cmake: invoke the compiler to test arch features

We require SSSE3, and optionally support AVX2, and the best way of testing
the compiler and compile flags is to run the compiler.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7439f50b8513bb568bde9e522e960598361b108c..fe486eedd2f29ab428e3f7af522ffba731acbab5 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -237,6 +237,9 @@ if (RELEASE_BUILD)
     endif()
 endif()
 
+# ensure we are building for the right target arch
+include (${CMAKE_MODULE_PATH}/arch.cmake)
+
 # testing a builtin takes a little more work
 CHECK_C_SOURCE_COMPILES("void *aa_test(void *x) { return __builtin_assume_aligned(x, 16);}\nint main(void) { return 0; }" HAVE_CC_BUILTIN_ASSUME_ALIGNED)
 CHECK_CXX_SOURCE_COMPILES("void *aa_test(void *x) { return __builtin_assume_aligned(x, 16);}\nint main(void) { return 0; }" HAVE_CXX_BUILTIN_ASSUME_ALIGNED)
@@ -403,7 +406,6 @@ set (hs_exec_SRCS
     src/fdr/flood_runtime.h
     src/fdr/fdr_loadval.h
     src/fdr/teddy.c
-    src/fdr/teddy_avx2.c
     src/fdr/teddy.h
     src/fdr/teddy_internal.h
     src/fdr/teddy_runtime_common.h
@@ -513,7 +515,6 @@ set (hs_exec_SRCS
     src/util/fatbit.h
     src/util/fatbit.c
     src/util/join.h
-    src/util/masked_move.c
     src/util/masked_move.h
     src/util/multibit.h
     src/util/multibit_internal.h
@@ -540,6 +541,14 @@ set (hs_exec_SRCS
     src/database.h
 )
 
+if (HAVE_AVX2)
+    set (hs_exec_SRCS
+        ${hs_exec_SRCS}
+        src/fdr/teddy_avx2.c
+        src/util/masked_move.c
+        )
+endif ()
+
 
 SET (hs_SRCS
     ${hs_HEADERS}

diff --git a/cmake/arch.cmake b/cmake/arch.cmake
new file mode 100644 (file)
index 0000000..c00401d
--- /dev/null
+++ b/cmake/arch.cmake
@@ -0,0 +1,42 @@
+# detect architecture features
+#
+# must be called after determining where compiler intrinsics are defined
+
+if (HAVE_C_X86INTRIN_H)
+    set (INTRIN_INC_H "x86intrin.h")
+elseif (HAVE_C_INTRIN_H)
+    set (INTRIN_INC_H "intrin.h")
+else ()
+    message (FATAL_ERROR "No intrinsics header found")
+endif ()
+
+
+set (CMAKE_REQUIRED_FLAGS "${CMAKE_C_FLAGS} ${EXTRA_C_FLAGS}")
+# ensure we have the minimum of SSSE3 - call a SSSE3 intrinsic
+CHECK_C_SOURCE_COMPILES("#include <${INTRIN_INC_H}>
+int main() {
+    __m128i a = _mm_set1_epi8(1);
+    (void)_mm_shuffle_epi8(a, a);
+}" HAVE_SSSE3)
+
+if (NOT HAVE_SSSE3)
+    message(FATAL_ERROR "A minimum of SSSE3 compiler support is required")
+endif ()
+
+# now look for AVX2
+CHECK_C_SOURCE_COMPILES("#include <${INTRIN_INC_H}>
+#if !defined(__AVX2__)
+#error no avx2
+#endif
+
+int main(){
+    __m256i z = _mm256_setzero_si256();
+    (void)_mm256_xor_si256(z, z);
+}" HAVE_AVX2)
+
+if (NOT HAVE_AVX2)
+    message(STATUS "Building without AVX2 support")
+endif ()
+
+unset (CMAKE_REQUIRED_FLAGS)
+unset (INTRIN_INC_H)