[X86][Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - allow AVX512 kmov intrinsics to be used in constexp #169895

0xzre · 2025-11-28T10:33:41Z

Resolves #166975

…allow AVX512 kmov intrinsics to be used in constexp

llvmbot · 2025-11-28T10:34:12Z

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-backend-x86

Author: Muhammad Abdul (0xzre)

Changes

Resolves #166975

Full diff: https://github.com/llvm/llvm-project/pull/169895.diff

9 Files Affected:

(modified) clang/include/clang/Basic/BuiltinsX86.td (+3-3)
(modified) clang/lib/AST/ByteCode/InterpBuiltin.cpp (+7)
(modified) clang/lib/AST/ExprConstant.cpp (+10)
(modified) clang/lib/Headers/avx512bwintrin.h (+4-4)
(modified) clang/lib/Headers/avx512dqintrin.h (+2-2)
(modified) clang/lib/Headers/avx512fintrin.h (+2-2)
(modified) clang/test/CodeGen/X86/avx512bw-builtins.c (+8)
(modified) clang/test/CodeGen/X86/avx512dq-builtins.c (+4)
(modified) clang/test/CodeGen/X86/avx512f-builtins.c (+4)

diff --git a/clang/include/clang/Basic/BuiltinsX86.td b/clang/include/clang/Basic/BuiltinsX86.td
index 98cea35beb0ea..36670a346a4ad 100644
--- a/clang/include/clang/Basic/BuiltinsX86.td
+++ b/clang/include/clang/Basic/BuiltinsX86.td
@@ -3160,15 +3160,15 @@ let Features = "avx512bw", Attributes = [NoThrow, Const] in {
   def kshiftridi : X86Builtin<"unsigned long long int(unsigned long long int, _Constant unsigned int)">;
 }
 
-let Features = "avx512dq", Attributes = [NoThrow, Const] in {
+let Features = "avx512dq", Attributes = [NoThrow, Const, Constexpr] in {
   def kmovb : X86Builtin<"unsigned char(unsigned char)">;
 }
 
-let Features = "avx512f", Attributes = [NoThrow, Const] in {
+let Features = "avx512f", Attributes = [NoThrow, Const, Constexpr] in {
   def kmovw : X86Builtin<"unsigned short(unsigned short)">;
 }
 
-let Features = "avx512bw", Attributes = [NoThrow, Const] in {
+let Features = "avx512bw", Attributes = [NoThrow, Const, Constexpr] in {
   def kmovd : X86Builtin<"unsigned int(unsigned int)">;
   def kmovq : X86Builtin<"unsigned long long int(unsigned long long int)">;
 }
diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index d21f42d94d3a5..e1beca9cd7ee4 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -5019,6 +5019,13 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const CallExpr *Call,
         S, OpPC, Call,
         [](const APSInt &LHS, const APSInt &RHS) { return LHS + RHS; });
 
+  case X86::BI__builtin_ia32_kmovb:
+  case X86::BI__builtin_ia32_kmovw:
+  case X86::BI__builtin_ia32_kmovd:
+  case X86::BI__builtin_ia32_kmovq:
+    return interp__builtin_elementwise_int_unaryop(
+        S, OpPC, Call, [](const APSInt &Src) { return Src; });
+
   case X86::BI__builtin_ia32_kunpckhi:
   case X86::BI__builtin_ia32_kunpckdi:
   case X86::BI__builtin_ia32_kunpcksi:
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 7b9380de6834d..c48ed9bad03fd 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -16900,6 +16900,16 @@ bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
         [](const APSInt &LHS, const APSInt &RHS) { return LHS + RHS; });
   }
 
+  case X86::BI__builtin_ia32_kmovb:
+  case X86::BI__builtin_ia32_kmovw:
+  case X86::BI__builtin_ia32_kmovd:
+  case X86::BI__builtin_ia32_kmovq: {
+    APSInt Val;
+    if (!EvaluateInteger(E->getArg(0), Val, Info))
+      return false;
+    return Success(Val, E);
+  }
+
   case clang::X86::BI__builtin_ia32_vec_ext_v4hi:
   case clang::X86::BI__builtin_ia32_vec_ext_v16qi:
   case clang::X86::BI__builtin_ia32_vec_ext_v8hi:
diff --git a/clang/lib/Headers/avx512bwintrin.h b/clang/lib/Headers/avx512bwintrin.h
index 67e8461560b04..89637f7570455 100644
--- a/clang/lib/Headers/avx512bwintrin.h
+++ b/clang/lib/Headers/avx512bwintrin.h
@@ -178,22 +178,22 @@ _kadd_mask64(__mmask64 __A, __mmask64 __B) {
 #define _kshiftri_mask64(A, I) \
   ((__mmask64)__builtin_ia32_kshiftridi((__mmask64)(A), (unsigned int)(I)))
 
