[PM/AA] Hoist the AliasResult enum out of the AliasAnalysis class.
This will allow classes to implement the AA interface without deriving
from the class or referencing an internal enum of some other class as
their return types.
Also, to a pretty fundamental extent, concepts such as 'NoAlias',
'MayAlias', and 'MustAlias' are first class concepts in LLVM and we
aren't saving anything by scoping them heavily.
My mild preference would have been to use a scoped enum, but that
feature is essentially completely broken AFAICT. I'm extremely
disappointed. For example, we cannot through any reasonable[1] means
construct an enum class (or analog) which has scoped names but converts
to a boolean in order to test for the possibility of aliasing.
[1]: Richard Smith came up with a "solution", but it requires class
templates, and lots of boilerplate setting up the enumeration multiple
times. Something like Boost.PP could potentially bundle this up, but
even that would be quite painful and it doesn't seem realistically worth
it. The enum class solution would probably work without the need for
a bool conversion.
Differential Revision: http://reviews.llvm.org/D10495
llvm-svn: 240255
diff --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp
index b16cdfe..d9423ce 100644
--- a/llvm/lib/Analysis/DependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -625,10 +625,9 @@
OS << "!\n";
}
-static AliasAnalysis::AliasResult underlyingObjectsAlias(AliasAnalysis *AA,
- const DataLayout &DL,
- const Value *A,
- const Value *B) {
+static AliasResult underlyingObjectsAlias(AliasAnalysis *AA,
+ const DataLayout &DL, const Value *A,
+ const Value *B) {
const Value *AObj = GetUnderlyingObject(A, DL);
const Value *BObj = GetUnderlyingObject(B, DL);
return AA->alias(AObj, AA->getTypeStoreSize(AObj->getType()),
@@ -3365,16 +3364,16 @@
switch (underlyingObjectsAlias(AA, F->getParent()->getDataLayout(), DstPtr,
SrcPtr)) {
- case AliasAnalysis::MayAlias:
- case AliasAnalysis::PartialAlias:
+ case MayAlias:
+ case PartialAlias:
// cannot analyse objects if we don't understand their aliasing.
DEBUG(dbgs() << "can't analyze may or partial alias\n");
return make_unique<Dependence>(Src, Dst);
- case AliasAnalysis::NoAlias:
+ case NoAlias:
// If the objects noalias, they are distinct, accesses are independent.
DEBUG(dbgs() << "no alias\n");
return nullptr;
- case AliasAnalysis::MustAlias:
+ case MustAlias:
break; // The underlying objects alias; test accesses for dependence.
}
@@ -3814,7 +3813,7 @@
Value *SrcPtr = getPointerOperand(Src);
Value *DstPtr = getPointerOperand(Dst);
assert(underlyingObjectsAlias(AA, F->getParent()->getDataLayout(), DstPtr,
- SrcPtr) == AliasAnalysis::MustAlias);
+ SrcPtr) == MustAlias);
// establish loop nesting levels
establishNestingLevels(Src, Dst);