Skip to content

[SROA] Unfold gep of index phi #83087

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 6 commits into from
Feb 28, 2024
Merged

[SROA] Unfold gep of index phi #83087

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
eaa5b4c
[SROA] Unfold gep of index phi
aeubanks Feb 27, 2024
e6edce3
Merge remote-tracking branch 'upstream/main' into sroa-phi
aeubanks Feb 27, 2024
04d38e7
address comments
aeubanks Feb 27, 2024
923de1f
check that pointer operand is not a instruction (besides an alloca) a…
aeubanks Feb 28, 2024
a6ffc0b
fold -> unfold
aeubanks Feb 28, 2024
a141663
also rename foldGEPSelect -> unfoldGEPSelect
aeubanks Feb 28, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
115 changes: 74 additions & 41 deletions llvm/lib/Transforms/Scalar/SROA.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3956,11 +3956,11 @@ class AggLoadStoreRewriter : public InstVisitor<AggLoadStoreRewriter, bool> {
return false;
}

// Fold gep (select cond, ptr1, ptr2), idx
// Unfold gep (select cond, ptr1, ptr2), idx
// => select cond, gep(ptr1, idx), gep(ptr2, idx)
// and gep ptr, (select cond, idx1, idx2)
// => select cond, gep(ptr, idx1), gep(ptr, idx2)
bool foldGEPSelect(GetElementPtrInst &GEPI) {
bool unfoldGEPSelect(GetElementPtrInst &GEPI) {
// Check whether the GEP has exactly one select operand and all indices
// will become constant after the transform.
SelectInst *Sel = dyn_cast<SelectInst>(GEPI.getPointerOperand());
Expand Down Expand Up @@ -4029,67 +4029,100 @@ class AggLoadStoreRewriter : public InstVisitor<AggLoadStoreRewriter, bool> {
return true;
}

// Fold gep (phi ptr1, ptr2) => phi gep(ptr1), gep(ptr2)
bool foldGEPPhi(GetElementPtrInst &GEPI) {
if (!GEPI.hasAllConstantIndices())
return false;
// Unfold gep (phi ptr1, ptr2), idx
// => phi ((gep ptr1, idx), (gep ptr2, idx))
// and gep ptr, (phi idx1, idx2)
// => phi ((gep ptr, idx1), (gep ptr, idx2))
bool unfoldGEPPhi(GetElementPtrInst &GEPI) {
// To prevent infinitely expanding recursive phis, bail if the GEP pointer
// operand (looking through the phi if it is the phi we want to unfold) is
// an instruction besides an alloca.
PHINode *Phi = dyn_cast<PHINode>(GEPI.getPointerOperand());
auto IsInvalidPointerOperand = [](Value *V) {
return isa<Instruction>(V) && !isa<AllocaInst>(V);
};
if (Phi) {
if (any_of(Phi->operands(), IsInvalidPointerOperand))
return false;
} else {
if (IsInvalidPointerOperand(GEPI.getPointerOperand()))
return false;
}
// Check whether the GEP has exactly one phi operand (including the pointer
// operand) and all indices will become constant after the transform.
for (Value *Op : GEPI.indices()) {
if (auto *SI = dyn_cast<PHINode>(Op)) {
if (Phi)
return false;

PHINode *PHI = cast<PHINode>(GEPI.getPointerOperand());
if (GEPI.getParent() != PHI->getParent() ||
llvm::any_of(PHI->incoming_values(), [](Value *In) {
Instruction *I = dyn_cast<Instruction>(In);
return !I || isa<GetElementPtrInst>(I) || isa<PHINode>(I) ||
succ_empty(I->getParent()) ||
!I->getParent()->isLegalToHoistInto();
}))
Phi = SI;
if (!all_of(Phi->incoming_values(),
[](Value *V) { return isa<ConstantInt>(V); }))
return false;
Comment on lines +4059 to +4061
Copy link
Member

@Artem-B Artem-B Feb 27, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

There may be merit in folding if we see any constant values. It should still be useful for SROA, but there's obviously a trade-off vs having the non-const GEPs around.

