[FunctionAttrs] Bail if initializes range overflows 64-bit signed int #137053
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Otherwise the range doesn't make sense since we interpret it as signed. Fixes llvm#134115
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@llvm/pr-subscribers-llvm-transforms Author: Arthur Eubanks (aeubanks) ChangesOtherwise the range doesn't make sense since we interpret it as signed. Fixes #134115 Full diff: https://github.com/llvm/llvm-project/pull/137053.diff 2 Files Affected:
diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
index bbfed2ac2c090..5af68df6f4463 100644
--- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -661,8 +661,12 @@ ArgumentAccessInfo getArgumentAccessInfo(const Instruction *I,
auto TypeSize = DL.getTypeStoreSize(Ty);
if (!TypeSize.isScalable() && Offset) {
int64_t Size = TypeSize.getFixedValue();
- return ConstantRange(APInt(64, *Offset, true),
- APInt(64, *Offset + Size, true));
+ APInt Low(64, *Offset, true);
+ APInt High(64, *Offset + Size, true);
+ // Bail if the range overflows signed 64-bit int.
+ if (Low.sge(High))
+ return std::nullopt;
+ return ConstantRange(Low, High);
}
return std::nullopt;
};
diff --git a/llvm/test/Transforms/FunctionAttrs/initializes.ll b/llvm/test/Transforms/FunctionAttrs/initializes.ll
index 861c61d683ae0..937595b5e9b74 100644
--- a/llvm/test/Transforms/FunctionAttrs/initializes.ll
+++ b/llvm/test/Transforms/FunctionAttrs/initializes.ll
@@ -635,3 +635,17 @@ define void @memset_offset_1_size_0(ptr %dst, ptr %src) {
call void @llvm.memmove.p0.p0.i64(ptr %dst.1, ptr %src, i64 0, i1 false)
ret void
}
+
+; We should bail if the range overflows a singed 64-bit int.
+define void @range_overflows_signed_64_bit_int(ptr %arg) {
+; CHECK: Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: write)
+; CHECK-LABEL: define void @range_overflows_signed_64_bit_int(
+; CHECK-SAME: ptr writeonly captures(none) [[ARG:%.*]]) #[[ATTR0]] {
+; CHECK-NEXT: [[GETELEMENTPTR:%.*]] = getelementptr i8, ptr [[ARG]], i64 9223372036854775804
+; CHECK-NEXT: store i32 0, ptr [[GETELEMENTPTR]], align 4
+; CHECK-NEXT: ret void
+;
+ %getelementptr = getelementptr i8, ptr %arg, i64 9223372036854775804
+ store i32 0, ptr %getelementptr
+ ret void
+}
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nikic
reviewed
Apr 23, 2025
| // Bail if the range overflows signed 64-bit int. | ||
| if (Low.sge(High)) | ||
| return std::nullopt; | ||
| return ConstantRange(Low, High); |
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Check isSignWrappedSet() on the result instead?
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I didn't see this, thanks for pointing it out. Although I ended up just using APInt::sadd_ov
| return ConstantRange(APInt(64, *Offset, true), | ||
| APInt(64, *Offset + Size, true)); | ||
| APInt Low(64, *Offset, true); | ||
| APInt High(64, *Offset + Size, true); |
Contributor
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This will probably still make ubsan unhappy for your test case?
IanWood1
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May 6, 2025
…llvm#137053) Otherwise the range doesn't make sense since we interpret it as signed. Fixes llvm#134115
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Otherwise the range doesn't make sense since we interpret it as signed.
Fixes #134115