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Merged
merged 2 commits into from
Jun 14, 2023
Merged

Two optimization improvements related to access instructions #66592

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63808be
DefinitInitialization: convert begin_access instructions of initializ…
eeckstein Jun 13, 2023
5c5cd9f
DeadObjectElimination: ignore begin_access and end_access instructions
eeckstein Jun 13, 2023
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16 changes: 16 additions & 0 deletions lib/SILOptimizer/Mandatory/DefiniteInitialization.cpp
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Expand Up @@ -2312,6 +2312,19 @@ void LifetimeChecker::handleSelfInitUse(unsigned UseID) {
}
}

// In case of `var` initializations, SILGen creates a dynamic begin/end_access
// pair around the initialization store. If it's an initialization (and not
// a re-assign) it's guaranteed that it's an exclusive access and we can
// convert the access to an `[init] [static]` access.
static void setStaticInitAccess(SILValue memoryAddress) {
if (auto *ba = dyn_cast<BeginAccessInst>(memoryAddress)) {
if (ba->getEnforcement() == SILAccessEnforcement::Dynamic) {
ba->setEnforcement(SILAccessEnforcement::Static);
if (ba->getAccessKind() == SILAccessKind::Modify)
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@eeckstein I think you might be able to take this even a step further and change SILGen to always emit these as inits, unknown. It would then be an error if access control Can not convert it to static. I did something like this for consuming parameters which use deinit. Anyways, just a friendly thought.

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I thought about this, too. But SILGen doesn't know yet if it's an init or re-assign. And e.g. in a class initializer you can let self escape (after all members are initialized) and then re-assign a member. I'm not sure if it's even safe to guard such a reassign-after-self-escape as a statically checked access.

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s/guanranteed/guaranteed

ba->setAccessKind(SILAccessKind::Init);
}
}
}

/// updateInstructionForInitState - When an instruction being analyzed moves
/// from being InitOrAssign to some concrete state, update it for that state.
Expand All @@ -2336,6 +2349,8 @@ void LifetimeChecker::updateInstructionForInitState(unsigned UseID) {
assert(!CA->isInitializationOfDest() &&
"should not modify copy_addr that already knows it is initialized");
CA->setIsInitializationOfDest(InitKind);
if (InitKind == IsInitialization)
setStaticInitAccess(CA->getDest());
return;
}

Expand Down Expand Up @@ -2382,6 +2397,7 @@ void LifetimeChecker::updateInstructionForInitState(unsigned UseID) {
MarkMustCheckInst::CheckKind::InitableButNotConsumable);
}
}
setStaticInitAccess(AI->getDest());
}

return;
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3 changes: 3 additions & 0 deletions lib/SILOptimizer/Transforms/DeadObjectElimination.cpp
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Expand Up @@ -280,6 +280,9 @@ static bool canZapInstruction(SILInstruction *Inst, bool acceptRefCountInsts,
if (isa<InitExistentialAddrInst>(Inst))
return true;

if (isa<BeginAccessInst>(Inst) || isa<EndAccessInst>(Inst))
return true;

