[X86][Clang] Add AVX512 kunpck intrinsics to be used in constexp #167683
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Add AVX-512 mask unpack intrinsics _mm512_kunpackd and _mm512_kunpackw to avx512fintrin.h alongside the existing _mm512_kunpackb intrinsic. These intrinsics extract and concatenate the lower halves of mask registers, using the existing backend support for __builtin_ia32_kunpckdi and __builtin_ia32_kunpcksi builtins. Also adds __mmask32 and __mmask64 type definitions to avx512fintrin.h for completeness. Tests already exist in clang/test/CodeGen/X86/avx512bw-builtins.c.
…expr support Add AVX-512 mask unpack intrinsics _mm512_kunpackd and _mm512_kunpackw to avx512fintrin.h alongside the existing _mm512_kunpackb intrinsic. These intrinsics extract and concatenate the lower halves of mask registers, using the existing backend support for __builtin_ia32_kunpckdi and __builtin_ia32_kunpcksi builtins. Also adds __mmask32 and __mmask64 type definitions to avx512fintrin.h for completeness. This patch adds constexpr support for all three kunpack intrinsics by: 1. Using __DEFAULT_FN_ATTRS_CONSTEXPR attribute 2. Adding builtin interpretation in ExprConstant.cpp for compile-time evaluation in constexpr contexts 3. Adding constexpr tests to verify correct behavior Tests already exist in clang/test/CodeGen/X86/avx512bw-builtins.c for runtime code generation validation.
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@llvm/pr-subscribers-backend-x86 @llvm/pr-subscribers-clang Author: Ahmed Nour (ahmednoursphinx) ChangesResolves #166976 Full diff: https://github.com/llvm/llvm-project/pull/167683.diff 4 Files Affected:
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 1bfea24b228e8..a0a1d0ce2a94b 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -16287,6 +16287,42 @@ bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
return Success((A | B) == 0, E);
}
+ case clang::X86::BI__builtin_ia32_kunpckhi: {
+ APSInt A, B;
+ if (!EvaluateInteger(E->getArg(0), A, Info) ||
+ !EvaluateInteger(E->getArg(1), B, Info))
+ return false;
+
+ // Extract lower 8 bits of each operand and concatenate
+ // Result = (A[7:0] << 8) | B[7:0]
+ APSInt Result = ((A & 0xFF) << 8) | (B & 0xFF);
+ return Success(Result, E);
+ }
+
+ case clang::X86::BI__builtin_ia32_kunpckdi: {
+ APSInt A, B;
+ if (!EvaluateInteger(E->getArg(0), A, Info) ||
+ !EvaluateInteger(E->getArg(1), B, Info))
+ return false;
+
+ // Extract lower 32 bits of each operand and concatenate
+ // Result = (A[31:0] << 32) | B[31:0]
+ APSInt Result = ((A & 0xFFFFFFFFULL) << 32) | (B & 0xFFFFFFFFULL);
+ return Success(Result, E);
+ }
+
+ case clang::X86::BI__builtin_ia32_kunpcksi: {
+ APSInt A, B;
+ if (!EvaluateInteger(E->getArg(0), A, Info) ||
+ !EvaluateInteger(E->getArg(1), B, Info))
+ return false;
+
+ // Extract lower 16 bits of each operand and concatenate
+ // Result = (A[15:0] << 16) | B[15:0]
