make it more consistent with its intended semantics.

The `linker_private_weak_def_auto' linkage type was meant to automatically hide
globals which never had their addresses taken. It has nothing to do with the
`linker_private' linkage type, which outputs the symbols with a `l' (ell) prefix
among other things.

The intended semantic is more like the `linkonce_odr' linkage type.

Change the name of the linkage type to `linkonce_odr_auto_hide'. And therefore
changing the semantics so that it produces the correct output for the linker.

Note: The old linkage name `linker_private_weak_def_auto' will still parse but
is not a synonym for `linkonce_odr_auto_hide'. This should be removed in 4.0.
<rdar://problem/11754934>

llvm-svn: 162114

TargetLowering: Use the large shift amount during legalize types. The legalizer may call us with an overly large type.

llvm-svn: 162101

Increment the MBB iterator at the top of the loop to properly handle the
current (and previous) instructions getting erased.

This fixes PR13625.

llvm-svn: 162099

Select instructions pick one of two virtual registers based on a
condition, like x86 cmov. On targets like ARM that support predication,
selects can sometimes be eliminated by predicating the instruction
defining one of the operands.

Teach PeepholeOptimizer to recognize select instructions, and ask the
target to optimize them.

llvm-svn: 162059

pointer.

llvm-svn: 161919

llvm-svn: 161853

llvm-svn: 161851

Add a roundToIntegral method to APFloat, which can be parameterized over various rounding modes.  Use this to implement SelectionDAG constant folding of FFLOOR, FCEIL, and FTRUNC.

llvm-svn: 161807

llvm-svn: 161805

llvm-svn: 161804

It never does anything when running 'make check', and it get's in the
way of updating live intervals in 2-addr.

The hook was originally added to help form IT blocks in Thumb2 code
before register allocation, but the pass ordering has changed since
then, and we run if-conversion after register allocation now.

When the MI scheduler is enabled, there will be no less than two
schedulers between 2-addr and Thumb2ITBlockPass, so this hook is
unlikely to help anything.

llvm-svn: 161794

llvm-svn: 161788

llvm-svn: 161783

llvm-svn: 161782

It is still possible to if-convert if the tail block has extra
predecessors, but the tail phis must be rewritten instead of being
removed.

llvm-svn: 161781

llvm-svn: 161729

This is common e.g. when doing rip-relative addressing on x86_64.

llvm-svn: 161728

Detect when there is not enough available ILP, so if-conversion can't
speculate instructions for free.

Compute the lengthening of the critical path when inserting a select
instruction that depends on the condition as well as both sides of the
if.

Reject conversions that would stretch the critical path by more than
half a mispredict penalty.

llvm-svn: 161713

llvm-svn: 161712

Trace::getResourceLength() computes the number of cycles required to
execute the trace when ignoring data dependencies. The number can be
compared to the critical path to estimate the trace ILP.

Trace::getPHIDepth() computes the data dependency depth of a PHI in a
trace successor that isn't necessarily part of the trace.

llvm-svn: 161711

They identify the PHI predecessors in both diamonds and triangles.

llvm-svn: 161689

When a trace ends with a back-edge, include PHIs in the loop header in
the height computations. This makes the critical path through a loop
more accurate by including the latencies of the last instructions in the
loop.

llvm-svn: 161688

When replacing Old with New, it can happen that New is already a
successor. Add the old and new edge weights instead of creating a
duplicate edge.

llvm-svn: 161653

No changes to these patches, MRI needed to be notified when changing
uses into defs and vice versa.

llvm-svn: 161644

This was the cause of the buildbot failures.

llvm-svn: 161643

These commits broke a number of buildbots.

llvm-svn: 161640

This makes it possible to speed up def_iterator by stopping at the first
use. This makes def_empty() and getUniqueVRegDef() much faster when
there are many uses.

In a +Asserts build, LiveVariables is 100x faster in one case because
getVRegDef() has an assertion that would scan to the end of a
def_iterator chain.

Spill weight calculation is significantly faster (300x in one case)
because isTriviallyReMaterializable() calls MRI->isConstantPhysReg(%RIP)
which calls def_empty(%RIP).

llvm-svn: 161634

Use a more conventional doubly linked list where the Prev pointers form
a cycle. This means it is no longer necessary to adjust the Prev
pointers when reallocating the VRegInfo array.

The test changes are required because the register allocation hint is
using the use-list order to break ties.

llvm-svn: 161633

Register MachineOperands are kept in linked lists accessible via MRI's
reg_iterator interfaces. The linked list management was handled partly
by MachineOperand methods, partly by MRI methods.

Move all of the list management into MRI, delete
MO::AddRegOperandToRegInfo() and MO::RemoveRegOperandFromRegInfo().

Be more explicit about handling the cases where an MRI pointer isn't
available.

llvm-svn: 161632

No test case, the crash only happens when the default use list order is
changed.

llvm-svn: 161627

handle the cases where the memory value type was illegal. 
PR 13111. 

llvm-svn: 161565

That particular optimization was probably premature anyway.

llvm-svn: 161541

We filter out MachineLoop back-edges during the trace-building PO
traversals, but it is possible to have CFG cycles that aren't natural
loops, and MachineLoopInfo doesn't include such cycles.

Use a standard visited set to detect such CFG cycles, and completely
ignore them when picking traces.

llvm-svn: 161532

llvm-svn: 161513

Thanks, Andy!

llvm-svn: 161507

llvm-svn: 161470

It caused an assertion failure when compiling consumer-typeset.

llvm-svn: 161463

We perform the following:
1> Use SUB instead of CMP for i8,i16,i32 and i64 in ISel lowering.
2> Modify MachineCSE to correctly handle implicit defs.
3> Convert SUB back to CMP if possible at peephole.

Removed pattern matching of (a>b) ? (a-b):0 and like, since they are handled
by peephole now.

rdar://11873276

llvm-svn: 161462

The getSumForBlock function was quadratic in the number of successors
because getSuccWeight would perform a linear search for an already known
iterator.

llvm-svn: 161460

llvm-svn: 161454