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Nov 4, 2025
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[IR] Add new function attribute nocreateundeforpoison #164809

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ac95b57
[IR] Add new function attribute nocreateundeforpoison
jayfoad Oct 23, 2025
40a3c93
Update standard intrinsics
jayfoad Oct 23, 2025
bf32374
Add comments
jayfoad Oct 23, 2025
8652177
Adopt nikic's wording
jayfoad Oct 31, 2025
ab58489
Merge branch 'main' into nocreateundeforpoison
jayfoad Nov 3, 2025
5657809
Update MLIR tests
jayfoad Nov 3, 2025
2477738
Update Clang tests
jayfoad Nov 3, 2025
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4 changes: 4 additions & 0 deletions llvm/docs/LangRef.rst
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Expand Up @@ -2741,6 +2741,10 @@ For example:
``"nooutline"``
This attribute indicates that outlining passes should not modify the
function.
``nocreateundeforpoison``
This attribute indicates that the result of the function will not be undef
or poison if all arguments are not undef and not poison. Otherwise, it is
undefined behavior.
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@arsenm arsenm Oct 24, 2025

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Does this need to clarify the interaction with fast math flags?

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@jayfoad jayfoad Oct 24, 2025

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Good point. I'm not sure exactly how to word it. How about:

Note that a call instruction with poison-generating fast math flags may still generate poison, even if the call site or called function have the nocreateundeforpoison attribute. In that sense, poison-generating fast math flags take priority over this attribute.

?

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@arsenm arsenm Oct 24, 2025

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Yes, something like that

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@arsenm arsenm Oct 24, 2025

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But same applies for other poison-generating metadata and attributes like range and !range

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@jayfoad jayfoad Oct 24, 2025

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For the interaction with other attributes: I do not want to come up with an order of precedence of attributes, saying which ones take priority over other ones, and I do not think it is necessary. The way I understand it is there are a bunch of reasons why a call might return poison, including:

  1. Having a range attribute on the return value, and returning a value outside that range
  2. Having arguments that are poison
  3. Not having the nocreateundeforpoison attribute
  4. ... and so on.

I'm not sure how to explain this succinctly in the LangRef. Maybe I need to invert the description:

``nocreateundeforpoison``
    Lack of this attribute indicates that the result of the function may be undef
    or poison even if all arguments are not undef and not poison. Returning
    undef or poison from a function or call site with this attribute triggers
    undefined behavior.

Does that help?

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@arsenm arsenm Oct 25, 2025

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I think phrasing it in terms of what it doesn't mean is worse. Can we phrase it in terms of... base value behavior?

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@jayfoad jayfoad Oct 29, 2025

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Not sure what you mean by "base value" and I don't see that term used elsewhere. Are you suggesting we separate out the callee's internal view of the return value and the caller's external view of it? (Like "intensional" and "extensional" definitions in logic/semantics.) nocreateundeforpoison says something about the internal view. Poison-generating attributes and fast math flags only affect the external view, e.g. nnan says that if the internal is NaN then the external is poison.

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@nikic nikic Oct 29, 2025

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I think something like this would be fine? "This attribute indicates that the result of the function (prior to application of return attributes/metadata) will not be undef or poison if all arguments are not undef and not poison."

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@jayfoad jayfoad Oct 31, 2025

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Thanks, I used that.


Call Site Attributes
----------------------
Expand Down
1 change: 1 addition & 0 deletions llvm/include/llvm/Bitcode/LLVMBitCodes.h
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Expand Up @@ -801,6 +801,7 @@ enum AttributeKindCodes {
ATTR_KIND_CAPTURES = 102,
ATTR_KIND_DEAD_ON_RETURN = 103,
ATTR_KIND_SANITIZE_ALLOC_TOKEN = 104,
ATTR_KIND_NO_CREATE_UNDEF_OR_POISON = 105,
};

enum ComdatSelectionKindCodes {
Expand Down
5 changes: 5 additions & 0 deletions llvm/include/llvm/IR/Attributes.td
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Expand Up @@ -183,6 +183,11 @@ def NoCallback : EnumAttr<"nocallback", IntersectAnd, [FnAttr]>;
/// Specify how the pointer may be captured.
def Captures : IntAttr<"captures", IntersectCustom, [ParamAttr]>;

