19964 Commits

Author SHA1 Message Date
Quentin Colombet
7f77b29db7 [GlobalISel] Add a type to MachineInstr.
We actually need that information only for generic instructions, therefore it
would be nice not to have to pay the extra memory consumption for all
instructions. Especially because a typed non-generic instruction does not make
sense.

The question is then, is it possible to have that information in a union or
something?
My initial thought was that we could have a derived class GenericMachineInstr
with additional information, but in practice it makes little to no sense since
generic MachineInstrs are likely turned into non-generic ones by just switching
the opcode. In other words, we don't want to go through the process of creating
a new, non-generic MachineInstr, object each time we do this switch. The memory
benefit probably is not worth the extra compile time.

Another option would be to keep the type of the MachineInstr in a side table.
This would induce an extra indirection though.

Anyway, I will file a PR to discuss about it and remember we need to come back
to it at some point.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260558 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-11 18:22:37 +00:00
Quentin Colombet
b5d0611e18 [GlobalISel] Add a hook in TargetConfigPass to run GlobalISel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260553 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-11 17:57:22 +00:00
Quentin Colombet
fa09f54ecd [GlobalISel][IRTranslator] Change the ownership of the MIRBuilder field.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260551 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-11 17:53:23 +00:00
Quentin Colombet
c778da675d [GlobalISel][IRTranslator] Fix a typo in assert.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260550 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-11 17:52:28 +00:00
Quentin Colombet
bbbe03f0d3 [GlobalISel][IRTranslator] Teach the pass how to translate Add instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260549 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-11 17:51:31 +00:00
Quentin Colombet
eb096dc0d4 [GlobalISel] Add a MachineIRBuilder class.
Helper class to build machine instrs. This is a higher abstraction
than MachineInstrBuilder.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260547 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-11 17:44:59 +00:00
Benjamin Kramer
a25f0be03b Drop the hidden visibility from DebugHandlerBase for now.
If a class has hidden visibility all derived classes and all classes
that have it as a member must have hidden visibility too. That may
be fixable here but requires changes to quite a lot of debug info
classes.

This is also one of the things that GCC enforces aggressively while
clang ignores it, making testing more annoying than necessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260529 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-11 15:41:56 +00:00
Quentin Colombet
30335031a5 [GlobalISel][MachineRegisterInfo] Add a method to create generic vregs.
For now, generic virtual registers will not have a register class. We may want
to change that. For instance, if we want to use all the methods from
TargetRegisterInfo with generic virtual registers, we need to either have some
sort of generic register classes that do what we want, or teach those methods
how to deal with nullptr register class.

Although the latter seems easy enough to do, we may still want to differenciate
generic register classes from nullptr to catch cases where nullptr gets
introduced by a bug of some sort.

Anyway, I will file a PR to keep track of that.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260474 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-11 00:19:17 +00:00
Quentin Colombet
d3bd0e5e8b [GlobalISel] Remember the size of generic virtual registers
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260468 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 23:43:48 +00:00
Quentin Colombet
f62b31051b [GlobalISel] More detailed skeleton for the IRTranslator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260456 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 22:59:27 +00:00
Reid Kleckner
430dfb18e5 [codeview] Describe int local variables using .cv_def_range
Summary:
Refactor common value, scope, and label tracking logic out of DwarfDebug
into a common base class called DebugHandlerBase.

Update an old LLVM IR test case to avoid an assertion in LexicalScopes.

Reviewers: dblaikie, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16931

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260432 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-10 20:55:49 +00:00
Ahmed Bougacha
3248c624fa [CodeGen] Prefer "if (SDValue R = ...)" to "if (R.getNode())". NFCI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260316 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-09 22:54:12 +00:00
Sanjay Patel
068c0ce5f1 [SelectionDAG] make getMemBasePlusOffset() accessible; NFCI
I reinvented this functionality in http://reviews.llvm.org/D16828 because it was
hidden away as a static function. The changes in x86 are not based on a complete
audit. I suspect there are other possible uses there, and there are almost certainly
more potential users in other targets.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260295 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-09 21:42:04 +00:00
Andrew Kaylor
fb2b3b0bed [regalloc][WinEH] Do not mark intervals as not spillable if they contain a regmask
Differential Revision: http://reviews.llvm.org/D16831



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260164 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-08 22:52:51 +00:00
Hans Wennborg
7dfc3433f3 [X86] Don't zero/sign-extend i1, i8, or i16 return values to 32 bits (PR22532)
This matches GCC and MSVC's behaviour, and saves on code size.

We were already not extending i1 return values on x86_64 after r127766. This
takes that patch further by applying it to x86 target as well, and also for i8
and i16.

The ABI docs have been unclear about the required behaviour here. The new i386
psABI [1] clearly states (Table 2.4, page 14) that i1, i8, and i16 return
vales do not need to be extended beyond 8 bits. The x86_64 ABI doc is being
updated to say the same [2].

