[clang] [X86][Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - Allow AVX/AVX512 IFMA madd52 intrinsics to be used in constexpr (PR #161056)
NagaChaitanya Vellanki via cfe-commits
cfe-commits at lists.llvm.org
Sun Sep 28 00:48:33 PDT 2025
https://github.com/chaitanyav updated https://github.com/llvm/llvm-project/pull/161056
>From 4b022cd6ccdd6adb1ed898dc0436f6c4dba1f442 Mon Sep 17 00:00:00 2001
From: NagaChaitanya Vellanki <pnagato at protonmail.com>
Date: Sun, 28 Sep 2025 00:29:57 -0700
Subject: [PATCH] [X86][Clang] VectorExprEvaluator::VisitCallExpr /
InterpretBuiltin - Allow AVX/AVX512 IFMA madd52 intrinsics to be used in
constexpr
Resolves #160498
---
clang/include/clang/Basic/BuiltinsX86.td | 42 +++++++-------
clang/lib/AST/ByteCode/InterpBuiltin.cpp | 19 +++++++
clang/lib/AST/ExprConstant.cpp | 51 +++++++++++++++++
clang/lib/Headers/avx512ifmaintrin.h | 71 ++++++++++++------------
clang/lib/Headers/avxifmaintrin.h | 18 ++++--
5 files changed, 142 insertions(+), 59 deletions(-)
diff --git a/clang/include/clang/Basic/BuiltinsX86.td b/clang/include/clang/Basic/BuiltinsX86.td
index 77e599587edc3..a5247629e255f 100644
--- a/clang/include/clang/Basic/BuiltinsX86.td
+++ b/clang/include/clang/Basic/BuiltinsX86.td
@@ -2101,27 +2101,6 @@ let Features = "avx512vl", Attributes = [NoThrow, RequiredVectorWidth<256>] in {
def movdqa64store256_mask : X86Builtin<"void(_Vector<4, long long int *>, _Vector<4, long long int>, unsigned char)">;
}
-let Features = "avx512ifma", Attributes = [NoThrow, Const, RequiredVectorWidth<512>] in {
- def vpmadd52huq512 : X86Builtin<"_Vector<8, long long int>(_Vector<8, long long int>, _Vector<8, long long int>, _Vector<8, long long int>)">;
- def vpmadd52luq512 : X86Builtin<"_Vector<8, long long int>(_Vector<8, long long int>, _Vector<8, long long int>, _Vector<8, long long int>)">;
-}
-
-let Features = "avx512ifma,avx512vl|avxifma", Attributes = [NoThrow, Const, RequiredVectorWidth<128>] in {
- def vpmadd52huq128 : X86Builtin<"_Vector<2, long long int>(_Vector<2, long long int>, _Vector<2, long long int>, _Vector<2, long long int>)">;
-}
-
-let Features = "avx512ifma,avx512vl|avxifma", Attributes = [NoThrow, Const, RequiredVectorWidth<256>] in {
- def vpmadd52huq256 : X86Builtin<"_Vector<4, long long int>(_Vector<4, long long int>, _Vector<4, long long int>, _Vector<4, long long int>)">;
-}
-
-let Features = "avx512ifma,avx512vl|avxifma", Attributes = [NoThrow, Const, RequiredVectorWidth<128>] in {
- def vpmadd52luq128 : X86Builtin<"_Vector<2, long long int>(_Vector<2, long long int>, _Vector<2, long long int>, _Vector<2, long long int>)">;
-}
-
-let Features = "avx512ifma,avx512vl|avxifma", Attributes = [NoThrow, Const, RequiredVectorWidth<256>] in {
- def vpmadd52luq256 : X86Builtin<"_Vector<4, long long int>(_Vector<4, long long int>, _Vector<4, long long int>, _Vector<4, long long int>)">;
-}
-
let Features = "avx512f", Attributes = [NoThrow, Const, RequiredVectorWidth<128>] in {