Copy link
Contributor Author

@aeubanks aeubanks Feb 27, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

folding as in changing the GEP to an i8 GEP with one constant index?

Copy link
Member

@Artem-B Artem-B Feb 27, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Nit: Not sure if "folding" is the right term here (or ta good name for the function). Considering that we're creating more IR instructions, "unfolding"/transforming would fit better, IMO.

What I mean is that instead of replacing phi of constant values with phi of geps with constant index only, we may want to allow replacing phis of mix of GEPs with constant and non-constant indices. GEP with constant index will help SROA directly, and gep with non-constant index may or may not be useful. It would likely be more amenable to further optimizations, as "phi" is often a roadblock for some optimizations that only look within one basic block.

Copy link
Contributor Author

@aeubanks aeubanks Feb 28, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

renamed to "unfold"

SROA is just focused on removing allocas. Other transforms may be blocked by phis, but it's not SROA's job to fix those. If we decide that's a canonical form, instcombine should do that transformation.

continue;
}

if (!isa<ConstantInt>(Op))
return false;
}

if (!Phi)
return false;

LLVM_DEBUG(dbgs() << " Rewriting gep(phi) -> phi(gep):\n";
dbgs() << " original: " << *PHI << "\n";
dbgs() << " original: " << *Phi << "\n";
dbgs() << " " << GEPI << "\n";);

SmallVector<Value *, 4> Index(GEPI.indices());
bool IsInBounds = GEPI.isInBounds();
IRB.SetInsertPoint(GEPI.getParent(), GEPI.getParent()->getFirstNonPHIIt());
PHINode *NewPN = IRB.CreatePHI(GEPI.getType(), PHI->getNumIncomingValues(),
PHI->getName() + ".sroa.phi");
for (unsigned I = 0, E = PHI->getNumIncomingValues(); I != E; ++I) {
BasicBlock *B = PHI->getIncomingBlock(I);
Value *NewVal = nullptr;
int Idx = NewPN->getBasicBlockIndex(B);
if (Idx >= 0) {
NewVal = NewPN->getIncomingValue(Idx);
} else {
Instruction *In = cast<Instruction>(PHI->getIncomingValue(I));
auto GetNewOps = [&](Value *PhiOp) {
SmallVector<Value *> NewOps;
for (Value *Op : GEPI.operands())
if (Op == Phi)
NewOps.push_back(PhiOp);
else
NewOps.push_back(Op);
return NewOps;
};

IRB.SetInsertPoint(In->getParent(), std::next(In->getIterator()));
Type *Ty = GEPI.getSourceElementType();
NewVal = IRB.CreateGEP(Ty, In, Index, In->getName() + ".sroa.gep",
IsInBounds);
}
NewPN->addIncoming(NewVal, B);
IRB.SetInsertPoint(Phi);
PHINode *NewPhi = IRB.CreatePHI(GEPI.getType(), Phi->getNumIncomingValues(),
Phi->getName() + ".sroa.phi");

bool IsInBounds = GEPI.isInBounds();
Type *SourceTy = GEPI.getSourceElementType();
// We only handle arguments, constants, and static allocas here, so we can
// insert GEPs at the beginning of the function after static allocas.
IRB.SetInsertPointPastAllocas(GEPI.getFunction());
for (unsigned I = 0, E = Phi->getNumIncomingValues(); I != E; ++I) {
Value *Op = Phi->getIncomingValue(I);
BasicBlock *BB = Phi->getIncomingBlock(I);
SmallVector<Value *> NewOps = GetNewOps(Op);

Value *NewGEP =
IRB.CreateGEP(SourceTy, NewOps[0], ArrayRef(NewOps).drop_front(),
Phi->getName() + ".sroa.gep", IsInBounds);
NewPhi->addIncoming(NewGEP, BB);
}

Visited.erase(&GEPI);
GEPI.replaceAllUsesWith(NewPN);
GEPI.replaceAllUsesWith(NewPhi);
GEPI.eraseFromParent();
Visited.insert(NewPN);
enqueueUsers(*NewPN);
Visited.insert(NewPhi);
enqueueUsers(*NewPhi);

