Avoid compiling different sources for different targets

Simplifies configuration and fixes a potential problem with inline functions.
Inline functions that fail to inline will have a callable body generated. If
such a body is generated with the SSE4 source, for example, it can generate
SSE4 instructions. Calls for that function in other sources can then end up
calling the SSE4-generated body outside of any CPU capability check.

CMakeLists.txt

@@ -344,8 +344,6 @@ endif()
 
 
 set(SSE2_SWITCH "")
-set(SSE3_SWITCH "")
-set(SSE4_1_SWITCH "")
 set(FPU_NEON_SWITCH "")
 
 set(OLD_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
@@ -356,14 +354,6 @@ endif()
 check_c_compiler_flag(-msse2 HAVE_MSSE2_SWITCH)
 if(HAVE_MSSE2_SWITCH)
     set(SSE2_SWITCH "-msse2")
-    check_c_compiler_flag(-msse3 HAVE_MSSE3_SWITCH)
-    if(HAVE_MSSE3_SWITCH)
-        set(SSE3_SWITCH "-msse3")
-        check_c_compiler_flag(-msse4.1 HAVE_MSSE4_1_SWITCH)
-        if(HAVE_MSSE4_1_SWITCH)
-            set(SSE4_1_SWITCH "-msse4.1")
-        endif()
-    endif()
 endif()
 check_c_compiler_flag(-mfpu=neon HAVE_MFPU_NEON_SWITCH)
 if(HAVE_MFPU_NEON_SWITCH)
@@ -372,11 +362,11 @@ endif()
 set(CMAKE_REQUIRED_FLAGS ${OLD_REQUIRED_FLAGS})
 unset(OLD_REQUIRED_FLAGS)
 
-check_include_file(xmmintrin.h HAVE_XMMINTRIN_H ${SSE2_SWITCH})
+check_include_file(xmmintrin.h HAVE_XMMINTRIN_H)
-check_include_file(emmintrin.h HAVE_EMMINTRIN_H ${SSE2_SWITCH})
+check_include_file(emmintrin.h HAVE_EMMINTRIN_H)
-check_include_file(pmmintrin.h HAVE_PMMINTRIN_H ${SSE3_SWITCH})
+check_include_file(pmmintrin.h HAVE_PMMINTRIN_H)
-check_include_file(smmintrin.h HAVE_SMMINTRIN_H ${SSE4_1_SWITCH})
+check_include_file(smmintrin.h HAVE_SMMINTRIN_H)
-check_include_file(arm_neon.h HAVE_ARM_NEON_H ${FPU_NEON_SWITCH})
+check_include_file(arm_neon.h HAVE_ARM_NEON_H)
 
 set(SSE_FLAGS )
 set(FPMATH_SET "0")
@@ -726,10 +716,6 @@ if(HAVE_XMMINTRIN_H AND HAVE_EMMINTRIN_H)
         set(HAVE_SSE 1)
         set(HAVE_SSE2 1)
         set(CORE_OBJS  ${CORE_OBJS} core/mixer/mixer_sse.cpp core/mixer/mixer_sse2.cpp)
-        if(SSE2_SWITCH)
-            set_source_files_properties(core/mixer/mixer_sse.cpp core/mixer/mixer_sse2.cpp
-                PROPERTIES COMPILE_FLAGS "${SSE2_SWITCH}")
-        endif()
         set(CPU_EXTS "${CPU_EXTS}, SSE, SSE2")
     endif()
 endif()
@@ -741,15 +727,11 @@ if(ALSOFT_REQUIRE_SSE2 AND NOT HAVE_SSE2)
 endif()
 
 option(ALSOFT_REQUIRE_SSE3 "Require SSE3 support" OFF)
-if(HAVE_EMMINTRIN_H)
+if(HAVE_PMMINTRIN_H)
     option(ALSOFT_CPUEXT_SSE3 "Enable SSE3 support" ON)
     if(HAVE_SSE2 AND ALSOFT_CPUEXT_SSE3)
         set(HAVE_SSE3 1)
         set(CORE_OBJS  ${CORE_OBJS} core/mixer/mixer_sse3.cpp)
-        if(SSE2_SWITCH)
-            set_source_files_properties(core/mixer/mixer_sse3.cpp PROPERTIES
-                COMPILE_FLAGS "${SSE3_SWITCH}")
-        endif()
         set(CPU_EXTS "${CPU_EXTS}, SSE3")
     endif()
 endif()
@@ -763,10 +745,6 @@ if(HAVE_SMMINTRIN_H)
     if(HAVE_SSE3 AND ALSOFT_CPUEXT_SSE4_1)
         set(HAVE_SSE4_1 1)
         set(CORE_OBJS  ${CORE_OBJS} core/mixer/mixer_sse41.cpp)
-        if(SSE4_1_SWITCH)
-            set_source_files_properties(core/mixer/mixer_sse41.cpp PROPERTIES
-                COMPILE_FLAGS "${SSE4_1_SWITCH}")
-        endif()
         set(CPU_EXTS "${CPU_EXTS}, SSE4.1")
     endif()
 endif()
@@ -781,10 +759,6 @@ if(HAVE_ARM_NEON_H)
     if(ALSOFT_CPUEXT_NEON)
         set(HAVE_NEON 1)
         set(CORE_OBJS  ${CORE_OBJS} core/mixer/mixer_neon.cpp)
-        if(FPU_NEON_SWITCH)
-            set_source_files_properties(core/mixer/mixer_neon.cpp PROPERTIES
-                COMPILE_FLAGS "${FPU_NEON_SWITCH}")
-        endif()
         set(CPU_EXTS "${CPU_EXTS}, Neon")
     endif()
 endif()

core/mixer/mixer_neon.cpp

@@ -16,6 +16,10 @@ struct BSincTag;
 struct FastBSincTag;
 
 
+#if defined(__GNUC__) && !defined(__clang__) && !defined(__ARM_NEON)
+#pragma GCC target("fpu=neon")
+#endif
+
 namespace {
 
 inline float32x4_t set_f4(float l0, float l1, float l2, float l3)

core/mixer/mixer_sse.cpp

@@ -15,6 +15,11 @@ struct BSincTag;
 struct FastBSincTag;
 
 
+/* SSE2 is required for any SSE support. */
+#if defined(__GNUC__) && !defined(__clang__) && !defined(__SSE2__)
+#pragma GCC target("sse2")
+#endif
+
 namespace {
 
 constexpr uint FracPhaseBitDiff{MixerFracBits - BSincPhaseBits};

core/mixer/mixer_sse2.cpp

@@ -30,6 +30,10 @@ struct SSE2Tag;
 struct LerpTag;
 
 
+#if defined(__GNUC__) && !defined(__clang__) && !defined(__SSE2__)
+#pragma GCC target("sse2")
+#endif
+
 template<>
 const float *Resample_<LerpTag,SSE2Tag>(const InterpState*, const float *RESTRICT src, uint frac,
     uint increment, const al::span<float> dst)

core/mixer/mixer_sse41.cpp

@@ -31,6 +31,10 @@ struct SSE4Tag;
 struct LerpTag;
 
 
+#if defined(__GNUC__) && !defined(__clang__) && !defined(__SSE4_1__)
+#pragma GCC target("sse4.1")
+#endif
+
 template<>
 const float *Resample_<LerpTag,SSE4Tag>(const InterpState*, const float *RESTRICT src, uint frac,
     uint increment, const al::span<float> dst)