def vcomisd : X86Builtin<"int(_Vector<2, double>, _Vector<2, double>, _Constant int, _Constant int)">;
def vcomiss : X86Builtin<"int(_Vector<4, float>, _Vector<4, float>, _Constant int, _Constant int)">;
@@ -3128,6 +3107,27 @@ let Features = "avx512bw", Attributes = [NoThrow, Const, Constexpr] in {
def kordi : X86Builtin<"unsigned long long int(unsigned long long int, unsigned long long int)">;
}
+let Features = "avx512ifma", Attributes = [NoThrow, Const, Constexpr, RequiredVectorWidth<512>] in {
+ def vpmadd52huq512 : X86Builtin<"_Vector<8, long long int>(_Vector<8, long long int>, _Vector<8, long long int>, _Vector<8, long long int>)">;
+ def vpmadd52luq512 : X86Builtin<"_Vector<8, long long int>(_Vector<8, long long int>, _Vector<8, long long int>, _Vector<8, long long int>)">;
+}
+
+let Features = "avx512ifma,avx512vl|avxifma", Attributes = [NoThrow, Const, Constexpr, RequiredVectorWidth<128>] in {
+ def vpmadd52huq128 : X86Builtin<"_Vector<2, long long int>(_Vector<2, long long int>, _Vector<2, long long int>, _Vector<2, long long int>)">;
+}
+
+let Features = "avx512ifma,avx512vl|avxifma", Attributes = [NoThrow, Const, Constexpr, RequiredVectorWidth<256>] in {
+ def vpmadd52huq256 : X86Builtin<"_Vector<4, long long int>(_Vector<4, long long int>, _Vector<4, long long int>, _Vector<4, long long int>)">;
+}
+
+let Features = "avx512ifma,avx512vl|avxifma", Attributes = [NoThrow, Const, Constexpr, RequiredVectorWidth<128>] in {
+ def vpmadd52luq128 : X86Builtin<"_Vector<2, long long int>(_Vector<2, long long int>, _Vector<2, long long int>, _Vector<2, long long int>)">;
+}
+
+let Features = "avx512ifma,avx512vl|avxifma", Attributes = [NoThrow, Const, Constexpr, RequiredVectorWidth<256>] in {
+ def vpmadd52luq256 : X86Builtin<"_Vector<4, long long int>(_Vector<4, long long int>, _Vector<4, long long int>, _Vector<4, long long int>)">;
+}
+
let Features = "avx512dq", Attributes = [NoThrow, Const] in {
def kortestcqi : X86Builtin<"int(unsigned char, unsigned char)">;
def kortestzqi : X86Builtin<"int(unsigned char, unsigned char)">;
diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index 891344d4e6ed0..4b29eee057a51 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -3564,6 +3564,25 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const CallExpr *Call,
return F;
});
+ case X86::BI__builtin_ia32_vpmadd52luq128:
+ case X86::BI__builtin_ia32_vpmadd52luq256:
+ case X86::BI__builtin_ia32_vpmadd52luq512:
+ return interp__builtin_elementwise_triop(
+ S, OpPC, Call, [](const APSInt &A, const APSInt &B, const APSInt &C) {
+ APSInt result = A * B + C;
+ APSInt mask(APSInt::getAllOnes(52).zext(64));
+ return result & mask;
+ });
+ case X86::BI__builtin_ia32_vpmadd52huq128:
+ case X86::BI__builtin_ia32_vpmadd52huq256:
+ case X86::BI__builtin_ia32_vpmadd52huq512:
+ return interp__builtin_elementwise_triop(
+ S, OpPC, Call, [](const APSInt &A, const APSInt &B, const APSInt &C) {
