Allow SIMD vector unit to be toggled on/off #172

Currently defaults to off but future versions may default to on

src/sharp.cc

@@ -26,6 +26,8 @@ NAN_MODULE_INIT(init) {
     Nan::GetFunction(Nan::New<v8::FunctionTemplate>(concurrency)).ToLocalChecked());
   Nan::Set(target, Nan::New("counters").ToLocalChecked(),
     Nan::GetFunction(Nan::New<v8::FunctionTemplate>(counters)).ToLocalChecked());
+  Nan::Set(target, Nan::New("simd").ToLocalChecked(),
+    Nan::GetFunction(Nan::New<v8::FunctionTemplate>(simd)).ToLocalChecked());
   Nan::Set(target, Nan::New("libvipsVersion").ToLocalChecked(),
     Nan::GetFunction(Nan::New<v8::FunctionTemplate>(libvipsVersion)).ToLocalChecked());
   Nan::Set(target, Nan::New("format").ToLocalChecked(),

src/utilities.cc

@@ -1,6 +1,7 @@
 #include <cmath>
 #include <node.h>
 #include <vips/vips.h>
+#include <vips/vector.h>
 
 #include "nan.h"
 
@@ -81,6 +82,20 @@ NAN_METHOD(counters) {
   info.GetReturnValue().Set(counters);
 }
 
+/*
+  Get and set use of SIMD vector unit instructions
+*/
+NAN_METHOD(simd) {
+  HandleScope();
+
+  // Set state
+  if (info[0]->IsBoolean()) {
+    vips_vector_set_enabled(To<bool>(info[0]).FromJust());
+  }
+  // Get state
+  info.GetReturnValue().Set(New<Boolean>(vips_vector_isenabled()));
+}
+
 /*
   Get libvips version
 */

src/utilities.h

@@ -6,6 +6,7 @@
 NAN_METHOD(cache);
 NAN_METHOD(concurrency);
 NAN_METHOD(counters);
+NAN_METHOD(simd);
 NAN_METHOD(libvipsVersion);
 NAN_METHOD(format);
 NAN_METHOD(_maxColourDistance);