LLVM_DEBUG(dbgs() << " to: ";
for (Value *In
: NewPN->incoming_values()) dbgs()
: NewPhi->incoming_values()) dbgs()
<< "\n " << *In;
dbgs() << "\n " << *NewPN << '\n');
dbgs() << "\n " << *NewPhi << '\n');

return true;
}

bool visitGetElementPtrInst(GetElementPtrInst &GEPI) {
if (foldGEPSelect(GEPI))
if (unfoldGEPSelect(GEPI))
return true;

if (isa<PHINode>(GEPI.getPointerOperand()) && foldGEPPhi(GEPI))
if (unfoldGEPPhi(GEPI))
return true;

enqueueUsers(GEPI);
Expand Down
20 changes: 10 additions & 10 deletions llvm/test/Transforms/SROA/phi-and-select.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -114,13 +114,13 @@ define i32 @test3(i32 %x) {
; CHECK-LABEL: @test3(
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i32 [[X:%.*]], label [[BB0:%.*]] [
; CHECK-NEXT: i32 1, label [[BB1:%.*]]
; CHECK-NEXT: i32 2, label [[BB2:%.*]]
; CHECK-NEXT: i32 3, label [[BB3:%.*]]
; CHECK-NEXT: i32 4, label [[BB4:%.*]]
; CHECK-NEXT: i32 5, label [[BB5:%.*]]
; CHECK-NEXT: i32 6, label [[BB6:%.*]]
; CHECK-NEXT: i32 7, label [[BB7:%.*]]
; CHECK-NEXT: i32 1, label [[BB1:%.*]]
; CHECK-NEXT: i32 2, label [[BB2:%.*]]
; CHECK-NEXT: i32 3, label [[BB3:%.*]]
; CHECK-NEXT: i32 4, label [[BB4:%.*]]
; CHECK-NEXT: i32 5, label [[BB5:%.*]]
; CHECK-NEXT: i32 6, label [[BB6:%.*]]
; CHECK-NEXT: i32 7, label [[BB7:%.*]]
; CHECK-NEXT: ]
; CHECK: bb0:
; CHECK-NEXT: br label [[EXIT:%.*]]
Expand Down Expand Up @@ -733,6 +733,7 @@ define void @PR20822(i1 %c1, i1 %c2, ptr %ptr) {
; CHECK-LABEL: @PR20822(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[F_SROA_0:%.*]] = alloca i32, align 4
; CHECK-NEXT: [[F1_SROA_GEP:%.*]] = getelementptr inbounds [[STRUCT_S:%.*]], ptr [[PTR:%.*]], i32 0, i32 0
; CHECK-NEXT: br i1 [[C1:%.*]], label [[IF_END:%.*]], label [[FOR_COND:%.*]]
; CHECK: for.cond:
; CHECK-NEXT: br label [[IF_END]]
Expand All @@ -742,9 +743,8 @@ define void @PR20822(i1 %c1, i1 %c2, ptr %ptr) {
; CHECK: if.then2:
; CHECK-NEXT: br label [[IF_THEN5]]
; CHECK: if.then5:
; CHECK-NEXT: [[F1:%.*]] = phi ptr [ [[PTR:%.*]], [[IF_THEN2]] ], [ [[F_SROA_0]], [[IF_END]] ]
; CHECK-NEXT: [[DOTFCA_0_GEP:%.*]] = getelementptr inbounds [[STRUCT_S:%.*]], ptr [[F1]], i32 0, i32 0
; CHECK-NEXT: store i32 0, ptr [[DOTFCA_0_GEP]], align 4
; CHECK-NEXT: [[F1_SROA_PHI:%.*]] = phi ptr [ [[F1_SROA_GEP]], [[IF_THEN2]] ], [ [[F_SROA_0]], [[IF_END]] ]
; CHECK-NEXT: store i32 0, ptr [[F1_SROA_PHI]], align 4
; CHECK-NEXT: ret void
;
entry:
Expand Down
141 changes: 123 additions & 18 deletions llvm/test/Transforms/SROA/phi-gep.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -65,15 +65,13 @@ end:
define i32 @test_sroa_phi_gep_poison(i1 %cond) {
; CHECK-LABEL: @test_sroa_phi_gep_poison(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[A:%.*]] = alloca [[PAIR:%.*]], align 4
; CHECK-NEXT: br i1 [[COND:%.*]], label [[IF_THEN:%.*]], label [[END:%.*]]
; CHECK: if.then:
; CHECK-NEXT: [[PHI_SROA_PHI_SROA_SPECULATE_LOAD_IF_THEN:%.*]] = load i32, ptr poison, align 4
; CHECK-NEXT: br label [[END]]
; CHECK: end:
; CHECK-NEXT: [[PHI:%.*]] = phi ptr [ [[A]], [[ENTRY:%.*]] ], [ poison, [[IF_THEN]] ]
