builtin.closure #

const closure_thunk = $if amd64 {
	[
		u8(0xF3),
		0x44,
		0x0F,
		0x7E,
		0x3D,
		0xF7,
		0xBF,
		0xFF,
		0xFF, // movq  xmm15, QWORD PTR [rip - userdata]
		0xFF,
		0x25,
		0xF9,
		0xBF,
		0xFF,
		0xFF, // jmp  QWORD PTR [rip - fn]
	]
} $else $if i386 {
	[
		u8(0xe8),
		0x00,
		0x00,
		0x00,
		0x00, // call here
		// here:
		0x59, // pop  ecx
		0x66,
		0x0F,
		0x6E,
		0xF9, // movd xmm7, ecx
		0xff,
		0xA1,
		0xff,
		0xbf,
		0xff,
		0xff, // jmp  DWORD PTR [ecx - 0x4001] # 
	]
} $else $if arm64 {
	[
		u8(0x11),
		0x00,
		0xFE,
		0x5C, // ldr d17, userdata
		0x30,
		0x00,
		0xFE,
		0x58, // ldr x16, fn
		0x00,
		0x02,
		0x1F,
		0xD6, // br  x16
	]
} $else $if arm32 {
	[
		u8(0x04),
		0xC0,
		0x4F,
		0xE2, // adr ip, here
		// here:
		0x01,
		0xC9,
		0x4C,
		0xE2, // sub  ip, ip, #0x4000
		0x90,
		0xCA,
		0x07,
		0xEE, // vmov s15, ip
		0x00,
		0xC0,
		0x9C,
		0xE5, // ldr  ip, [ip, 0]
		0x1C,
		0xFF,
		0x2F,
		0xE1, // bx   ip
	]
} $else $if rv64 {
	[
		u8(0x97),
		0xCF,
		0xFF,
		0xFF, // auipc t6, 0xffffc
		0x03,
		0xBF,
		0x8F,
		0x00, // ld    t5, 8(t6)
		0x07,
		0xB3,
		0x0F,
		0x00, // fld   ft6, 0(t6)
		0x67,
		0x00,
		0x0F,
		0x00, // jr    t5
	]
} $else $if rv32 {
	[
		u8(0x97),
		0xCF,
		0xFF,
		0xFF, // auipc t6, 0xffffc
		0x03,
		0xAF,
		0x4F,
		0x00, // lw    t5, 4(t6)
		0x07,
		0xAB,
		0x0F,
		0x00, // flw   fs6, 0(t6)
		0x67,
		0x00,
		0x0F,
		0x00, // jr    t5
	]
} $else $if s390x {
	[
		u8(0xC0),
		0x70,
		0xFF,
		0xFF,
		0xE0,
		0x00, // larl %r7, -16384
		0x68,
		0xF0,
		0x70,
		0x00, // ld   %f15, 0(%r7)
		0xE3,
		0x70,
		0x70,
		0x08,
		0x00,
		0x04, // lg   %r7, 8(%r7)
		0x07,
		0xF7, // br   %r7
	]
} $else $if ppc64le {
	[
		u8(0xa6),
		0x02,
		0x08,
		0x7c, // mflr   %r0
		0x05,
		0x00,
		0x00,
		0x48, // bl     here
		0xa6,
		0x02,
		0xc8,
		0x7d, // here:  mflr %r14
		0xf8,
		0xbf,
		0xce,
		0x39, // addi   %r14, %r14, -16392
		0x00,
		0x00,
		0xce,
		0xc9, // lfd    %f14, 0(%r14)
		0x08,
		0x00,
		0xce,
		0xe9, // ld     %r14, 8(%r14)
		0xa6,
		0x03,
		0x08,
		0x7c, // mtlr   %r0
		0xa6,
		0x03,
		0xc9,
		0x7d, // mtctr  %r14
		0x20,
		0x04,
		0x80,
		0x4e, // bctr
	]
} $else $if loongarch64 {
	[
		u8(0x92),
		0xFF,
		0xFF,
		0x1D, // pcaddu12i t6, -4
		0x48,
		0x02,
		0x80,
		0x2B, // fld.d     f8, t6, 0
		0x51,
		0x22,
		0xC0,
		0x28, // ld.d      t5, t6, 8
		0x20,
		0x02,
		0x00,
		0x4C, // jr        t5
	]
} $else {
	[]u8{}
}

refer to https://godbolt.org/z/r7P3EYv6c for a complete assembly vfmt off