Fix loop rerolling pass failure with non-consant loop lower bound

The loop rerolling pass was failing with an assertion failure from a
failed cast on loops like this:

  void foo(int *A, int *B, int m, int n) {
    for (int i = m; i < n; i+=4) {
      A[i+0] = B[i+0] * 4;
      A[i+1] = B[i+1] * 4;
      A[i+2] = B[i+2] * 4;
      A[i+3] = B[i+3] * 4;
    }
  }

The code was casting the SCEV-expanded code for the new
induction variable to a phi-node. When the loop had a non-constant
lower bound, the SCEV expander would end the code expansion with an
add insted of a phi node and the cast would fail.

It looks like the cast to a phi node was only needed to get the
induction variable value coming from the backedge to compute the end
of loop condition. This patch changes the loop reroller to compare
the induction variable to the number of times the backedge is taken
instead of the iteration count of the loop. In other words, we stop
the loop when the current value of the induction variable ==
IterationCount-1. Previously, the comparison was comparing the
induction variable value from the next iteration == IterationCount.

This problem only seems to occur on 32-bit targets. For some reason,
the loop is not rerolled on 64-bit targets.

PR18290


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198425 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "Revert "Debug Info: Type Units: Simplify type hashing using IR-provided unique names.""

This reverts commit r198398, thus reapplying r198397.

I had accidentally introduced an endianness issue when applying the hash
to the type unit. Using support::ulittle64_t in the reinterpret_cast in
addDwarfTypeUnitType fixes this issue.

Original commit message:

Debug Info: Type Units: Simplify type hashing using IR-provided unique
names.

What's good for LTO metadata size problems ought to be good for non-LTO
debug info size too, so let's rely on the same uniqueness in both cases.
If it's insufficient for non-LTO for whatever reason (since we now won't
be uniquing CU-local types or any C types - but these are likely to not
be the most significant contributors to type bloat) we should consider a
frontend solution that'll help both LTO and non-LTO alike, rather than
using DWARF-level DIE-hashing that only helps non-LTO debug info size.

It's also much simpler this way and benefits C++ even more since we can
deduplicate lexically separate definitions of the same C++ type since
they have the same mangled name.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198436 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64][NEON] Added SXTL and SXTL2 instruction aliases



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198437 91177308-0d34-0410-b5e6-96231b3b80d8
Make the llvm mangler depend only on DataLayout.

Before this patch any program that wanted to know the final symbol name of a
GlobalValue had to link with Target.

This patch implements a compromise solution where the mangler uses DataLayout.
This way, any tool that already links with Target (llc, clang) gets the exact
behavior as before and new IR files can be mangled without linking with Target.

With this patch the mangler is constructed with just a DataLayout and DataLayout
is extended to include the information the Mangler needs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198438 91177308-0d34-0410-b5e6-96231b3b80d8
For disassembly when adding a symbolic operand that is a C++
symbol name, also put the human readable name in a comment.

Also fix a bug in LLVMDisasmInstruction() that was not flushing
the raw_svector_ostream for the disassembled instruction string
before copying it to the output buffer that was causing truncation
of the output.

rdar://10173828


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198441 91177308-0d34-0410-b5e6-96231b3b80d8
Fix typo.

Thanks to Owen Anderson for noticing it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198443 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "For disassembly when adding a symbolic operand that is a C++ symbol name, also put the human readable name in a comment."

This reverts commit r198441.

This change doesn't build on Windows, and doesn't do the right thing on
Linux and other platforms that don't use a _Z prefix instead of __Z for
C++ names.

It also had no tests, so it wasn't clear how to fix it forward.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198445 91177308-0d34-0410-b5e6-96231b3b80d8
FileCheck: Print a nice error message for missing closing ']' in regex vars.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198449 91177308-0d34-0410-b5e6-96231b3b80d8
[Mips]Work around MIPS linker issues exposed by commit r198087 until bug 18360 is resolved

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198451 91177308-0d34-0410-b5e6-96231b3b80d8
Add a LLVM_DUMP_METHOD macro.

The motivation is to mark dump methods as used in debug builds so that they can
be called from lldb, but to not do so in release builds so that they can be
dead-stripped.

There's lots of potential follow-up work suggested in the thread
"Should dump methods be LLVM_ATTRIBUTE_USED only in debug builds?" on cfe-dev,
but everyone seems to agreen on this subset.

Macro name chosen by fair coin toss.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198456 91177308-0d34-0410-b5e6-96231b3b80d8
Fix MSVC warning about missing return in DataLayout

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198465 91177308-0d34-0410-b5e6-96231b3b80d8