20  * Compute out = in1 + in2 mod p. 'out' parameter must have been initialized
25 int fp_add(fp_t out, fp_src_t in1, fp_src_t in2)  in fp_add()  argument
31 	ret = fp_check_initialized(in2); EG(ret, err);  in fp_add()
33 	MUST_HAVE(((&(in1->ctx->p)) == (&(in2->ctx->p))), ret, err);  in fp_add()
37 	SHOULD_HAVE(!nn_cmp(&in2->fp_val, &(in2->ctx->p), &cmp) && (cmp < 0), ret, err);  in fp_add()
40 			 &(in2->fp_val), &(in1->ctx->p));  in fp_add()
70  * Compute out = in1 - in2 mod p. 'out' parameter must have been initialized
75 int fp_sub(fp_t out, fp_src_t in1, fp_src_t in2)  in fp_sub()  argument
81 	ret = fp_check_initialized(in2); EG(ret, err);  in fp_sub()
83 	MUST_HAVE(((&(in1->ctx->p)) == (&(in2->ctx->p))), ret, err);  in fp_sub()
87 	SHOULD_HAVE(!nn_cmp(&in2->fp_val, &(in2->ctx->p), &cmp) && (cmp < 0), ret, err);  in fp_sub()
90 			 &(in2->fp_val), &(in1->ctx->p));  in fp_sub()