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[GlobalOpt] Look through non-PointerType constant expressions. #125205

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[GlobalOpt] Look through non-PointerType constant expressions. #125205

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15 changes: 12 additions & 3 deletions llvm/lib/Transforms/Utils/GlobalStatus.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -78,8 +78,14 @@ static bool analyzeGlobalAux(const Value *V, GlobalStatus &GS,
return true;
} else {
// Ignore dead constant users.
if (!isSafeToDestroyConstant(C))
return true;
if (!isSafeToDestroyConstant(C)) {
if (CE) {
if (VisitedUsers.insert(CE).second)
if (analyzeGlobalAux(CE, GS, VisitedUsers))
return true;
} else
return true;
}
}
} else if (const Instruction *I = dyn_cast<Instruction>(UR)) {
if (!GS.HasMultipleAccessingFunctions) {
Expand Down Expand Up @@ -166,9 +172,12 @@ static bool analyzeGlobalAux(const Value *V, GlobalStatus &GS,
if (MTI->getArgOperand(1) == V)
GS.IsLoaded = true;
} else if (const MemSetInst *MSI = dyn_cast<MemSetInst>(I)) {
assert(MSI->getArgOperand(0) == V && "Memset only takes one pointer!");
if (MSI->getArgOperand(0) != V || MSI->getArgOperand(1) == V)
return true;
if (MSI->isVolatile())
return true;
assert(MSI->getArgOperand(0) == V &&
"First argument must be the pointer!");
GS.StoredType = GlobalStatus::Stored;
} else if (const auto *CB = dyn_cast<CallBase>(I)) {
if (CB->getIntrinsicID() == Intrinsic::threadlocal_address) {
Expand Down
2 changes: 0 additions & 2 deletions llvm/test/Transforms/GlobalOpt/cleanup-pointer-root-users-ptrtoint-add-constexpr.ll
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Expand Up @@ -12,8 +12,6 @@ declare i32 @fn1()
define void @stores_single_use_gep_constexpr() {
; CHECK-LABEL: @stores_single_use_gep_constexpr(
; CHECK-NEXT: entry:
; CHECK-NEXT: store ptr @fn0, ptr @global.20ptr, align 8
; CHECK-NEXT: store ptr @fn1, ptr getelementptr inbounds ([[STRUCT_GLOBAL_20PTR:%.*]], ptr @global.20ptr, i64 0, i32 1), align 8
; CHECK-NEXT: ret void
;
entry:
Expand Down
5 changes: 2 additions & 3 deletions llvm/test/Transforms/GlobalOpt/read-with-constexpr-users.ll
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Expand Up @@ -5,15 +5,14 @@
@H = internal global [2 x i64 ] zeroinitializer

;.
; CHECK: @G = internal global [2 x i64] zeroinitializer
; CHECK: @G = internal constant [2 x i64] zeroinitializer
; CHECK: @H = internal global [2 x i64] zeroinitializer
;.
define i64 @G_used_by_gep_inttoptr_exprs() {
; CHECK-LABEL: define i64 @G_used_by_gep_inttoptr_exprs() local_unnamed_addr {
; CHECK-NEXT: [[L:%.*]] = load i64, ptr @G, align 8
; CHECK-NEXT: [[GEP:%.*]] = getelementptr i8, ptr inttoptr (i64 add (i64 ptrtoint (ptr getelementptr inbounds nuw (i8, ptr @G, i64 16) to i64), i64 8) to ptr), i64 1
; CHECK-NEXT: [[C:%.*]] = icmp eq ptr [[GEP]], @G
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[C]], i64 [[L]], i64 9
; CHECK-NEXT: [[SEL:%.*]] = select i1 [[C]], i64 0, i64 9
; CHECK-NEXT: ret i64 [[SEL]]
;
%l = load i64, ptr @G, align 8
Expand Down