; CHECK-NEXT: [[GEP:%.*]] = getelementptr inbounds [[PAIR]], ptr [[PHI]], i32 0, i32 1
; CHECK-NEXT: [[LOAD:%.*]] = load i32, ptr [[GEP]], align 4
; CHECK-NEXT: ret i32 [[LOAD]]
; CHECK-NEXT: [[PHI_SROA_PHI_SROA_SPECULATED:%.*]] = phi i32 [ undef, [[ENTRY:%.*]] ], [ [[PHI_SROA_PHI_SROA_SPECULATE_LOAD_IF_THEN]], [[IF_THEN]] ]
; CHECK-NEXT: ret i32 [[PHI_SROA_PHI_SROA_SPECULATED]]
;
entry:
%a = alloca %pair, align 4
Expand All @@ -94,17 +92,13 @@ end:
define i32 @test_sroa_phi_gep_global(i1 %cond) {
; CHECK-LABEL: @test_sroa_phi_gep_global(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[A:%.*]] = alloca [[PAIR:%.*]], align 4
; CHECK-NEXT: [[GEP_A:%.*]] = getelementptr inbounds [[PAIR]], ptr [[A]], i32 0, i32 1
; CHECK-NEXT: store i32 1, ptr [[GEP_A]], align 4
; CHECK-NEXT: br i1 [[COND:%.*]], label [[IF_THEN:%.*]], label [[END:%.*]]
; CHECK: if.then:
; CHECK-NEXT: [[PHI_SROA_PHI_SROA_SPECULATE_LOAD_IF_THEN:%.*]] = load i32, ptr getelementptr inbounds ([[PAIR:%.*]], ptr @g, i32 0, i32 1), align 4
; CHECK-NEXT: br label [[END]]
; CHECK: end:
; CHECK-NEXT: [[PHI:%.*]] = phi ptr [ [[A]], [[ENTRY:%.*]] ], [ @g, [[IF_THEN]] ]
; CHECK-NEXT: [[GEP:%.*]] = getelementptr inbounds [[PAIR]], ptr [[PHI]], i32 0, i32 1
; CHECK-NEXT: [[LOAD:%.*]] = load i32, ptr [[GEP]], align 4
; CHECK-NEXT: ret i32 [[LOAD]]
; CHECK-NEXT: [[PHI_SROA_PHI_SROA_SPECULATED:%.*]] = phi i32 [ 1, [[ENTRY:%.*]] ], [ [[PHI_SROA_PHI_SROA_SPECULATE_LOAD_IF_THEN]], [[IF_THEN]] ]
; CHECK-NEXT: ret i32 [[PHI_SROA_PHI_SROA_SPECULATED]]
;
entry:
%a = alloca %pair, align 4
Expand Down Expand Up @@ -245,15 +239,15 @@ define i32 @test_sroa_invoke_phi_gep(i1 %cond) personality ptr @__gxx_personalit
; CHECK-NEXT: br i1 [[COND:%.*]], label [[CALL:%.*]], label [[END:%.*]]
; CHECK: call:
; CHECK-NEXT: [[B:%.*]] = invoke ptr @foo()
; CHECK-NEXT: to label [[END]] unwind label [[INVOKE_CATCH:%.*]]
; CHECK-NEXT: to label [[END]] unwind label [[INVOKE_CATCH:%.*]]
; CHECK: end:
; CHECK-NEXT: [[PHI:%.*]] = phi ptr [ [[A]], [[ENTRY:%.*]] ], [ [[B]], [[CALL]] ]
; CHECK-NEXT: [[GEP:%.*]] = getelementptr inbounds [[PAIR]], ptr [[PHI]], i32 0, i32 1
; CHECK-NEXT: [[LOAD:%.*]] = load i32, ptr [[GEP]], align 4
; CHECK-NEXT: ret i32 [[LOAD]]
; CHECK: invoke_catch:
; CHECK-NEXT: [[RES:%.*]] = landingpad { ptr, i32 }
; CHECK-NEXT: catch ptr null
; CHECK-NEXT: catch ptr null
; CHECK-NEXT: ret i32 0
;
entry:
Expand Down Expand Up @@ -468,10 +462,10 @@ define i32 @test_sroa_phi_gep_multiple_values_from_same_block(i32 %arg) {
; CHECK-LABEL: @test_sroa_phi_gep_multiple_values_from_same_block(
; CHECK-NEXT: bb.1:
; CHECK-NEXT: switch i32 [[ARG:%.*]], label [[BB_3:%.*]] [
; CHECK-NEXT: i32 1, label [[BB_2:%.*]]
; CHECK-NEXT: i32 2, label [[BB_2]]
; CHECK-NEXT: i32 3, label [[BB_4:%.*]]
; CHECK-NEXT: i32 4, label [[BB_4]]
; CHECK-NEXT: i32 1, label [[BB_2:%.*]]
; CHECK-NEXT: i32 2, label [[BB_2]]
; CHECK-NEXT: i32 3, label [[BB_4:%.*]]
; CHECK-NEXT: i32 4, label [[BB_4]]
; CHECK-NEXT: ]
; CHECK: bb.2:
; CHECK-NEXT: br label [[BB_4]]
Expand Down Expand Up @@ -504,6 +498,117 @@ bb.4: ; preds = %bb.1, %bb.1, %bb
ret i32 %load
}