+ APSInt Result = ((A & 0xFFFF) << 16) | (B & 0xFFFF);
+ return Success(Result, E);
+ }
+
case clang::X86::BI__builtin_ia32_lzcnt_u16:
case clang::X86::BI__builtin_ia32_lzcnt_u32:
case clang::X86::BI__builtin_ia32_lzcnt_u64: {
@@ -16413,6 +16449,21 @@ bool IntExprEvaluator::VisitBuiltinCallExpr(const CallExpr *E,
return Success(APValue(Result), E);
}
+ case X86::BI__builtin_ia32_kunpckhi:
+ case X86::BI__builtin_ia32_kunpcksi:
+ case X86::BI__builtin_ia32_kunpckdi: {
+ return HandleMaskBinOp([](const APSInt &LHS, const APSInt &RHS) {
+ // Unpack: concatenate lower half of RHS with lower half of LHS
+ unsigned HalfBits = LHS.getBitWidth() / 2;
+ APSInt Mask = APSInt::getMaxValue(LHS.getBitWidth(), LHS.isUnsigned());
+ Mask = Mask.trunc(HalfBits).zext(LHS.getBitWidth());
+
+ APSInt LowerLHS = LHS & Mask;
+ APSInt LowerRHS = RHS & Mask;
+ return LowerRHS | (LowerLHS << HalfBits);
+ });
+ }
+
case X86::BI__builtin_ia32_kaddqi:
case X86::BI__builtin_ia32_kaddhi:
case X86::BI__builtin_ia32_kaddsi:
diff --git a/clang/lib/Headers/avx512bwintrin.h b/clang/lib/Headers/avx512bwintrin.h
index 4a02c96620335..d247f648b9eb5 100644
--- a/clang/lib/Headers/avx512bwintrin.h
+++ b/clang/lib/Headers/avx512bwintrin.h
@@ -1606,15 +1606,14 @@ _mm512_maskz_set1_epi8(__mmask64 __M, char __A) {
(__v64qi) _mm512_setzero_si512());
}
-static __inline__ __mmask64 __DEFAULT_FN_ATTRS _mm512_kunpackd(__mmask64 __A,
- __mmask64 __B) {
+static __inline__ __mmask64 __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_kunpackd(__mmask64 __A, __mmask64 __B) {
return (__mmask64) __builtin_ia32_kunpckdi ((__mmask64) __A,
(__mmask64) __B);
}
-static __inline__ __mmask32 __DEFAULT_FN_ATTRS
-_mm512_kunpackw (__mmask32 __A, __mmask32 __B)
-{
+static __inline__ __mmask32 __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_kunpackw(__mmask32 __A, __mmask32 __B) {
return (__mmask32) __builtin_ia32_kunpcksi ((__mmask32) __A,
(__mmask32) __B);
}
diff --git a/clang/lib/Headers/avx512fintrin.h b/clang/lib/Headers/avx512fintrin.h
index 997e9608e112f..badc30a7eb26c 100644
--- a/clang/lib/Headers/avx512fintrin.h
+++ b/clang/lib/Headers/avx512fintrin.h
@@ -40,6 +40,8 @@ typedef long long __m512i_u __attribute__((__vector_size__(64), __aligned__(1)))
typedef unsigned char __mmask8;
typedef unsigned short __mmask16;
+typedef unsigned int __mmask32;
+typedef unsigned long long __mmask64;
/* Rounding mode macros. */
#define _MM_FROUND_TO_NEAREST_INT 0x00
@@ -8094,12 +8096,21 @@ _kortest_mask16_u8(__mmask16 __A, __mmask16 __B, unsigned char *__C) {
return (unsigned char)__builtin_ia32_kortestzhi(__A, __B);
}
-static __inline__ __mmask16 __DEFAULT_FN_ATTRS
-_mm512_kunpackb (__mmask16 __A, __mmask16 __B)
-{
+static __inline__ __mmask16 __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_kunpackb(__mmask16 __A, __mmask16 __B) {
return (__mmask16) __builtin_ia32_kunpckhi ((__mmask16) __A, (__mmask16) __B);
}