// If Inst does not read or write to memory, have side effects, and is not a
// terminator, we can zap it.
if (!Inst->mayHaveSideEffects() && !Inst->mayReadFromMemory() &&
Expand Down
2 changes: 1 addition & 1 deletion test/Concurrency/default_actor_definit.swift
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Expand Up @@ -40,7 +40,7 @@ actor C {
// CHECK-LABEL: sil hidden @$s21default_actor_definit1CC1yACSgSi_tcfc
// CHECK: builtin "initializeDefaultActor"(%1 : $C)
// CHECK: [[X:%.*]] = ref_element_addr %1 : $C, #C.x
// CHECK-NEXT: [[ACCESS:%.*]] = begin_access [modify] [dynamic] [[X]] : $*String
// CHECK-NEXT: [[ACCESS:%.*]] = begin_access [init] [static] [[X]] : $*String
// CHECK-NEXT: store {{.*}} to [[ACCESS]] : $*String
// CHECK-NEXT: end_access [[ACCESS]] : $*String
// CHECK: cond_br {{%.*}}, bb1, bb2
Expand Down
4 changes: 3 additions & 1 deletion test/SILOptimizer/dead_alloc_elim.sil
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Expand Up @@ -127,7 +127,9 @@ sil @store_to_trivial_property : $@convention(thin) (Int) -> () {
bb0(%0 : $Int):
%20 = alloc_ref [stack] $NontrivialDestructor
%21 = ref_element_addr %20 : $NontrivialDestructor, #NontrivialDestructor.i
store %0 to %21 : $*Int
%22 = begin_access [modify] [dynamic] %21 : $*Int
store %0 to %22 : $*Int
end_access %22 : $*Int
set_deallocating %20 : $NontrivialDestructor
dealloc_ref %20 : $NontrivialDestructor
dealloc_stack_ref %20 : $NontrivialDestructor
Expand Down
5 changes: 2 additions & 3 deletions test/SILOptimizer/default-cmo.swift
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Expand Up @@ -80,9 +80,8 @@ public func getSubmoduleKlassMember() -> Int {
}

// CHECK-LABEL: sil @$s4Main26getSubmoduleKlassMemberTBDSiyF
// CHECK: [[F:%[0-9]+]] = function_ref @$s9ModuleTBD20submoduleKlassMemberSiyF
// CHECK: [[I:%[0-9]+]] = apply [[F]]
// CHECK: return [[I]]
// CHECK-NOT: function_ref
// CHECK-NOT: apply
// CHECK: } // end sil function '$s4Main26getSubmoduleKlassMemberTBDSiyF'
public func getSubmoduleKlassMemberTBD() -> Int {
return ModuleTBD.submoduleKlassMember()
Expand Down
4 changes: 2 additions & 2 deletions test/SILOptimizer/definite_init_actor.swift
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Expand Up @@ -83,7 +83,7 @@ actor BoringActor {
// CHECK-LABEL: sil hidden @$s4test14SingleVarActorC10iterationsACSi_tYacfc : $@convention(method) @async (Int, @owned SingleVarActor) -> @owned SingleVarActor {
// CHECK: bb0({{%[0-9]+}} : $Int, [[SELF:%[0-9]+]] : $SingleVarActor):
// CHECK: [[MYVAR_REF:%[0-9]+]] = ref_element_addr [[SELF]] : $SingleVarActor, #SingleVarActor.myVar
// CHECK: [[MYVAR:%[0-9]+]] = begin_access [modify] [dynamic] [[MYVAR_REF]] : $*Int
// CHECK: [[MYVAR:%[0-9]+]] = begin_access [init] [static] [[MYVAR_REF]] : $*Int
// CHECK: store {{%[0-9]+}} to [[MYVAR]] : $*Int
// CHECK-NEXT: end_access [[MYVAR]]
// CHECK-NEXT: hop_to_executor [[SELF]] : $SingleVarActor
Expand Down Expand Up @@ -196,7 +196,7 @@ actor MultiVarActor {
// CHECK-LABEL: sil hidden @$s4test13MultiVarActorC10doNotThrowACSb_tYaKcfc : $@convention(method) @async (Bool, @owned MultiVarActor) -> (@owned MultiVarActor, @error any Error) {
// CHECK: bb0({{%[0-9]+}} : $Bool, [[SELF:%[0-9]+]] : $MultiVarActor):
// CHECK: [[REF:%[0-9]+]] = ref_element_addr [[SELF]] : $MultiVarActor, #MultiVarActor.firstVar
// CHECK: [[VAR:%[0-9]+]] = begin_access [modify] [dynamic] [[REF]] : $*Int
// CHECK: [[VAR:%[0-9]+]] = begin_access [init] [static] [[REF]] : $*Int
// CHECK: store {{%[0-9]+}} to [[VAR]] : $*Int
// CHECK-NEXT: end_access [[VAR]]
// CHECK-NEXT: hop_to_executor %1 : $MultiVarActor
Expand Down
4 changes: 2 additions & 2 deletions test/SILOptimizer/definite_init_failable_initializers.swift
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Expand Up @@ -735,7 +735,7 @@ class FailableBaseClass {
// CHECK: bb0(%0 : $FailableBaseClass):
// CHECK: [[CANARY:%.*]] = apply
// CHECK-NEXT: [[MEMBER_ADDR:%.*]] = ref_element_addr %0
// CHECK-NEXT: [[WRITE:%.*]] = begin_access [modify] [dynamic] [[MEMBER_ADDR]] : $*Canary
// CHECK-NEXT: [[WRITE:%.*]] = begin_access [init] [static] [[MEMBER_ADDR]] : $*Canary
// CHECK-NEXT: store [[CANARY]] to [[WRITE]]
// CHECK-NEXT: end_access [[WRITE]] : $*Canary
// CHECK-NEXT: strong_release %0
Expand Down Expand Up @@ -849,7 +849,7 @@ class FailableDerivedClass : FailableBaseClass {
// CHECK: [[CANARY_FUN:%.*]] = function_ref @$s35definite_init_failable_initializers6CanaryCACycfC :
// CHECK: [[CANARY:%.*]] = apply [[CANARY_FUN]](
// CHECK-NEXT: [[MEMBER_ADDR:%.*]] = ref_element_addr [[SELF]]
// CHECK-NEXT: [[WRITE:%.*]] = begin_access [modify] [dynamic] [[MEMBER_ADDR]] : $*Canary
// CHECK-NEXT: [[WRITE:%.*]] = begin_access [init] [static] [[MEMBER_ADDR]] : $*Canary
// CHECK-NEXT: store [[CANARY]] to [[WRITE]]
// CHECK-NEXT: end_access [[WRITE]] : $*Canary
// CHECK-NEXT: strong_release [[SELF]]
Expand Down
53 changes: 53 additions & 0 deletions test/SILOptimizer/definite_init_markuninitialized_rootself.sil
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Expand Up @@ -21,6 +21,17 @@ class RootClassWithNontrivialStoredProperties {
}

