DebugInfo: Simplify solution to avoid DW_AT_artificial on inlined parameters.

Originally committed in r207717, I clearly didn't look very closely at
the code to understand how existing things were working...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209680 91177308-0d34-0410-b5e6-96231b3b80d8
DebugInfo: partially revert cleanup committed in r209680

I'm not sure exactly where/how we end up with an abstract DbgVariable
with a null DIE, but we do... looking into it & will add a test and/or
fix when I figure it out.

Currently shows up in selfhost or compiler-rt builds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209683 91177308-0d34-0410-b5e6-96231b3b80d8
Wording fix for llvm.global_dtors docs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209687 91177308-0d34-0410-b5e6-96231b3b80d8
Factor out comparison of Instruction "special" states.

No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209688 91177308-0d34-0410-b5e6-96231b3b80d8
No need for those tests to go thru llvm-as and/or llvm-dis.

opt can handle them by itself.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209689 91177308-0d34-0410-b5e6-96231b3b80d8
Don't pre-populate the set of keys in the map with variable locations history.

Current implementation of calculateDbgValueHistory already creates the
keys in the expected order (user variables are listed in order of appearance),
and should do so later by contract.

No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209690 91177308-0d34-0410-b5e6-96231b3b80d8
remove constant terms

The delinearization is needed only to remove the non linearity induced by
expressions involving multiplications of parameters and induction variables.
There is no problem in dealing with constant times parameters, or constant times
an induction variable.

For this reason, the current patch discards all constant terms and multipliers
before running the delinearization algorithm on the terms. The only thing
remaining in the term expressions are parameters and multiply expressions of
parameters: these simplified term expressions are passed to the array shape
recognizer that will not recognize constant dimensions anymore: these will be
recognized as different strides in parametric subscripts.

The only important special case of a constant dimension is the size of elements.
Instead of relying on the delinearization to infer the size of an element,
compute the element size from the base address type. This is a much more precise
way of computing the element size than before, as we would have mixed together
the size of an element with the strides of the innermost dimension.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209691 91177308-0d34-0410-b5e6-96231b3b80d8
remove BasePointer before delinearizing

No functional change is intended: instead of relying on the delinearization to
come up with the base pointer as a remainder of the divisions in the
delinearization, we just compute it from the array access and use that value.
We substract the base pointer from the SCEV to be delinearized and that
simplifies the work of the delinearizer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209692 91177308-0d34-0410-b5e6-96231b3b80d8
do not use the GCD to compute the delinearization strides

We do not need to compute the GCD anymore after we removed the constant
coefficients from the terms: the terms are now all parametric expressions and
there is no need to recognize constant terms that divide only a subset of the
terms. We only rely on the size of the terms, i.e., the number of operands in
the multiply expressions, to sort the terms and recognize the parametric
dimensions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209693 91177308-0d34-0410-b5e6-96231b3b80d8
avoid type mismatch when building SCEVs

This is a corner case I have stumbled upon when dealing with ARM64 type
conversions. I was not able to extract a testcase for the community codebase to
fail on. The patch conservatively discards a division that would have ended up
in an ICE due to a type mismatch when building a multiply expression. I have
also added code to a place that builds add expressions and in which we should be
careful not to pass in operands of different types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209694 91177308-0d34-0410-b5e6-96231b3b80d8
Factor out looking for prologue end into a function

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209697 91177308-0d34-0410-b5e6-96231b3b80d8
Change representation of instruction ranges where variable is accessible.

Use more straightforward way to represent the set of instruction
ranges where the location of a user variable is defined - vector of pairs
of instructions (defining start/end of each range),
instead of a flattened vector of instructions where some instructions
are supposed to start the range, and the rest are supposed to "clobber" it.

Simplify the code which generates actual .debug_loc entries.

No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209698 91177308-0d34-0410-b5e6-96231b3b80d8