There are two attempted optimisations in reMaterializeTrivialDef, trying to
avoid promoting the size of a register too much when rematerializing.
Unfortunately, both appear to be flawed. First, we see if the original register
would have worked, but this is inadequate. Consider:

    v1 = SOMETHING (v1 is QQ)
    v2:Q0 = COPY v1:Q1 (v1, v2 are QQ)
    ...
    uses of v2

In this case even though v2 *could* be used directly as the output of
SOMETHING, this would set the wrong bits of the QQ register involved. The
correct rematerialization must be:

    v2:Q0_Q1 = SOMETHING (v2 promoted to QQQ)
    ...
    uses of v2:Q1_Q2

For the second optimisation, if the correct remat is "v2:idx = SOMETHING" then
we can't necessarily expect v2 itself to be valid for SOMETHING, but we do try
to hunt for a class between v1 and v2 that works. Unfortunately, this is also
wrong:

    v1 = SOMETHING (v1 is QQ)
    v2:Q0_Q1 = COPY v1 (v1 is QQ, v2 is QQQ)
    ...
    uses of v2 as a QQQ

The canonical rematerialization here is "v2:Q0_Q1 = SOMETHING". However current
logic would decide that v2 could be a QQ (no interest is taken in later uses).

This patch, therefore, always accepts the widened register class without trying
to be clever. Generally there is no penalty to this (e.g. in the common GR32 <
GR64 case, expanding the width doesn't matter because it's not like you were
going to do anything else with the high bits of a GR32 register). It can
increase register pressure in cases like the ARM VFP regs though (multiple
non-overlapping but equivalent subregisters). This situation can be
spotted by the fact that both source and destination in the
not-quite-coalesced pair have a sub-register index and
rematerialisation is skipped in that situation.

Unfortunately, no in-tree targets actually expose this as far as I can tell
(there are so few isAsCheapAsAMove instructions for it to trigger on) so I've
been unable to produce a test. It was exposed in our ARM64 SPEC tests though,
and I will be adding a test there that we should be able to contribute
soon(TM).

rdar://problem/15775279

llvm-svn: 199376

flag from clang, and disable zero-base shadow support on all platforms
where it is not the default behavior.

- It is completely unused, as far as we know.
- It is ABI-incompatible with non-zero-base shadow, which means all
objects in a process must be built with the same setting. Failing to
do so results in a segmentation fault at runtime.
- It introduces a backward dependency of compiler-rt on user code,
which is uncommon and complicates testing.

This is the LLVM part of a larger change.

llvm-svn: 199371

llvm-svn: 199369

llvm-svn: 199366

llvm-svn: 199365

Allow x86 mov instructions to/from memory with absolute address to be encoded and disassembled with a segment override prefix. Fixes PR16962.

llvm-svn: 199364

llvm-svn: 199363

This patch adds the capability to dump export table contents. An example
output is this:

  Export Table:
   Ordinal      RVA  Name
         5   0x2008  exportfn1
         6   0x2010  exportfn2

By adding this feature to llvm-objdump, we will be able to use it to check
export table contents in LLD's tests. Currently we are doing binary
comparison in the tests, which is fragile and not readable to humans.

llvm-svn: 199358

llvm-svn: 199357

Move copying of global initializers below the cloning of functions.

The BlockAddress doesn't have access to the correct basic blocks until the
functions have been cloned. This causes the BlockAddress to point to the old
values. Just wait until the functions have been cloned before copying the
initializers.
PR13163

llvm-svn: 199354

Remove use of OpSize for populating VEX_PP field. A prefix encoding is now used instead. Simplify some other code. No functional changes intended.

llvm-svn: 199353

llvm-svn: 199352

underlying object of unknown size.

Fixes PR18460.

llvm-svn: 199351

Patch by Andrew MacPherson. I just tweaked the comment.

llvm-svn: 199350

DataRefImpl (a union of two integers and a pointer) is not the ideal data type
to represent a reference to an import directory entity. We should just use the
pointer to the import table and an offset instead to simplify. No functionality
change.

llvm-svn: 199349

Use DiagnosticInfo to emit the warning.

llvm-svn: 199346

than it needs to be by 1 bit but I need to finish some other things so 
that all the boundary cases will work in that situation. constpool.c
in test-suite will fail to assemble under our new internal test-suite sync
without this change.

llvm-svn: 199343

ARM assembly syntax uses @ for a comment, execpt for the second
parameter of the .symver directive which requires @ as part of the
symbol name. This commit fixes the parsing of this directive by
adding a special case for ARM for this one argumnet.

