Insert instructions to the entry basic block which initializes the global
pointer register. 


This is the first of the series of patches which clean up the way global pointer
register is used. The patches will make the following improvements:

- Make $gp an allocatable temporary register rather than reserving it.
- Use a virtual register as the global pointer register and let the register
  allocator decide which register to assign to it or whether spill/reloads are
  needed.
- Make sure $gp is valid at the entry of a called function, which is necessary
  for functions using lazy binding.
- Remove the need for emitting .cprestore and .cpload directives.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156671 91177308-0d34-0410-b5e6-96231b3b80d8
Don't look for empty live ranges in the unions.

Empty live ranges represent undef and still get allocated, but they
won't appear in LiveIntervalUnions.

Patch by Patrik Hägglund!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156685 91177308-0d34-0410-b5e6-96231b3b80d8
Hoist simpler checks above llvm::PointerMayBeCaptured. No functional change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156687 91177308-0d34-0410-b5e6-96231b3b80d8
Make the following changes in MipsAsmPrinter.cpp:

- Remove code which lowers pseudo SETGP01.
- Fix LowerSETGP01. The first two of the three instructions that are emitted to
  initialize the global pointer register now use register $2.
- Stop emitting .cpload directive.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156689 91177308-0d34-0410-b5e6-96231b3b80d8
Speed up computeComposites() by using the new SubReg -> SubIdx map.

TableGen doesn't need to search through the SubRegs map to find an
inverse entry.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156690 91177308-0d34-0410-b5e6-96231b3b80d8
Make the following changes in MipsFrameLowering.cpp:

- Stop emitting instructions needed to initialize the global pointer register.
- Stop emitting .cprestore directive.
- Do not take into account the $gp save slot when computing stack size.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156691 91177308-0d34-0410-b5e6-96231b3b80d8
Make the following changes in MipsISelLowering.cpp:

- Stop creating stack frame objects needed for saving $gp.
- Insert a node that copies the global pointer register to register $gp
  before the call node. This will ensure $gp is valid at the entry of the
  called function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156692 91177308-0d34-0410-b5e6-96231b3b80d8
Do not add the pass which restores $gp after every function call.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156693 91177308-0d34-0410-b5e6-96231b3b80d8
Stop reserving register $gp. Do not call isGPFI to check whether a frame object
is the $gp save slot.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156694 91177308-0d34-0410-b5e6-96231b3b80d8
Delete all functions that are no longer needed in MipsFunctionInfo, including
the ones that get or set the frame index for the $gp save slot. 

Remove the piece of code in MipsFunctionInfo::getGlobalBaseReg() which returns
GP. This function should always return a virtual register.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156695 91177308-0d34-0410-b5e6-96231b3b80d8
Remove MipsEmitGPRestore.cpp.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156696 91177308-0d34-0410-b5e6-96231b3b80d8
Fix test cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156697 91177308-0d34-0410-b5e6-96231b3b80d8
Support for Hexagon feature, New Value Jump.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156698 91177308-0d34-0410-b5e6-96231b3b80d8
Make sure new value jump is enabled for Hexagon V5 as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156700 91177308-0d34-0410-b5e6-96231b3b80d8
Teach Function::hasAddressTaken that BlockAddress doesn't really take
the address of a function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156703 91177308-0d34-0410-b5e6-96231b3b80d8
Recommited r156374 with critical fixes in BitcodeReader/Writer:
Ordinary patch for PR1255.
Added new case-ranges orientated methods for adding/removing cases in SwitchInst. After this patch cases will internally representated as ConstantArray-s instead of ConstantInt, externally cases wrapped within the ConstantRangesSet object.
Old methods of SwitchInst are also works well, but marked as deprecated. So on this stage we have no side effects except that I added support for case ranges in BitcodeReader/Writer, of course test for Bitcode is also added. Old "switch" format is also supported.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156704 91177308-0d34-0410-b5e6-96231b3b80d8
AsmParser: Add support for .ifb and .ifnb directives.

Based on a patch from PaX Team.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156705 91177308-0d34-0410-b5e6-96231b3b80d8
AsmParser: Add support for .ifc and .ifnc directives.

Based on a patch from PaX Team.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156706 91177308-0d34-0410-b5e6-96231b3b80d8
AsmParser: ignore the .extern directive.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156707 91177308-0d34-0410-b5e6-96231b3b80d8
AsmParser: Give a nice error message for .code16gcc, which is currently unsupported.

Patch by Team PaX!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156708 91177308-0d34-0410-b5e6-96231b3b80d8