/// Result will not be undef or poison if all arguments are not undef and not
/// poison.
def NoCreateUndefOrPoison
: EnumAttr<"nocreateundeforpoison", IntersectAnd, [FnAttr]>;

/// Function is not a source of divergence.
def NoDivergenceSource : EnumAttr<"nodivergencesource", IntersectAnd, [FnAttr]>;

Expand Down
84 changes: 48 additions & 36 deletions llvm/include/llvm/IR/Intrinsics.td
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Expand Up @@ -186,6 +186,10 @@ def IntrSpeculatable : IntrinsicProperty;
// defined by the hasSideEffects property of the TableGen Instruction class.
def IntrHasSideEffects : IntrinsicProperty;

// Result will not be undef or poison if all arguments are not undef and not
// poison.
def IntrNoCreateUndefOrPoison : IntrinsicProperty;

//===----------------------------------------------------------------------===//
// IIT constants and utils
//===----------------------------------------------------------------------===//
Expand Down Expand Up @@ -1039,7 +1043,7 @@ def int_experimental_memset_pattern
// FIXME: Add version of these floating point intrinsics which allow non-default
// rounding modes and FP exception handling.

let IntrProperties = [IntrNoMem, IntrSpeculatable] in {
let IntrProperties = [IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison] in {
def int_fma : DefaultAttrsIntrinsic<[llvm_anyfloat_ty],
[LLVMMatchType<0>, LLVMMatchType<0>,
LLVMMatchType<0>]>;
Expand All @@ -1052,16 +1056,8 @@ let IntrProperties = [IntrNoMem, IntrSpeculatable] in {
// environment so they can be treated as readnone.
def int_sqrt : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_powi : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>, llvm_anyint_ty]>;
def int_asin : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_acos : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_atan : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_atan2 : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>, LLVMMatchType<0>]>;
def int_sin : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_cos : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_tan : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_sinh : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_cosh : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_tanh : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_pow : DefaultAttrsIntrinsic<[llvm_anyfloat_ty],
[LLVMMatchType<0>, LLVMMatchType<0>]>;
def int_log : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
Expand All @@ -1080,12 +1076,6 @@ let IntrProperties = [IntrNoMem, IntrSpeculatable] in {
def int_nearbyint : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_round : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_roundeven : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_sincos : DefaultAttrsIntrinsic<[LLVMMatchType<0>, LLVMMatchType<0>],
[llvm_anyfloat_ty]>;
def int_sincospi : DefaultAttrsIntrinsic<[LLVMMatchType<0>, LLVMMatchType<0>],
[llvm_anyfloat_ty]>;
def int_modf : DefaultAttrsIntrinsic<[LLVMMatchType<0>, LLVMMatchType<0>],
[llvm_anyfloat_ty]>;

// Truncate a floating point number with a specific rounding mode
def int_fptrunc_round : DefaultAttrsIntrinsic<[ llvm_anyfloat_ty ],
Expand All @@ -1097,6 +1087,8 @@ let IntrProperties = [IntrNoMem, IntrSpeculatable] in {
def int_arithmetic_fence : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>],
[IntrNoMem]>;

// If the value doesn't fit an unspecified value is returned (but this
// is not poison).
def int_lround : DefaultAttrsIntrinsic<[llvm_anyint_ty], [llvm_anyfloat_ty]>;
def int_llround : DefaultAttrsIntrinsic<[llvm_anyint_ty], [llvm_anyfloat_ty]>;
def int_lrint : DefaultAttrsIntrinsic<[llvm_anyint_ty], [llvm_anyfloat_ty]>;
Expand All @@ -1110,29 +1102,49 @@ let IntrProperties = [IntrNoMem, IntrSpeculatable] in {
def int_frexp : DefaultAttrsIntrinsic<[llvm_anyfloat_ty, llvm_anyint_ty], [LLVMMatchType<0>]>;
}

let IntrProperties = [IntrNoMem, IntrSpeculatable] in {
// These functions do not read memory, but are sensitive to the
// rounding mode. LLVM purposely does not model changes to the FP
// environment so they can be treated as readnone.
def int_asin : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
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@nikic nikic Oct 23, 2025

