6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-03-02 22:32:08 +00:00
Code Issues Projects Releases Wiki Activity

[objc-arc] Make sure that multiple owners is propogated correctly through the pass via the usage of a global data structure.

Browse Source 
rdar://13750319

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182669 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Michael Gottesman 2013-05-24 20:44:02 +00:00
parent 36fe3f2b56
commit 35e88e57ea
2 changed files with 113 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
lib/Transforms/ObjCARC/ObjCARCOpts.cpp
View File

@ -30,6 +30,7 @@
#include "ObjCARCAliasAnalysis.h"
#include "ProvenanceAnalysis.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
@ -454,18 +455,8 @@ namespace {
/// sequence.
SmallPtrSet<Instruction *, 2> ReverseInsertPts;
/// Does this pointer have multiple owners?
///
/// In the presence of multiple owners with the same provenance caused by
/// allocas, we can not assume that the frontend will emit balanced code
/// since it could put the release on the pointer loaded from the
/// alloca. This confuses the optimizer so we must be more conservative in
/// that case.
bool MultipleOwners;
RRInfo() :
KnownSafe(false), IsTailCallRelease(false), ReleaseMetadata(0),
MultipleOwners(false) {}
KnownSafe(false), IsTailCallRelease(false), ReleaseMetadata(0) {}
void clear();
@ -478,7 +469,6 @@ namespace {
void RRInfo::clear() {
KnownSafe = false;
IsTailCallRelease = false;
MultipleOwners = false;
ReleaseMetadata = 0;
Calls.clear();
ReverseInsertPts.clear();
@ -569,7 +559,6 @@ PtrState::Merge(const PtrState &Other, bool TopDown) {
RRI.IsTailCallRelease = RRI.IsTailCallRelease &&
Other.RRI.IsTailCallRelease;
RRI.Calls.insert(Other.RRI.Calls.begin(), Other.RRI.Calls.end());
RRI.MultipleOwners |= Other.RRI.MultipleOwners;
// Merge the insert point sets. If there are any differences,
// that makes this a partial merge.
@ -1058,6 +1047,9 @@ namespace {
bool Changed;
ProvenanceAnalysis PA;
// This is used to track if a pointer is stored into an alloca.
DenseSet<const Value *> MultiOwnersSet;
/// A flag indicating whether this optimization pass should run.
bool Run;
@ -1943,7 +1935,7 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst,
BBState::ptr_iterator I = MyStates.findPtrBottomUpState(
StripPointerCastsAndObjCCalls(SI->getValueOperand()));
if (I != MyStates.bottom_up_ptr_end())
I->second.RRI.MultipleOwners = true;
MultiOwnersSet.insert(I->first);
}
}
break;
@ -2515,7 +2507,8 @@ ObjCARCOpt::ConnectTDBUTraversals(DenseMap<const BasicBlock *, BBState>
assert(It != Retains.end());
const RRInfo &NewRetainRRI = It->second;
KnownSafeTD &= NewRetainRRI.KnownSafe;
MultipleOwners |= NewRetainRRI.MultipleOwners;
MultipleOwners =
MultipleOwners || MultiOwnersSet.count(GetObjCArg(NewRetain));
for (SmallPtrSet<Instruction *, 2>::const_iterator
LI = NewRetainRRI.Calls.begin(),
LE = NewRetainRRI.Calls.end(); LI != LE; ++LI) {
@ -2903,8 +2896,14 @@ bool ObjCARCOpt::OptimizeSequences(Function &F) {
bool NestingDetected = Visit(F, BBStates, Retains, Releases);
// Transform.
return PerformCodePlacement(BBStates, Retains, Releases, F.getParent()) &&
NestingDetected;
bool AnyPairsCompletelyEliminated = PerformCodePlacement(BBStates, Retains,
Releases,
F.getParent());
// Cleanup.
MultiOwnersSet.clear();
return AnyPairsCompletelyEliminated && NestingDetected;
}
/// Check if there is a dependent call earlier that does not have anything in

97
test/Transforms/ObjCARC/allocas.ll
View File

@ -197,6 +197,103 @@ entry:
ret void
}
; Make sure that if a store is in a different basic block we handle known safe
; conservatively.
; CHECK: define void @test2a(i8* %x)
; CHECK: @objc_retain(i8* %x)
; CHECK: @objc_retain(i8* %x)
; CHECK: @objc_release(i8* %y)
; CHECK: @objc_release(i8* %x)
; CHECK: ret void
; CHECK: }
define void @test2a(i8* %x) {
entry:
%A = alloca i8*
store i8* %x, i8** %A, align 8
%y = load i8** %A
br label %bb1
bb1:
br label %bb2
bb2:
br label %bb3
bb3:
tail call i8* @objc_retain(i8* %x)
tail call i8* @objc_retain(i8* %x)
call void @use_alloca(i8** %A)
call void @objc_release(i8* %y), !clang.imprecise_release !0
call void @use_pointer(i8* %x)
call void @objc_release(i8* %x), !clang.imprecise_release !0
ret void
}
; CHECK: define void @test2b(i8* %x)
; CHECK: @objc_retain(i8* %x)
; CHECK: @objc_retain(i8* %x)
; CHECK: @objc_release(i8* %y)
; CHECK: @objc_release(i8* %x)
; CHECK: ret void
; CHECK: }
define void @test2b(i8* %x) {
entry:
%A = alloca i8*
%gep1 = getelementptr i8** %A, i32 0
store i8* %x, i8** %gep1, align 8
%gep2 = getelementptr i8** %A, i32 0
%y = load i8** %gep2
br label %bb1
bb1:
br label %bb2
bb2:
br label %bb3
bb3:
tail call i8* @objc_retain(i8* %x)
tail call i8* @objc_retain(i8* %x)
call void @use_alloca(i8** %A)
call void @objc_release(i8* %y), !clang.imprecise_release !0
call void @use_pointer(i8* %x)
call void @objc_release(i8* %x), !clang.imprecise_release !0
ret void
}
; CHECK: define void @test2c(i8* %x)
; CHECK: @objc_retain(i8* %x)
; CHECK: @objc_retain(i8* %x)
; CHECK: @objc_release(i8* %y)
; CHECK: @objc_release(i8* %x)
; CHECK: ret void
; CHECK: }
define void @test2c(i8* %x) {
entry:
%A = alloca i8*, i32 3
%gep1 = getelementptr i8** %A, i32 2
store i8* %x, i8** %gep1, align 8
%gep2 = getelementptr i8** %A, i32 2
%y = load i8** %gep2
tail call i8* @objc_retain(i8* %x)
br label %bb1
bb1:
br label %bb2
bb2:
br label %bb3
bb3:
tail call i8* @objc_retain(i8* %x)
call void @use_alloca(i8** %A)
call void @objc_release(i8* %y), !clang.imprecise_release !0
call void @use_pointer(i8* %x)
call void @objc_release(i8* %x), !clang.imprecise_release !0
ret void
}
!0 = metadata !{}