+ APSInt result = A * B + C;
+ APSInt mask(APSInt::getAllOnes(52).zext(64));
+ return (result >> 52) & mask;
+ });
+
case X86::BI__builtin_ia32_vpshldd128:
case X86::BI__builtin_ia32_vpshldd256:
case X86::BI__builtin_ia32_vpshldd512:
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index b706b14945b6d..092d91f908b43 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -60,10 +60,12 @@
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/LSP/Logging.h"
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/Support/SipHash.h"
#include "llvm/Support/TimeProfiler.h"
#include "llvm/Support/raw_ostream.h"
+
#include <cstring>
#include <functional>
#include <limits>
@@ -11869,6 +11871,55 @@ bool VectorExprEvaluator::VisitCallExpr(const CallExpr *E) {
return Success(APValue(ResultElements.data(), ResultElements.size()), E);
}
+ case X86::BI__builtin_ia32_vpmadd52luq128:
+ case X86::BI__builtin_ia32_vpmadd52luq256:
+ case X86::BI__builtin_ia32_vpmadd52luq512: {
+ APValue A, B, C;
+ if (!EvaluateAsRValue(Info, E->getArg(0), A) ||
+ !EvaluateAsRValue(Info, E->getArg(1), B) ||
+ !EvaluateAsRValue(Info, E->getArg(2), C))
+ return false;
+
+ unsigned ALen = A.getVectorLength();
+ SmallVector<APValue, 4> ResultElements;
+ ResultElements.reserve(ALen);
+
+ for (unsigned EltNum = 0; EltNum < ALen; EltNum += 1) {
+ APInt AElt = A.getVectorElt(EltNum).getInt();
+ APInt BElt = B.getVectorElt(EltNum).getInt();
+ APInt CElt = C.getVectorElt(EltNum).getInt();
+ APInt ResElt(AElt * BElt + CElt);
+ APInt Mask(64, 0x000FFFFFFFFFFFFFULL);
+ ResultElements.push_back(APValue(APSInt(ResElt.trunc(64) & Mask)));
+ }
+
+ return Success(APValue(ResultElements.data(), ResultElements.size()), E);
+ }
+ case X86::BI__builtin_ia32_vpmadd52huq128:
+ case X86::BI__builtin_ia32_vpmadd52huq256:
+ case X86::BI__builtin_ia32_vpmadd52huq512: {
+ APValue A, B, C;
+ if (!EvaluateAsRValue(Info, E->getArg(0), A) ||
+ !EvaluateAsRValue(Info, E->getArg(1), B) ||
+ !EvaluateAsRValue(Info, E->getArg(2), C))
+ return false;
+
+ unsigned ALen = A.getVectorLength();
+ SmallVector<APValue, 4> ResultElements;
+ ResultElements.reserve(ALen);
+
+ for (unsigned EltNum = 0; EltNum < ALen; EltNum += 1) {
+ APInt AElt = A.getVectorElt(EltNum).getInt();
+ APInt BElt = B.getVectorElt(EltNum).getInt();
+ APInt CElt = C.getVectorElt(EltNum).getInt();
+ APInt ResElt(AElt * BElt + CElt);
+ APInt Mask(64, 0x000FFFFFFFFFFFFFULL);
+ ResultElements.push_back(
+ APValue(APSInt(ResElt.lshr(52).trunc(64) & Mask)));
+ }
+
+ return Success(APValue(ResultElements.data(), ResultElements.size()), E);
+ }
case clang::X86::BI__builtin_ia32_vprotbi:
case clang::X86::BI__builtin_ia32_vprotdi:
case clang::X86::BI__builtin_ia32_vprotqi:
diff --git a/clang/lib/Headers/avx512ifmaintrin.h b/clang/lib/Headers/avx512ifmaintrin.h
index f01b322ce7787..6d800f25e5798 100644
--- a/clang/lib/Headers/avx512ifmaintrin.h
+++ b/clang/lib/Headers/avx512ifmaintrin.h
@@ -19,52 +19,55 @@