class SomeClass {}

final class IntClass {
var i: Int
init(_ i: Int)
}

final class GenericClass<T> {
var t: T
init(_ t: T)
}

sil @getSomeClass : $@convention(thin) () -> @owned SomeClass
sil @getSomeOptionalClass : $@convention(thin) () -> Optional<SomeClass>

Expand Down Expand Up @@ -131,3 +142,45 @@ bb0(%0 : @owned $RootClassWithNontrivialStoredProperties):
%13 = tuple ()
return %13 : $()
}

// CHECK-LABEL: sil [ossa] @init_IntClass :
// CHECK: [[ACCESS:%.*]] = begin_access [init] [static]
// CHECK: store %0 to [trivial] [[ACCESS]]
// CHECK: [[ACCESS2:%.*]] = begin_access [modify] [dynamic]
// CHECK: store %0 to [trivial] [[ACCESS2]]
// CHECK: } // end sil function 'init_IntClass'
sil [ossa] @init_IntClass : $@convention(method) (Int, @owned IntClass) -> @owned IntClass {
bb0(%0 : $Int, %1 : @owned $IntClass):
%4 = mark_uninitialized [rootself] %1 : $IntClass
%5 = begin_borrow %4 : $IntClass
%6 = ref_element_addr %5 : $IntClass, #IntClass.i
%7 = begin_access [modify] [dynamic] %6 : $*Int
assign %0 to %7 : $*Int
end_access %7 : $*Int
%10 = begin_access [modify] [dynamic] %6 : $*Int
assign %0 to %10 : $*Int
end_access %10 : $*Int
end_borrow %5 : $IntClass
return %4 : $IntClass
}

