Use a StringRefMemoryObject. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221503 91177308-0d34-0410-b5e6-96231b3b80d8
[AArch64] Keep flags on condition vreg when instantiating a CB branch.

Reversing a CB* instruction used to drop the flags on the condition. On the
included testcase, this lead to a read from an undefined vreg.
Using addOperand keeps the flags, here <undef>.

Differential Revision: http://reviews.llvm.org/D6159


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221507 91177308-0d34-0410-b5e6-96231b3b80d8
Add Position-independent Code model Module API.

Summary:
This makes PIC levels a Module flag attribute, which can be queried by the
backend.  The flag is named `PIC Level`, and can have a value of:

  0 - Backend-default
  1 - Small-model (-fpic)
  2 - Large-model (-fPIC)

These match the `-pic-level' command line argument for clang, and the value of the
preprocessor macro `__PIC__'.

Test Plan:
New flags tests specific for the 'PIC Level' module flag.
Tests to be added as part of a future commit for PowerPC, which will use this new API.

Reviewers: rafael, echristo

Reviewed By: rafael, echristo

Subscribers: rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D5882

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221510 91177308-0d34-0410-b5e6-96231b3b80d8
SCCP: overdefined calls cannot become constant

We would attempt to fold away a call instruction which had been marked
overdefined.  However, it's not valid to transition to constant from
overdefined.

This fixes PR21512.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221513 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-symbolizer: teach it about PowerPC64 ELF function descriptors

Summary:
Teach llvm-symbolizer about PowerPC64 ELF function descriptors. Symbols in the .opd section point to function descriptors, the first word of which is a pointer to the real function. For the purposes of symbolizing we pretend that the symbol points directly to the function.

This is enough to get decent function names in stack traces for unoptimized binaries, which fixes the sanitizer print-stack-trace test on PowerPC64 Linux.

Reviewers: kcc, willschm, samsonov

Reviewed By: samsonov

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D6110

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221514 91177308-0d34-0410-b5e6-96231b3b80d8
Merge branch 'master', remote-tracking branch 'trunk/master'