llvm-svn: 37524

llvm-svn: 37523

simultaneously.  Move that pass to SimpleRegisterCoalescing.

This makes it easier to implement alternative register allocation and
coalescing strategies while maintaining reuse of the existing live
interval analysis.

llvm-svn: 37520

llvm-svn: 37518

how much will be used.

llvm-svn: 37515

llvm-svn: 37511

is too slow.

llvm-svn: 37509

llvm-svn: 37503

llvm-svn: 37496

ifcvt a triangle: don't merge ifcvt block with rejoin block if it can fall through to it. If merged, the resulting block is not a candidate for iterative ifcvting since it contains both predicated and non-predicated code.

llvm-svn: 37487

llvm-svn: 37485

Evan, please check that this is in fact correct.

llvm-svn: 37471

same, only output one copy of the common part.

llvm-svn: 37470

llvm-svn: 37467

correct machine basic block - do not rely on the eh.exception intrinsic
being in the landing pad: the loop optimizers can move it out.

llvm-svn: 37463

If a unconditional branch is added to branch to the false path during ifcvt, the predicated block cannot be iteratively ifcvted.

llvm-svn: 37456

llvm-svn: 37451

llvm-svn: 37449

llvm-svn: 37444

llvm-svn: 37441

llvm-svn: 37440

llvm-svn: 37433

If the predicated block requires an early exit, end the block there and add a unconditional branch to false block. AnalyzeBranch() does not understand early exits.

llvm-svn: 37430

llvm-svn: 37429

llvm-svn: 37427

llvm-svn: 37421

llvm-svn: 37420

llvm-svn: 37413

that the CSE map always contains explicit alignment information. This allows
more loads to be CSE'd when there is a mix of explicit-alignment loads and
implicit-alignment loads.

Also, in SelectionDAG::FindModifiedNodeSlot, add the operands to the
FoldingSetNodeID before the load/store information instead of after, so
that it matches what is done elsewhere.

llvm-svn: 37411

Let IfConverter loose. Allow more aggressive subsumptions; reorder basic blocks to expose more ifcvt opportunities; code clean up and fixes.

llvm-svn: 37409

llvm-svn: 37408

(landing pad) when an exception unwinds through the call.  This doesn't
quite match the way the dwarf unwinder works: by default it only jumps to
the landing pad if the catch or filter specification matches, and otherwise
it keeps on unwinding.  There are two ways of specifying to the unwinder
that it should "always" (more on why there are quotes here later) jump to
the landing pad: follow the specification by a 0 typeid, or follow it by
the typeid for the NULL typeinfo.  GCC does the first, and this patch makes
LLVM do the same as gcc.  However there is a problem: the unwinder performs
optimizations based on C++ semantics (it only expects destructors to be
run if the 0 typeid fires - known as "cleanups"), meaning it assumes that no
exceptions will be raised and that the raised exception will be reraised
at the end of the cleanup code.  So if someone writes their own LLVM code
using the exception intrinsics they will get a nasty surprise if they don't
follow these rules.  The other possibility of using the typeid corresponding
to NULL (catch-all) causes the unwinder to make no assumptions, so this is
probably what we should use in the long-run.  However since we are still
having trouble getting exception handling working properly, for the moment
it seems best to closely imitate GCC.

llvm-svn: 37399

simplifies the code in DwarfWriter, allows for multiple filters and
makes it trivial to specify filters accompanied by cleanups or catch-all
specifications (see next patch).  What a deal!  Patch blessed by Anton.

llvm-svn: 37398

llvm-svn: 37397

llvm-svn: 37394

llvm-svn: 37393

See test/CodeGen/X86/test-pic-jtbl.ll for a case where it works well;
shaves another 10K off our favorite benchmark.  I was hesitant about
this because of compile speed, but seems to do OK on a bootstrap.

llvm-svn: 37392

llvm-svn: 37387

as a null i8 pointer not as a 0 i32.

llvm-svn: 37383

Ifcvt triangle: don't ifcvt 'true' BB if it has other predecessors; don't merge 'false' BB if it has other predecessors.

llvm-svn: 37382