Differential Revision: http://reviews.llvm.org/D16907

 [1]. https://01.org/sites/default/files/file_attach/intel386-psabi-1.0.pdf
 [2]. https://groups.google.com/d/msg/x86-64-abi/E8O33onbnGQ/_RFWw_ixDQAJ

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260133 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-08 19:34:30 +00:00
Matt Arsenault
98d69cc318 SelectionDAG: Lower some range metadata to AssertZext
If a range has a lower bound of 0, add an AssertZext from the
nearest floor power of two.

This allows operations with some workitem intrinsics with known
maximum ranges to use fast 24-bit multiplies.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@260109 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-08 16:28:19 +00:00
Sanjoy Das
0ba13f53fe [StatepointLower] Use None instead of Optional<int>()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259956 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-05 23:40:04 +00:00
Wei Mi
f2ca031646 Some stackslots are allocated to vregs which have no real reference.
LiveRangeEdit::eliminateDeadDef is used to remove dead define instructions
after rematerialization. To remove a VNI for a vreg from its LiveInterval,
LiveIntervals::removeVRegDefAt is used. However, after non-PHI VNIs are all
removed, PHI VNI are still left in the LiveInterval. Such unused vregs will
be kept in RegsToSpill[] at the end of InlineSpiller::reMaterializeAll and
spiller will allocate stackslot for them.

The fix is to get rid of unused reg by checking whether it has non-dbg
reference instead of whether it has non-empty interval.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259895 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-05 18:14:24 +00:00
Matt Arsenault
4b9655d7ac Fix printing of f16 machine operands
Only single and double FP immediates are correctly printed by
MachineInstr::print() during debug output. Half float type goes to
APFloat::convertToDouble() and hits assertion it is not a double
semantics. This diff prints half machine operands correctly.

This cannot currently be hit by any in-tree target.

Patch by Stanislav Mekhanoshin

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259857 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-05 00:50:18 +00:00
Nemanja Ivanovic
60f6cd1467 Enable the %s modifier in inline asm template string
This patch corresponds to review:
http://reviews.llvm.org/D16847

There are some files in glibc that use the output operand modifier even though
it was deprecated in GCC. This patch just adds support for it to prevent issues
with such files.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259798 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-04 16:18:08 +00:00
Petar Jovanovic
8ed0526e77 [Power PC] softening long double type
This patch implements softening of long double type (ppcf128) on ppc32
architecture and enables operations for this type for soft float.

Patch by Strahinja Petrovic.

Differential Revision: http://reviews.llvm.org/D15811


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259791 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-04 14:43:50 +00:00
Jonas Paulsson
ebc5f75de7 [ScheduleDagInstrs] Improved comments
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259783 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-04 13:08:48 +00:00
Sanjay Patel
4b77eeb789 rangify; NFCI
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259722 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 22:44:14 +00:00
Reid Kleckner
6741ccc7ca [codeview] Remove EmitLabelDiff in favor emitAbsoluteSymbolDiff
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259700 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 21:24:42 +00:00
Reid Kleckner
0495e3ce8d [codeview] Use the MCStreamer interface directly instead of AsmPrinter
This is mostly about having shorter lines and standardizing on one
interface, but it also avoids some needless indirection.

No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259697 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 21:15:48 +00:00
Keno Fischer
7119b269cd [DWARFDebug] Fix another case of overlapping ranges
Summary:
In r257979, I added code to ensure that we wouldn't merge DebugLocEntries if
the pieces they describe overlap. Unfortunately, I failed to cover the case,
where there may have multiple active Expressions in the entry, in which case we
need to make sure that no two values overlap before we can perform the merge.

This fixed PR26148.

Reviewers: aprantl
Differential Revision: http://reviews.llvm.org/D16742

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259696 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 21:13:33 +00:00
Tim Shen
33bf0bd3ea [SelectionDAG] Fix CombineToPreIndexedLoadStore O(n^2) behavior
This patch consists of two parts: a performance fix in DAGCombiner.cpp
and a correctness fix in SelectionDAG.cpp.

The test case tests the bug that's uncovered by the performance fix, and
fixed by the correctness fix.

The performance fix keeps the containers required by the
hasPredecessorHelper (which is a lazy DFS) and reuse them. Since
hasPredecessorHelper is called in a loop, the overall efficiency reduced
from O(n^2) to O(n), where n is the number of SDNodes.

The correctness fix keeps iterating the neighbor list even if it's time
to early return. It will return after finishing adding all neighbors to
Worklist, so that no neighbors are discarded due to the original early
return.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259691 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 20:58:55 +00:00
Jonas Paulsson
8e9339f574 [ScheduleDAGInstrs::buildSchedGraph()] Handling of memory dependecies rewritten.
Recommited, after some fixing with test cases.