__attribute__((__always_inline__, __nodebug__, __target__("avx512ifma"), \
__min_vector_width__(512)))
-static __inline__ __m512i __DEFAULT_FN_ATTRS
-_mm512_madd52hi_epu64 (__m512i __X, __m512i __Y, __m512i __Z)
-{
- return (__m512i)__builtin_ia32_vpmadd52huq512((__v8di) __X, (__v8di) __Y,
- (__v8di) __Z);
+#if defined(__cplusplus) && (__cplusplus >= 201103L)
+#define __DEFAULT_FN_ATTRS_CONSTEXPR __DEFAULT_FN_ATTRS constexpr
+#else
+#define __DEFAULT_FN_ATTRS_CONSTEXPR __DEFAULT_FN_ATTRS
+#endif
+
+static __inline__ __m512i __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_madd52hi_epu64(__m512i __X, __m512i __Y, __m512i __Z) {
+ return (__m512i)__builtin_ia32_vpmadd52huq512((__v8di)__X, (__v8di)__Y,
+ (__v8di)__Z);
}
-static __inline__ __m512i __DEFAULT_FN_ATTRS
-_mm512_mask_madd52hi_epu64 (__m512i __W, __mmask8 __M, __m512i __X, __m512i __Y)
-{
- return (__m512i)__builtin_ia32_selectq_512(__M,
- (__v8di)_mm512_madd52hi_epu64(__W, __X, __Y),
- (__v8di)__W);
+static __inline__ __m512i __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_mask_madd52hi_epu64(__m512i __W, __mmask8 __M, __m512i __X,
+ __m512i __Y) {
+ return (__m512i)__builtin_ia32_selectq_512(
+ __M, (__v8di)_mm512_madd52hi_epu64(__W, __X, __Y), (__v8di)__W);
}
-static __inline__ __m512i __DEFAULT_FN_ATTRS
-_mm512_maskz_madd52hi_epu64 (__mmask8 __M, __m512i __X, __m512i __Y, __m512i __Z)
-{
- return (__m512i)__builtin_ia32_selectq_512(__M,
- (__v8di)_mm512_madd52hi_epu64(__X, __Y, __Z),
- (__v8di)_mm512_setzero_si512());
+static __inline__ __m512i __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_maskz_madd52hi_epu64(__mmask8 __M, __m512i __X, __m512i __Y,
+ __m512i __Z) {
+ return (__m512i)__builtin_ia32_selectq_512(
+ __M, (__v8di)_mm512_madd52hi_epu64(__X, __Y, __Z),
+ (__v8di)_mm512_setzero_si512());
}
-static __inline__ __m512i __DEFAULT_FN_ATTRS
-_mm512_madd52lo_epu64 (__m512i __X, __m512i __Y, __m512i __Z)
-{
- return (__m512i)__builtin_ia32_vpmadd52luq512((__v8di) __X, (__v8di) __Y,
- (__v8di) __Z);
+static __inline__ __m512i __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_madd52lo_epu64(__m512i __X, __m512i __Y, __m512i __Z) {
+ return (__m512i)__builtin_ia32_vpmadd52luq512((__v8di)__X, (__v8di)__Y,
+ (__v8di)__Z);
}
-static __inline__ __m512i __DEFAULT_FN_ATTRS
-_mm512_mask_madd52lo_epu64 (__m512i __W, __mmask8 __M, __m512i __X, __m512i __Y)
-{
- return (__m512i)__builtin_ia32_selectq_512(__M,
- (__v8di)_mm512_madd52lo_epu64(__W, __X, __Y),
- (__v8di)__W);
+static __inline__ __m512i __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_mask_madd52lo_epu64(__m512i __W, __mmask8 __M, __m512i __X,
+ __m512i __Y) {
+ return (__m512i)__builtin_ia32_selectq_512(
+ __M, (__v8di)_mm512_madd52lo_epu64(__W, __X, __Y), (__v8di)__W);
}
-static __inline__ __m512i __DEFAULT_FN_ATTRS
-_mm512_maskz_madd52lo_epu64 (__mmask8 __M, __m512i __X, __m512i __Y, __m512i __Z)
-{
- return (__m512i)__builtin_ia32_selectq_512(__M,