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Add a TODO to move these into the IntrNoCreateUndefOrPoison case above? I don't think any of these produce poison, they were just missing from the switch...

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@jayfoad jayfoad Oct 23, 2025

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Done.

def int_acos : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_atan : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_atan2 : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>, LLVMMatchType<0>]>;
def int_tan : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_sinh : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_cosh : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_tanh : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [LLVMMatchType<0>]>;
def int_sincos : DefaultAttrsIntrinsic<[LLVMMatchType<0>, LLVMMatchType<0>],
[llvm_anyfloat_ty]>;
def int_sincospi : DefaultAttrsIntrinsic<[LLVMMatchType<0>, LLVMMatchType<0>],
[llvm_anyfloat_ty]>;
def int_modf : DefaultAttrsIntrinsic<[LLVMMatchType<0>, LLVMMatchType<0>],
[llvm_anyfloat_ty]>;
}

def int_minnum : DefaultAttrsIntrinsic<[llvm_anyfloat_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable, Commutative]
[IntrNoMem, IntrSpeculatable, Commutative, IntrNoCreateUndefOrPoison]
>;
def int_maxnum : DefaultAttrsIntrinsic<[llvm_anyfloat_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable, Commutative]
[IntrNoMem, IntrSpeculatable, Commutative, IntrNoCreateUndefOrPoison]
>;
def int_minimum : DefaultAttrsIntrinsic<[llvm_anyfloat_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable, Commutative]
[IntrNoMem, IntrSpeculatable, Commutative, IntrNoCreateUndefOrPoison]
>;
def int_maximum : DefaultAttrsIntrinsic<[llvm_anyfloat_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable, Commutative]
[IntrNoMem, IntrSpeculatable, Commutative, IntrNoCreateUndefOrPoison]
>;
def int_minimumnum : DefaultAttrsIntrinsic<[llvm_anyfloat_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable, Commutative]
[IntrNoMem, IntrSpeculatable, Commutative, IntrNoCreateUndefOrPoison]
>;
def int_maximumnum : DefaultAttrsIntrinsic<[llvm_anyfloat_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable, Commutative]
[IntrNoMem, IntrSpeculatable, Commutative, IntrNoCreateUndefOrPoison]
>;

// Internal interface for object size checking
Expand Down Expand Up @@ -1164,7 +1176,7 @@ let IntrProperties = [IntrInaccessibleMemOnly] in {
def int_is_fpclass
: DefaultAttrsIntrinsic<[LLVMScalarOrSameVectorWidth<0, llvm_i1_ty>],
[llvm_anyfloat_ty, llvm_i32_ty],
[IntrNoMem, IntrSpeculatable, ImmArg<ArgIndex<1>>]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison, ImmArg<ArgIndex<1>>]>;

//===--------------- Constrained Floating Point Intrinsics ----------------===//
//
Expand Down Expand Up @@ -1406,7 +1418,7 @@ def int_expect_with_probability : DefaultAttrsIntrinsic<[llvm_anyint_ty],
//

// None of these intrinsics accesses memory at all.
let IntrProperties = [IntrNoMem, IntrSpeculatable] in {
let IntrProperties = [IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison] in {
def int_bswap: DefaultAttrsIntrinsic<[llvm_anyint_ty], [LLVMMatchType<0>]>;
def int_ctpop: DefaultAttrsIntrinsic<[llvm_anyint_ty], [LLVMMatchType<0>]>;
def int_bitreverse : DefaultAttrsIntrinsic<[llvm_anyint_ty], [LLVMMatchType<0>]>;
Expand Down Expand Up @@ -1522,7 +1534,7 @@ def int_adjust_trampoline : DefaultAttrsIntrinsic<
//