define i64 @test_phi_idx_mem2reg_const(i1 %arg) {
; CHECK-LABEL: @test_phi_idx_mem2reg_const(
; CHECK-NEXT: bb:
; CHECK-NEXT: br i1 [[ARG:%.*]], label [[BB1:%.*]], label [[BB2:%.*]]
; CHECK: bb1:
; CHECK-NEXT: br label [[END:%.*]]
; CHECK: bb2:
; CHECK-NEXT: br label [[END]]
; CHECK: end:
; CHECK-NEXT: [[PHI_SROA_PHI_SROA_SPECULATED:%.*]] = phi i64 [ 2, [[BB1]] ], [ 3, [[BB2]] ]
; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ 0, [[BB1]] ], [ 1, [[BB2]] ]
; CHECK-NEXT: ret i64 [[PHI_SROA_PHI_SROA_SPECULATED]]
;
bb:
%alloca = alloca [2 x i64], align 8
%gep1 = getelementptr inbounds i64, ptr %alloca, i64 1
store i64 2, ptr %alloca
store i64 3, ptr %gep1
br i1 %arg, label %bb1, label %bb2

bb1:
br label %end

bb2:
br label %end

end:
%phi = phi i64 [ 0, %bb1 ], [ 1, %bb2 ]
%getelementptr = getelementptr inbounds i64, ptr %alloca, i64 %phi
%load = load i64, ptr %getelementptr
ret i64 %load
}

