AliasAnalysis consumers, PartialAlias will be treated as MayAlias.
For AliasAnalysis chaining, MayAlias says "procede to the next analysis".
PartialAlias will be used to indicate that the query should terminate,
even though it didn't reach MustAlias or NoAlias.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121507 91177308-0d34-0410-b5e6-96231b3b80d8
memcpy's like:
memcpy(A, B)
memcpy(A, C)
we cannot delete the first memcpy as dead if A and C might be aliases.
If so, we actually get:
memcpy(A, B)
memcpy(A, A)
which is not correct to transform into:
memcpy(A, A)
This patch was heavily influenced by Jakub Staszak's patch in PR8728, thanks
Jakub!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120974 91177308-0d34-0410-b5e6-96231b3b80d8
destination location of a memcpy/memmove. I'm not clear about whether
TBAA works on these, so I'm leaving it out for now. Dan, please revisit
this when convenient.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119928 91177308-0d34-0410-b5e6-96231b3b80d8
references. For example, this allows gvn to eliminate the load in
this example:
void foo(int n, int* p, int *q) {
p[0] = 0;
p[1] = 1;
if (n) {
*q = p[0];
}
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118714 91177308-0d34-0410-b5e6-96231b3b80d8
to optionally look for constant or local (alloca) memory.
Teach BasicAliasAnalysis::pointsToConstantMemory to look through Select
and Phi nodes, and to support looking for local memory.
Remove FunctionAttrs' PointsToLocalOrConstantMemory function, now that
AliasAnalysis knows all the tricks that it knew.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118412 91177308-0d34-0410-b5e6-96231b3b80d8
isn't a good level of abstraction for memdep. Instead, generalize
AliasAnalysis::alias and related interfaces with a new Location
class for describing a memory location. For now, this is the same
Pointer and Size as before, plus an additional field for a TBAA tag.
Also, introduce a fixed MD_tbaa metadata tag kind.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113858 91177308-0d34-0410-b5e6-96231b3b80d8
AliasAnalysis, and some code for implementing the new query on top of
existing implementations by making standard alias and getModRefInfo
queries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113329 91177308-0d34-0410-b5e6-96231b3b80d8
eliminate several const_casts.
Make CallSite implicitly convertible to ImmutableCallSite.
Rename the getModRefBehavior for intrinsic IDs to
getIntrinsicModRefBehavior to avoid overload ambiguity with CallSite,
which happens to be implicitly convertible to bool.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110155 91177308-0d34-0410-b5e6-96231b3b80d8
interface needs implementations to be consistent, so any code which
wants to support different semantics must use a different interface.
It's not currently worthwhile to add a new interface for this new
concept.
Document that AliasAnalysis doesn't support cross-function queries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107776 91177308-0d34-0410-b5e6-96231b3b80d8
properly handles instructions and arguments defined in different
functions, or across recursive function iterations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107109 91177308-0d34-0410-b5e6-96231b3b80d8
memcpy, memset and other intrinsics that only access their arguments
to be readnone if the intrinsic's arguments all point to local memory.
This improves the testcase in the README to readonly, but it could in
theory be made readnone, however this would involve more sophisticated
analysis that looks through the memcpy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92829 91177308-0d34-0410-b5e6-96231b3b80d8
