On 32-bit targets with SSE, enable SSE/SSE2 codegen by default

Two new CMake options are available for 32-bit targets that accept -msse:
ALSOFT_ENABLE_SSE_CODEGEN and ALSOFT_ENABLE_SSE2_CODEGEN, which default to
TRUE. This should not affect MSVC, which already defaults to SSE2 codegen.

1 files changed, 28 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c27c6e4e..b7de4a69 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -432,6 +432,30 @@ IF(HAVE_MFPU_NEON_SWITCH)
     SET(FPU_NEON_SWITCH "-mfpu=neon")
 ENDIF()
 
+SET(FPMATH_SET "0")
+IF(HAVE_MSSE_SWITCH AND CMAKE_SIZEOF_VOID_P MATCHES "4")
+    OPTION(ALSOFT_ENABLE_SSE_CODEGEN "Enable SSE code generation instead of x87 for 32-bit targets." TRUE)
+    IF(HAVE_MSSE2_SWITCH)
+        OPTION(ALSOFT_ENABLE_SSE2_CODEGEN "Enable SSE2 code generation instead of x87 for 32-bit targets." TRUE)
+    ENDIF()
+
+    IF(HAVE_MSSE2_SWITCH AND ALSOFT_ENABLE_SSE2_CODEGEN)
+        CHECK_C_COMPILER_FLAG("${SSE2_SWITCH} -mfpmath=sse" HAVE_MFPMATH_SSE_2)
+        IF(ALSOFT_ENABLE_SSE2_CODEGEN AND HAVE_MFPMATH_SSE_2)
+            SET(C_FLAGS ${C_FLAGS} ${SSE2_SWITCH} -mfpmath=sse)
+            SET(FPMATH_SET 2)
+        ENDIF()
+    ENDIF()
+    IF(ALSOFT_ENABLE_SSE_CODEGEN AND NOT FPMATH_SET)
+        CHECK_C_COMPILER_FLAG("${SSE_SWITCH} -mfpmath=sse" HAVE_MFPMATH_SSE)
+        IF(ALSOFT_ENABLE_SSE_CODEGEN AND HAVE_MFPMATH_SSE)
+            SET(C_FLAGS ${C_FLAGS} ${SSE_SWITCH} -mfpmath=sse)
+            SET(FPMATH_SET 1)
+        ENDIF()
+    ENDIF()
+ENDIF()
+
+
 CHECK_C_SOURCE_COMPILES("int foo(const char *str, ...) __attribute__((format(printf, 1, 2)));
                          int main() {return 0;}" HAVE_GCC_FORMAT)
 
@@ -1471,6 +1495,10 @@ MESSAGE(STATUS "")
 MESSAGE(STATUS "Building with support for CPU extensions:")
 MESSAGE(STATUS "    ${CPU_EXTS}")
 MESSAGE(STATUS "")
+IF(FPMATH_SET)
+    MESSAGE(STATUS "Building with SSE${FPMATH_SET} codegen")
+    MESSAGE(STATUS "")
+ENDIF()
 
 IF(WIN32)
     IF(NOT HAVE_DSOUND)