[SystemZ] Avoid using i8 constants for immediate fields

Immediate fields that have no natural MVT type tended to use i8 if the
field was small enough.  This was a bit confusing since i8 isn't a legal
type for the target.  Fields for short immediates in a 32-bit or 64-bit
operation use i32 or i64 instead, so it would be better to do the same
for all fields.

No behavioral change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212702 91177308-0d34-0410-b5e6-96231b3b80d8
[SystemZ] Add MC support for LEDBRA, LEXBRA and LDXBRA

These instructions aren't used for codegen since the original L*DB instructions
are suitable for fround.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212703 91177308-0d34-0410-b5e6-96231b3b80d8
[x86] Add another combine that is particularly useful for the new vector
shuffle lowering: match shuffle patterns equivalent to an unpcklwd or
unpckhwd instruction.

This allows us to use generic lowering code for v8i16 shuffles and match
the unpack pattern late.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212705 91177308-0d34-0410-b5e6-96231b3b80d8
[SystemZ] Tweak instruction format classifications
    
There's no real need to have Shift as a separate format type from Binary.
The comments for other format types were too specific and in some cases
no longer accurate.

Just a clean-up, no behavioral change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212707 91177308-0d34-0410-b5e6-96231b3b80d8
Revert r212640, "Add trunc (select c, a, b) -> select c (trunc a), (trunc b) combine."

This caused miscompilation on, at least, x86-64. SExt(i1 cond) confused other optimizations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212708 91177308-0d34-0410-b5e6-96231b3b80d8
llvm/test/CodeGen/X86/shift-parts.ll: FileCheck-ize. (from r212640)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212709 91177308-0d34-0410-b5e6-96231b3b80d8
SpecialCaseList.h: Fix -Wdocumentation with \code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212710 91177308-0d34-0410-b5e6-96231b3b80d8
[SystemZ] Use SystemZCallingConv.td to define callee-saved registers
    
Just a clean-up.  No behavioral change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212711 91177308-0d34-0410-b5e6-96231b3b80d8