"
llvm-svn: 306815
2017-06-30 10:39:09 +00:00
Nikolai Bozhenov 6710ba07c7 Revert r306528
llvm-svn: 306536
2017-06-28 12:15:13 +00:00
Nikolai Bozhenov 77b5536e4e [ValueTracking] Enabling existing ValueTracking patch by default.
The original patch was an improvement to IR ValueTracking on non-negative
integers. It has been checked in to trunk (D18777, r284022). But was disabled by
default due to performance regressions.
Perf impact has improved. The patch would be enabled by default.

Reviewers: reames

Differential Revision: https://reviews.llvm.org/D34101

Patch by: Olga Chupina <olga.chupina@intel.com>

llvm-svn: 306528
2017-06-28 10:08:08 +00:00
Nikolai Bozhenov b01e6b5a52 [InstCombine] Canonicalize clamp of float types to minmax in fast mode.
Summary:
This commit allows matchSelectPattern to recognize clamp of float
arguments in the presence of FMF the same way as already done for
integers.

This case is a little different though. With integers, given the
min/max pattern is recognized, DAGBuilder starts selecting MIN/MAX
"automatically". That is not the case for float, because for them only
full FMINNAN/FMINNUM/FMAXNAN/FMAXNUM ISD nodes exist and they do care
about NaNs. On the other hand, some backends (e.g. X86) have only
FMIN/FMAX nodes that do not care about NaNS and the former NAN/NUM
nodes are illegal thus selection is not happening. So I decided to do
such kind of transformation in IR (InstCombiner) instead of
complicating the logic in the backend.

Reviewers: spatel, jmolloy, majnemer, efriedma, craig.topper

Reviewed By: efriedma

Subscribers: hiraditya, javed.absar, n.bozhenov, llvm-commits

Patch by Andrei Elovikov <andrei.elovikov@intel.com>

Differential Revision: https://reviews.llvm.org/D33186

llvm-svn: 306525
2017-06-28 09:26:20 +00:00
Craig Topper 7b66ffe875 [ValueTracking][InstCombine] Use m_Shr instead m_CombineOr(m_LShr, m_AShr). NFC
llvm-svn: 306205
2017-06-24 06:24:04 +00:00
Craig Topper f93b7b1c1f [ValueTracking] Correct early out in computeKnownBitsFromOperator to work with non power of 2 bit widths
There's an early out that's trying to detect when we don't know any bits that make up the legal range of a shift. The code subtracts one from BitWidth which creates a mask in the lower bits for power of 2 bit widths. This is then ANDed with the known bits to see if any of those bits are known. If the bit width isn't a power of 2 this creates a non-sensical mask.

This patch corrects this by rounding up to a power of 2 before doing the subtract and mask.

Differential Revision: https://reviews.llvm.org/D34165

llvm-svn: 305400
2017-06-14 17:04:59 +00:00
Sanjay Patel 2ad88f81f0 fix typos/formatting; NFC
llvm-svn: 305243
2017-06-12 22:34:37 +00:00
Sanjay Patel fef83e8fb9 [ValueTracking] fix typo; NFC
llvm-svn: 305080
2017-06-09 14:21:18 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Craig Topper 3002d5b0bf [ValueTracking] Remove scalar only restriction from isKnownNonEqual. The computeKnownBits and isKnownNonZero calls this code relies on should work fine for vectors.
This will be used by another commit to remove some code from InstSimplify that is redundant for scalars, but was needed for vectors due to this issue.

llvm-svn: 304774
2017-06-06 07:13:15 +00:00
Craig Topper 8e662f7f81 [ValueTracking] Use the computeKnownBits version that returns a KnownBits object instead of taking one by reference. NFC
llvm-svn: 304772
2017-06-06 07:13:11 +00:00
Craig Topper 8365df825e [ValueTracking] Use APInt::intersects to avoid some temporary APInts. NFC
llvm-svn: 304771
2017-06-06 07:13:09 +00:00
Galina Kistanova 244621faad Added LLVM_FALLTHROUGH to address warning: this statement may fall through. NFC.
llvm-svn: 304361
2017-05-31 22:16:24 +00:00
Zaara Syeda 3a7578c658 [PPC] Inline expansion of memcmp
This patch does an inline expansion of memcmp.
It changes the memcmp library call into an inline expansion when the size is
known at compile time and is under a target specified threshold.
This expansion is implemented in CodeGenPrepare and expands into straight line
code. The target specifies a maximum load size and the expansion works by using
this size to load the two sources, compare, and exit early if a difference is
found. It also has a special case when the memcmp result is used in a compare
to zero equality.

