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[Verifier] Make verifier fail when global variable size exceeds address space size #179625

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steffenlarsen merged 4 commits into from
Feb 10, 2026
+33 −3
Merged

[Verifier] Make verifier fail when global variable size exceeds address space size #179625

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36d580c
[Verifier] Make verifier fail when global variable size exceeds addre…
Feb 4, 2026
e5a604a
Remove scalable check and -1
Feb 4, 2026
ae0335b
Fix merge-base-offset tests
Feb 4, 2026
a9d486f
Merge branch 'main' into steffen/verify_global_var_size
steffenlarsen Feb 9, 2026
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10 changes: 10 additions & 0 deletions llvm/lib/IR/Verifier.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -955,6 +955,16 @@ void Verifier::visitGlobalVariable(const GlobalVariable &GV) {
"Global @" + GV.getName() + " has illegal target extension type",
GVType);

// Check that the the address space can hold all bits of the type, recognized
// by an access in the address space being able to reach all bytes of the
// type.
Check(GVType->isScalableTy() || !GVType->isSized() ||
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GV.getGlobalSize(DL) == 0 ||
isUIntN(DL.getAddressSizeInBits(GV.getAddressSpace()),
GV.getGlobalSize(DL) - 1),

@nikic nikic Feb 4, 2026

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Strictly speaking objects can only take up half the address space. But even if we don't enforce that as an IR well-formedness requirement, I think we should at least be dropping the -1 here, otherwise we're still going to be dealing with overflow issues.

"Global variable is too large to fit into the address space", &GV,
GVType);

@nikic nikic Feb 4, 2026

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Probably worth noting that this doesn't catch cases that overflow during the size calculation, but that's something we can handle separately...


if (!GV.hasInitializer()) {
visitGlobalValue(GV);
return;
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2 changes: 1 addition & 1 deletion llvm/test/CodeGen/LoongArch/merge-base-offset-tlsle.ll
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Expand Up @@ -661,7 +661,7 @@ if.end:
ret void
}

@g_a64 = dso_local thread_local(localexec) global [614750729487779976 x i64] zeroinitializer, align 8
@g_a64 = dso_local thread_local(localexec) global [536870912 x i64] zeroinitializer, align 8

define dso_local ptr @tlsle_load_addr_offset_1() nounwind {
; LA32-LABEL: tlsle_load_addr_offset_1:
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2 changes: 1 addition & 1 deletion llvm/test/CodeGen/LoongArch/merge-base-offset.ll
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Expand Up @@ -959,7 +959,7 @@ label:
ret ptr %0
}

@g_a64 = dso_local global [614750729487779976 x i64] zeroinitializer, align 8
@g_a64 = dso_local global [536870912 x i64] zeroinitializer, align 8

define dso_local ptr @load_addr_offset_1() nounwind {
; LA32-LABEL: load_addr_offset_1:
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2 changes: 1 addition & 1 deletion llvm/test/Transforms/GlobalOpt/large-element-size.ll
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Expand Up @@ -6,7 +6,7 @@ target datalayout = "p:32:32"
%struct.t.1 = type { %struct.u.0, %struct.u.0, %struct.u.0, %struct.u.0, i32, i32, i32, i32 }
%struct.u.0 = type { i32, i32, i32, i8 }

@s = external global [700 x [24000 x %struct.s.2]], align 1
@s = external global [700 x [2400 x %struct.s.2]], align 1
@p = global ptr getelementptr (i8, ptr @s, i64 2247483647), align 1

; CHECK: @p = local_unnamed_addr global ptr getelementptr (i8, ptr @s, i32 -2047483649), align 1
21 changes: 21 additions & 0 deletions llvm/test/Verifier/global-var-too-big.ll
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@@ -0,0 +1,21 @@
; RUN: not opt -S -passes=verify < %s 2>&1 | FileCheck %s

target datalayout = "e-m:e-p1:16:16-p2:32:32-p3:64:64-i8:8-i32:32-i64:64"

; Too large for 16-bit address space.
@G1 = internal addrspace(1) global [65537 x i8] zeroinitializer, align 4

; Too large for 32-bit address space.
@G2 = internal addrspace(2) global [2147483649 x i16] zeroinitializer, align 4

; Fit within the address spaces
@G3 = internal addrspace(1) global [65536 x i8] zeroinitializer, align 4
@G4 = internal addrspace(2) global [2147483648 x i16] zeroinitializer, align 4

; CHECK: Global variable is too large to fit into the address space
; CHECK-NEXT: ptr addrspace(1) @G1
; CHECK-NEXT: [65537 x i8]
; CHECK: Global variable is too large to fit into the address space
; CHECK-NEXT: ptr addrspace(2) @G2
; CHECK-NEXT: [2147483649 x i16]
; CHECK-NOT: Global variable is too large to fit into the address space