Updated test cases:
test/CodeGen/AArch64/arm64-misched-memdep-bug.ll
test/CodeGen/AArch64/tailcall_misched_graph.ll

Temporarily disabled test cases:
test/CodeGen/AMDGPU/split-vector-memoperand-offsets.ll
test/CodeGen/PowerPC/ppc64-fastcc.ll (partially updated)
test/CodeGen/PowerPC/vsx-fma-m.ll
test/CodeGen/PowerPC/vsx-fma-sp.ll

http://reviews.llvm.org/D8705
Reviewers: Hal Finkel, Andy Trick.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259673 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 17:52:29 +00:00
Jun Bum Lim
ccdf189e3e [MachineCopyPropagation] Fix comment. NFC
Reviewers: MatzeB, qcolombet, jmolloy, mcrosier

Subscribers: llvm-commits, mcrosier

Differential Revision: http://reviews.llvm.org/D16806

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259656 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 15:56:27 +00:00
Marcello Maggioni
ecdde6284c RegCoalescer: Making sure re-materialization defines all subranges
The register coalescer can rematerialize constants that define
more of a register than the copy it is going to replace was going
to do.
This is valid in the case the register was undef before the
copy happened.
This patch makes sure that all the subranges defined by the new
rematerialization instructions have at least a dead def.

Review: http://reviews.llvm.org/D16693

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259614 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-03 00:22:32 +00:00
David Majnemer
76ee76499a [codeview] Improve readability of codeview assembly output
Strictly speaking, this is not an improvement in functionality per se
but a usability improvement to those debugging codeview.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259601 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-02 23:18:23 +00:00
Matthias Braun
34a1c16a99 MachineVerifier: Check that defs/uses are live in subregisters as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259552 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-02 20:04:51 +00:00
David Majnemer
b20745dd5e [codeview] Correctly handle inlining functions post-dominated by unreachable
CodeView requires us to accurately describe the extent of the inlined
code.  We did this by grabbing the next debug location in source order
and using *that* to denote where we stopped inlining.  However, this is
not sufficient or correct in instances where there is no next debug
location or the next debug location belongs to the start of another
function.

To get this correct, use the end symbol of the function to denote the
last possible place the inlining could have stopped at.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259548 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-02 19:22:34 +00:00
Eugene Zelenko
380d47d651 Fix Clang-tidy readability-redundant-control-flow warnings; other minor fixes.
Differential revision: http://reviews.llvm.org/D16793


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259539 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-02 18:20:45 +00:00
Reid Kleckner
617bba8af8 [codeview] Wire up the .cv_inline_linetable directive
This directive emits the binary annotations that describe line and code
deltas in inlined call sites. Single-stepping through inlined frames in
windbg now works.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259535 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-02 17:41:18 +00:00
David Majnemer
a101dc9a9c [RegisterCoalescer] Better DebugLoc for reMaterializeTrivialDef
When rematerializing a computation by replacing the copy, use the copy's
location.  The location of the copy is more representative of the
original program.

This partially fixes PR10003.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259469 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-02 06:41:55 +00:00
Matthias Braun
6aca1f7711 MachineVerifier: Use report_context() instead of ad-hoc messages.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259457 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-02 02:44:25 +00:00
Anna Zaks
59203823d7 [safestack] Make sure the unsafe stack pointer is popped in all cases
The unsafe stack pointer is only popped in moveStaticAllocasToUnsafeStack so it won't happen if there are no static allocas.

Fixes https://llvm.org/bugs/show_bug.cgi?id=26122

Differential Revision: http://reviews.llvm.org/D16339

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259447 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-02 01:03:11 +00:00
Balaram Makam
60101204f1 AArch64: Implement missed conditional compare sequences.
Summary:
This is an extension to the existing implementation of r242436 which
restricts to only select inputs. This version fixes missed opportunities
in pr26084 by attempting to lower conditional compare sequences of
and/or trees with setcc leafs. This will additionaly handle the case
when a tree with select input is not a conjunction-disjunction tree
but some of the sub trees are conjunction-disjunction trees.

Reviewers: jmolloy, t.p.northover, mcrosier, MatzeB

Subscribers: mcrosier, llvm-commits, junbuml, haicheng, mssimpso, gberry

Differential Revision: http://reviews.llvm.org/D16291

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259387 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-01 19:13:07 +00:00
Geoff Berry
f4cc19cd22 [PrologEpilogInserter] Add some debug output for callee-save frame object allocation
Reviewers: mcrosier

Subscribers: mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D16733

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259367 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-01 16:47:51 +00:00
Amjad Aboud
71a555ed90 Improved macro emission in dwarf.
Changed emitting offset of macinfo entry into compiler unit DIE to use "addSectionLabel" method rather than explicitly calculating size/offset of macro entry.

