aboutsummaryrefslogtreecommitdiff
path: root/llvm/lib/Analysis/AliasAnalysis.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'llvm/lib/Analysis/AliasAnalysis.cpp')
-rw-r--r--llvm/lib/Analysis/AliasAnalysis.cpp61
1 files changed, 5 insertions, 56 deletions
diff --git a/llvm/lib/Analysis/AliasAnalysis.cpp b/llvm/lib/Analysis/AliasAnalysis.cpp
index e249c38..7887c76 100644
--- a/llvm/lib/Analysis/AliasAnalysis.cpp
+++ b/llvm/lib/Analysis/AliasAnalysis.cpp
@@ -245,7 +245,6 @@ ModRefInfo AAResults::getModRefInfo(const CallBase *Call,
Result = clearRef(Result);
if (onlyAccessesArgPointees(MRB) || onlyAccessesInaccessibleOrArgMem(MRB)) {
- bool IsMustAlias = true;
ModRefInfo AllArgsMask = ModRefInfo::NoModRef;
if (doesAccessArgPointees(MRB)) {
for (const auto &I : llvm::enumerate(Call->args())) {
@@ -260,8 +259,6 @@ ModRefInfo AAResults::getModRefInfo(const CallBase *Call,
ModRefInfo ArgMask = getArgModRefInfo(Call, ArgIdx);
AllArgsMask = unionModRef(AllArgsMask, ArgMask);
}
- // Conservatively clear IsMustAlias unless only MustAlias is found.
- IsMustAlias &= (ArgAlias == AliasResult::MustAlias);
}
}
// Return NoModRef if no alias found with any argument.
@@ -269,8 +266,6 @@ ModRefInfo AAResults::getModRefInfo(const CallBase *Call,
return ModRefInfo::NoModRef;
// Logical & between other AA analyses and argument analysis.
Result = intersectModRef(Result, AllArgsMask);
- // If only MustAlias found above, set Must bit.
- Result = IsMustAlias ? setMust(Result) : clearMust(Result);
}
// If Loc is a constant memory location, the call definitely could not
@@ -329,7 +324,6 @@ ModRefInfo AAResults::getModRefInfo(const CallBase *Call1,
if (!doesAccessArgPointees(Call2B))
return ModRefInfo::NoModRef;
ModRefInfo R = ModRefInfo::NoModRef;
- bool IsMustAlias = true;
for (auto I = Call2->arg_begin(), E = Call2->arg_end(); I != E; ++I) {
const Value *Arg = *I;
if (!Arg->getType()->isPointerTy())
@@ -355,23 +349,12 @@ ModRefInfo AAResults::getModRefInfo(const CallBase *Call1,
ModRefInfo ModRefC1 = getModRefInfo(Call1, Call2ArgLoc, AAQI);
ArgMask = intersectModRef(ArgMask, ModRefC1);
- // Conservatively clear IsMustAlias unless only MustAlias is found.
- IsMustAlias &= isMustSet(ModRefC1);
-
R = intersectModRef(unionModRef(R, ArgMask), Result);
- if (R == Result) {
- // On early exit, not all args were checked, cannot set Must.
- if (I + 1 != E)
- IsMustAlias = false;
+ if (R == Result)
break;
- }
}
- if (isNoModRef(R))
- return ModRefInfo::NoModRef;
-
- // If MustAlias found above, set Must bit.
- return IsMustAlias ? setMust(R) : clearMust(R);
+ return R;
}
// If Call1 only accesses memory through arguments, check if Call2 references
@@ -380,7 +363,6 @@ ModRefInfo AAResults::getModRefInfo(const CallBase *Call1,
if (!doesAccessArgPointees(Call1B))
return ModRefInfo::NoModRef;
ModRefInfo R = ModRefInfo::NoModRef;
- bool IsMustAlias = true;
for (auto I = Call1->arg_begin(), E = Call1->arg_end(); I != E; ++I) {
const Value *Arg = *I;
if (!Arg->getType()->isPointerTy())
@@ -398,22 +380,11 @@ ModRefInfo AAResults::getModRefInfo(const CallBase *Call1,
(isRefSet(ArgModRefC1) && isModSet(ModRefC2)))
R = intersectModRef(unionModRef(R, ArgModRefC1), Result);
- // Conservatively clear IsMustAlias unless only MustAlias is found.
