llvm-svn: 106770

CoalescerPair can determine if a copy can be coalesced, and which register gets
merged away. The old logic in SimpleRegisterCoalescing had evolved into
something a bit too convoluted.

This second attempt fixes some crashes that only occurred Linux.

llvm-svn: 106769

llvm-svn: 106768

[L]oad, [u]se, [d]ef, or [S]tore slots.

This makes it easier to see if two indices refer to the same instruction,
avoiding mental mod 4 calculations.

llvm-svn: 106766

which trivially fold away.

llvm-svn: 106765

llvm-svn: 106764

enough special case, and it theoretically allows more folding because
it works even when x is unanalyzable.

llvm-svn: 106763

form so they can be narrowed to 16-bit instructions.

llvm-svn: 106762

was over-complicated.

llvm-svn: 106760

llvm-svn: 106759

handling of pointer types.

llvm-svn: 106757

instead of a StringRef, avoiding the need to copy the string in the
common case.

llvm-svn: 106754

Also keep track of the original DstREg before subregister adjustments.

llvm-svn: 106753

llvm-svn: 106752

In this case it is essential that the kill is real because the spiller will
decide to omit a spill if it thinks there is a later kill.

llvm-svn: 106751

llvm-svn: 106750

as many tests as possible.

llvm-svn: 106749

when the condition is constant. This optimization shouldn't be
necessary, because codegen shouldn't be able to find dead control
paths that the IR-level optimizer can't find. And it's undesirable,
because it encourages bugpoint to leave "br i1 false" branches
in its output. And it wasn't updating the CFG.

I updated all the tests I could, but some tests are too reduced
and I wasn't able to meaningfully preserve them.

llvm-svn: 106748

llvm-svn: 106747

llvm-svn: 106746

llvm-svn: 106745

llvm-svn: 106744

llvm-svn: 106743

llvm-svn: 106740

llvm-svn: 106737

llvm-svn: 106736

llvm-svn: 106734

llvm-svn: 106731

llvm-svn: 106730

llvm-svn: 106729

llvm-svn: 106728

rdar://8013734

llvm-svn: 106725

llvm-svn: 106724

llvm-svn: 106723

Patch by Ben Ransford!

llvm-svn: 106722

bt instruction, which was exposed by r106263.

llvm-svn: 106718

llvm-svn: 106717

case where the bit mask has exactly one bit.

llvm-svn: 106716

Whiny buildbots.

llvm-svn: 106710

llvm-svn: 106709