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-rw-r--r--include/llvm/Support/CFG.h6
-rw-r--r--lib/Transforms/Scalar/ObjCARC.cpp53
-rw-r--r--test/Transforms/ObjCARC/no-objc-arc-exceptions.ll122
3 files changed, 175 insertions, 6 deletions
diff --git a/include/llvm/Support/CFG.h b/include/llvm/Support/CFG.h
index 6e354f9..f5dc8ea 100644
--- a/include/llvm/Support/CFG.h
+++ b/include/llvm/Support/CFG.h
@@ -71,6 +71,12 @@ public:
unsigned getOperandNo() const {
return It.getOperandNo();
}
+
+ /// getUse - Return the operand Use in the predecessor's terminator
+ /// of the successor.
+ Use &getUse() const {
+ return It.getUse();
+ }
};
typedef PredIterator<BasicBlock, Value::use_iterator> pred_iterator;
diff --git a/lib/Transforms/Scalar/ObjCARC.cpp b/lib/Transforms/Scalar/ObjCARC.cpp
index 673e1a4..dd3e758 100644
--- a/lib/Transforms/Scalar/ObjCARC.cpp
+++ b/lib/Transforms/Scalar/ObjCARC.cpp
@@ -1655,6 +1655,10 @@ namespace {
/// metadata.
unsigned CopyOnEscapeMDKind;
+ /// NoObjCARCExceptionsMDKind - The Metadata Kind for
+ /// clang.arc.no_objc_arc_exceptions metadata.
+ unsigned NoObjCARCExceptionsMDKind;
+
Constant *getRetainRVCallee(Module *M);
Constant *getAutoreleaseRVCallee(Module *M);
Constant *getReleaseCallee(Module *M);
@@ -2406,7 +2410,15 @@ ObjCARCOpt::CheckForCFGHazards(const BasicBlock *BB,
bool SomeSuccHasSame = false;
bool AllSuccsHaveSame = true;
PtrState &S = MyStates.getPtrTopDownState(Arg);
- for (succ_const_iterator SI(TI), SE(TI, false); SI != SE; ++SI) {
+ succ_const_iterator SI(TI), SE(TI, false);
+
+ // If the terminator is an invoke marked with the
+ // clang.arc.no_objc_arc_exceptions metadata, the unwind edge can be
+ // ignored, for ARC purposes.
+ if (isa<InvokeInst>(TI) && TI->getMetadata(NoObjCARCExceptionsMDKind))
+ --SE;
+
+ for (; SI != SE; ++SI) {
PtrState &SuccS = BBStates[*SI].getPtrBottomUpState(Arg);
switch (SuccS.GetSeq()) {
case S_None:
@@ -2441,7 +2453,15 @@ ObjCARCOpt::CheckForCFGHazards(const BasicBlock *BB,
bool SomeSuccHasSame = false;
bool AllSuccsHaveSame = true;
PtrState &S = MyStates.getPtrTopDownState(Arg);
- for (succ_const_iterator SI(TI), SE(TI, false); SI != SE; ++SI) {
+ succ_const_iterator SI(TI), SE(TI, false);
+
+ // If the terminator is an invoke marked with the
+ // clang.arc.no_objc_arc_exceptions metadata, the unwind edge can be
+ // ignored, for ARC purposes.
+ if (isa<InvokeInst>(TI) && TI->getMetadata(NoObjCARCExceptionsMDKind))
+ --SE;
+
+ for (; SI != SE; ++SI) {
PtrState &SuccS = BBStates[*SI].getPtrBottomUpState(Arg);
switch (SuccS.GetSeq()) {
case S_None: {
@@ -2486,7 +2506,13 @@ ObjCARCOpt::VisitBottomUp(BasicBlock *BB,
succ_const_iterator SI(TI), SE(TI, false);
if (SI == SE)
MyStates.SetAsExit();
- else
+ else {
+ // If the terminator is an invoke marked with the
+ // clang.arc.no_objc_arc_exceptions metadata, the unwind edge can be
+ // ignored, for ARC purposes.
+ if (isa<InvokeInst>(TI) && TI->getMetadata(NoObjCARCExceptionsMDKind))
+ --SE;
+
do {
const BasicBlock *Succ = *SI++;
if (Succ == BB)
@@ -2507,6 +2533,7 @@ ObjCARCOpt::VisitBottomUp(BasicBlock *BB,
}
break;
} while (SI != SE);
+ }
// Visit all the instructions, bottom-up.
for (BasicBlock::iterator I = BB->end(), E = BB->begin(); I != E; --I) {
@@ -2668,7 +2695,18 @@ ObjCARCOpt::VisitTopDown(BasicBlock *BB,
MyStates.SetAsEntry();
else
do {
- const BasicBlock *Pred = *PI++;
+ unsigned OperandNo = PI.getOperandNo();
+ const Use &Us = PI.getUse();
+ ++PI;
+
+ // Skip invoke unwind edges on invoke instructions marked with
+ // clang.arc.no_objc_arc_exceptions.