Differential Revision: https://reviews.llvm.org/D28637

llvm-svn: 304313
2017-05-31 17:12:38 +00:00
Craig Topper a2025eaaef [ValueTracking] Add OptimizationRemarkEmitter to the other signature for commuteKnownBits.
This is needed for an upcoming patch.

llvm-svn: 303772
2017-05-24 16:53:03 +00:00
Matthias Braun 50ec0b5dce SimplifyLibCalls: Optimize wcslen
Refactor the strlen optimization code to work for both strlen and wcslen.

This especially helps with programs in the wild where people pass
L"string"s to const std::wstring& function parameters and the wstring
constructor gets inlined.

This also fixes a lingerind API problem/bug in getConstantStringInfo()
where zeroinitializers would always give you an empty string (without a
length) back regardless of the actual length of the initializer which
did not work well in the TrimAtNul==false causing the PR mentioned
below.

Note that the fixed getConstantStringInfo() needed fixes to SelectionDAG
memcpy lowering and may lead to some cases for out-of-bounds
zeroinitializer accesses not getting optimized anymore. So some code
with UB may produce out of bound memory reads now instead of just
producing zeros.

The refactoring "accidentally" fixes http://llvm.org/PR32124

Differential Revision: https://reviews.llvm.org/D32839

llvm-svn: 303461
2017-05-19 22:37:09 +00:00
Craig Topper 1a36b7d836 [ValueTracking] Replace all uses of ComputeSignBit with computeKnownBits.
This patch finishes off the conversion of ComputeSignBit to computeKnownBits.

Differential Revision: https://reviews.llvm.org/D33166

llvm-svn: 303035
2017-05-15 06:39:41 +00:00
Craig Topper bb9737247a [InstCombine] Merge duplicate functionality between InstCombine and ValueTracking
Summary:
Merge overflow computation for signed add,
appearing both in InstCombine and ValueTracking.

As part of the merge,
cleanup the interface for overflow checks in InstCombine.

Patch by Yoav Ben-Shalom.

Reviewers: craig.topper, majnemer

Reviewed By: craig.topper

Subscribers: takuto.ikuta, llvm-commits

Differential Revision: https://reviews.llvm.org/D32946

llvm-svn: 303029
2017-05-15 02:44:08 +00:00
Craig Topper 8df66c602a [KnownBits] Add bit counting methods to KnownBits struct and use them where possible
This patch adds min/max population count, leading/trailing zero/one bit counting methods.

The min methods return answers based on bits that are known without considering unknown bits. The max methods give answers taking into account the largest count that unknown bits could give.

Differential Revision: https://reviews.llvm.org/D32931

llvm-svn: 302925
2017-05-12 17:20:30 +00:00
Craig Topper 868813ffbb [ValueTracking] Use KnownOnes to provide a better bound on known zeros for ctlz/cttz intrinics
This patch uses KnownOnes of the input of ctlz/cttz to bound the value that can be returned from these intrinsics. This makes these intrinsics more similar to the handling for ctpop which already uses known bits to produce a similar bound.

Differential Revision: https://reviews.llvm.org/D32521

llvm-svn: 302444
2017-05-08 17:22:34 +00:00
Craig Topper 6e11a05e7e [ValueTracking] Introduce a version of computeKnownBits that returns a KnownBits struct. Begin using it to replace internal usages of ComputeSignBit
This introduces a new interface for computeKnownBits that returns the KnownBits object instead of requiring it to be pre-constructed and passed in by reference.

This is a much more convenient interface as it doesn't require the caller to figure out the BitWidth to pre-construct the object. It's so convenient that I believe we can use this interface to remove the special ComputeSignBit flavor of computeKnownBits.

As a step towards that idea, this patch replaces all of the internal usages of ComputeSignBit with this new interface. As you can see from the patch there were a couple places where we called ComputeSignBit which really called computeKnownBits, and then called computeKnownBits again directly. I've reduced those places to only making one call to computeKnownBits. I bet there are probably external users that do it too.

A future patch will update the external users and remove the ComputeSignBit interface. I'll also working on moving more locations to the KnownBits returning interface for computeKnownBits.

Differential Revision: https://reviews.llvm.org/D32848

llvm-svn: 302437
2017-05-08 16:22:48 +00:00
Craig Topper f0aeee01c3 [KnownBits] Add wrapper methods for setting and clear all bits in the underlying APInts in KnownBits.
This adds routines for reseting KnownBits to unknown, making the value all zeros or all ones. It also adds methods for querying if the value is zero, all ones or unknown.