// Expose the carry flag from add operations on two integrals.
let IntrProperties = [IntrNoMem, IntrSpeculatable] in {
let IntrProperties = [IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison] in {
def int_sadd_with_overflow : DefaultAttrsIntrinsic<[llvm_anyint_ty,
LLVMScalarOrSameVectorWidth<0, llvm_i1_ty>],
[LLVMMatchType<0>, LLVMMatchType<0>]>;
Expand All @@ -1548,16 +1560,16 @@ let IntrProperties = [IntrNoMem, IntrSpeculatable] in {
//
def int_sadd_sat : DefaultAttrsIntrinsic<[llvm_anyint_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable, Commutative]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison, Commutative]>;
def int_uadd_sat : DefaultAttrsIntrinsic<[llvm_anyint_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable, Commutative]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison, Commutative]>;
def int_ssub_sat : DefaultAttrsIntrinsic<[llvm_anyint_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison]>;
def int_usub_sat : DefaultAttrsIntrinsic<[llvm_anyint_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison]>;
def int_sshl_sat : DefaultAttrsIntrinsic<[llvm_anyint_ty],
[LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable]>;
Expand Down Expand Up @@ -1612,22 +1624,22 @@ def int_abs : DefaultAttrsIntrinsic<

def int_smax : DefaultAttrsIntrinsic<
[llvm_anyint_ty], [LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison]>;
def int_smin : DefaultAttrsIntrinsic<
[llvm_anyint_ty], [LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison]>;
def int_umax : DefaultAttrsIntrinsic<
[llvm_anyint_ty], [LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison]>;
def int_umin : DefaultAttrsIntrinsic<
[llvm_anyint_ty], [LLVMMatchType<0>, LLVMMatchType<0>],
[IntrNoMem, IntrSpeculatable]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison]>;
def int_scmp : DefaultAttrsIntrinsic<
[llvm_anyint_ty], [llvm_anyint_ty, LLVMMatchType<1>],
[IntrNoMem, IntrSpeculatable, Range<RetIndex, -1, 2>]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison, Range<RetIndex, -1, 2>]>;
def int_ucmp : DefaultAttrsIntrinsic<
[llvm_anyint_ty], [llvm_anyint_ty, LLVMMatchType<1>],
[IntrNoMem, IntrSpeculatable, Range<RetIndex, -1, 2>]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison, Range<RetIndex, -1, 2>]>;

//===------------------------- Memory Use Markers -------------------------===//
//
Expand Down Expand Up @@ -1869,7 +1881,7 @@ def int_convert_from_fp16 : DefaultAttrsIntrinsic<[llvm_anyfloat_ty], [llvm_i16_
}

// Saturating floating point to integer intrinsics
let IntrProperties = [IntrNoMem, IntrSpeculatable] in {
let IntrProperties = [IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison] in {
def int_fptoui_sat : DefaultAttrsIntrinsic<[llvm_anyint_ty], [llvm_anyfloat_ty]>;
def int_fptosi_sat : DefaultAttrsIntrinsic<[llvm_anyint_ty], [llvm_anyfloat_ty]>;
}
Expand All @@ -1892,7 +1904,7 @@ def int_fake_use : DefaultAttrsIntrinsic<[], [llvm_vararg_ty],
// First argument must be pointer or vector of pointer. This is checked by the
// verifier.
def int_ptrmask: DefaultAttrsIntrinsic<[llvm_any_ty], [LLVMMatchType<0>, llvm_anyint_ty],
[IntrNoMem, IntrSpeculatable]>;
[IntrNoMem, IntrSpeculatable, IntrNoCreateUndefOrPoison]>;

