IndVarSimplify: Don't let LFTR compare against a poison value

LinearFunctionTestReplace tries to use the *next* indvar to compare
against when possible.  However, it may be the case that the calculation
for the next indvar has NUW/NSW flags and that it may only be safely
used inside the loop.  Using it in a comparison to calculate the exit
condition could result in observing poison.

This fixes PR20680.

Differential Revision: http://reviews.llvm.org/D5174

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217102 91177308-0d34-0410-b5e6-96231b3b80d8
Enabling LLVM & Clang to be cross-compiled using CMake from a single configuration command line

The basic idea is similar to the existing cross compilation support. A directory must be configured to build host versions of tablegen tools and llvm-config. This directory can be user provided (and configured), or it can be created during the build. During a build the native build directory will be configured and built to supply the tablegen tools used during the build. A user could also explicitly provide the tablegen executables to run on the CMake command line.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217105 91177308-0d34-0410-b5e6-96231b3b80d8
[asan] fix debug info produced for asan-coverage=2

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217106 91177308-0d34-0410-b5e6-96231b3b80d8
Don't treat 0 as a special value for int attributes.

Split the get() to not use a default value. This way
attributes can be added that have 0 as a legitimate value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217107 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Try to keep i32 mul on SALU

Also fix bug this exposed where when legalizing an immediate
operand, a v_mov_b32 would be created with a VSrc dest register.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217108 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Un-move pattern I forgot to remove in last commit

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217109 91177308-0d34-0410-b5e6-96231b3b80d8
Revert accidentally committed r217107

"Don't treat 0 as a special value for int attributes."

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217110 91177308-0d34-0410-b5e6-96231b3b80d8