This is a simple AliasAnalysis implementation which works by making
ScalarEvolution queries. ScalarEvolution has a more complete understanding
of arithmetic than BasicAA's collection of ad-hoc checks, so it handles
some cases that BasicAA misses, for example p[i] and p[i+1] within the
same iteration of a loop.
This is currently experimental. It may be that the main use for this pass
will be to help find cases where BasicAA can be profitably extended, or
to help in the development of the overall AliasAnalysis infrastructure,
however it's also possible that it could grow up to become a directly
useful pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80098 91177308-0d34-0410-b5e6-96231b3b80d8
For now this only computes the allocated size of the memory pointed to by a
pointer, and offset a pointer from allocated pointer.
The actual checkLimits part will come later, after another round of review.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75657 91177308-0d34-0410-b5e6-96231b3b80d8
Use it by requiring it through the pass manager, then calling its createSSI
method on the variables that you want in SSI form.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74780 91177308-0d34-0410-b5e6-96231b3b80d8
is that, for functions whose bodies are entirely guarded by an if-statement, it
can be profitable to pull the test out of the callee and into the caller.
This code has had some cursory testing, but still has a number of known issues
on the LLVM test suite.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73338 91177308-0d34-0410-b5e6-96231b3b80d8
the set of blocks in which values are used, the set in which
values are live-through, and the set in which values are
killed. For the live-through and killed sets, conservative
approximations are used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67309 91177308-0d34-0410-b5e6-96231b3b80d8
to work out (in a very simplistic way) which function
arguments (pointer arguments only) are only dereferenced
and so do not escape. Mark such arguments 'nocapture'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61525 91177308-0d34-0410-b5e6-96231b3b80d8
which source/line a certain BB/instruction comes from, original variable names,
and original (unmangled) C++ name of functions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61085 91177308-0d34-0410-b5e6-96231b3b80d8
This triggers only 60 times in llvm-test (look at .llvm.bc, not .linked.rbc)
and so it probably wont be turned on by default. Also, may of those are likely
to go away when PR2973 is fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58557 91177308-0d34-0410-b5e6-96231b3b80d8
Unfortunately this means removing one regression test
of GlobalsModRef because I couldn't work out how to
perform it without MarkModRef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56342 91177308-0d34-0410-b5e6-96231b3b80d8
can get the readnone/readonly attributes, and gives them it.
The plan is to remove markmodref (which did the same thing
by querying GlobalsModRef) and delete the analogous
functionality from GlobalsModRef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56341 91177308-0d34-0410-b5e6-96231b3b80d8
attributes on functions, based on the result of
alias analysis. It's not hardwired to use
GlobalsModRef even though this is the only (AFAIK)
alias analysis that results in this pass actually
doing something. Enable as follows:
opt ... -globalsmodref-aa -markmodref ...
Advantages of this pass: (1) records the result
of globalsmodref in the bitcode, meaning it is
available for use by later passes (currently
the pass manager isn't smart enough to magically
make an advanced alias analysis available to all
later passes), which may expose more optimization
opportunities; (2) hopefully speeds up compilation
when code is optimized twice, for example when a
file is compiled to bitcode, then later LTO is done
on it: marking functions readonly/readnone when
producing the initial bitcode should speed up alias
analysis during LTO; (3) good for discovering that
globalsmodref doesn't work very well :)
Not currently turned on by default.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55604 91177308-0d34-0410-b5e6-96231b3b80d8
by an instance of LibCallInfo to provide mod/ref info of
standard library functions. This is powerful enough to
say that 'sqrt' is readonly except that it modifies errno,
or that "printf doesn't store to memory unless the %n
constraint is present" etc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50827 91177308-0d34-0410-b5e6-96231b3b80d8
could work don't work fully. This fixes PR1705. Oh yeah, we don't have
packed types anymore either ;-)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47322 91177308-0d34-0410-b5e6-96231b3b80d8
as the current DSE, but it only a linear scan over each block, rather than quadratic. Eventually
(once it has been improved somewhat), this will replace the current DSE.
NOTE: This has not yet been extensively tested.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@38517 91177308-0d34-0410-b5e6-96231b3b80d8