-static __inline__ unsigned int __DEFAULT_FN_ATTRS
+static __inline__ unsigned int __DEFAULT_FN_ATTRS_CONSTEXPR
 _cvtmask32_u32(__mmask32 __A) {
   return (unsigned int)__builtin_ia32_kmovd((__mmask32)__A);
 }
 
-static __inline__ unsigned long long __DEFAULT_FN_ATTRS
+static __inline__ unsigned long long __DEFAULT_FN_ATTRS_CONSTEXPR
 _cvtmask64_u64(__mmask64 __A) {
   return (unsigned long long)__builtin_ia32_kmovq((__mmask64)__A);
 }
 
-static __inline__ __mmask32 __DEFAULT_FN_ATTRS
+static __inline__ __mmask32 __DEFAULT_FN_ATTRS_CONSTEXPR
 _cvtu32_mask32(unsigned int __A) {
   return (__mmask32)__builtin_ia32_kmovd((__mmask32)__A);
 }
 
-static __inline__ __mmask64 __DEFAULT_FN_ATTRS
+static __inline__ __mmask64 __DEFAULT_FN_ATTRS_CONSTEXPR
 _cvtu64_mask64(unsigned long long __A) {
   return (__mmask64)__builtin_ia32_kmovq((__mmask64)__A);
 }
diff --git a/clang/lib/Headers/avx512dqintrin.h b/clang/lib/Headers/avx512dqintrin.h
index f200b22f27ee1..40041d0118b08 100644
--- a/clang/lib/Headers/avx512dqintrin.h
+++ b/clang/lib/Headers/avx512dqintrin.h
@@ -123,12 +123,12 @@ _kadd_mask16(__mmask16 __A, __mmask16 __B) {
 #define _kshiftri_mask8(A, I) \
   ((__mmask8)__builtin_ia32_kshiftriqi((__mmask8)(A), (unsigned int)(I)))
 
-static __inline__ unsigned int __DEFAULT_FN_ATTRS
+static __inline__ unsigned int __DEFAULT_FN_ATTRS_CONSTEXPR
 _cvtmask8_u32(__mmask8 __A) {
   return (unsigned int)__builtin_ia32_kmovb((__mmask8)__A);
 }
 
-static __inline__ __mmask8 __DEFAULT_FN_ATTRS
+static __inline__ __mmask8 __DEFAULT_FN_ATTRS_CONSTEXPR
 _cvtu32_mask8(unsigned int __A) {
   return (__mmask8)__builtin_ia32_kmovb((__mmask8)__A);
 }
diff --git a/clang/lib/Headers/avx512fintrin.h b/clang/lib/Headers/avx512fintrin.h
index 806a13c414c10..35ff99c31a414 100644
--- a/clang/lib/Headers/avx512fintrin.h
+++ b/clang/lib/Headers/avx512fintrin.h
@@ -8069,12 +8069,12 @@ _mm512_kxor(__mmask16 __A, __mmask16 __B) {
 #define _kshiftri_mask16(A, I) \
   ((__mmask16)__builtin_ia32_kshiftrihi((__mmask16)(A), (unsigned int)(I)))
 
-static __inline__ unsigned int __DEFAULT_FN_ATTRS
+static __inline__ unsigned int __DEFAULT_FN_ATTRS_CONSTEXPR
 _cvtmask16_u32(__mmask16 __A) {
   return (unsigned int)__builtin_ia32_kmovw((__mmask16)__A);
 }
 
-static __inline__ __mmask16 __DEFAULT_FN_ATTRS
+static __inline__ __mmask16 __DEFAULT_FN_ATTRS_CONSTEXPR
 _cvtu32_mask16(unsigned int __A) {
   return (__mmask16)__builtin_ia32_kmovw((__mmask16)__A);
 }
diff --git a/clang/test/CodeGen/X86/avx512bw-builtins.c b/clang/test/CodeGen/X86/avx512bw-builtins.c
index c9c30dab389db..b90a66dd6422a 100644
--- a/clang/test/CodeGen/X86/avx512bw-builtins.c
+++ b/clang/test/CodeGen/X86/avx512bw-builtins.c
@@ -576,6 +576,14 @@ __mmask64 test_cvtu64_mask64(__m512i A, __m512i B, unsigned long long C) {
   return _mm512_mask_cmpneq_epu8_mask(_cvtu64_mask64(C), A, B);
 }
 
