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
The hasNoModRefInfoForCalls isn't worth it as a filter because
basicaa provides m/r info and everything chains to it, so remove
it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89599 91177308-0d34-0410-b5e6-96231b3b80d8
being used for atomic intrinsics, it seems the
access may be volatile. No code was exploiting
the original non-volatile definition, so only
the comment needs changing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64464 91177308-0d34-0410-b5e6-96231b3b80d8
they are useful to analyses other than BasicAliasAnalysis.cpp. Include
the full comment for isIdentifiedObject in the header file. Thanks to
Chris for suggeseting this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63589 91177308-0d34-0410-b5e6-96231b3b80d8
If a MachineInstr doesn't have a memoperand but has an opcode that
is known to load or store, assume its memory reference may alias
*anything*, including stack slots which the compiler completely
controls.
To partially compensate for this, teach the ScheduleDAG building
code to do basic getUnderlyingValue analysis. This greatly
reduces the number of instructions that require restrictive
dependencies. This code will need to be revisited when we start
doing real alias analysis, but it should suffice for now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63370 91177308-0d34-0410-b5e6-96231b3b80d8