of reserved registers.

Use RegisterClassInfo in RABasic as well. This slightly changes som
allocation orders because RegisterClassInfo puts CSR aliases last.

llvm-svn: 132581

Previously, these aliases would be ordered alphabetically. (BH, BL)

Print out the computed allocation orders.

llvm-svn: 132580

llvm-svn: 132559

When compiling a program with lots of small functions like
483.xalancbmk, this makes RAFast 11% faster.

Add some comments to clarify the difference between unallocatable and
reserved registers. It's quite subtle.

The fast register allocator depends on EFLAGS' not being allocatable on
x86. That way it can completely avoid tracking liveness, and it won't
mind when there are multiple uses of a single def.

llvm-svn: 132514

Part of rdar://9119939

llvm-svn: 132510

Some register classes are only used for instruction operand constraints.
They should never be used for virtual registers. Previously, those
register classes were given an empty allocation order, but now you can
say 'let isAllocatable=0' in the register class definition.

TableGen calculates if a register is part of any allocatable register
class, and makes that information available in TargetRegisterDesc::inAllocatableClass.

The goal here is to eliminate use cases for overriding allocation_order_*
methods.

llvm-svn: 132508

I was confused whether new uint8_t[] would zero-initialize the returned
array, and it seems that so is gcc-4.0.

This should fix the test failures on darwin 9.

llvm-svn: 132500

llvm-svn: 132488

llvm-svn: 132487

During post RA scheduling, do not try to chase reg defs. to preserve DBG_VALUEs. This approach has several downsides, for example, it does not work when dbg value is a constant integer, it does not work if reg is defined more than once, it places end of debug value range markers in the wrong place. It even causes misleading incorrect debug info when duplicate DBG_VALUE instructions point to same reg def. 

Instead, use simpler approach and let DBG_VALUE follow its predecessor instruction. After live debug value analysis pass, all DBG_VALUE instruction are placed at the right place. Thanks Jakob for the hint!

llvm-svn: 132483

llvm-svn: 132479

This saves two virtual function calls and an Allocatable BitVector test,
making RAFast run 2% faster.

llvm-svn: 132471

Found by valgrind.

llvm-svn: 132457

llvm-svn: 132456

No functional change.

llvm-svn: 132455

register classes.

It provides information for each register class that cannot be
determined statically, like:

- The number of allocatable registers in a class after filtering out the
  reserved and invalid registers.

- The preferred allocation order with registers that overlap callee-saved
  registers last.

- The last callee-saved register that overlaps a given physical register.

This information usually doesn't change between functions, so it is
reused for compiling multiple functions when possible.  The many
possible combinations of reserved and callee saves registers makes it
unfeasible to compute this information statically in TableGen.

Use RegisterClassInfo to count available registers in various heuristics
in SimpleRegisterCoalescing, making the pass run 4% faster.

llvm-svn: 132450

llvm-svn: 132433

llvm-svn: 132427

llvm-svn: 132424

types if the vector type is legal.

Fixes rdar://9306086

llvm-svn: 132420

the TargetLowering enum.

llvm-svn: 132418

This commit caused regressions in i386 flops-[568], matrix, salsa20,
256.bzip2, and enc-md5.

llvm-svn: 132413

rdar://problem/5660695

llvm-svn: 132411

llvm-svn: 132396

This patch is another step in the direction of adding vector select. In this
patch we add a flag to enable a new type legalization decision - to promote
integer elements in vectors. Currently, the rest of the codegen does not support
this kind of legalization.  This flag will be removed when the transition is
complete.

llvm-svn: 132394

For targets with no itinerary (x86) it is a nop by default. For
targets with issue width already expressed in the itinerary (ARM) it
bypasses a scoreboard check but otherwise does not affect the
schedule. It does make the code more consistent and complete and
allows new targets to specify their issue width in an arbitrary way.

llvm-svn: 132385

turns out that it could cause an infinite loop in some situations. If this code
is triggered and it converts a cleanup into a catchall, but that cleanup was in
already in a cleanup, then the _Unwind_SjLj_Resume could infinite loop. I.e.,
the code doesn't consume the exception object and passes it on to
_Unwind_SjLj_Resume. But _USjLjR expects it to be consumed (since it's landing
at a catchall instead of a cleanup). So it uses the values that are presently
there, which are the values that tell it to jump to the fake landing pad.
<rdar://problem/9508402>

llvm-svn: 132381

llvm-svn: 132377

llvm-svn: 132373

llvm-svn: 132371

When assigned ranges are evicted, they are put in the RS_Evicted stage and are
not allowed to evict anything else. That prevents looping automatically.

When evicting ranges just to get a cheaper register, use only spill weights to
find the possible candidates. Avoid breaking hints for this purpose, it is not
worth it.

Start implementing more complex eviction heuristics, guarded by the temporary
-complex-eviction flag. The initial version permits a heavier range to be
evicted if it doesn't have any uses where the evicting range is live. This makes
it a good candidate for live ranfge splitting.

llvm-svn: 132358

llvm-svn: 132309

handler's data area starts with a 4-byte reference to the personality
function, followed by the DWARF LSDA.

llvm-svn: 132302

This commit seems to have broken a darwin 9 tester.

llvm-svn: 132299

This only affects targets like Mips where branch instructions may kill virtual
registers. Most other targets branch on flag values, so virtual registers are
not involved.

The problem is that MachineBasicBlock::updateTerminator deletes branches and
inserts new ones while LiveVariables keeps a list of pointers to instructions
that kill virtual registers. That list wasn't properly updated in
MBB::SplitCriticalEdge.

llvm-svn: 132298

handler.

At this moment, only GCC-style exceptions are supported. Other kinds
of exceptions, including "traditional" SEH and Microsoft Visual C++ exceptions,
need more work--and an compiler exception model that isn't specific to
GCC-style exceptions!

In particular, I imagine that it would be possible to mix "traditional" SEH
with GCC-style EH or Microsoft C++ EH. Currently LLVM has no way (beyond some
target-specific defaults and whole-module compiler switches) of knowing which
scheme to use when.

llvm-svn: 132283

Refactor the type legalizer. Switch TargetLowering to a new enum - LegalizeTypeAction.
This patch does not change the behavior of the type legalizer. The codegen
produces the same code.
This infrastructural change is needed in order to enable complex decisions
for vector types (needed by the vector-select patch).

llvm-svn: 132263

llvm-svn: 132256

transformed by the inliner into a branch to the enclosing landing pad
(when inlined through an invoke).  If not so optimized, it is lowered
DWARF EH preparation into a call to _Unwind_Resume (or _Unwind_SjLj_Resume
as appropriate).  Its chief advantage is that it takes both the
exception value and the selector value as arguments, meaning that there
is zero effort in recovering these;  however, the frontend is required
to pass these down, which is not actually particularly difficult.

Also document the behavior of landing pads a bit better, and make it
clearer that it's okay that personality functions don't always land at
landing pads.  This is just a fact of life.  Don't write optimizations that
rely on pushing things over an unwind edge.

llvm-svn: 132253

llvm-svn: 132250