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[MemoryBuiltins] Fix crash on large global variables #178391

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[MemoryBuiltins] Fix crash on large global variables #178391

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b682e0e
[MemoryBuiltins] Fix crash on large global variables
Jan 28, 2026
3734bbf
Remove undef
Jan 28, 2026
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3 changes: 2 additions & 1 deletion llvm/lib/Analysis/MemoryBuiltins.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1045,7 +1045,8 @@ OffsetSpan ObjectSizeOffsetVisitor::visitGlobalAlias(GlobalAlias &GA) {
OffsetSpan ObjectSizeOffsetVisitor::visitGlobalVariable(GlobalVariable &GV) {
if (!GV.getValueType()->isSized() || GV.hasExternalWeakLinkage() ||
((!GV.hasInitializer() || GV.isInterposable()) &&
Options.EvalMode != ObjectSizeOpts::Mode::Min))
Options.EvalMode != ObjectSizeOpts::Mode::Min) ||
!isUIntN(IntTyBits, GV.getGlobalSize(DL)))
return ObjectSizeOffsetVisitor::unknown();

APInt Size(IntTyBits, GV.getGlobalSize(DL));
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21 changes: 21 additions & 0 deletions llvm/test/Transforms/DeadStoreElimination/large-global-var.ll
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@@ -0,0 +1,21 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
; RUN: opt < %s -passes=dse -S | FileCheck %s

target datalayout = "e-m:e-p:32:32-i8:8-i32:32-i64:64"

; The data-layout only allows 32-bit indexing, but the array is too large to be
; fully accessible through that index-space.
@G = internal global [39969271929 x i32] zeroinitializer, align 4

define void @func() {
; CHECK-LABEL: define void @func() {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: store i32 0, ptr getelementptr (i8, ptr @G, i64 24), align 4
; CHECK-NEXT: store i32 0, ptr getelementptr (i8, ptr @G, i64 20), align 4
; CHECK-NEXT: ret void
;
entry:
store i32 0, ptr getelementptr (i8, ptr @G, i64 24), align 4
store i32 0, ptr getelementptr (i8, ptr @G, i64 20), align 4
ret void
}