check availability of SSE* instructions on target platform

Checking sse instructions on build host by reading /proc/cpuinfo is not usable for crosscompilation.
georgmartius · Jan 28, 2022 · e480227 · e480227
1 parent f9166e9
commit e480227
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diff --git a/CMakeModules/FindSSE.cmake b/CMakeModules/FindSSE.cmake
@@ -1,104 +1,69 @@
-# Check if SSE instructions are available on the machine where 
-# the project is compiled.
+# Check if SSE instructions are available by the compiler and target platform (be aware of cross compilation)
+include(CheckCCompilerFlag)
 
-IF(CMAKE_SYSTEM_NAME MATCHES "Linux")
-   EXEC_PROGRAM(cat ARGS "/proc/cpuinfo" OUTPUT_VARIABLE CPUINFO)
+check_c_compiler_flag(-msse2 HAVE_SSE2)
+check_c_compiler_flag(-msse3 HAVE_SSE3)
+check_c_compiler_flag(-mssse3 HAVE_SSSE3)
+check_c_compiler_flag(-msse4.1 HAVE_SSE4_1)
 
-   STRING(REGEX REPLACE "^.*(sse2).*$" "\\1" SSE_THERE "${CPUINFO}")
-   STRING(COMPARE EQUAL "sse2" "${SSE_THERE}" SSE2_TRUE)
-   IF (SSE2_TRUE)
-      set(SSE2_FOUND true CACHE BOOL "SSE2 available on host")
-   ELSE (SSE2_TRUE)
-      set(SSE2_FOUND false CACHE BOOL "SSE2 available on host")
-   ENDIF (SSE2_TRUE)
+# Some compilers understand SSE flags, even when target platform doesn't support it (Clang with arm target)
+# It is necessary try to compile actual code
+if(HAVE_SSE2)
+      try_compile(SSE_OK "${PROJECT_BINARY_DIR}"
+          "${PROJECT_SOURCE_DIR}/CMakeModules/TestSSE2.c"
+          COMPILE_DEFINITIONS "-msse2" )
+      if(NOT SSE_OK)
+            message(STATUS "SSE2 test compilation fails")
+            set(HAVE_SSE2 FALSE)
+      endif()
+endif()
 
-   # /proc/cpuinfo apparently omits sse3 :(
-   STRING(REGEX REPLACE "^.*[^s](sse3).*$" "\\1" SSE_THERE "${CPUINFO}")
-   STRING(COMPARE EQUAL "sse3" "${SSE_THERE}" SSE3_TRUE)
-   IF (NOT SSE3_TRUE)
-      STRING(REGEX REPLACE "^.*(T2300).*$" "\\1" SSE_THERE "${CPUINFO}")
-      STRING(COMPARE EQUAL "T2300" "${SSE_THERE}" SSE3_TRUE)
-   ENDIF (NOT SSE3_TRUE)
+if(HAVE_SSE3)
+      try_compile(SSE_OK "${PROJECT_BINARY_DIR}"
+          "${PROJECT_SOURCE_DIR}/CMakeModules/TestSSE3.c"
+          COMPILE_DEFINITIONS "-msse3" )
+      if(NOT SSE_OK)
+            message(STATUS "SSE3 test compilation fails")
+            set(HAVE_SSE3 FALSE)
+      endif()
+endif()
 
-   STRING(REGEX REPLACE "^.*(ssse3).*$" "\\1" SSE_THERE "${CPUINFO}")
-   STRING(COMPARE EQUAL "ssse3" "${SSE_THERE}" SSSE3_TRUE)
-   IF (SSE3_TRUE OR SSSE3_TRUE)
-      set(SSE3_FOUND true CACHE BOOL "SSE3 available on host")
-   ELSE (SSE3_TRUE OR SSSE3_TRUE)
-      set(SSE3_FOUND false CACHE BOOL "SSE3 available on host")
-   ENDIF (SSE3_TRUE OR SSSE3_TRUE)
-   IF (SSSE3_TRUE)
-      set(SSSE3_FOUND true CACHE BOOL "SSSE3 available on host")
-   ELSE (SSSE3_TRUE)
-      set(SSSE3_FOUND false CACHE BOOL "SSSE3 available on host")
-   ENDIF (SSSE3_TRUE)
+if(HAVE_SSSE3)
+      try_compile(SSE_OK "${PROJECT_BINARY_DIR}"
+          "${PROJECT_SOURCE_DIR}/CMakeModules/TestSSSE3.c"
+          COMPILE_DEFINITIONS "-mssse3" )
+      if(NOT SSE_OK)
+            message(STATUS "SSE3 test compilation fails")
+            set(HAVE_SSSE3 FALSE)
+      endif()
+endif()
 
