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Don't convert objc_autoreleaseReturnValue to objc_autorelease if the result 

is returned through a bitcast.

llvm-svn: 137402
This commit is contained in:
Dan Gohman 2011-08-12 00:36:31 +00:00
parent 9b25cee36f
commit 10a18d55ce
2 changed files with 24 additions and 6 deletions
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19
llvm/lib/Transforms/Scalar/ObjCARC.cpp
View File

@ -1925,12 +1925,19 @@ void
ObjCARCOpt::OptimizeAutoreleaseRVCall(Function &F, Instruction *AutoreleaseRV) {
// Check for a return of the pointer value.
const Value *Ptr = GetObjCArg(AutoreleaseRV);
for (Value::const_use_iterator UI = Ptr->use_begin(), UE = Ptr->use_end();
UI != UE; ++UI) {
const User *I = *UI;
if (isa<ReturnInst>(I) || GetBasicInstructionClass(I) == IC_RetainRV)
return;
}
SmallVector<const Value *, 2> Users;
Users.push_back(Ptr);
do {
Ptr = Users.pop_back_val();
for (Value::const_use_iterator UI = Ptr->use_begin(), UE = Ptr->use_end();
UI != UE; ++UI) {
const User *I = *UI;
if (isa<ReturnInst>(I) || GetBasicInstructionClass(I) == IC_RetainRV)
return;
if (isa<BitCastInst>(I))
Users.push_back(I);
}
} while (!Users.empty());
Changed = true;
++NumPeeps;

11
llvm/test/Transforms/ObjCARC/rv.ll
View File

@ -329,3 +329,14 @@ define void @test23(i8* %p) {
call i8* @objc_autoreleaseReturnValue(i8* %p)
ret void
}
; Don't convert autoreleaseRV to autorelease if the result is returned,
; even through a bitcast.
; CHECK: define {}* @test24(
; CHECK: tail call i8* @objc_autoreleaseReturnValue(i8* %p)
define {}* @test24(i8* %p) {
%t = call i8* @objc_autoreleaseReturnValue(i8* %p)
%s = bitcast i8* %p to {}*
ret {}* %s
}