Fixes PR30730.
This is a re-commit of a pulled commit. The commit was pulled because some
software projects contained uses of Altivec vectors that violated alignment
requirements. Known issues have now been fixed.

Committing on behalf of Lei Huang.

Differential Revision: https://reviews.llvm.org/D26861

llvm-svn: 301892

r288279 mistakenly added it to all arches, but it's only available
from v8.1 onwards.

The testcase is awkward, because (I suspect) of PR32873.

Spotted by inspection.

llvm-svn: 301890

Because it was a callee-saved register, we automatically generated code
to spill and unspill its original value so that it is restored after the
function returns.

The problem is that this code was being generated before the epilogue.
The epilogue itself uses the Y register, which could be prematurely
restored by the CSR restoration process.

This removes R29R28 from the CSR list and changes the prologue/epilogue
code to handle it explicitly.

llvm-svn: 301887

This change caused buildbot failures, apparently because we're not
passing around types that InstSimplify is used to seeing. I'm not overly
familiar with InstSimplify, so I'm reverting this until I can figure out
what exactly is wrong.

llvm-svn: 301885

Rename parameters and locals to CamelCase, doxygenize the header, and
run clang-format on the whole thing.

llvm-svn: 301883

Differential Revision: https://reviews.llvm.org/D32716

llvm-svn: 301882

This is a temporary measure while we figure out a way to get the frame
pointer working correctly.

llvm-svn: 301881

In particular (since it wouldn't fit nicely in the summary):
(select (icmp eq V 0) P (getelementptr P V)) -> (getelementptr P V)

Differential Revision: https://reviews.llvm.org/D31435

llvm-svn: 301880

[X86] Reduce code for setting operations actions by merging into loops across multiple types/ops. NFCI.

llvm-svn: 301879

llvm-svn: 301878

llvm-svn: 301877

llvm-svn: 301852

This tracks whether MaxCallFrameSize is computed yet. Ideally we would
assert and fail when the value is queried before it is computed, however
this fails various targets that need to be fixed first.

Differential Revision: https://reviews.llvm.org/D32570

llvm-svn: 301851

llvm-svn: 301850

In the testcase attached,  we believe %tmp1 implies %tmp4.
where:
  br i1 %tmp1, label %bb2, label %bb7
  br i1 %tmp4, label %bb5, label %bb7

because Wwhile looking at PredicateInfo stuffs we end up calling
isImpliedTrueByMatchingCmp() with the arguments backwards.

Differential Revision:  https://reviews.llvm.org/D32718

llvm-svn: 301849

If we have ~(~X & Y), it only makes sense to transform it to (X | ~Y) when we do not need 
the intermediate (~X & Y) value. In that case, we would need an extra instruction to 
generate ~Y + 'or' (as shown in the test changes).

It's ok if we have multiple uses of ~X or Y, however. In those cases, we may not reduce the
instruction count or critical path, but we might improve throughput because we can generate 
~X and ~Y in parallel. Whether that actually makes perf sense or not for a target is something 
we can't answer in IR.

Differential Revision: https://reviews.llvm.org/D32703

llvm-svn: 301848

lldb-dwarfdump gets a new "--verify" option that will verify a single file's DWARF debug info and will print out any errors that it finds. It will return an non-zero exit status if verification fails, and a zero exit status if verification succeeds. Adding the --quiet option will suppress any output the STDOUT or STDERR.

The first part of the verify does the following:

- verifies that all CU relative references (DW_FORM_ref1, DW_FORM_ref2, DW_FORM_ref4, DW_FORM_ref8, DW_FORM_ref_udata) have valid CU offsets
- verifies that all DW_FORM_ref_addr references have valid .debug_info offsets
- verifies that all DW_AT_ranges attributes have valid .debug_ranges offsets
- verifies that all DW_AT_stmt_list attributes have valid .debug_line offsets
- verifies that all DW_FORM_strp attributes have valid .debug_str offsets

Unit tests were added for each of the above cases.

