This patch fills the last necessary bits to enable exceptions
handling in LLVM. Currently only on x86-32/linux.

In fact, this patch adds necessary intrinsics (and their lowering) which
represent really weird target-specific gcc builtins used inside unwinder.

After corresponding llvm-gcc patch will land (easy) exceptions should be
more or less workable. However, exceptions handling support should not be 
thought as 'finished': I expect many small and not so small glitches
everywhere.

llvm-svn: 39855

llvm-svn: 38501

llvm-svn: 37894

llvm-svn: 37342

llvm-svn: 37066

llvm-svn: 36916

Don't spill extra register to align the stack.

llvm-svn: 36814

Patch by Raul Herbster.

llvm-svn: 36690

llvm-svn: 36626

argument space for call sites in the function immediately on entry to the
current function. This eliminates the need for add/sub sp brackets around call
sites. However, this is not always a good idea. If the "call frame" is large and
the target load / store instructions have small immediate field to encode sp
offset, this can cause poor codegen. In the worst case, this can make it
impossible to scavenge a register if the reserved spill slot is pushed too far
apart from sp / fp.

llvm-svn: 36607

llvm-svn: 36514

llvm-svn: 36512

llvm-svn: 36452

Reported by Raul Herbster.

llvm-svn: 36262

target for tabs checking.

llvm-svn: 36146

llvm-svn: 35627

llvm-svn: 35205

llvm-svn: 35163

llvm-svn: 34990

llvm-svn: 34987

llvm-svn: 34966

llvm-svn: 34824

llvm-svn: 34785

- Some code clean up.

llvm-svn: 34783

llvm-svn: 34763

llvm-svn: 34711

llvm-svn: 34708

llvm-svn: 34692

llvm-svn: 34537

llvm-svn: 34514

llvm-svn: 34482

llvm-svn: 34428

Revert patches that caused the problem. Evan, please investigate and reapply
when you've discovered the problem.

llvm-svn: 34399

llvm-svn: 34376

llvm-svn: 34013

llvm-svn: 34011

llvm-svn: 34010

llvm-svn: 34009

that is the case, whenever we use it as a scratch register, save it to R12
first and then restore it after the use.
This is a temporary and truly horrible workaround!

llvm-svn: 33999

- If there is a dynamic alloca, in the epilogue, restore the value of sp
  using r7 - offset.
- Other bug fixes.

llvm-svn: 33997