Constant uniquing tables. This allows distinct ConstantExpr objects
with the same operation and different flags.
Even though a ConstantExpr "a + b" is either always overflowing or
never overflowing (due to being a ConstantExpr), it's still necessary
to be able to represent it both with and without overflow flags at
the same time within the IR, because the safety of the flag may
depend on the context of the use. If the constant really does overflow,
it wouldn't ever be safe to use with the flag set, however the use
may be in code that is never actually executed.
This also makes it possible to merge all the flags tests into a single test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80998 91177308-0d34-0410-b5e6-96231b3b80d8
Use CallbackVH, instead of WeakVH, to hold MDNode elements.
Use FoldingSetNode to unique MDNodes in a context.
Use CallbackVH hooks to update context's MDNodeSet appropriately.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80868 91177308-0d34-0410-b5e6-96231b3b80d8
Use FoldingSetNode to unique MDNodes in a context.
Use CallbackVH hooks to update context's MDNodeSet appropriately.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80839 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes leaks from LLVMContext in multithreaded apps.
Since constants are only deleted if they have no uses, it is safe to not delete
a Module on shutdown, as many single-threaded tools do.
Multithreaded apps should however delete the Module before destroying the
Context to ensure that there are no leaks (assuming they use a different context
for each thread).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80590 91177308-0d34-0410-b5e6-96231b3b80d8
