Add detecting native target infomation

Author: flyfish30

build.zig

@@ -48,12 +48,14 @@ pub fn build(b: *std.Build) void {
     }
 
     // the native cpu_arch is null, so we should detect current cpu_arch
-    // if (target.cpu_arch == .x86_64) {
-    // exe.addIncludePath(.{ .path = "./inc" });
-    // const cfiles = [_][]const u8{"src/x86_64_intrins.c"};
-    // const cflags = [_][]const u8{"-O2"};
-    // exe.addCSourceFiles(&cfiles, &cflags);
-    // }
+    const target_info = std.zig.system.NativeTargetInfo.detect(target) catch
+        @panic("Couldn't detect native target info");
+    if (target_info.target.cpu.arch == .x86_64) {
+        exe.addIncludePath(.{ .path = "./inc" });
+        const cfiles = [_][]const u8{"src/x86_64_intrins.c"};
+        const cflags = [_][]const u8{"-O2"};
+        exe.addCSourceFiles(&cfiles, &cflags);
+    }
 
     // This declares intent for the executable to be installed into the
     // standard location when the user invokes the "install" step (the default

src/simd_x86_64.zig

@@ -14,7 +14,7 @@ const VecU8Index = VectorIndex(@Vector(VecLen(u8), u8));
 
 const c = @cImport({
     @cInclude("immintrin.h");
-    // @cInclude("x86_64_intrins.h");
+    @cInclude("x86_64_intrins.h");
 });
 
 pub const SimdSamples = struct {