circom/c/buildasm/cmpops.asm.ejs

<% function retOne() { %>
        mov qword [rdi], 1
        add rsp, <%= (n64+1)*8 %>
        ret
<% } %>

<% function retZero() { %>
        mov qword [rdi], 0
        add rsp, <%= (n64+1)*8 %>
        ret
<% } %>

<% function cmpLong(op, eq) { %>

<%
    if (eq==true) {
        if (["leq","geq"].indexOf(op) >= 0) retOne();
        if (["lt","gt"].indexOf(op) >= 0) retZero();
    }
%>


<%   const label_gt = global.tmpLabel() %>
<%   const label_lt = global.tmpLabel() %>
<%   for (let i=n64-1; i>=0; i--) { %>
        mov     rax, [rsp + <%= 8+(i*8) %>]
        cmp     [half + <%= (i*8) %>], rax     ; comare with (q-1)/2
        jc <%=label_lt%>                           ; half<rax => e1-e2 is neg => e1 < e2
        jnz <%=label_gt%>                       ; half>rax => e1 -e2 is pos => e1 > e2
<%   } %>
                                                ; half == rax => e1-e2 is pos => e1 > e2
<%=label_gt%>:
<%   if (["geq","gt"].indexOf(op) >= 0) retOne(); else retZero(); %>
<%=label_lt%>:
<%   if (["leq","lt"].indexOf(op) >= 0) retOne(); else retZero(); %>
<% } // cmpLong%>

<% function cmpOp(op) { %>
;;;;;;;;;;;;;;;;;;;;;;
; <%= op %>
;;;;;;;;;;;;;;;;;;;;;;
; Adds two elements of any kind
; Params:
;   rsi <= Pointer to element 1
;   rdx <= Pointer to element 2
;   rdi <= Pointer to result can be zero or one.
; Modified Registers:
;    r8, r9, 10, r11, rax, rcx
;;;;;;;;;;;;;;;;;;;;;;
<%=name%>_<%=op%>:
    sub     rsp, <%= (n64+1)*8 %>  ; Save space for the result of the substraction
    push    rdi                    ; Save rdi
    lea     rdi, [rsp+8]           ; We pushed rdi so we need to add 8
    call    <%=name%>_sub          ; Do a substraction
    call    <%=name%>_toNormal     ; Convert it to normal
    pop     rdi

    mov     rax, [rsp]             ; We already poped do no need to add 8
    bt      rax, 63                ; check is result is long
    jc      <%=op%>_longCmp

<%=op%>_shortCmp:
    cmp     eax, 0
    je      <%=op%>_s_eq
    js      <%=op%>_s_lt
<%=op%>_s_gt:
<%   if (["geq","gt", "neq"].indexOf(op) >= 0) retOne(); else retZero(); %>
<%=op%>_s_lt:
<%   if (["leq","lt", "neq"].indexOf(op) >= 0) retOne(); else retZero(); %>
<%=op%>_s_eq:
<%   if (["eq","geq", "leq"].indexOf(op) >= 0) retOne(); else retZero(); %>

<%=op%>_longCmp:

<% for (let i=n64-1; i>=0; i--) { %>
    cmp     qword [rsp + <%= 8+(i*8) %>], 0
    jnz <%=op%>_neq
<% } %>
<%=op%>_eq:
<% if (op == "eq") {
        retOne();
   } else if (op == "neq") {
        retZero();
   } else {
        cmpLong(op, true);
   }
%>
<%=op%>_neq:
<% if (op == "neq") {
        retOne();
   } else if (op == "eq") {
        retZero();
   } else {
        cmpLong(op, false);
   }
%>


<% } %>

<%= cmpOp("eq") %>
<%= cmpOp("neq") %>
<%= cmpOp("lt") %>
<%= cmpOp("gt") %>
<%= cmpOp("leq") %>
<%= cmpOp("geq") %>