Don't include target flags if the compiler already has them on

include/simdjson/builtin.h

@@ -1,28 +1,7 @@
 #ifndef SIMDJSON_BUILTIN_H
 #define SIMDJSON_BUILTIN_H
 
-#include "simdjson/implementation-base.h"
+#include "simdjson/implementations.h"
-
-#ifndef SIMDJSON_BUILTIN_IMPLEMENTATION
-#if SIMDJSON_CAN_ALWAYS_RUN_HASWELL
-#define SIMDJSON_BUILTIN_IMPLEMENTATION haswell
-#include "simdjson/haswell.h"
-#elif SIMDJSON_CAN_ALWAYS_RUN_WESTMERE
-#define SIMDJSON_BUILTIN_IMPLEMENTATION westmere
-#include "simdjson/westmere.h"
-#elif SIMDJSON_CAN_ALWAYS_RUN_ARM64
-#define SIMDJSON_BUILTIN_IMPLEMENTATION arm64
-#include "simdjson/arm64.h"
-#elif SIMDJSON_CAN_ALWAYS_RUN_PPC64
-#define SIMDJSON_BUILTIN_IMPLEMENTATION ppc64
-#include "simdjson/ppc64.h"
-#elif SIMDJSON_CAN_ALWAYS_RUN_FALLBACK
-#define SIMDJSON_BUILTIN_IMPLEMENTATION fallback
-#include "simdjson/fallback.h"
-#else
-#error "All possible implementations (including fallback) have been disabled! simdjson will not run."
-#endif
-#endif // SIMDJSON_BUILTIN_IMPLEMENTATION
 
 namespace simdjson {
   /**

include/simdjson/haswell.h

@@ -5,7 +5,13 @@
 
 #if SIMDJSON_IMPLEMENTATION_HASWELL
 
+#ifndef SIMDJSON_CAN_ALWAYS_RUN_HASWELL
 #define SIMDJSON_TARGET_HASWELL SIMDJSON_TARGET_REGION("avx2,bmi,pclmul,lzcnt")
+#define SIMDJSON_UNTARGET_HASWELL SIMDJSON_UNTARGET_REGION
+#else
+#define SIMDJSON_TARGET_HASWELL
+#define SIMDJSON_UNTARGET_HASWELL
+#endif
 
 namespace simdjson {
 /**
@@ -16,7 +22,7 @@ namespace haswell {
 } // namespace simdjson
 
 //
-// These two need to be included outside SIMDJSON_TARGET_REGION
+// These two need to be included outside SIMDJSON_TARGET_HASWELL
 //
 #include "simdjson/haswell/implementation.h"
 #include "simdjson/haswell/intrinsics.h"

include/simdjson/haswell/end.h

@@ -1,2 +1,2 @@
-SIMDJSON_UNTARGET_REGION
+SIMDJSON_UNTARGET_HASWELL
 #undef SIMDJSON_IMPLEMENTATION

include/simdjson/haswell/implementation.h

@@ -3,7 +3,7 @@
 
 #include "simdjson/implementation.h"
 
-// The constructor may be executed on any host, so we take care not to use SIMDJSON_TARGET_REGION
+// The constructor may be executed on any host, so we take care not to use SIMDJSON_TARGET_HASWELL
 namespace simdjson {
 namespace haswell {
 

include/simdjson/haswell/intrinsics.h

@@ -45,7 +45,7 @@ SIMDJSON_TARGET_HASWELL
 static simdjson_really_inline uint64_t _blsr_u64(uint64_t n) {
   return (n - 1) & n;
 }
-SIMDJSON_UNTARGET_REGION
+SIMDJSON_UNTARGET_HASWELL
 #endif //  _blsr_u64
 #endif // SIMDJSON_CLANG_VISUAL_STUDIO
 

include/simdjson/implementation-base.h

@@ -51,4 +51,21 @@
 #endif
 #define SIMDJSON_CAN_ALWAYS_RUN_FALLBACK SIMDJSON_IMPLEMENTATION_FALLBACK
 
+// Determine the best builtin implementation
+#ifndef SIMDJSON_BUILTIN_IMPLEMENTATION
+#if SIMDJSON_CAN_ALWAYS_RUN_HASWELL
+#define SIMDJSON_BUILTIN_IMPLEMENTATION haswell
+#elif SIMDJSON_CAN_ALWAYS_RUN_WESTMERE
+#define SIMDJSON_BUILTIN_IMPLEMENTATION westmere
+#elif SIMDJSON_CAN_ALWAYS_RUN_ARM64
+#define SIMDJSON_BUILTIN_IMPLEMENTATION arm64
+#elif SIMDJSON_CAN_ALWAYS_RUN_PPC64
+#define SIMDJSON_BUILTIN_IMPLEMENTATION ppc64
+#elif SIMDJSON_CAN_ALWAYS_RUN_FALLBACK
+#define SIMDJSON_BUILTIN_IMPLEMENTATION fallback
+#else
+#error "All possible implementations (including fallback) have been disabled! simdjson will not run."
+#endif
+#endif // SIMDJSON_BUILTIN_IMPLEMENTATION
+
 #endif // SIMDJSON_IMPLEMENTATION_BASE_H

include/simdjson/westmere.h

@@ -5,7 +5,13 @@
 
 #if SIMDJSON_IMPLEMENTATION_WESTMERE
 
+#ifndef SIMDJSON_CAN_ALWAYS_RUN_WESTMERE
 #define SIMDJSON_TARGET_WESTMERE SIMDJSON_TARGET_REGION("sse4.2,pclmul")
+#define SIMDJSON_UNTARGET_WESTMERE SIMDJSON_UNTARGET_REGION
+#else
+#define SIMDJSON_TARGET_WESTMERE
+#define SIMDJSON_UNTARGET_WESTMERE
+#endif
 
 namespace simdjson {
 /**
@@ -16,7 +22,7 @@ namespace westmere {
 } // namespace simdjson
 
 //
-// These two need to be included outside SIMDJSON_TARGET_REGION
+// These two need to be included outside SIMDJSON_TARGET_WESTMERE
 //
 #include "simdjson/westmere/implementation.h"
 #include "simdjson/westmere/intrinsics.h"

include/simdjson/westmere/end.h

@@ -1,2 +1,2 @@
-SIMDJSON_UNTARGET_REGION
+SIMDJSON_UNTARGET_WESTMERE
 #undef SIMDJSON_IMPLEMENTATION

include/simdjson/westmere/implementation.h

@@ -3,7 +3,7 @@
 
 #include "simdjson/implementation.h"
 
-// The constructor may be executed on any host, so we take care not to use SIMDJSON_TARGET_REGION
+// The constructor may be executed on any host, so we take care not to use SIMDJSON_TARGET_WESTMERE
 namespace simdjson {
 namespace westmere {