To make the change we had to move the AllowAtInIdentifier variable
to the MCAsmLexer interface (from AsmLexer) and expose a setter for
the value.  The ELFAsmParser then toggles this value when parsing
the second argument to the .symver directive for a target that
uses @ as a comment symbol

llvm-svn: 199339

Add a hook in the C API of LTO so that clients of the code generator can set
their own handler for the LLVM diagnostics.
The handler is defined like this:
typedef void (*lto_diagnostic_handler_t)(lto_codegen_diagnostic_severity_t
severity, const char *diag, void *ctxt)
- severity says how bad this is.
- diag is a string that contains the diagnostic message.
- ctxt is the registered context for this handler.

This hook is more general than the lto_get_error_message, since this function
keeps only the latest message and can only be queried when something went wrong
(no warning for instance).

<rdar://problem/15517596>

llvm-svn: 199338

This was never used for anything so we should just get rid of it.

llvm-svn: 199337

This fixes a regression intruced by r199135.

Revision 199135 tried to simplify part of the logic in method
DAGCombiner::SimplifyVBinOp introducing calls to method BuildVectorSDNode::isConstant().

However, that revision wrongly changed the check performed by method
SimplifyVBinOp to identify dag nodes that can be folded.
Before revision 199135, that method only tried to simplify vector binary operations
if both operands were build_vector of Constant/ConstantFP/Undef only.

After revision 199135, method SimplifyVBinop tried to
simplify also vector binary operations with only one constant operand.

This fixes the problem restoring the old behavior of SimplifyVBinOp.

llvm-svn: 199328

I did write a version returning ErrorOr<OwningPtr<Binary> >, but it is too
cumbersome to use without std::move. I will keep the patch locally and submit
when we switch to c++11.

llvm-svn: 199326

the | and & bitwise operators.

rdar://15570412

llvm-svn: 199323

llvm-svn: 199316

llvm-svn: 199315

MSVC on x64 requires that we create image relative symbol
references to refer to RTTI data. Seeing as how there is no way to
explicitly make reference to a given relocation type in LLVM IR, pattern
match expressions of the form &foo - &__ImageBase.

Differential Revision: http://llvm-reviews.chandlerc.com/D2523

llvm-svn: 199312

llvm-svn: 199301

llvm-svn: 199299

Add OpSize16 to the two byte forms of INC/DEC that we only use in 64-bit mode and a 64-bit only LEA. Even though we'll not be in 16-bit mode when we use them it makes their tables consistent with their 32-bit counterparts.

llvm-svn: 199297

llvm-svn: 199296

There has been an old FIXME to find the right cut-off for when it's worth
analyzing and potentially transforming a switch to a lookup table.

The switches always have two or more cases. I could not measure any speed-up
by transforming a switch with two cases. A switch with three cases gets a nice
speed-up, and I couldn't measure any compile-time regression, so I think this
is the right threshold.

In a Clang self-host, this causes 480 new switches to be transformed,
and reduces the final binary size with 8 KB.

llvm-svn: 199294

strides

Fixes PR18480.

llvm-svn: 199291

llvm-svn: 199288

The GNU as behavior is a bit different and very strange. It will mark any
label that contains an instruction. We can implement that, but using the
type looks more natural since gas will not mark a function if a .word is
used to output the instructions!

llvm-svn: 199287

When expanding neon pseudo stores, it may miss the implicit uses of sub
regs, which may cause post RA scheduler reorder instructions that
breakes anti dependency.

For example:
  VST1d64QPseudo %R0<kill>, 16, %Q9_Q10, pred:14, pred:%noreg
  will be expanded to
    VST1d64Q %R0<kill>, 16, %D18, pred:14, pred:%noreg;

An instruction that defines %D20 may be scheduled before the store by
mistake.

This patches adds implicit uses for such case. For the example above, it
emits:
  VST1d64Q %R0<kill>, 8, %D18, pred:14, pred:%noreg, %Q9_Q10<imp-use>

llvm-svn: 199282

llvm-svn: 199279

presence of CU ranges.

llvm-svn: 199276

llvm-svn: 199275

llvm-svn: 199269

The changes caused by folding an sp-adjustment into a "pop" previously
disrupted the forward search for the final real instruction in a
terminating block. This switches to a backward search (skipping debug
instrs).

This fixes PR18399.

Patch by Zhaoshi.

llvm-svn: 199266