Method buildWriteFuncs

gapil/compiler/plugins/encoder/encoder.go:78–115

()

}

func (e *encoder) buildWriteFuncs() {
	e.funcs.writeVarint = e.M.Function(e.T.Void, "write_varint", e.T.CtxPtr, e.T.BufPtr, e.T.Uint64).
		LinkOnceODR()
	e.C.Build(e.funcs.writeVarint, func(s *compiler.S) {
		buf, val := s.Parameter(1), s.Parameter(2)
		// while (i >= 0x80) {
		// 	bytes[length] = static_cast<uint8>(i | 0x80);
		// 	i >>= 7;
		// 	++length;
		// }
		// bytes[length] = static_cast<uint8>(i);
		i := s.LocalInit("i", val.Cast(e.T.Uint64))
		length := s.LocalInit("length", s.Scalar(uint32(0)))
		bytes := s.Local("bytes", e.T.TypeOf([10]byte{}))
		s.While(func() *codegen.Value {
			return s.GreaterOrEqualTo(i.Load(), s.Scalar(uint64(0x80)))
		}, func() {
			v, idx := i.Load(), length.Load()
			bytes.Index(0, idx).Store(s.Or(v, s.Scalar(uint64(0x80))).Cast(e.T.Uint8))
			i.Store(s.ShiftRight(v, s.Scalar(uint64(7))))
			length.Store(s.Add(idx, s.Scalar(uint32(1))))
		})
		bytes.Index(0, length.Load()).Store(i.Load().Cast(e.T.Uint8))
		e.AppendBuffer(s, buf, s.Add(length.Load(), s.Scalar(uint32(1))), bytes.Index(0, 0))
	})

	e.funcs.writeZigzag = e.M.Function(e.T.Void, "write_zigzag", e.T.CtxPtr, e.T.BufPtr, e.T.Uint64).
		LinkOnceODR()
	e.C.Build(e.funcs.writeZigzag, func(s *compiler.S) {
		buf, val := s.Parameter(1), s.Parameter(2)
		// (n << 1) ^ (n >> 63)
		val = val.Cast(e.T.Int64)
		lhs := s.ShiftLeft(val, s.Scalar(int64(1)))
		rhs := s.ShiftRight(val, s.Scalar(int64(63)))
		zigzag := s.Xor(lhs, rhs)
		e.writeVarint(s, buf, zigzag)
	})
}

// mgEncode returns the mangling function for an encode method on the given
// class.