ARM: Don't form a t2LDRi8 or t2STRi8 with an offset of zero.

The load/store optimizer splits LDRD/STRD into two instructions when the
register pairing doesn't work out. For negative offsets in Thumb2, it uses
t2STRi8 to do that. That's fine, except for the case when the offset is in
the range [-4,-1]. In that case, we'll also form a second t2STRi8 with
the original offset plus 4, resulting in a t2STRi8 with a non-negative
offset, which ends up as if it were an STRT, which is completely bogus.
Similarly for loads.

No testcase, unfortunately, as any I've been able to construct is both large
and extremely fragile.

rdar://11193937

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154141 91177308-0d34-0410-b5e6-96231b3b80d8
Deduplicate ARM call-related instructions.

We had special instructions for iOS because r9 is call-clobbered, but
that is represented dynamically by the register mask operands now, so
there is no need for the pseudo-instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154144 91177308-0d34-0410-b5e6-96231b3b80d8
Sink the return instruction collection until after we're done deleting
dead code, including dead return instructions in some cases. Otherwise,
we end up having a bogus poniter to a return instruction that blows up
much further down the road.

It turns out that this pattern is both simpler to code, easier to update
in the face of enhancements to the inliner cleanup, and likely cheaper
given that it won't add dead instructions to the list.

Thanks to John Regehr's numerous test cases for teasing this out.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154157 91177308-0d34-0410-b5e6-96231b3b80d8
Actually finish this sentence in the comment the way I intended. Thanks
Matt for pointing this out.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154158 91177308-0d34-0410-b5e6-96231b3b80d8
Add the tests that were supposed to go with r153935 that I forgot svn add

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154165 91177308-0d34-0410-b5e6-96231b3b80d8
Allow 256-bit shuffles to be split if a 128-bit lane contains elements from a single source. This is a rewrite of the 256-bit shuffle splitting code based on similar code from legalize types. Fixes PR12413.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154166 91177308-0d34-0410-b5e6-96231b3b80d8
DenseMap: Perform the pod-like object optimization when the value type is POD-like, not the DenseMapInfo for it.

Purge now unused template arguments. This has been broken since r91421. Patch by Lubos Lunak!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154170 91177308-0d34-0410-b5e6-96231b3b80d8
Fix narrowing conversion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154171 91177308-0d34-0410-b5e6-96231b3b80d8
Test case for PR12413

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154172 91177308-0d34-0410-b5e6-96231b3b80d8
Make GVN's propagateEquality non-recursive.  No intended functionality change.
The modifications are a lot more trivial than they appear to be in the diff!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154174 91177308-0d34-0410-b5e6-96231b3b80d8
Tweak this test to ensure the inliner did indeed fire. Thanks to Richard
Smith for pointing this out in review.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154178 91177308-0d34-0410-b5e6-96231b3b80d8
Sink the collection of return instructions until after *all*
simplification has been performed. This is a bit less efficient
(requires another ilist walk of the basic blocks) but shouldn't matter
in practice. More importantly, it's just too much work to keep track of
all the various ways the return instructions can be mutated while
simplifying them. This fixes yet another crasher, reported by Daniel
Dunbar.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154179 91177308-0d34-0410-b5e6-96231b3b80d8
Reintroduce InlineCostAnalyzer::getInlineCost() variant with explicit callee
parameter until we have a more sensible API for doing the same thing.

Reviewed by Chandler.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154180 91177308-0d34-0410-b5e6-96231b3b80d8
Allow negative immediates in ARM and Thumb2 compares.

ARM and Thumb2 mode can use cmn instructions to compare against negative
immediates. Thumb1 mode can't.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154183 91177308-0d34-0410-b5e6-96231b3b80d8
Remove llvm-ld and llvm-stub (which is only used by llvm-ld).