Differential Revision: https://reviews.llvm.org/D32637

llvm-svn: 302262
2017-05-05 17:36:09 +00:00
Craig Topper 6b3940a4b3 [ValueTracking] Remove handling for BitWidth being 0 in ComputeSignBit and isKnownNonZero.
I don't believe its possible to have non-zero values here since DataLayout became required. The APInt constructor inside of the KnownBits object will assert if this ever happens.

llvm-svn: 302089
2017-05-03 22:25:19 +00:00
Craig Topper d938fd1397 [KnownBits] Add zext, sext, and trunc methods to KnownBits
This patch adds zext, sext, and trunc methods to KnownBits and uses them where possible.

Differential Revision: https://reviews.llvm.org/D32784

llvm-svn: 302088
2017-05-03 22:07:25 +00:00
Matt Arsenault 6a288c1e32 Replace hardcoded intrinsic list with speculatable attribute.
No change in which intrinsics should be speculated.

llvm-svn: 301995
2017-05-03 02:26:10 +00:00
Sanjoy Das 08989c7ecd Rename isKnownNotFullPoison to programUndefinedIfPoison; NFC
Summary:
programUndefinedIfPoison makes more sense, given what the function
does; and I'm about to add a function with a name similar to
isKnownNotFullPoison (so do the rename to avoid confusion).

Reviewers: broune, majnemer, bjarke.roune

Reviewed By: broune

Subscribers: mcrosier, llvm-commits, mzolotukhin

Differential Revision: https://reviews.llvm.org/D30444

llvm-svn: 301776
2017-04-30 19:41:19 +00:00
Craig Topper ca48af3c87 [KnownBits] Add methods for determining if the known bits represent a negative/nonnegative number and add methods for changing the negative/nonnegative state
Summary: This patch adds isNegative, isNonNegative for querying whether the sign bit is known. It also adds makeNegative and makeNonNegative for controlling the sign bit.

Reviewers: RKSimon, spatel, davide

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32651

llvm-svn: 301747
2017-04-29 16:43:11 +00:00
Matt Arsenault cf5e7fe358 [ValueTracking] Teach isSafeToSpeculativelyExecute() about the speculatable attribute
Patch by Tom Stellard

llvm-svn: 301688
2017-04-28 21:13:09 +00:00
Daniel Berlin 4d0fe64ae3 Kill off the old SimplifyInstruction API by converting remaining users.
llvm-svn: 301673
2017-04-28 19:55:38 +00:00
Craig Topper 9eb2d72a1d [ValueTracking] Use APInt::isSubsetOf and APInt::intersects. NFC
llvm-svn: 301654
2017-04-28 16:57:55 +00:00
Craig Topper f42b23f7d8 [ValueTracking] Convert computeKnownBitsFromRangeMetadata to use KnownBits struct.
llvm-svn: 301626
2017-04-28 06:28:56 +00:00
Craig Topper b45eabcf82 [ValueTracking] Introduce a KnownBits struct to wrap the two APInts for computeKnownBits
This patch introduces a new KnownBits struct that wraps the two APInt used by computeKnownBits. This allows us to treat them as more of a unit.

Initially I've just altered the signatures of computeKnownBits and InstCombine's simplifyDemandedBits to pass a KnownBits reference instead of two separate APInt references. I'll do similar to the SelectionDAG version of computeKnownBits/simplifyDemandedBits as a separate patch.

I've added a constructor that allows initializing both APInts to the same bit width with a starting value of 0. This reduces the repeated pattern of initializing both APInts. Once place default constructed the APInts so I added a default constructor for those cases.

Going forward I would like to add more methods that will work on the pairs. For example trunc, zext, and sext occur on both APInts together in several places. We should probably add a clear method that can be used to clear both pieces. Maybe a method to check for conflicting information. A method to return (Zero|One) so we don't write it out everywhere. Maybe a method for (Zero|One).isAllOnesValue() to determine if all bits are known. I'm sure there are many other methods we can come up with.

Differential Revision: https://reviews.llvm.org/D32376

llvm-svn: 301432
2017-04-26 16:39:58 +00:00
Craig Topper f3dbd17d0a [APInt] Use isSubsetOf, intersects, and bit counting methods to reduce temporary APInts
This patch uses various APInt methods to reduce temporary APInt creation.

This should be all of the unrelated cleanups that got buried in D32376(creating a KnownBits struct) as well as some pointed out by Simon during the review of that. Plus a few improvements to use counting instead of masking.

I've left out any places where we do something like (KnownZero & KnownOne) != 0 as I plan to add a helper method to KnownBits to ask that question and didn't want to thrash that code an additional time.