// Intrinsic to wrap a thread local variable.
def int_threadlocal_address : DefaultAttrsIntrinsic<[llvm_anyptr_ty], [LLVMMatchType<0>],
Expand Down
76 changes: 6 additions & 70 deletions llvm/lib/Analysis/ValueTracking.cpp
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Expand Up @@ -7419,84 +7419,20 @@ static bool canCreateUndefOrPoison(const Operator *Op, UndefPoisonKind Kind,
if (cast<ConstantInt>(II->getArgOperand(1))->isNullValue())
return false;
break;
case Intrinsic::ctpop:
case Intrinsic::bswap:
case Intrinsic::bitreverse:
case Intrinsic::fshl:
case Intrinsic::fshr:
case Intrinsic::smax:
case Intrinsic::smin:
case Intrinsic::scmp:
case Intrinsic::umax:
case Intrinsic::umin:
case Intrinsic::ucmp:
case Intrinsic::ptrmask:
case Intrinsic::fptoui_sat:
case Intrinsic::fptosi_sat:
case Intrinsic::sadd_with_overflow:
case Intrinsic::ssub_with_overflow:
case Intrinsic::smul_with_overflow:
case Intrinsic::uadd_with_overflow:
case Intrinsic::usub_with_overflow:
case Intrinsic::umul_with_overflow:
case Intrinsic::sadd_sat:
case Intrinsic::uadd_sat:
case Intrinsic::ssub_sat:
case Intrinsic::usub_sat:
return false;
case Intrinsic::sshl_sat:
case Intrinsic::ushl_sat:
return includesPoison(Kind) &&
!shiftAmountKnownInRange(II->getArgOperand(1));
case Intrinsic::fma:
case Intrinsic::fmuladd:
case Intrinsic::sqrt:
case Intrinsic::powi:
case Intrinsic::sin:
case Intrinsic::cos:
case Intrinsic::pow:
case Intrinsic::log:
case Intrinsic::log10:
case Intrinsic::log2:
case Intrinsic::exp:
case Intrinsic::exp2:
case Intrinsic::exp10:
case Intrinsic::fabs:
case Intrinsic::copysign:
case Intrinsic::floor:
case Intrinsic::ceil:
case Intrinsic::trunc:
case Intrinsic::rint:
case Intrinsic::nearbyint:
case Intrinsic::round:
case Intrinsic::roundeven:
case Intrinsic::fptrunc_round:
case Intrinsic::canonicalize:
case Intrinsic::arithmetic_fence:
case Intrinsic::minnum:
case Intrinsic::maxnum:
case Intrinsic::minimum:
case Intrinsic::maximum:
case Intrinsic::minimumnum:
case Intrinsic::maximumnum:
case Intrinsic::is_fpclass:
case Intrinsic::ldexp:
case Intrinsic::frexp:
return false;
case Intrinsic::lround:
case Intrinsic::llround:
case Intrinsic::lrint:
case Intrinsic::llrint:
// If the value doesn't fit an unspecified value is returned (but this
// is not poison).
return false;
if (!includesPoison(Kind) ||
shiftAmountKnownInRange(II->getArgOperand(1)))
return false;
break;
}
}
[[fallthrough]];
case Instruction::CallBr:
case Instruction::Invoke: {
const auto *CB = cast<CallBase>(Op);
return !CB->hasRetAttr(Attribute::NoUndef);
return !CB->hasRetAttr(Attribute::NoUndef) &&
!CB->hasFnAttr(Attribute::NoCreateUndefOrPoison);
}
case Instruction::InsertElement:
case Instruction::ExtractElement: {
Expand Down
2 changes: 2 additions & 0 deletions llvm/lib/Bitcode/Reader/BitcodeReader.cpp
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Expand Up @@ -2257,6 +2257,8 @@ static Attribute::AttrKind getAttrFromCode(uint64_t Code) {
return Attribute::Captures;
case bitc::ATTR_KIND_DEAD_ON_RETURN:
return Attribute::DeadOnReturn;
case bitc::ATTR_KIND_NO_CREATE_UNDEF_OR_POISON:
return Attribute::NoCreateUndefOrPoison;
}
}