-   STRING(REGEX REPLACE "^.*(sse4_1).*$" "\\1" SSE_THERE "${CPUINFO}")
-   STRING(COMPARE EQUAL "sse4_1" "${SSE_THERE}" SSE41_TRUE)
-   IF (SSE41_TRUE)
-      set(SSE4_1_FOUND true CACHE BOOL "SSE4.1 available on host")
-   ELSE (SSE41_TRUE)
-      set(SSE4_1_FOUND false CACHE BOOL "SSE4.1 available on host")
-   ENDIF (SSE41_TRUE)
-ELSEIF(CMAKE_SYSTEM_NAME MATCHES "Darwin")
-   EXEC_PROGRAM("/usr/sbin/sysctl -n machdep.cpu.features" OUTPUT_VARIABLE
-      CPUINFO)
+if(HAVE_SSE4_1)
+      try_compile(SSE_OK "${PROJECT_BINARY_DIR}"
+          "${PROJECT_SOURCE_DIR}/CMakeModules/TestSSE41.c"
+          COMPILE_DEFINITIONS "-msse4.1" )
+      if(NOT SSE_OK)
+            message(STATUS "SSE4.1 test compilation fails")
+            set(HAVE_SSE4_1 FALSE)
+      endif()
+endif()
 
-   STRING(REGEX REPLACE "^.*[^S](SSE2).*$" "\\1" SSE_THERE "${CPUINFO}")
-   STRING(COMPARE EQUAL "SSE2" "${SSE_THERE}" SSE2_TRUE)
-   IF (SSE2_TRUE)
-      set(SSE2_FOUND true CACHE BOOL "SSE2 available on host")
-   ELSE (SSE2_TRUE)
-      set(SSE2_FOUND false CACHE BOOL "SSE2 available on host")
-   ENDIF (SSE2_TRUE)
-
-   STRING(REGEX REPLACE "^.*[^S](SSE3).*$" "\\1" SSE_THERE "${CPUINFO}")
-   STRING(COMPARE EQUAL "SSE3" "${SSE_THERE}" SSE3_TRUE)
-   IF (SSE3_TRUE)
-      set(SSE3_FOUND true CACHE BOOL "SSE3 available on host")
-   ELSE (SSE3_TRUE)
-      set(SSE3_FOUND false CACHE BOOL "SSE3 available on host")
-   ENDIF (SSE3_TRUE)
-
-   STRING(REGEX REPLACE "^.*(SSSE3).*$" "\\1" SSE_THERE "${CPUINFO}")
-   STRING(COMPARE EQUAL "SSSE3" "${SSE_THERE}" SSSE3_TRUE)
-   IF (SSSE3_TRUE)
-      set(SSSE3_FOUND true CACHE BOOL "SSSE3 available on host")
-   ELSE (SSSE3_TRUE)
-      set(SSSE3_FOUND false CACHE BOOL "SSSE3 available on host")
-   ENDIF (SSSE3_TRUE)
-
-   STRING(REGEX REPLACE "^.*(SSE4.1).*$" "\\1" SSE_THERE "${CPUINFO}")
-   STRING(COMPARE EQUAL "SSE4.1" "${SSE_THERE}" SSE41_TRUE)
-   IF (SSE41_TRUE)
-      set(SSE4_1_FOUND true CACHE BOOL "SSE4.1 available on host")
-   ELSE (SSE41_TRUE)
-      set(SSE4_1_FOUND false CACHE BOOL "SSE4.1 available on host")
-   ENDIF (SSE41_TRUE)
-ELSEIF(CMAKE_SYSTEM_NAME MATCHES "Windows")
-   # TODO
-   set(SSE2_FOUND   true  CACHE BOOL "SSE2 available on host")
-   set(SSE3_FOUND   false CACHE BOOL "SSE3 available on host")
-   set(SSSE3_FOUND  false CACHE BOOL "SSSE3 available on host")
-   set(SSE4_1_FOUND false CACHE BOOL "SSE4.1 available on host")
-ELSE(CMAKE_SYSTEM_NAME MATCHES "Linux")
-   set(SSE2_FOUND   true  CACHE BOOL "SSE2 available on host")
-   set(SSE3_FOUND   false CACHE BOOL "SSE3 available on host")
-   set(SSSE3_FOUND  false CACHE BOOL "SSSE3 available on host")
-   set(SSE4_1_FOUND false CACHE BOOL "SSE4.1 available on host")
-ENDIF(CMAKE_SYSTEM_NAME MATCHES "Linux")
+set(SSE2_FOUND   HAVE_SSE2   CACHE BOOL "SSE2 available on target")
+set(SSE3_FOUND   HAVE_SSE3   CACHE BOOL "SSE3 available on target")
+set(SSSE3_FOUND  HAVE_SSSE3  CACHE BOOL "SSSE3 available on target")
+set(SSE4_1_FOUND HAVE_SSE4_1 CACHE BOOL "SSE4.1 available on target")
 