+ if (const InvokeInst *II = dyn_cast<InvokeInst>(Us.getUser()))
+ if (OperandNo == II->getNumArgOperands() + 2 &&
+ II->getMetadata(NoObjCARCExceptionsMDKind))
+ continue;
+
+ const BasicBlock *Pred = cast<TerminatorInst>(Us.getUser())->getParent();
if (Pred == BB)
continue;
DenseMap<const BasicBlock *, BBState>::iterator I = BBStates.find(Pred);
@@ -2850,7 +2888,8 @@ ComputePostOrders(Function &F,
OnStack.insert(EntryBB);
do {
dfs_next_succ:
- succ_iterator End = succ_end(SuccStack.back().first);
+ TerminatorInst *TI = cast<TerminatorInst>(&SuccStack.back().first->back());
+ succ_iterator End = succ_iterator(TI, true);
while (SuccStack.back().second != End) {
BasicBlock *BB = *SuccStack.back().second++;
if (Visited.insert(BB)) {
@@ -2871,7 +2910,7 @@ ComputePostOrders(Function &F,
SmallVector<BasicBlock *, 4> Exits;
for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) {
BasicBlock *BB = I;
- if (BB->getTerminator()->getNumSuccessors() == 0)
+ if (cast<TerminatorInst>(&BB->back())->getNumSuccessors() == 0)
Exits.push_back(BB);
}
@@ -3507,6 +3546,8 @@ bool ObjCARCOpt::doInitialization(Module &M) {
M.getContext().getMDKindID("clang.imprecise_release");
CopyOnEscapeMDKind =
M.getContext().getMDKindID("clang.arc.copy_on_escape");
+ NoObjCARCExceptionsMDKind =
+ M.getContext().getMDKindID("clang.arc.no_objc_arc_exceptions");
// Intuitively, objc_retain and others are nocapture, however in practice
// they are not, because they return their argument value. And objc_release
diff --git a/test/Transforms/ObjCARC/no-objc-arc-exceptions.ll b/test/Transforms/ObjCARC/no-objc-arc-exceptions.ll
new file mode 100644
index 0000000..9728f6e
--- /dev/null
+++ b/test/Transforms/ObjCARC/no-objc-arc-exceptions.ll
@@ -0,0 +1,122 @@
+; RUN: opt -S -objc-arc < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+%struct.__block_byref_x = type { i8*, %struct.__block_byref_x*, i32, i32, i32 }
+%struct.__block_descriptor = type { i64, i64 }
+@_NSConcreteStackBlock = external global i8*
+@__block_descriptor_tmp = external hidden constant { i64, i64, i8*, i8*, i8*, i8* }
+
+; The optimizer should make use of the !clang.arc.no_objc_arc_exceptions
+; metadata and eliminate the retainBlock+release pair here.
+; rdar://10803830.
+
+; CHECK: define void @test0(
+; CHECK-NOT: @objc
+; CHECK: }
+define void @test0() {
+entry:
+ %x = alloca %struct.__block_byref_x, align 8
+ %block = alloca <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>, align 8
+ %byref.isa = getelementptr inbounds %struct.__block_byref_x* %x, i64 0, i32 0
+ store i8* null, i8** %byref.isa, align 8
+ %byref.forwarding = getelementptr inbounds %struct.__block_byref_x* %x, i64 0, i32 1
+ store %struct.__block_byref_x* %x, %struct.__block_byref_x** %byref.forwarding, align 8
+ %byref.flags = getelementptr inbounds %struct.__block_byref_x* %x, i64 0, i32 2
+ store i32 0, i32* %byref.flags, align 8
+ %byref.size = getelementptr inbounds %struct.__block_byref_x* %x, i64 0, i32 3
+ store i32 32, i32* %byref.size, align 4
+ %block.isa = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 0
+ store i8* bitcast (i8** @_NSConcreteStackBlock to i8*), i8** %block.isa, align 8
+ %block.flags = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 1
+ store i32 1107296256, i32* %block.flags, align 8
+ %block.reserved = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 2
+ store i32 0, i32* %block.reserved, align 4
+ %block.invoke = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 3
+ store i8* bitcast (void (i8*)* @__foo_block_invoke_0 to i8*), i8** %block.invoke, align 8
+ %block.descriptor = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 4
+ store %struct.__block_descriptor* bitcast ({ i64, i64, i8*, i8*, i8*, i8* }* @__block_descriptor_tmp to %struct.__block_descriptor*), %struct.__block_descriptor** %block.descriptor, align 8
+ %block.captured = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 5
+ %t1 = bitcast %struct.__block_byref_x* %x to i8*
+ store i8* %t1, i8** %block.captured, align 8
+ %t2 = bitcast <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block to i8*
+ %t3 = call i8* @objc_retainBlock(i8* %t2) nounwind, !clang.arc.copy_on_escape !4
+ %t4 = getelementptr inbounds i8* %t3, i64 16
+ %t5 = bitcast i8* %t4 to i8**
+ %t6 = load i8** %t5, align 8
+ %t7 = bitcast i8* %t6 to void (i8*)*
+ invoke void %t7(i8* %t3)
+ to label %invoke.cont unwind label %lpad, !clang.arc.no_objc_arc_exceptions !4
+
+invoke.cont: ; preds = %entry
+ call void @objc_release(i8* %t3) nounwind, !clang.imprecise_release !4
+ call void @_Block_object_dispose(i8* %t1, i32 8)
+ ret void
+
+lpad: ; preds = %entry
+ %t8 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__objc_personality_v0 to i8*)
+ cleanup
+ call void @_Block_object_dispose(i8* %t1, i32 8)
+ resume { i8*, i32 } %t8
+}
+
+; There is no !clang.arc.no_objc_arc_exceptions
+; metadata here, so the optimizer shouldn't eliminate anything.
