[clang] bd3aa88 - [Headers][X86] Allow SSE MOVD/Q scalar<->vector cvt intrinsics to be used in constexpr (#153192)

[via cfe-commits]

Author: Simon Pilgrim
Date: 2025-08-12T15:29:16+01:00
New Revision: bd3aa88802625486eea82672586ac97052d4c7ec

URL: https://github.com/llvm/llvm-project/commit/bd3aa88802625486eea82672586ac97052d4c7ec
DIFF: https://github.com/llvm/llvm-project/commit/bd3aa88802625486eea82672586ac97052d4c7ec.diff

LOG: [Headers][X86] Allow SSE MOVD/Q scalar<->vector cvt intrinsics to be used in constexpr (#153192)

Added: 
    

Modified: 
    clang/lib/Headers/emmintrin.h
    clang/test/CodeGen/X86/sse2-builtins.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/Headers/emmintrin.h b/clang/lib/Headers/emmintrin.h
index 60d2000dfb809..e632191113c4a 100644
--- a/clang/lib/Headers/emmintrin.h
+++ b/clang/lib/Headers/emmintrin.h
@@ -3381,7 +3381,8 @@ static __inline__ __m128i __DEFAULT_FN_ATTRS _mm_cvttps_epi32(__m128 __a) {
 /// \param __a
 ///    A 32-bit signed integer operand.
 /// \returns A 128-bit vector of [4 x i32].
-static __inline__ __m128i __DEFAULT_FN_ATTRS _mm_cvtsi32_si128(int __a) {
+static __inline__ __m128i __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm_cvtsi32_si128(int __a) {
   return __extension__(__m128i)(__v4si){__a, 0, 0, 0};
 }
 
@@ -3396,7 +3397,8 @@ static __inline__ __m128i __DEFAULT_FN_ATTRS _mm_cvtsi32_si128(int __a) {
 /// \param __a
 ///    A 64-bit signed integer operand containing the value to be converted.
 /// \returns A 128-bit vector of [2 x i64] containing the converted value.
-static __inline__ __m128i __DEFAULT_FN_ATTRS _mm_cvtsi64_si128(long long __a) {
+static __inline__ __m128i __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm_cvtsi64_si128(long long __a) {
   return __extension__(__m128i)(__v2di){__a, 0};
 }
 
@@ -3411,7 +3413,8 @@ static __inline__ __m128i __DEFAULT_FN_ATTRS _mm_cvtsi64_si128(long long __a) {
 ///    A vector of [4 x i32]. The least significant 32 bits are moved to the
 ///    destination.
 /// \returns A 32-bit signed integer containing the moved value.
-static __inline__ int __DEFAULT_FN_ATTRS _mm_cvtsi128_si32(__m128i __a) {
+static __inline__ int __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm_cvtsi128_si32(__m128i __a) {
   __v4si __b = (__v4si)__a;
   return __b[0];
 }
@@ -3427,7 +3430,8 @@ static __inline__ int __DEFAULT_FN_ATTRS _mm_cvtsi128_si32(__m128i __a) {
 ///    A vector of [2 x i64]. The least significant 64 bits are moved to the
 ///    destination.
 /// \returns A 64-bit signed integer containing the moved value.
-static __inline__ long long __DEFAULT_FN_ATTRS _mm_cvtsi128_si64(__m128i __a) {
+static __inline__ long long __DEFAULT_FN_ATTRS_CONSTEXPR
+_mm_cvtsi128_si64(__m128i __a) {
   return __a[0];
 }
 

diff  --git a/clang/test/CodeGen/X86/sse2-builtins.c b/clang/test/CodeGen/X86/sse2-builtins.c
index 23013dd75d641..4ff14adcea0e1 100644
--- a/clang/test/CodeGen/X86/sse2-builtins.c
+++ b/clang/test/CodeGen/X86/sse2-builtins.c
@@ -581,12 +581,14 @@ int test_mm_cvtsi128_si32(__m128i A) {
   // CHECK: extractelement <4 x i32> %{{.*}}, i32 0
   return _mm_cvtsi128_si32(A);
 }
+TEST_CONSTEXPR(_mm_cvtsi128_si32((__m128i)(__v4si){+1, -2, -3, +4}) == +1);
 
 long long test_mm_cvtsi128_si64(__m128i A) {
   // CHECK-LABEL: test_mm_cvtsi128_si64
   // CHECK: extractelement <2 x i64> %{{.*}}, i32 0
   return _mm_cvtsi128_si64(A);
 }
+TEST_CONSTEXPR(_mm_cvtsi128_si64((__m128i)(__v2di){42LL, -42LL}) == 42LL);
 
 __m128d test_mm_cvtsi32_sd(__m128d A, int B) {
   // CHECK-LABEL: test_mm_cvtsi32_sd
@@ -604,6 +606,7 @@ __m128i test_mm_cvtsi32_si128(int A) {
   // CHECK: insertelement <4 x i32> %{{.*}}, i32 0, i32 3
   return _mm_cvtsi32_si128(A);
 }
+TEST_CONSTEXPR(match_v4si(_mm_cvtsi32_si128(55), 55, 0, 0, 0));
 
 #ifdef __x86_64__
 __m128d test_mm_cvtsi64_sd(__m128d A, long long B) {
@@ -621,6 +624,7 @@ __m128i test_mm_cvtsi64_si128(long long A) {
   // CHECK: insertelement <2 x i64> %{{.*}}, i64 0, i32 1
   return _mm_cvtsi64_si128(A);
 }
+TEST_CONSTEXPR(match_v2di(_mm_cvtsi64_si128(-99LL), -99LL, 0LL));
 
 __m128d test_mm_cvtss_sd(__m128d A, __m128 B) {
   // CHECK-LABEL: test_mm_cvtss_sd