+static __inline__ __mmask64 __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_kunpackd(__mmask64 __A, __mmask64 __B) {
+ return (__mmask64)__builtin_ia32_kunpckdi((__mmask64)__A, (__mmask64)__B);
+}
+
+static __inline__ __mmask32 __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm512_kunpackw(__mmask32 __A, __mmask32 __B) {
+ return (__mmask32)__builtin_ia32_kunpcksi((__mmask32)__A, (__mmask32)__B);
+}
+
static __inline__ __mmask16 __DEFAULT_FN_ATTRS_CONSTEXPR
_mm512_kxnor(__mmask16 __A, __mmask16 __B) {
return (__mmask16) __builtin_ia32_kxnorhi ((__mmask16) __A, (__mmask16) __B);
diff --git a/clang/test/CodeGen/X86/avx512f-builtins.c b/clang/test/CodeGen/X86/avx512f-builtins.c
index 17778b52d3671..9dcc749910175 100644
--- a/clang/test/CodeGen/X86/avx512f-builtins.c
+++ b/clang/test/CodeGen/X86/avx512f-builtins.c
@@ -9126,6 +9126,24 @@ __mmask16 test_mm512_kunpackb(__m512i __A, __m512i __B, __m512i __C, __m512i __D
__E, __F);
}
+TEST_CONSTEXPR(_mm512_kunpackb(0xFF00, 0x00FF) == 0xFF00);
+TEST_CONSTEXPR(_mm512_kunpackb(0xABCD, 0x1234) == 0xCD34);
+TEST_CONSTEXPR(_mm512_kunpackb(0x00FF, 0xFF00) == 0x0000);
+TEST_CONSTEXPR(_mm512_kunpackb(0xAAAA, 0x5555) == 0xAA55);
+TEST_CONSTEXPR(_mm512_kunpackb(0x1234, 0xABCD) == 0x34CD);
+
+TEST_CONSTEXPR(_mm512_kunpackw(0xFFFF0000u, 0x0000FFFFu) == 0x0000FFFFu);
+TEST_CONSTEXPR(_mm512_kunpackw(0xABCD1234u, 0x56789ABCu) == 0x12349ABCu);
+TEST_CONSTEXPR(_mm512_kunpackw(0x0000FFFFu, 0xFFFF0000u) == 0x00000000u);
+TEST_CONSTEXPR(_mm512_kunpackw(0xAAAA5555u, 0x5555AAAAu) == 0x5555AAAAu);
+TEST_CONSTEXPR(_mm512_kunpackw(0x12345678u, 0xABCDEF12u) == 0x5678EF12u);
+
+TEST_CONSTEXPR(_mm512_kunpackd(0xFFFFFFFF00000000ull, 0x00000000FFFFFFFFull) == 0x00000000FFFFFFFFull);
+TEST_CONSTEXPR(_mm512_kunpackd(0xABCDEF0123456789ull, 0x0123456789ABCDEFull) == 0x234567899ABCDEFull);
+TEST_CONSTEXPR(_mm512_kunpackd(0x00000000FFFFFFFFull, 0xFFFFFFFF00000000ull) == 0x0000000000000000ull);
+TEST_CONSTEXPR(_mm512_kunpackd(0xAAAA5555AAAA5555ull, 0x5555AAAA5555AAAAull) == 0xAAAA55555555AAAAull);
+TEST_CONSTEXPR(_mm512_kunpackd(0x123456789ABCDEFull, 0xFEDCBA9876543210ull) == 0x89ABCDEF76543210ull);
+
__mmask16 test_mm512_kxnor(__m512i __A, __m512i __B, __m512i __C, __m512i __D, __m512i __E, __m512i __F) {
// CHECK-LABEL: test_mm512_kxnor
// CHECK: [[LHS:%.*]] = bitcast i16 %{{.*}} to <16 x i1>
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RKSimon
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Nov 12, 2025
RKSimon
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Still missing InterpBuiltin and BuiltinsX86.td fixes
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✅ With the latest revision this PR passed the C/C++ code formatter. |
RKSimon
requested changes
Nov 16, 2025
RKSimon
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/27581 Here is the relevant piece of the build log for the reference |
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Resolves #166976