[fusion] unify detection scheme to the best one that we have (which w…

…e have had in h2o)

CMakeLists.txt

@@ -10,18 +10,12 @@ IF (CMAKE_VERSION VERSION_LESS 3.13.0)
 ENDIF ()
 
 FIND_PACKAGE(PkgConfig REQUIRED)
-INCLUDE(cmake/dtrace-utils.cmake)
 INCLUDE(cmake/boringssl-adjust.cmake)
+INCLUDE(cmake/dtrace-utils.cmake)
+INCLUDE(cmake/fusion.cmake)
 
 CHECK_DTRACE(${PROJECT_SOURCE_DIR}/picotls-probes.d)
-IF ((CMAKE_SIZEOF_VOID_P EQUAL 8) AND
-    (CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64") OR
-     (CMAKE_SYSTEM_PROCESSOR STREQUAL "amd64") OR
-     (CMAKE_SYSTEM_PROCESSOR STREQUAL "AMD64"))
-    SET(WITH_FUSION_DEFAULT "ON")
-ELSE ()
-    SET(WITH_FUSION_DEFAULT "OFF")
-ENDIF ()
+CHECK_FUSION_PREREQUISITES()
 
 OPTION(WITH_DTRACE "use USDT (userspace Dtrace probes)" ${HAVE_DTRACE})
 OPTION(WITH_FUSION "build 'fusion' AES-GCM engine" ${WITH_FUSION_DEFAULT})

cmake/fusion.cmake

@@ -0,0 +1,29 @@
+INCLUDE(CheckCSourceCompiles)
+INCLUDE(CMakePushCheckState)
+
+FUNCTION (CHECK_FUSION_PREREQUISITES)
+    MESSAGE(STATUS "Detecting fusion support")
+
+    CMAKE_PUSH_CHECK_STATE()
+    SET(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -mavx2 -maes -mpclmul -mvaes -mvpclmulqdq")
+    CHECK_C_SOURCE_COMPILES("
+    #include <emmintrin.h>
+    #include <immintrin.h>
+    int main(void) {
+        __m256i  ord0, ord1, ord2, ord3 = _mm256_setzero_si256();
+        ord0 = _mm256_aesenc_epi128(ord1, ord2);
+        ord3 = _mm256_aesenclast_epi128(ord0, ord1);
+        ord1 = _mm256_clmulepi64_epi128(ord3, ord2, 0x00);
+        return 0;
+    }
+    " CC_HAS_AESNI256)
+    CMAKE_POP_CHECK_STATE()
+
+    IF (CC_HAS_AESNI256)
+        MESSAGE(STATUS "Can use fusion")
+        SET(WITH_FUSION_DEFAULT "ON" PARENT_SCOPE)
+    ELSE ()
+        MESSAGE(STATUS "Cannot use fusion")
+        SET(WITH_FUSION_DEFAULT "OFF" PARENT_SCOPE)
+    ENDIF ()
+ENDFUNCTION ()

picotls.xcodeproj/project.pbxproj

@@ -205,6 +205,7 @@
 		081F00CC291A358800534A86 /* asn1.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = asn1.h; sourceTree = "<group>"; };
 		081F00CD291A358800534A86 /* pembase64.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = pembase64.h; sourceTree = "<group>"; };
 		081F00CE291A358800534A86 /* ptlsbcrypt.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = ptlsbcrypt.h; sourceTree = "<group>"; };
+		0883D3272AEF8F2500B711CC /* fusion.cmake */ = {isa = PBXFileReference; lastKnownFileType = text; path = fusion.cmake; sourceTree = "<group>"; };
 		08A835E12995E04100D872CE /* chacha20poly1305.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = chacha20poly1305.h; sourceTree = "<group>"; };
 		08A835EB2996971300D872CE /* boringssl-adjust.cmake */ = {isa = PBXFileReference; lastKnownFileType = text; path = "boringssl-adjust.cmake"; sourceTree = "<group>"; };
 		08B3298229419DFC009D6766 /* ech-live.t */ = {isa = PBXFileReference; lastKnownFileType = text; path = "ech-live.t"; sourceTree = "<group>"; xcLanguageSpecificationIdentifier = xcode.lang.perl; };
@@ -527,6 +528,7 @@
 			children = (
 				08A835EB2996971300D872CE /* boringssl-adjust.cmake */,
 				E95EBCCA227EA0180022C32D /* dtrace-utils.cmake */,
+				0883D3272AEF8F2500B711CC /* fusion.cmake */,
 			);
 			path = cmake;
 			sourceTree = "<group>";