+
+; CHECK: define void @test0_no_metadata(
+; CHECK: call i8* @objc_retainBlock(
+; CHECK: invoke
+; CHECK: call void @objc_release(
+; CHECK: }
+define void @test0_no_metadata() {
+entry:
+ %x = alloca %struct.__block_byref_x, align 8
+ %block = alloca <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>, align 8
+ %byref.isa = getelementptr inbounds %struct.__block_byref_x* %x, i64 0, i32 0
+ store i8* null, i8** %byref.isa, align 8
+ %byref.forwarding = getelementptr inbounds %struct.__block_byref_x* %x, i64 0, i32 1
+ store %struct.__block_byref_x* %x, %struct.__block_byref_x** %byref.forwarding, align 8
+ %byref.flags = getelementptr inbounds %struct.__block_byref_x* %x, i64 0, i32 2
+ store i32 0, i32* %byref.flags, align 8
+ %byref.size = getelementptr inbounds %struct.__block_byref_x* %x, i64 0, i32 3
+ store i32 32, i32* %byref.size, align 4
+ %block.isa = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 0
+ store i8* bitcast (i8** @_NSConcreteStackBlock to i8*), i8** %block.isa, align 8
+ %block.flags = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 1
+ store i32 1107296256, i32* %block.flags, align 8
+ %block.reserved = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 2
+ store i32 0, i32* %block.reserved, align 4
+ %block.invoke = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 3
+ store i8* bitcast (void (i8*)* @__foo_block_invoke_0 to i8*), i8** %block.invoke, align 8
+ %block.descriptor = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 4
+ store %struct.__block_descriptor* bitcast ({ i64, i64, i8*, i8*, i8*, i8* }* @__block_descriptor_tmp to %struct.__block_descriptor*), %struct.__block_descriptor** %block.descriptor, align 8
+ %block.captured = getelementptr inbounds <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block, i64 0, i32 5
+ %t1 = bitcast %struct.__block_byref_x* %x to i8*
+ store i8* %t1, i8** %block.captured, align 8
+ %t2 = bitcast <{ i8*, i32, i32, i8*, %struct.__block_descriptor*, i8* }>* %block to i8*
+ %t3 = call i8* @objc_retainBlock(i8* %t2) nounwind, !clang.arc.copy_on_escape !4
+ %t4 = getelementptr inbounds i8* %t3, i64 16
+ %t5 = bitcast i8* %t4 to i8**
+ %t6 = load i8** %t5, align 8
+ %t7 = bitcast i8* %t6 to void (i8*)*
+ invoke void %t7(i8* %t3)
+ to label %invoke.cont unwind label %lpad
+
+invoke.cont: ; preds = %entry
+ call void @objc_release(i8* %t3) nounwind, !clang.imprecise_release !4
+ call void @_Block_object_dispose(i8* %t1, i32 8)
+ ret void
+
+lpad: ; preds = %entry
+ %t8 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__objc_personality_v0 to i8*)
+ cleanup
+ call void @_Block_object_dispose(i8* %t1, i32 8)
+ resume { i8*, i32 } %t8
+}
+
+declare i8* @objc_retainBlock(i8*)
+declare void @objc_release(i8*)
+declare void @_Block_object_dispose(i8*, i32)
+declare i32 @__objc_personality_v0(...)
+declare void @__foo_block_invoke_0(i8* nocapture) uwtable ssp
+
+!4 = metadata !{}
generated by cgit v1.1 at 2024-09-22 22:34:41 +0000