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[eager-specializer] Handle functions with don’t have return basic blocks #8723

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Merged
merged 1 commit into from
Apr 12, 2017
Merged

[eager-specializer] Handle functions with don’t have return basic blocks #8723

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7 changes: 5 additions & 2 deletions lib/SILOptimizer/IPO/EagerSpecializer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -324,7 +324,10 @@ class EagerDispatch {
/// given specialized function. Converts call arguments. Emits an invocation of
/// the specialized function. Handle the return value.
void EagerDispatch::emitDispatchTo(SILFunction *NewFunc) {
SILBasicBlock *OldReturnBB = &*GenericFunc->findReturnBB();
SILBasicBlock *OldReturnBB = nullptr;
auto ReturnBB = GenericFunc->findReturnBB();
if (ReturnBB != GenericFunc->end())
OldReturnBB = &*ReturnBB;
// 1. Emit a cascading sequence of type checks blocks.

// First split the entry BB, moving all instructions to the FailedTypeCheckBB.
Expand Down Expand Up @@ -395,7 +398,7 @@ void EagerDispatch::emitDispatchTo(SILFunction *NewFunc) {
Result = Builder.createTuple(Loc, VoidTy, { });

// Function marked as @NoReturn must be followed by 'unreachable'.
if (NewFunc->isNoReturnFunction())
if (NewFunc->isNoReturnFunction() || !OldReturnBB)
Builder.createUnreachable(Loc);
else {
auto resultTy = GenericFunc->getConventions().getSILResultType();
Expand Down
51 changes: 51 additions & 0 deletions test/SILOptimizer/eager_specialize.sil
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Expand Up @@ -643,6 +643,57 @@ bb0(%0 : $*T, %1 : $*S):
// CHECK: br bb2
// CHECK: } // end sil function '_T016eager_specialize34checkExplicitPartialSpecializationyx_q_tr0_lF'

/////////////////////////////////////////////////////////////////////////
// Check that functions with unreachable instructions can be specialized.
/////////////////////////////////////////////////////////////////////////

protocol P {
}

struct T : P {
init()
}

extension P {
public static func f(_ x: Self) -> Self
}

sil @error : $@convention(thin) () -> Never

// CHECK-LABEL: sil @_T016eager_specialize1PPAAE1fxxFZ : $@convention(method) <Self where Self : P> (@in Self, @thick Self.Type) -> @out Self
// CHECK: %3 = metatype $@thick Self.Type
// CHECK: %4 = metatype $@thick T.Type
// CHECK: %5 = unchecked_bitwise_cast %3 : $@thick Self.Type to $Builtin.Word
// CHECK: %6 = unchecked_bitwise_cast %4 : $@thick T.Type to $Builtin.Word
// CHECK: %7 = builtin "cmp_eq_Word"(%5 : $Builtin.Word, %6 : $Builtin.Word) : $Builtin.Int1
// CHECK: cond_br %7, bb2, bb1

// CHECK: bb1:
// CHECK: %9 = function_ref @error : $@convention(thin) () -> Never
// CHECK: %10 = apply %9() : $@convention(thin) () -> Never
// CHECK: unreachable

// CHECK: bb2:
// CHECK: %12 = unchecked_addr_cast %0 : $*Self to $*T
// CHECK: %13 = unchecked_addr_cast %1 : $*Self to $*T
// CHECK: %14 = load %13 : $*T
// CHECK: %15 = unchecked_trivial_bit_cast %2 : $@thick Self.Type to $@thick T.Type
// CHECK: %16 = function_ref @_T016eager_specialize1PPAAE1fxxFZ4main1TV_Tg5 : $@convention(method) (T, @thick T.Type) -> T
// CHECK: %17 = apply %16(%14, %15) : $@convention(method) (T, @thick T.Type) -> T
// CHECK: store %17 to %12 : $*T
// CHECK: %19 = tuple ()
// CHECK: unreachable
// CHECK: } // end sil function '_T016eager_specialize1PPAAE1fxxFZ'

sil [_specialize exported: false, kind: full, where Self == T] @_T016eager_specialize1PPAAE1fxxFZ : $@convention(method) <Self where Self : P> (@in Self, @thick Self.Type) -> @out Self {
bb0(%0 : $*Self, %1 : $*Self, %2 : $@thick Self.Type):
// function_ref error
%5 = function_ref @error : $@convention(thin) () -> Never
%6 = apply %5() : $@convention(thin) () -> Never
unreachable
} // end sil function '_T016eager_specialize1PPAAE1fxxFZ'


////////////////////////////////////////////////////////////////////
// Check that IRGen generates efficient code for fixed-size Trivial
// constraints.
Expand Down