InstCombine: Improvement to check if signed addition overflows.

This patch implements two things:

1. If we know one number is positive and another is negative, we return true as
    signed addition of two opposite signed numbers will never overflow.

2. Implemented TODO : If one of the operands only has one non-zero bit, and if
    the other operand has a known-zero bit in a more significant place than it
    (not including the sign bit) the ripple may go up to and fill the zero, but
    won't change the sign. e.x -  (x & ~4) + 1

We make sure that we are ignoring 0 at MSB.

Patch by Suyog Sarda.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210186 91177308-0d34-0410-b5e6-96231b3b80d8
Support: add additional comment for ARM EH structure

Replicate the fact that ARM::WinEH::RuntimeFunction purposefully does not merge
functions to accommodate raw data access use cases in tools such as readobj.
Pointed out by Renato during post-commit review.

No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210189 91177308-0d34-0410-b5e6-96231b3b80d8
Support: style/documentation cleanup for format

This is purely a documentation/whitespace cleanup for the format support
functions.

The current style does not duplicate the function/class names in the
documentation; conform to this style.

Additionally, there was a large amount of duplication of comments that added no
real value.  Use block comments for the related sets of functions which are used
for type deduction and parameter container classes.

No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210190 91177308-0d34-0410-b5e6-96231b3b80d8
tools: introduce StreamWriter::printBoolean

Add a helper print method to print a boolean value as "Yes" or "No".  This is
intended to be used by the Windows ARM EH printer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210191 91177308-0d34-0410-b5e6-96231b3b80d8
tools: initial implementation of WoA EH decoding

Add support to llvm-readobj to decode Windows ARM Exception Handling data.  This
uses the previously added datastructures to decode the information into a format
that can be used by tests.  This is a necessary step to add support for emitting
Windows on ARM exception handling information.

A fair amount of formatting inspiration is drawn from the Win64 EH printer as
well as the ARM EHABI printer.  This allows for a reasonably thorough look into
the encoded data.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210192 91177308-0d34-0410-b5e6-96231b3b80d8
tools: fix silly typo in llvm-readobj

Case insensitive case preserving file systems are not a good choice for
development.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210193 91177308-0d34-0410-b5e6-96231b3b80d8
tools: fix parenthesis warning from GCC

Add parenthesis as suggested by GCC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210194 91177308-0d34-0410-b5e6-96231b3b80d8
XFAIL: test/DebugInfo/missing-abstract-variable.ll on mips and ppc64 due to an inlined parameter that goes missing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210200 91177308-0d34-0410-b5e6-96231b3b80d8
Two small enhancements for the JIT.

When JITting a large project such as Boost it's quite hard to figure out the problematic inline asm without debug location. This patch provides debug location printout before the JIT aborts due to inline asm. printDebugLoc() was exposed from MachineInstr.cpp and reused here.

If the JIT run with debug info, don't bomb on DBG_VALUE but ignore them.

http://reviews.llvm.org/D3416



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210201 91177308-0d34-0410-b5e6-96231b3b80d8
Clauses in a landingpad are always Constant. Use a stricter type.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210203 91177308-0d34-0410-b5e6-96231b3b80d8
Add a Constant version of stripPointerCasts.

Thanks to rnk for the suggestion.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210205 91177308-0d34-0410-b5e6-96231b3b80d8
Don't emit structors for available_externally globals (PR19933)

We would previously assert here when trying to figure out the section
for the global.

This makes us handle the situation more gracefully since the IR isn't
malformed.

Differential Revision: http://reviews.llvm.org/D4022

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210215 91177308-0d34-0410-b5e6-96231b3b80d8
Explain why we skip DbgInfoIntrinsics when looking at line numbers in .gcno file emission.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210218 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: Reapply r209984 (reverted in r210143), asserting that abstract DbgVariables have DIEs.

Abstract variables within abstract scopes that are entirely optimized
away in their first inlining are omitted because their scope is not
present so the variable is never created. Instead, we should ensure the
scope is created so the variable can be added, even if it's been
optimized away in its first inlining.

This fixes the incorrect debug info in missing-abstract-variable.ll
(added in r210143) and passes an asserts self-hosting build, so
hopefully there's not more of these issues left behind... *fingers
crossed*.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210221 91177308-0d34-0410-b5e6-96231b3b80d8
Use nullptr

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210222 91177308-0d34-0410-b5e6-96231b3b80d8
Remove uses of the TargetMachine from X86FrameLowering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210223 91177308-0d34-0410-b5e6-96231b3b80d8
80-columns.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210224 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Match rsq instructions

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210226 91177308-0d34-0410-b5e6-96231b3b80d8