Differential Revision: https://reviews.llvm.org/D32707

llvm-svn: 301844

This is to prepare for an upcoming change which uses pointers instead of
GUIDs to represent references.

Differential Revision: https://reviews.llvm.org/D32469

llvm-svn: 301843

[APInt] In operator!, handle single word case by comparing VAL to 0 directly and handle multiword case by comparing countLeadingZerosSlowCase() to BitWidth.

We were using operator=(0) which implicitly calls countLeadingZeros but only to compare with 64 to determine if we can compare VAL or pVal[0] to uint64_t. By handling the multiword case with countLeadingZerosSlowCase==BitWidth we can prevent a load of pVal[0] from being inserted inline at each call site. This saves a little bit of code size.

llvm-svn: 301842

NFC

llvm-svn: 301841

llvm-svn: 301838

llvm-svn: 301835

Since the shuffle refactor, this is only used during BUILD_VECTOR lowering.

llvm-svn: 301834

Differential Revision: https://reviews.llvm.org/D32195

llvm-svn: 301832

A .cur instruction can be identified by checking isCVINew() && mayLoad().

Patch by Colin LeMahieu.

llvm-svn: 301829

Patch by Colin LeMahieu.

llvm-svn: 301828

Patch by Colin LeMahieu.

llvm-svn: 301827

Patch by Colin LeMahieu.

llvm-svn: 301823

Otherwise an indeterminate value gets read, causing a bunch of UBSan failures.

llvm-svn: 301819

This was an omission in r301813.  I had made the supporting changes to
make this happen, but I forgot to actually update the PrevPair
declaration.

llvm-svn: 301817

We may not be able to rewrite indirect branch target, but we also want to take it into
account when folding, i.e. if it and all its successor's predecessors go to the same
destination, we can fold, i.e. no need to thread.

llvm-svn: 301816

In cases where an instruction (a call site, say) is RAUW'ed with some
other value (this is possible via the `returned` attribute, for
instance), we want the slot in UnknownInsts to point to the original
Instruction we wanted to track, not the value it got replaced by.

Fixes PR32587.

This relands r301426.

llvm-svn: 301814

This relands r301425.

llvm-svn: 301813

This relands r301424.

llvm-svn: 301812

llvm-svn: 301811

In preparation for introducing writing capabilities for each of
these classes, I would like to adopt a Foo / FooRef naming
convention, where Foo indicates that the class can manipulate and
serialize Foos, and FooRef indicates that it is an immutable view of
an existing Foo.  In other words, Foo is a writer and FooRef is a
reader.  This patch names some existing readers to conform to the
FooRef convention, while offering no functional change.

llvm-svn: 301810

Summary:
This frees up one slot in the HandleBaseKind enum, which I will use
later to add a new kind of value handle.  The size of the
HandleBaseKind enum is important because we store a HandleBaseKind in
the low two bits of a (in the worst case) 4 byte aligned pointer.

Reviewers: davide, chandlerc

Subscribers: mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D32634

llvm-svn: 301809

llvm-svn: 301808

Patch by: Gergely Angeli!

Differential Revision: https://reviews.llvm.org/D31936

llvm-svn: 301807

[SelectionDAG] Use known ones to provide a better bound for the known zeros for CTTZ/CTLZ operations.

This is the SelectionDAG version of D32521. If know where at least one 1 is located in the input to these intrinsics we can place an upper bound on the number of bits needed to represent the count and thus increase the number of known zeros in the output.

I think we can also refine this further for CTTZ_UNDEF/CTLZ_UNDEF by assuming that the answer will never be BitWidth. I've left this out for now because it caused other test failures across multiple targets. Usually because of turning ADD into OR based on this new information.

I'll fix CTPOP in a future patch.

Differential Revision: https://reviews.llvm.org/D32692

llvm-svn: 301806