Fix a typo in comments in r216862, NFC

PR20766 -> PR20776. Thanks Roman Divacky for the catch!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216883 91177308-0d34-0410-b5e6-96231b3b80d8
Add a convenience method to copy wrapping, exact, and fast-math flags (NFC).

The loop vectorizer preserves wrapping, exact, and fast-math properties of scalar instructions.
This patch adds a convenience method to make that operation easier because we need to do this
in the loop vectorizer, SLP vectorizer, and possibly other places.

Although this is a 'no functional change' patch, I've added a testcase to verify that the exact
flag is preserved by the loop vectorizer. The wrapping and fast-math flags are already checked
in existing testcases.

Differential Revision: http://reviews.llvm.org/D5138



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216886 91177308-0d34-0410-b5e6-96231b3b80d8
Use an integer constant for FABS / FNEG (x86).

This change will ease refactoring LowerFABS() and LowerFNEG() 
since they have a lot of overlap.

Remove the creation of a floating point constant from an integer
because it's going to be used for a bitwise integer op anyway.

No change to codegen expected, but the verbose comment string
for asm output may change from float values to hex (integer),
depending on whether the constant already exists or not.

Differential Revision: http://reviews.llvm.org/D5052



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216889 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "Revert two GEP-related InstCombine commits"

This reverts commit r216698 which reverted r216523 and r216598.

We would attempt to perform the transformation even if the match()
failed because, as a side effect, it would set V.  This would trick us
into believing that we correctly found a place to correctly apply the
transform.

An additional test case was added to getelementptr.ll so that we might
not regress in the future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216890 91177308-0d34-0410-b5e6-96231b3b80d8
SROA: Don't insert instructions before a PHI

SROA may decide that it needs to insert a bitcast and would set it's
insertion point before a PHI.  This will create an invalid module
right quick.

Instead, choose the first insertion point in the basic block that holds
our PHI.

This fixes PR20822.

Differential Revision: http://reviews.llvm.org/D5141

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216891 91177308-0d34-0410-b5e6-96231b3b80d8
MC: remove unnecessary enumeration prefix

This is an enum class, and will be appropriately prefixed, making the encoding
type prefix redundant.  No change to any uses as the use of this was not yet
introduced.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216893 91177308-0d34-0410-b5e6-96231b3b80d8
CodeGen: split out the Win64Exception emitter

Move the Windows unwind information emitter into a separate header.  This is not
related to DWARF based emission.  NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216894 91177308-0d34-0410-b5e6-96231b3b80d8
CodeGen: indicate Windows unwind data format

The structures for Windows unwinding are shared across multiple platforms.
Indicate the encoding to be used for the particular target.  Use this to switch
the unwind emitter instantiated by the AsmPrinter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216895 91177308-0d34-0410-b5e6-96231b3b80d8