- IsMustAlias &= isMustSet(ModRefC2);
-
- if (R == Result) {
- // On early exit, not all args were checked, cannot set Must.
- if (I + 1 != E)
- IsMustAlias = false;
+ if (R == Result)
break;
- }
}
- if (isNoModRef(R))
- return ModRefInfo::NoModRef;
-
- // If MustAlias found above, set Must bit.
- return IsMustAlias ? setMust(R) : clearMust(R);
+ return R;
}
return Result;
@@ -489,8 +460,6 @@ ModRefInfo AAResults::getModRefInfo(const LoadInst *L,
AliasResult AR = alias(MemoryLocation::get(L), Loc, AAQI);
if (AR == AliasResult::NoAlias)
return ModRefInfo::NoModRef;
- if (AR == AliasResult::MustAlias)
- return ModRefInfo::MustRef;
}
// Otherwise, a load just reads.
return ModRefInfo::Ref;
@@ -519,10 +488,6 @@ ModRefInfo AAResults::getModRefInfo(const StoreInst *S,
// been modified by this store.
if (pointsToConstantMemory(Loc, AAQI))
return ModRefInfo::NoModRef;
-
- // If the store address aliases the pointer as must alias, set Must.
- if (AR == AliasResult::MustAlias)
- return ModRefInfo::MustMod;
}
// Otherwise, a store just writes.
@@ -564,10 +529,6 @@ ModRefInfo AAResults::getModRefInfo(const VAArgInst *V,
// been modified by this va_arg.
if (pointsToConstantMemory(Loc, AAQI))
return ModRefInfo::NoModRef;
-
- // If the va_arg aliases the pointer as must alias, set Must.
- if (AR == AliasResult::MustAlias)
- return ModRefInfo::MustModRef;
}
// Otherwise, a va_arg reads and writes.
@@ -633,10 +594,6 @@ ModRefInfo AAResults::getModRefInfo(const AtomicCmpXchgInst *CX,
// it.
if (AR == AliasResult::NoAlias)
return ModRefInfo::NoModRef;
-
- // If the cmpxchg address aliases the pointer as must alias, set Must.
- if (AR == AliasResult::MustAlias)
- return ModRefInfo::MustModRef;
}
return ModRefInfo::ModRef;
@@ -661,10 +618,6 @@ ModRefInfo AAResults::getModRefInfo(const AtomicRMWInst *RMW,
// it.
if (AR == AliasResult::NoAlias)
return ModRefInfo::NoModRef;
-
- // If the atomicrmw address aliases the pointer as must alias, set Must.
- if (AR == AliasResult::MustAlias)
- return ModRefInfo::MustModRef;
}
return ModRefInfo::ModRef;
@@ -738,7 +691,6 @@ ModRefInfo AAResults::callCapturesBefore(const Instruction *I,
unsigned ArgNo = 0;
ModRefInfo R = ModRefInfo::NoModRef;
- bool IsMustAlias = true;
// Set flag only if no May found and all operands processed.
for (auto CI = Call->data_operands_begin(), CE = Call->data_operands_end();
CI != CE; ++CI, ++ArgNo) {
@@ -757,8 +709,6 @@ ModRefInfo AAResults::callCapturesBefore(const Instruction *I,
// 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 (AR != AliasResult::MustAlias)
- IsMustAlias = false;
if (AR == AliasResult::NoAlias)
continue;
if (Call->doesNotAccessMemory(ArgNo))
@@ -767,10 +717,9 @@ ModRefInfo AAResults::callCapturesBefore(const Instruction *I,
R = ModRefInfo::Ref;
continue;
}
- // Not returning MustModRef since we have not seen all the arguments.
return ModRefInfo::ModRef;
}
- return IsMustAlias ? setMust(R) : clearMust(R);
+ return R;
}
/// canBasicBlockModify - Return true if it is possible for execution of the
generated by cgit v1.1 at 2025-10-09 22:51:02 +0000