// CHECK-LABEL: sil [ossa] @init_GenericClass :
// CHECK: [[ACCESS:%.*]] = begin_access [init] [static]
// CHECK: copy_addr %0 to [init] [[ACCESS]]
// CHECK: [[ACCESS2:%.*]] = begin_access [modify] [dynamic]
// CHECK: copy_addr [take] %0 to [[ACCESS2]]
// CHECK: } // end sil function 'init_GenericClass'
sil [ossa] @init_GenericClass : $@convention(method) <T> (@in T, @owned GenericClass<T>) -> @owned GenericClass<T> {
bb0(%0 : $*T, %1 : @owned $GenericClass<T>):
%4 = mark_uninitialized [rootself] %1 : $GenericClass<T>
%5 = begin_borrow %4 : $GenericClass<T>
%8 = ref_element_addr %5 : $GenericClass<T>, #GenericClass.t
%9 = begin_access [modify] [dynamic] %8 : $*T
copy_addr %0 to %9 : $*T
end_access %9 : $*T
%12 = begin_access [modify] [dynamic] %8 : $*T
copy_addr [take] %0 to %12 : $*T
end_access %12 : $*T
end_borrow %5 : $GenericClass<T>
return %4 : $GenericClass<T>
}
6 changes: 3 additions & 3 deletions test/SILOptimizer/definite_init_root_class.swift
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Expand Up @@ -31,7 +31,7 @@ class FirstClass {
// CHECK: [[INIT:%.*]] = function_ref @$s24definite_init_root_class10OtherClassCACycfC : $@convention(method) (@thick OtherClass.Type) -> @owned OtherClass
// CHECK: [[OTHER:%.*]] = apply [[INIT]]([[METATYPE]]) : $@convention(method) (@thick OtherClass.Type) -> @owned OtherClass
// CHECK: [[X_ADDR:%.*]] = ref_element_addr %1 : $FirstClass, #FirstClass.x
// CHECK: [[X_ACCESS:%.*]] = begin_access [modify] [dynamic] %15 : $*OtherClass
// CHECK: [[X_ACCESS:%.*]] = begin_access [init] [static] %15 : $*OtherClass
// CHECK: [[ONE:%.*]] = integer_literal $Builtin.Int1, -1
// CHECK: store [[ONE]] to [[CONTROL]] : $*Builtin.Int1
// CHECK: store [[OTHER]] to [[X_ACCESS]] : $*OtherClass
Expand Down Expand Up @@ -115,7 +115,7 @@ class SecondClass {
// CHECK: [[INIT:%.*]] = function_ref @$s24definite_init_root_class10OtherClassCACycfC : $@convention(method) (@thick OtherClass.Type) -> @owned OtherClass
// CHECK: [[OTHER:%.*]] = apply [[INIT]]([[METATYPE]]) : $@convention(method) (@thick OtherClass.Type) -> @owned OtherClass
// CHECK: [[X_ADDR:%.*]] = ref_element_addr %1 : $SecondClass, #SecondClass.x
// CHECK: [[X_ACCESS:%.*]] = begin_access [modify] [dynamic] [[X_ADDR]] : $*OtherClass
// CHECK: [[X_ACCESS:%.*]] = begin_access [init] [static] [[X_ADDR]] : $*OtherClass
// CHECK: [[ONE:%.*]] = integer_literal $Builtin.Int2, 1
// CHECK: store [[ONE]] to [[CONTROL]] : $*Builtin.Int2
// CHECK: store [[OTHER]] to [[X_ACCESS]] : $*OtherClass
Expand All @@ -138,7 +138,7 @@ class SecondClass {
// CHECK: [[INIT:%.*]] = function_ref @$s24definite_init_root_class10OtherClassCACycfC : $@convention(method) (@thick OtherClass.Type) -> @owned OtherClass
// CHECK: [[OTHER:%.*]] = apply [[INIT]]([[METATYPE]]) : $@convention(method) (@thick OtherClass.Type) -> @owned OtherClass
// CHECK: [[Y_ADDR:%.*]] = ref_element_addr %1 : $SecondClass, #SecondClass.y
// CHECK: [[Y_ACCESS:%.*]] = begin_access [modify] [dynamic] [[Y_ADDR]] : $*OtherClass
// CHECK: [[Y_ACCESS:%.*]] = begin_access [init] [static] [[Y_ADDR]] : $*OtherClass
// CHECK: [[THREE:%.*]] = integer_literal $Builtin.Int2, -1
// CHECK: store [[THREE]] to [[CONTROL]] : $*Builtin.Int2
// CHECK: store [[OTHER]] to [[Y_ACCESS]] : $*OtherClass
Expand Down
12 changes: 6 additions & 6 deletions test/SILOptimizer/devirt_speculative_init.swift
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Expand Up @@ -20,17 +20,17 @@ public class BigCat : Cat {
}
}