+TEST_CONSTEXPR(_cvtmask32_u32((__mmask32)0xDEADBEEF) == 0xDEADBEEF);
+TEST_CONSTEXPR(_cvtu32_mask32(0x13579BDF) == (__mmask32)0x13579BDF);
+TEST_CONSTEXPR(_cvtu32_mask32(_cvtmask32_u32((__mmask32)0x2468ACE0)) == (__mmask32)0x2468ACE0);
+
+TEST_CONSTEXPR(_cvtmask64_u64((__mmask64)0x123456789ABCDEF0ULL) == 0x123456789ABCDEF0ULL);
+TEST_CONSTEXPR(_cvtu64_mask64(0x0F0F0F0F0F0F0F0FULL) == (__mmask64)0x0F0F0F0F0F0F0F0FULL);
+TEST_CONSTEXPR(_cvtu64_mask64(_cvtmask64_u64((__mmask64)0xF0F0F0F0F0F0F0F0ULL)) == (__mmask64)0xF0F0F0F0F0F0F0F0ULL);
+
 __mmask32 test_load_mask32(__mmask32 *A, __m512i B, __m512i C) {
   // CHECK-LABEL: test_load_mask32
   // CHECK: [[LOAD:%.*]] = load i32, ptr %{{.*}}
diff --git a/clang/test/CodeGen/X86/avx512dq-builtins.c b/clang/test/CodeGen/X86/avx512dq-builtins.c
index 542d4446a3690..fd536c4c33df1 100644
--- a/clang/test/CodeGen/X86/avx512dq-builtins.c
+++ b/clang/test/CodeGen/X86/avx512dq-builtins.c
@@ -384,6 +384,10 @@ __mmask8 test_cvtu32_mask8(__m512i A, __m512i B, unsigned int C) {
   return _mm512_mask_cmpneq_epu64_mask(_cvtu32_mask8(C), A, B);
 }
 
+TEST_CONSTEXPR(_cvtmask8_u32((__mmask8)0x5A) == 0x5A);
+TEST_CONSTEXPR(_cvtu32_mask8(0xB7) == (__mmask8)0xB7);
+TEST_CONSTEXPR(_cvtu32_mask8(_cvtmask8_u32((__mmask8)0xDE)) == (__mmask8)0xDE);
+
 __mmask8 test_load_mask8(__mmask8 *A, __m512i B, __m512i C) {
   // CHECK-LABEL: test_load_mask8
   // CHECK: [[LOAD:%.*]] = load i8, ptr %{{.*}}
diff --git a/clang/test/CodeGen/X86/avx512f-builtins.c b/clang/test/CodeGen/X86/avx512f-builtins.c
index 6401a0e55a83b..3c903c4b8f867 100644
--- a/clang/test/CodeGen/X86/avx512f-builtins.c
+++ b/clang/test/CodeGen/X86/avx512f-builtins.c
@@ -9596,6 +9596,10 @@ __mmask16 test_cvtu32_mask16(__m512i A, __m512i B, unsigned int C) {
   return _mm512_mask_cmpneq_epu32_mask(_cvtu32_mask16(C), A, B);
 }
 
+TEST_CONSTEXPR(_cvtmask16_u32((__mmask16)0xBEEF) == 0xBEEF);
+TEST_CONSTEXPR(_cvtu32_mask16(0xCAFE) == (__mmask16)0xCAFE);
+TEST_CONSTEXPR(_cvtu32_mask16(_cvtmask16_u32((__mmask16)0x1357)) == (__mmask16)0x1357);
+
 __mmask16 test_load_mask16(__mmask16 *A, __m512i B, __m512i C) {
   // CHECK-LABEL: test_load_mask16
   // CHECK: [[LOAD:%.*]] = load i16, ptr %{{.*}}{{$}}

github-actions · 2025-11-28T10:35:23Z

✅ With the latest revision this PR passed the C/C++ code formatter.

RKSimon

minor style comment

RKSimon · 2025-11-30T16:23:30Z

clang/test/CodeGen/X86/avx512bw-builtins.c


+TEST_CONSTEXPR(_cvtmask32_u32((__mmask32)0xDEADBEEF) == 0xDEADBEEF);
+TEST_CONSTEXPR(_cvtu32_mask32(0x13579BDF) == (__mmask32)0x13579BDF);
+TEST_CONSTEXPR(_cvtu32_mask32(_cvtmask32_u32((__mmask32)0x2468ACE0)) == (__mmask32)0x2468ACE0);


(style) place each TEST_CONSTEXPR below the correspond intrinsic test - we don't want them to become disconnected

[X86][Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - …

8af38c0

…allow AVX512 kmov intrinsics to be used in constexp

llvmbot added clang Clang issues not falling into any other category backend:X86 clang:frontend Language frontend issues, e.g. anything involving "Sema" clang:headers Headers provided by Clang, e.g. for intrinsics clang:bytecode Issues for the clang bytecode constexpr interpreter labels Nov 28, 2025

RKSimon self-requested a review November 28, 2025 11:35

fix format clang

dcdf950

RKSimon requested changes Nov 30, 2025

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[X86][Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - allow AVX512 kmov intrinsics to be used in constexp #169895

[X86][Clang] VectorExprEvaluator::VisitCallExpr / InterpretBuiltin - allow AVX512 kmov intrinsics to be used in constexp #169895

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