 if(NOT SSE2_FOUND)
-      MESSAGE(STATUS "Could not find hardware support for SSE2 on this machine.")
+      MESSAGE(STATUS "SSE2 is not supported on target platform.")
 endif(NOT SSE2_FOUND)
 if(NOT SSE3_FOUND)
-      MESSAGE(STATUS "Could not find hardware support for SSE3 on this machine.")
+      MESSAGE(STATUS "SSE3 is not supported on target platform.")
 endif(NOT SSE3_FOUND)
 if(NOT SSSE3_FOUND)
-      MESSAGE(STATUS "Could not find hardware support for SSSE3 on this machine.")
+      MESSAGE(STATUS "SSSE3 is not supported on target platform.")
 endif(NOT SSSE3_FOUND)
 if(NOT SSE4_1_FOUND)
-      MESSAGE(STATUS "Could not find hardware support for SSE4.1 on this machine.")
+      MESSAGE(STATUS "SSE4.1 is not supported on target platform.")
 endif(NOT SSE4_1_FOUND)
 
 mark_as_advanced(SSE2_FOUND SSE3_FOUND SSSE3_FOUND SSE4_1_FOUND)
diff --git a/CMakeModules/TestSSE2.c b/CMakeModules/TestSSE2.c
@@ -0,0 +1,20 @@
+#include <stdio.h>
+
+//include sse and sse2 headers
+#include <xmmintrin.h>
+#include <emmintrin.h>
+
+/* __m128 is ugly to write */
+typedef __m128d v2df;  // vector of 2 double (sse2)
+
+int main(int argc, char **argv)
+{
+  v2df calcx = _mm_setr_pd(2.0, 3.0);
+  v2df xx = _mm_mul_pd(calcx, calcx);
+  double d;
+  _mm_storel_pd(&d, xx);
+  printf("%f\n", d);
+  _mm_storeh_pd(&d, xx);
+  printf("%f\n", d);
+  return 0;
+}
diff --git a/CMakeModules/TestSSE3.c b/CMakeModules/TestSSE3.c
@@ -0,0 +1,20 @@
+#include <stdio.h>
+
+//include sse and sse2 headers
+#include <xmmintrin.h>
+#include <emmintrin.h>
+
+/* __m128 is ugly to write */
+typedef __m128d v2df;  // vector of 2 double (sse2)
+
+int main(int argc, char **argv)
+{
+  v2df calcx = _mm_setr_pd(2.0, 3.0);
+  v2df xx = _mm_mul_pd(calcx, calcx);
+  double d;
+  _mm_storel_pd(&d, xx);
+  printf("%f\n", d);
+  _mm_storeh_pd(&d, xx);
+  printf("%f\n", d);
+  return 0;
+}
diff --git a/CMakeModules/TestSSE41.c b/CMakeModules/TestSSE41.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+//include sse, sse2 and sse4.1 headers
+#include <xmmintrin.h>
+#include <emmintrin.h>
+#include <smmintrin.h>
+
+int main(int argc, char **argv)
+{
+  __m128i a = _mm_set_epi32(1, 2, 3, 4);
+  __m128i b = _mm_set_epi32(1, 2, 3, 4);
+  int i = _mm_testz_si128(a, b);
+  printf("%d\n", i);
+  return 0;
+}
diff --git a/CMakeModules/TestSSSE3.c b/CMakeModules/TestSSSE3.c
@@ -0,0 +1,16 @@
+#include <stdio.h>
+
+//include sse, sse2 and ssse3 headers
+#include <xmmintrin.h>
+#include <emmintrin.h>
+#include <tmmintrin.h>
+
+int main(int argc, char **argv)
+{
+  __m128i calcx = _mm_set_epi32(1, 2, 3, 4);
+  __m128i xx = _mm_hadd_epi32(calcx, calcx);
+  int i;
+  _mm_storeu_si32(&i, xx);
+  printf("%d\n", i);
+  return 0;
+}