Differential Revision: https://reviews.llvm.org/D32495

llvm-svn: 301338
2017-04-25 17:46:30 +00:00
Craig Topper 2d9afa7745 [ValueTracking] Use APInt::operator|=(uint64_t) instead of creating a temporary APInt. NFC
llvm-svn: 301325
2017-04-25 16:48:14 +00:00
Craig Topper da8ff4181c [ValueTracking] Use APInt instead of auto. NFC
This is a pre-commit for a patch I'm working on to turn KnownZero/One into a struct. Once I do that the type here will be less obvious.

llvm-svn: 301324
2017-04-25 16:48:09 +00:00
Craig Topper 9c932d31e1 [ValueTracking] Use BitWidth local variable instead of re-reading it from KnownZero. NFC
This is a pre-commit for a patch that I'm working on to merge KnownZero/KnownOne into a KnownBits struct which would have had to touch this line.

llvm-svn: 301323
2017-04-25 16:48:03 +00:00
Craig Topper 72f31a8381 [ValueTracking] Use APInt::setAllBits and APInt::intersects to simplify some code. NFC
llvm-svn: 300997
2017-04-21 16:43:32 +00:00
Craig Topper bcfd2d1789 [APInt] Rename getSignBit to getSignMask
getSignBit is a static function that creates an APInt with only the sign bit set. getSignMask seems like a better name to convey its functionality. In fact several places use it and then store in an APInt named SignMask.

Differential Revision: https://reviews.llvm.org/D32108

llvm-svn: 300856
2017-04-20 16:56:25 +00:00
Craig Topper 9b71a402c2 [APInt] Cast calls to add/sub/mul overflow methods to void if only their overflow bool out param is used.
This is preparation for a clang change to improve the [[nodiscard]] warning to not be ignored on methods that return a class marked [[nodiscard]] that are defined in the class itself. See D32207.

We should consider adding wrapper methods to APInt that return the overflow flag directly and discard the APInt result. This would eliminate the void casts and the need to create a bool before the call to pass to the out param.

llvm-svn: 300758
2017-04-19 21:09:45 +00:00
Craig Topper fc947bcfba [APInt] Use lshrInPlace to replace lshr where possible
This patch uses lshrInPlace to replace code where the object that lshr is called on is being overwritten with the result.

This adds an lshrInPlace(const APInt &) version as well.

Differential Revision: https://reviews.llvm.org/D32155

llvm-svn: 300566
2017-04-18 17:14:21 +00:00
Craig Topper d23004c37b Introduce APInt::isSignBitSet/isSignBitClear. Use in place isSignBitSet in place of isNegative in known bits tracking.
This makes statements like KnownZero.isNegative() (which means the value we're tracking is positive) less confusing.

llvm-svn: 300457
2017-04-17 16:38:20 +00:00
Craig Topper da886c665b [InstCombine][ValueTracking] When computing known bits for Srem make sure we don't compute known bits for the LHS twice.
If we already called computeKnownBits for the RHS being a constant power of 2, we've already computed everything we can and should just stop. I think previously we would still recurse if we had determined the result was negative or had not determined the sign bit at all.

llvm-svn: 300432
2017-04-16 21:46:12 +00:00
Craig Topper 66df10ff63 [ValueTracking] Calculate the KnownZeros for Intrinsic::ctpop without using a temporary APInt to count leading zeros on.
The APInt was created from an 'unsigned' and we just wanted to know how many bits the value needed to represent it. We can just use Log2_32 from MathExtras.h to get the info.

llvm-svn: 300309
2017-04-14 06:43:34 +00:00
Craig Topper 1281deaa00 [ValueTracking] Use APInt::isNegative(). NFC
llvm-svn: 300308
2017-04-14 06:43:32 +00:00
Craig Topper f8631cd1de [ValueTracking] Use APInt::sext instead of zext and setBitsFrom. NFC
llvm-svn: 300307
2017-04-14 06:43:29 +00:00
Craig Topper e953dec673 [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.

llvm-svn: 300256
2017-04-13 20:39:37 +00:00
Craig Topper a80f2041f7 [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.
llvm-svn: 300239
2017-04-13 19:04:45 +00:00
Craig Topper 9ce07b6a15 [ValueTracking] Move a temporary APInt instead of copying it.
llvm-svn: 300233
2017-04-13 18:25:53 +00:00
Craig Topper 854824139e [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.

llvm-svn: 300118
2017-04-12 22:29:23 +00:00
Craig Topper 885fa12e8a [APInt] Remove shift functions from APIntOps namespace. Replace the few users with the APInt class methods. NFCI
llvm-svn: 299248
2017-03-31 20:01:16 +00:00