[x86] Fix a large collection of bugs that crept in as I fleshed out the
AVX support.

New test cases included. Note that none of the existing test cases
covered these buggy code paths. =/ Also, it is clear from this that
SHUFPS and SHUFPD are the most bug prone shuffle instructions in x86. =[

These were all detected by fuzz-testing. (I <3 fuzz testing.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218522 91177308-0d34-0410-b5e6-96231b3b80d8
[x86] In the new vector shuffle lowering, when trying to do another
layer of tie-breaking sorting, it really helps to check that you're in
a tie first. =] Otherwise the whole thing cycles infinitely. Test case
added, another one found through fuzz testing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218523 91177308-0d34-0410-b5e6-96231b3b80d8
[x86] The mnemonic is SHUFPS not SHUPFS. =[ I'm very bad at spelling
sadly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218524 91177308-0d34-0410-b5e6-96231b3b80d8
Ignore annotation function calls in cost computation

The annotation instructions are dropped during codegen and have no
impact on size.  In some cases, the annotations were preventing the
unroller from unrolling a loop because the annotation calls were
pushing the cost over the unrolling threshold.

Differential Revision: http://reviews.llvm.org/D5335



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218525 91177308-0d34-0410-b5e6-96231b3b80d8