Expand Down
2 changes: 2 additions & 0 deletions llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
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Expand Up @@ -956,6 +956,8 @@ static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
return bitc::ATTR_KIND_CAPTURES;
case Attribute::DeadOnReturn:
return bitc::ATTR_KIND_DEAD_ON_RETURN;
case Attribute::NoCreateUndefOrPoison:
return bitc::ATTR_KIND_NO_CREATE_UNDEF_OR_POISON;
case Attribute::EndAttrKinds:
llvm_unreachable("Can not encode end-attribute kinds marker.");
case Attribute::None:
Expand Down
1 change: 1 addition & 0 deletions llvm/lib/Transforms/Utils/CodeExtractor.cpp
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Expand Up @@ -933,6 +933,7 @@ Function *CodeExtractor::constructFunctionDeclaration(
case Attribute::CoroDestroyOnlyWhenComplete:
case Attribute::CoroElideSafe:
case Attribute::NoDivergenceSource:
case Attribute::NoCreateUndefOrPoison:
continue;
// Those attributes should be safe to propagate to the extracted function.
case Attribute::AlwaysInline:
Expand Down
6 changes: 6 additions & 0 deletions llvm/test/Bitcode/attributes.ll
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Expand Up @@ -521,6 +521,11 @@ define void @f_sanitize_alloc_token() sanitize_alloc_token {
ret void;
}

; CHECK: define void @f_no_create_undef_or_poison() #56
define void @f_no_create_undef_or_poison() nocreateundeforpoison {
ret void;
}

; CHECK: define void @f87() [[FNRETTHUNKEXTERN:#[0-9]+]]
define void @f87() fn_ret_thunk_extern { ret void }

Expand Down Expand Up @@ -633,6 +638,7 @@ define void @dead_on_return(ptr dead_on_return %p) {
; CHECK: attributes #53 = { sanitize_realtime }
; CHECK: attributes #54 = { sanitize_realtime_blocking }
; CHECK: attributes #55 = { sanitize_alloc_token }
; CHECK: attributes #56 = { nocreateundeforpoison }
; CHECK: attributes [[FNRETTHUNKEXTERN]] = { fn_ret_thunk_extern }
; CHECK: attributes [[SKIPPROFILE]] = { skipprofile }
; CHECK: attributes [[OPTDEBUG]] = { optdebug }
Expand Down
3 changes: 2 additions & 1 deletion llvm/test/CodeGen/AArch64/replace-with-veclib-armpl.ll
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Expand Up @@ -780,6 +780,7 @@ define <vscale x 4 x float> @llvm_tanh_vscale_f32(<vscale x 4 x float> %in) #0 {

attributes #0 = { "target-features"="+sve" }
;.
; CHECK: attributes #[[ATTR0:[0-9]+]] = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
; CHECK: attributes #[[ATTR0:[0-9]+]] = { nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none) }
; CHECK: attributes #[[ATTR1]] = { "target-features"="+sve" }
; CHECK: attributes #[[ATTR2:[0-9]+]] = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
;.
2 changes: 1 addition & 1 deletion llvm/test/CodeGen/AMDGPU/amdgpu-simplify-libcall-rootn.ll
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Expand Up @@ -1489,7 +1489,7 @@ attributes #2 = { noinline }
!0 = !{float 3.0}
;.
; CHECK: attributes #[[ATTR0]] = { strictfp }
; CHECK: attributes #[[ATTR1:[0-9]+]] = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
; CHECK: attributes #[[ATTR1:[0-9]+]] = { nocallback nocreateundeforpoison nofree nosync nounwind speculatable willreturn memory(none) }
; CHECK: attributes #[[ATTR2:[0-9]+]] = { nounwind memory(read) }
; CHECK: attributes #[[ATTR3]] = { noinline }
; CHECK: attributes #[[ATTR4]] = { nobuiltin }
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