- (__v8di)_mm512_madd52lo_epu64(__X, __Y, __Z),
- (__v8di)_mm512_setzero_si512());
+static __inline__ __m512i __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_maskz_madd52lo_epu64(__mmask8 __M, __m512i __X, __m512i __Y,
+ __m512i __Z) {
+ return (__m512i)__builtin_ia32_selectq_512(
+ __M, (__v8di)_mm512_madd52lo_epu64(__X, __Y, __Z),
+ (__v8di)_mm512_setzero_si512());
}
#undef __DEFAULT_FN_ATTRS
+#undef __DEFAULT_FN_ATTRS_CONSTEXPR
#endif
diff --git a/clang/lib/Headers/avxifmaintrin.h b/clang/lib/Headers/avxifmaintrin.h
index 5c782d2a5b865..1a9aaaf53affa 100644
--- a/clang/lib/Headers/avxifmaintrin.h
+++ b/clang/lib/Headers/avxifmaintrin.h
@@ -22,6 +22,14 @@
__attribute__((__always_inline__, __nodebug__, __target__("avxifma"), \
__min_vector_width__(256)))
+#if defined(__cplusplus) && (__cplusplus >= 201103L)
+#define __DEFAULT_FN_ATTRS256_CONSTEXPR __DEFAULT_FN_ATTRS256 constexpr
+#define __DEFAULT_FN_ATTRS128_CONSTEXPR __DEFAULT_FN_ATTRS128 constexpr
+#else
+#define __DEFAULT_FN_ATTRS256_CONSTEXPR __DEFAULT_FN_ATTRS256
+#define __DEFAULT_FN_ATTRS128_CONSTEXPR __DEFAULT_FN_ATTRS128
+#endif
+
// must vex-encoding
/// Multiply packed unsigned 52-bit integers in each 64-bit element of \a __Y
@@ -55,7 +63,7 @@
/// ENDFOR
/// dst[MAX:128] := 0
/// \endcode
-static __inline__ __m128i __DEFAULT_FN_ATTRS128
+static __inline__ __m128i __DEFAULT_FN_ATTRS128_CONSTEXPR
_mm_madd52hi_avx_epu64(__m128i __X, __m128i __Y, __m128i __Z) {
return (__m128i)__builtin_ia32_vpmadd52huq128((__v2di)__X, (__v2di)__Y,
(__v2di)__Z);
@@ -92,7 +100,7 @@ _mm_madd52hi_avx_epu64(__m128i __X, __m128i __Y, __m128i __Z) {
/// ENDFOR
/// dst[MAX:256] := 0
/// \endcode
-static __inline__ __m256i __DEFAULT_FN_ATTRS256
+static __inline__ __m256i __DEFAULT_FN_ATTRS256_CONSTEXPR
_mm256_madd52hi_avx_epu64(__m256i __X, __m256i __Y, __m256i __Z) {
return (__m256i)__builtin_ia32_vpmadd52huq256((__v4di)__X, (__v4di)__Y,
(__v4di)__Z);
@@ -129,7 +137,7 @@ _mm256_madd52hi_avx_epu64(__m256i __X, __m256i __Y, __m256i __Z) {
/// ENDFOR
/// dst[MAX:128] := 0
/// \endcode
-static __inline__ __m128i __DEFAULT_FN_ATTRS128
+static __inline__ __m128i __DEFAULT_FN_ATTRS128_CONSTEXPR
_mm_madd52lo_avx_epu64(__m128i __X, __m128i __Y, __m128i __Z) {
return (__m128i)__builtin_ia32_vpmadd52luq128((__v2di)__X, (__v2di)__Y,
(__v2di)__Z);
@@ -166,12 +174,14 @@ _mm_madd52lo_avx_epu64(__m128i __X, __m128i __Y, __m128i __Z) {
/// ENDFOR
/// dst[MAX:256] := 0
/// \endcode
-static __inline__ __m256i __DEFAULT_FN_ATTRS256
+static __inline__ __m256i __DEFAULT_FN_ATTRS256_CONSTEXPR
_mm256_madd52lo_avx_epu64(__m256i __X, __m256i __Y, __m256i __Z) {
return (__m256i)__builtin_ia32_vpmadd52luq256((__v4di)__X, (__v4di)__Y,
(__v4di)__Z);
}
#undef __DEFAULT_FN_ATTRS128
#undef __DEFAULT_FN_ATTRS256
+#undef __DEFAULT_FN_ATTRS256_CONSTEXPR
+#undef __DEFAULT_FN_ATTRS128_CONSTEXPR
#endif // __AVXIFMAINTRIN_H
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