define i64 @test_phi_idx_mem2reg_not_const(i1 %arg, i64 %idx) {
; CHECK-LABEL: @test_phi_idx_mem2reg_not_const(
; CHECK-NEXT: bb:
; CHECK-NEXT: [[ALLOCA:%.*]] = alloca [2 x i64], align 8
; CHECK-NEXT: [[GEP1:%.*]] = getelementptr inbounds i64, ptr [[ALLOCA]], i64 1
; CHECK-NEXT: store i64 2, ptr [[ALLOCA]], align 4
; CHECK-NEXT: store i64 3, ptr [[GEP1]], align 4
; CHECK-NEXT: br i1 [[ARG:%.*]], label [[BB1:%.*]], label [[BB2:%.*]]
; CHECK: bb1:
; CHECK-NEXT: br label [[END:%.*]]
; CHECK: bb2:
; CHECK-NEXT: br label [[END]]
; CHECK: end:
; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ 0, [[BB1]] ], [ [[IDX:%.*]], [[BB2]] ]
; CHECK-NEXT: [[GETELEMENTPTR:%.*]] = getelementptr inbounds i64, ptr [[ALLOCA]], i64 [[PHI]]
; CHECK-NEXT: [[LOAD:%.*]] = load i64, ptr [[GETELEMENTPTR]], align 4
; CHECK-NEXT: ret i64 [[LOAD]]
;
bb:
%alloca = alloca [2 x i64], align 8
%gep1 = getelementptr inbounds i64, ptr %alloca, i64 1
store i64 2, ptr %alloca
store i64 3, ptr %gep1
br i1 %arg, label %bb1, label %bb2

bb1:
br label %end

bb2:
br label %end

end:
%phi = phi i64 [ 0, %bb1 ], [ %idx, %bb2 ]
%getelementptr = getelementptr inbounds i64, ptr %alloca, i64 %phi
%load = load i64, ptr %getelementptr
ret i64 %load
}

define i64 @test_phi_mem2reg_pointer_op_is_non_const_gep(i1 %arg, i64 %idx) {
; CHECK-LABEL: @test_phi_mem2reg_pointer_op_is_non_const_gep(
; CHECK-NEXT: bb:
; CHECK-NEXT: [[ALLOCA:%.*]] = alloca [2 x i64], align 8
; CHECK-NEXT: [[GEP1:%.*]] = getelementptr inbounds i64, ptr [[ALLOCA]], i64 1
; CHECK-NEXT: store i64 2, ptr [[ALLOCA]], align 4
; CHECK-NEXT: store i64 3, ptr [[GEP1]], align 4
; CHECK-NEXT: br i1 [[ARG:%.*]], label [[BB1:%.*]], label [[BB2:%.*]]
; CHECK: bb1:
; CHECK-NEXT: br label [[END:%.*]]
; CHECK: bb2:
; CHECK-NEXT: br label [[END]]
; CHECK: end:
; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ 0, [[BB1]] ], [ 1, [[BB2]] ]
; CHECK-NEXT: [[GETELEMENTPTR:%.*]] = getelementptr inbounds i64, ptr [[ALLOCA]], i64 [[IDX:%.*]]
; CHECK-NEXT: [[GETELEMENTPTR2:%.*]] = getelementptr inbounds i64, ptr [[GETELEMENTPTR]], i64 [[PHI]]
; CHECK-NEXT: [[LOAD:%.*]] = load i64, ptr [[GETELEMENTPTR]], align 4
; CHECK-NEXT: ret i64 [[LOAD]]
;
bb:
%alloca = alloca [2 x i64], align 8
%gep1 = getelementptr inbounds i64, ptr %alloca, i64 1
store i64 2, ptr %alloca
store i64 3, ptr %gep1
br i1 %arg, label %bb1, label %bb2

bb1:
br label %end

bb2:
br label %end

end:
%phi = phi i64 [ 0, %bb1 ], [ 1, %bb2 ]
%getelementptr = getelementptr inbounds i64, ptr %alloca, i64 %idx
%getelementptr2 = getelementptr inbounds i64, ptr %getelementptr, i64 %phi
%load = load i64, ptr %getelementptr
ret i64 %load
}

declare ptr @foo()

declare i32 @__gxx_personality_v0(...)
Expand Down