Differential Revision: http://reviews.llvm.org/D16292


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259358 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-01 14:09:41 +00:00
David Majnemer
25f74b9089 Revert r258580 and r258581.
Those commits created an artificial edge from a cleanup to a synthesized
catchswitch in order to get the MSVC personality routine to execute
cleanups which don't cleanupret and are not wrapped by a catchswitch.

This worked well enough but is not a complete solution in situations
where there the cleanup infinite loops.

However, the real deal breaker behind this approach comes about from a
degenerate case where the cleanup is post-dominated by unreachable *and*
throws an exception.  This ends poorly because the catchswitch will
inadvertently catch the exception.

Because of this we should go back to our previous behavior of not
executing certain cleanups (identical behavior with the Itanium ABI
implementation in clang, GCC and ICC).

N.B. I think this could be salvaged by making the catchpad rethrow the
exception and properly transforming throwing calls in the cleanup into
invokes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259338 91177308-0d34-0410-b5e6-96231b3b80d8
2016-02-01 03:29:38 +00:00
Tim Shen
a750479355 [SelectionDAG] Eliminate exponential behavior in WalkChainUsers
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259315 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-31 03:59:34 +00:00
Matthias Braun
5e08bd340a Avoid overly large SmallPtrSet/SmallSet
These sets perform linear searching in small mode so it is never a good
idea to use SmallSize/N bigger than 32.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259283 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-30 01:24:31 +00:00
Manman Ren
77c763c1a3 [Objective-C] Support a new special module flag.
"Objective-C Class Properties" will be put into the objc_imageinfo struct.

rdar://23891898


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259270 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-29 23:51:00 +00:00
Yaron Keren
55307987a1 Annotate dump() methods with LLVM_DUMP_METHOD, addressing Richard Smith r259192 post commit comment.
clang part in r259232, this is the LLVM part of the patch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259240 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-29 20:50:44 +00:00
Reid Kleckner
b5d1bc265b [codeview] Begin to add support for inlined call sites
Summary:
There are three parts to inlined call frames:
1. The inlinee line subsection
2. The inline site symbol record
3. The function ids referenced by both

This change starts by emitting function ids (3) for all subprograms and
emitting the base inline site symbol record (2). The actual line numbers
in (2) use an encoded format that will come next, along with the inlinee
line subsection.

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D16333

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259217 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-29 18:16:43 +00:00
Jonas Paulsson
c8d11e8593 Temporarily revert "[ScheduleDAGInstrs::buildSchedGraph()] Handling of memory dependecies rewritten."
Some buildbot failures needs to be debugged.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259213 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-29 17:22:43 +00:00
Jonas Paulsson
72374d2610 [ScheduleDAGInstrs::buildSchedGraph()] Handling of memory dependecies rewritten.
The buildSchedGraph() was in need of reworking as the AA features had been
added on top of earlier code. It was very difficult to understand, and buggy.
There had been found cases where scheduling dependencies had actually been
missed (see r228686).

AliasChain, RejectMemNodes, adjustChainDeps() and iterateChainSucc() have
been removed. There are instead now just the four maps from Value to SUs, which
have been renamed to Stores, Loads, NonAliasStores and NonAliasLoads.

An unknown store used to become the AliasChain, but now becomes a store mapped
to 'unknownValue' (in Stores). What used to be PendingLoads is instead the
list of SUs mapped to 'unknownValue' in Loads.

RejectMemNodes and adjustChainDeps() used to be a safety-net for everything.
The SU maps were sometimes cleared and SUs were put in RejectMemNodes, where
adjustChainDeps() would look. Instead of this, a more straight forward approach
is used in maintaining the SU maps without clearing them and simply letting
them grow over time. Instead of the cutt-off in adjustChainDeps() search, a
reduction of maps will be done if needed (see below).

Each SUnit either becomes the BarrierChain, or is put into one of the maps. For
each SUnit encountered, all the information about previous ones are still
available until a new BarrierChain is set, at which point the maps are cleared.

For huge regions, the algorithm becomes slow, therefore the maps will get
reduced at a threshold (current default is 1000 nodes), by a fraction (default 1/2).
These values can be tuned by use of CL options in case some test case shows that
they need to be changed (-dag-maps-huge-region and -dag-maps-reduction-size).

There has not been any considerable change observed in output quality or compile
time. There may now be more DAG edges inserted than before (i.e. if A->B->C,
then A->C is not needed). However, in a comparison run there were fewer total
calls to AA, and a somewhat improved compile time, which means this seems to
be not a problem.

http://reviews.llvm.org/D8705
Reviewers: Hal Finkel, Andy Trick.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259201 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-29 16:11:18 +00:00
Junmo Park
7d3e90397f Minor code cleanup. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259139 91177308-0d34-0410-b5e6-96231b3b80d8
2016-01-29 01:39:39 +00:00