public func make(type: Cat.Type, cats: Int) {
type.init(cats: cats)
public func make(type: Cat.Type, cats: Int) -> Cat {
return type.init(cats: cats)
}

// CHECK-LABEL: sil @$s23devirt_speculative_init4make4type4catsyAA3CatCm_SitF : $@convention(thin) (@thick Cat.Type, Int) -> ()
// CHECK-LABEL: sil @$s23devirt_speculative_init4make4type4catsAA3CatCAFm_SitF : $@convention(thin) (@thick Cat.Type, Int) -> @owned Cat {
// CHECK: checked_cast_br [exact] %0 : $@thick Cat.Type to @thick Cat.Type, bb2, bb3
// CHECK: bb1:
// CHECK: bb1{{.*}}:
// CHECK: return
// CHECK: bb2({{%.*}} : $@thick Cat.Type):
// CHECK: alloc_ref [stack] $Cat
// CHECK: alloc_ref $Cat
// CHECK: br bb1
// CHECK: bb3:
// CHECK: alloc_ref [stack] $BigCat
// CHECK: alloc_ref $BigCat
// CHECK: br bb1
3 changes: 1 addition & 2 deletions test/SILOptimizer/merge_exclusivity.swift
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Expand Up @@ -377,8 +377,7 @@ private struct EscapedTransform<T>: WriteProt {

// TESTSIL-LABEL: sil [noinline] @$s17merge_exclusivity14run_MergeTest9yySiF : $@convention(thin)
// TESTSIL: [[REFADDR:%.*]] = ref_element_addr {{.*}} : $StreamClass, #StreamClass.buffer
// TESTSIL-NEXT: [[B1:%.*]] = begin_access [modify] [{{.*}}] [no_nested_conflict] [[REFADDR]]
// TESTSIL: end_access [[B1]]
// TESTSIL-NEXT: store {{.*}} to [[REFADDR]]
// TESTSIL: [[BCONF:%.*]] = begin_access [modify] [{{.*}}] [[REFADDR]]
// TESTSIL: end_access [[BCONF]]
// TESTSIL: [[BCONF:%.*]] = begin_access [modify] [{{.*}}] [[REFADDR]]
Expand Down
2 changes: 1 addition & 1 deletion test/sil-func-extractor/basic.swift
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Expand Up @@ -46,7 +46,7 @@
// EXTRACT-INIT-LABEL: sil @$s5basic7VehicleC1nACSi_tcfc : $@convention(method) (Int, @owned Vehicle) -> @owned Vehicle {
// EXTRACT-INIT: bb0
// EXTRACT-INIT-NEXT: ref_element_addr
// EXTRACT-INIT-NEXT: begin_access [modify] [dynamic]
// EXTRACT-INIT-NEXT: begin_access [init] [static]
// EXTRACT-INIT-NEXT: store
// EXTRACT-INIT-NEXT: end_access
// EXTRACT-INIT-NEXT: return
Expand Down