Besides a general consistently benefit, the extra layer of indirection
allows the mechanical part of https://reviews.llvm.org/D23256 that
requires touching every transformation and analysis to be factored out
cleanly.
Thanks to David for the suggestion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278077 91177308-0d34-0410-b5e6-96231b3b80d8
As it turns out, modref queries are broken with CFLAA. Specifically,
the data source we were using for determining modref behaviors
explicitly ignores operations on non-pointer values. So, it wouldn't
note e.g. storing an i32 to an i32* (or loading an i64 from an i64*).
It also ignores external function calls, rather than acting
conservatively for them.
(N.B. These operations, where necessary, *are* tracked by CFLAA; we just
use a different mechanism to do so. Said mechanism is relatively
imprecise, so it's unlikely that we can provide reasonably good modref
answers with it as implemented.)
Patch by Jia Chen.
Differential Revision: https://reviews.llvm.org/D22978
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277366 91177308-0d34-0410-b5e6-96231b3b80d8
This patch teaches FunctionInfo about offsets.
Like the last patch, this one doesn't introduce any visible
functionality change (the core algorithm knows nothing about offsets;
they're just plumbed through). Tests will come when we start acting
differently because of the offsets.
Patch by Jia Chen.
(N.B. I made a tiny change to Jia's patch to avoid warnings by GCC: I
put DenseMapInfo specializations in the `llvm` namespace. Only realized
that those appeared when compiling locally. :) )
Differential Revision: https://reviews.llvm.org/D22634
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@276486 91177308-0d34-0410-b5e6-96231b3b80d8
This patch simplifies the graph builder by encoding nodes as {Value,
Dereference Level} pairs. This lets us kill edge types, and allows us to
get rid of hacks in StratifiedSets (like addAttrsBelow/...). This
simplification also allows us to remove InstantiatedRelations and
InstantiatedAttrs.
Patch by Jia Chen.
Differential Revision: http://reviews.llvm.org/D22080
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275122 91177308-0d34-0410-b5e6-96231b3b80d8
StratifiedSets (as implemented) is very fast, but its accuracy is also
limited. If we take a more aggressive andersens-like approach, we can be
way more accurate, but we'll also end up being slower.
So, we've decided to split CFLAA into CFLSteensAA and CFLAndersAA.
Long-term, we want to end up in a place where CFLSteens is queried
first; if it can provide an answer, great (since queries are basically
map lookups). Otherwise, we'll fall back to CFLAnders, BasicAA, etc.
This patch splits everything out so we can try to do something like
that when we get a reasonable CFLAnders implementation.
Patch by Jia Chen.
Differential Revision: http://reviews.llvm.org/D21910
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274589 91177308-0d34-0410-b5e6-96231b3b80d8
