Add some switches helpful for debugging:

-print-before=<Pass Name>

Dump IR before running pass <Pass Name>.

-print-before-all

Dump IR before running each pass.

-print-after-all

Dump IR after running each pass.

These are helpful when tracking down a miscompilation.  It is easy to
get IR dumps and do diffs on them, etc.

To make this work well, add a new getPrinterPass API to Pass so that
each kind of pass (ModulePass, FunctionPass, etc.) can create a Pass
suitable for dumping out the kind of object the Pass works on.

llvm-svn: 100143

Do not eagerly record known previous location. DBG_VALUE may not cause a new label due to one or other reason.

llvm-svn: 100134

llvm-svn: 100133

- Do not try to infer GV alignment unless its type is sized. It's not possible to infer alignment if it has opaque type.

llvm-svn: 100118

llvm-svn: 100117

Update comment, rename a local variable.

llvm-svn: 100116

1. Makes it possible to lower with floating point loads and stores.
2. Avoid unaligned loads / stores unless it's fast.
3. Fix some memcpy lowering logic bug related to when to optimize a
   load from constant string into a constant.
4. Adjust x86 memcpy lowering threshold to make it more sane.
5. Fix x86 target hook so it uses vector and floating point memory
   ops more effectively.
rdar://7774704

llvm-svn: 100090

llvm-svn: 100065

llvm-svn: 100062

llvm-svn: 100058

* Set the "DestA" and "DestB" according to how they're understood by the
  method. I.e., if one or both of them should point to the "fall through" block,
  then point to the fall through block.

* Improve the loop that removes superfluous edges to be more understandable.

llvm-svn: 100056

Debug info can now properly represent functions inside classes inside other functions.  Partial fix for Radar 7424645.

llvm-svn: 100048

llvm-svn: 100038

POD-like anyway, so we don't even care about calling their d'tors (DIEBlock
being the exception).

~6% less mallocs and ~1% compile time improvement on clang -O0 -g oggenc.c

llvm-svn: 100035

llvm-svn: 99999

llvm-svn: 99998

llvm-svn: 99995

llvm-svn: 99993

llvm-svn: 99992

llvm-svn: 99989

llvm-svn: 99986

instructions.  In addition to being a convenience,
they are faster than the old apis, particularly when
not going from an MDKindID like people should be
doing.

llvm-svn: 99982

llvm-svn: 99948

llvm-svn: 99938

e.g., llvm.memcpy.i32(i8*, i8*, i32, i32) -> llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i32, i1)
A update of langref will occur in a subsequent checkin.

llvm-svn: 99928

only a single type of object to be allocated. Use it to make VNInfo destruction
typesafe.

llvm-svn: 99919

create symbols.  It is extremely error prone and a source of a lot
of the remaining integrated assembler bugs on x86-64.

This fixes rdar://7807601.

llvm-svn: 99902

llvm-svn: 99901

llvm-svn: 99899

llvm-svn: 99895

llvm-svn: 99883

llvm-svn: 99882

on all objects it has allocated, if they are all of the same size and alignment.
Use this to destruct all VNInfos allocated in LiveIntervalAnalysis (PR6653).

valnos is not reliable for this purpose, as seen in r99400
(which still leaked, and sometimes caused double frees).

llvm-svn: 99881

llvm-svn: 99879

catch-all. The "dominates" way won't catch all of the selectors which must be
changed.

llvm-svn: 99850

transform. I.e., if a clean-up eh.selector call dominates the invoke of an
_Unwind_Resume_or_Rethrow, then we convert the eh.selector into a
catch-all. This patch, however, uses the DominatorTree information, and doesn't
go through the whole rigmarole of starting at the eh.exception call, finding the
corresponding URoR and eh.selector calls, and trying to trace through any number
of instruction types to get to them.

llvm-svn: 99846

Encode start location of debug value, communicated through DBG_VALUE machine instruction, in a variable's DIE. 

llvm-svn: 99845

llvm-svn: 99840

llvm-svn: 99836

llvm-svn: 99833