Introduce a symbolic constant for ~0u for use with AliasAnalysis.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110091 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index b025ec6..229e9e5 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -334,7 +334,7 @@
// is impossible to alias the pointer we're checking. If not, we have to
// assume that the call could touch the pointer, even though it doesn't
// escape.
- if (!isNoAlias(cast<Value>(CI), ~0U, P, ~0U)) {
+ if (!isNoAlias(cast<Value>(CI), UnknownSize, P, UnknownSize)) {
PassedAsArg = true;
break;
}
@@ -353,7 +353,7 @@
default: break;
case Intrinsic::memcpy:
case Intrinsic::memmove: {
- unsigned Len = ~0U;
+ unsigned Len = UnknownSize;
if (ConstantInt *LenCI = dyn_cast<ConstantInt>(II->getArgOperand(2)))
Len = LenCI->getZExtValue();
Value *Dest = II->getArgOperand(0);
@@ -490,7 +490,8 @@
// out if the indexes to the GEP tell us anything about the derived pointer.
if (const GEPOperator *GEP2 = dyn_cast<GEPOperator>(V2)) {
// Do the base pointers alias?
- AliasResult BaseAlias = aliasCheck(UnderlyingV1, ~0U, UnderlyingV2, ~0U);
+ AliasResult BaseAlias = aliasCheck(UnderlyingV1, UnknownSize,
+ UnderlyingV2, UnknownSize);
// If we get a No or May, then return it immediately, no amount of analysis
// will improve this situation.
@@ -527,10 +528,10 @@
// pointer, we know they cannot alias.
// If both accesses are unknown size, we can't do anything useful here.
- if (V1Size == ~0U && V2Size == ~0U)
+ if (V1Size == UnknownSize && V2Size == UnknownSize)
return MayAlias;
- AliasResult R = aliasCheck(UnderlyingV1, ~0U, V2, V2Size);
+ AliasResult R = aliasCheck(UnderlyingV1, UnknownSize, V2, V2Size);
if (R != MustAlias)
// If V2 may alias GEP base pointer, conservatively returns MayAlias.
// If V2 is known not to alias GEP base pointer, then the two values
@@ -778,8 +779,8 @@
// If the size of one access is larger than the entire object on the other
// side, then we know such behavior is undefined and can assume no alias.
if (TD)
- if ((V1Size != ~0U && isObjectSmallerThan(O2, V1Size, *TD)) ||
- (V2Size != ~0U && isObjectSmallerThan(O1, V2Size, *TD)))
+ if ((V1Size != UnknownSize && isObjectSmallerThan(O2, V1Size, *TD)) ||
+ (V2Size != UnknownSize && isObjectSmallerThan(O1, V2Size, *TD)))
return NoAlias;
// FIXME: This isn't aggressively handling alias(GEP, PHI) for example: if the