From feb8cbf7846bb3a5b01403e2b0a205b55b702fcf Mon Sep 17 00:00:00 2001
From: Nathan Moinvaziri <nathan@nathanm.com>
Date: Sun, 17 Sep 2023 15:25:41 -0700
Subject: [PATCH] Don't run test intrinsic code with native flag in CMake.

Native flag should already determine what code will run on the architecture.
This appears to have just been an extra run check with limited benefits. Any
compiler that compiles code not available on the native platform is buggy and
not our problem.
---
 cmake/detect-intrinsics.cmake | 33 +++++++++++----------------------
 1 file changed, 11 insertions(+), 22 deletions(-)

diff --git a/cmake/detect-intrinsics.cmake b/cmake/detect-intrinsics.cmake
index 1076bae112..fe1848e62c 100644
--- a/cmake/detect-intrinsics.cmake
+++ b/cmake/detect-intrinsics.cmake
@@ -1,17 +1,6 @@
 # detect-intrinsics.cmake -- Detect compiler intrinsics support
 # Licensed under the Zlib license, see LICENSE.md for details
 
-# Macro to check if source compiles
-# (and, when compiling very natively, also runs).
-macro(check_c_source_compile_or_run source flag)
-    if(CMAKE_CROSSCOMPILING OR NOT WITH_NATIVE_INSTRUCTIONS)
-        check_c_source_compiles("${source}" ${flag})
-    else()
-        check_c_source_runs("${source}" ${flag})
-    endif()
-endmacro()
-
-
 macro(check_acle_compiler_flag)
     if(MSVC)
         # Both ARM and ARM64-targeting msvc support intrinsics, but
@@ -55,7 +44,7 @@ macro(check_armv6_compiler_flag)
     endif()
     # Check whether compiler supports ARMv6 inline asm
     set(CMAKE_REQUIRED_FLAGS "${ARMV6FLAG} ${NATIVEFLAG}")
-    check_c_source_compile_or_run(
+    check_c_source_compiles(
         "unsigned int f(unsigned int a, unsigned int b) {
             unsigned int c;
             __asm__ __volatile__ ( \"uqsub16 %0, %1, %2\" : \"=r\" (c) : \"r\" (a), \"r\" (b) );
@@ -65,7 +54,7 @@ macro(check_armv6_compiler_flag)
         HAVE_ARMV6_INLINE_ASM
     )
     # Check whether compiler supports ARMv6 intrinsics
-    check_c_source_compile_or_run(
+    check_c_source_compiles(
         "#if defined(_MSC_VER)
         #include <intrin.h>
         #else
@@ -111,7 +100,7 @@ macro(check_avx512_intrinsics)
     endif()
     # Check whether compiler supports AVX512 intrinsics
     set(CMAKE_REQUIRED_FLAGS "${AVX512FLAG} ${NATIVEFLAG}")
-    check_c_source_compile_or_run(
+    check_c_source_compiles(
         "#include <immintrin.h>
         __m512i f(__m512i y) {
           __m512i x = _mm512_set1_epi8(2);
@@ -122,7 +111,7 @@ macro(check_avx512_intrinsics)
     )
 
     # Evidently both GCC and clang were late to implementing these
-    check_c_source_compile_or_run(
+    check_c_source_compiles(
         "#include <immintrin.h>
         __mmask16 f(__mmask16 x) { return _knot_mask16(x); }
         int main(void) { return 0; }"
@@ -157,7 +146,7 @@ macro(check_avx512vnni_intrinsics)
 
     # Check whether compiler supports AVX512vnni intrinsics
     set(CMAKE_REQUIRED_FLAGS "${AVX512VNNIFLAG} ${NATIVEFLAG}")
-    check_c_source_compile_or_run(
+    check_c_source_compiles(
         "#include <immintrin.h>
         __m512i f(__m512i x, __m512i y) {
             __m512i z = _mm512_setzero_epi32();
@@ -185,7 +174,7 @@ macro(check_avx2_intrinsics)
     endif()
     # Check whether compiler supports AVX2 intrinics
     set(CMAKE_REQUIRED_FLAGS "${AVX2FLAG} ${NATIVEFLAG}")
-    check_c_source_compile_or_run(
+    check_c_source_compiles(
         "#include <immintrin.h>
         __m256i f(__m256i x) {
             const __m256i y = _mm256_set1_epi16(1);
@@ -254,7 +243,7 @@ macro(check_pclmulqdq_intrinsics)
     if(NOT (APPLE AND "${ARCH}" MATCHES "i386"))
         # The pclmul code currently crashes on Mac in 32bit mode. Avoid for now.
         set(CMAKE_REQUIRED_FLAGS "${PCLMULFLAG} ${NATIVEFLAG}")
-        check_c_source_compile_or_run(
+        check_c_source_compiles(
             "#include <immintrin.h>
             #include <wmmintrin.h>
             __m128i f(__m128i a, __m128i b) { return _mm_clmulepi64_si128(a, b, 0x10); }
@@ -276,7 +265,7 @@ macro(check_vpclmulqdq_intrinsics)
     # Check whether compiler supports VPCLMULQDQ intrinsics
     if(NOT (APPLE AND "${ARCH}" MATCHES "i386"))
         set(CMAKE_REQUIRED_FLAGS "${VPCLMULFLAG} ${NATIVEFLAG}")
-        check_c_source_compile_or_run(
+        check_c_source_compiles(
             "#include <immintrin.h>
             #include <wmmintrin.h>
             __m512i f(__m512i a) {
@@ -454,7 +443,7 @@ macro(check_sse2_intrinsics)
     endif()
     # Check whether compiler supports SSE2 intrinsics
     set(CMAKE_REQUIRED_FLAGS "${SSE2FLAG} ${NATIVEFLAG}")
-    check_c_source_compile_or_run(
+    check_c_source_compiles(
         "#include <immintrin.h>
         __m128i f(__m128i x, __m128i y) { return _mm_sad_epu8(x, y); }
         int main(void) { return 0; }"
@@ -477,7 +466,7 @@ macro(check_ssse3_intrinsics)
     endif()
     # Check whether compiler supports SSSE3 intrinsics
     set(CMAKE_REQUIRED_FLAGS "${SSSE3FLAG} ${NATIVEFLAG}")
-    check_c_source_compile_or_run(
+    check_c_source_compiles(
         "#include <immintrin.h>
         __m128i f(__m128i u) {
           __m128i v = _mm_set1_epi32(1);
@@ -502,7 +491,7 @@ macro(check_sse42_intrinsics)
     endif()
     # Check whether compiler supports SSE4.2 intrinsics
     set(CMAKE_REQUIRED_FLAGS "${SSE42FLAG} ${NATIVEFLAG}")
-    check_c_source_compile_or_run(
+    check_c_source_compiles(
         "#include <nmmintrin.h>
         unsigned int f(unsigned int a, unsigned int b) { return _mm_crc32_u32(a, b); }
         int main(void) { return 0; }"