@@ -33,6 +33,51 @@ mpz_set(*r, zero);
     }
 }
 
+void ZqField::eq(PBigInt r, PBigInt a, PBigInt b) {
+    int c = mpz_cmp(*a, *b);
+    if (c==0) {
+        mpz_set(*r, one);
+    } else {
+        mpz_set(*r, zero);
+    }
+}
+
+void ZqField::gt(PBigInt r, PBigInt a, PBigInt b) {
+    int c = mpz_cmp(*a, *b);
+    if (c>0) {
+        mpz_set(*r, one);
+    } else {
+        mpz_set(*r, zero);
+    }
+}
+
+void ZqField::leq(PBigInt r, PBigInt a, PBigInt b) {
+    int c = mpz_cmp(*a, *b);
+    if (c<=0) {
+        mpz_set(*r, one);
+    } else {
+        mpz_set(*r, zero);
+    }
+}
+
+void ZqField::geq(PBigInt r, PBigInt a, PBigInt b) {
+    int c = mpz_cmp(*a, *b);
+    if (c>=0) {
+        mpz_set(*r, one);
+    } else {
+        mpz_set(*r, zero);
+    }
+}
+
+void ZqField::neq(PBigInt r, PBigInt a, PBigInt b) {
+    int c = mpz_cmp(*a, *b);
+    if (c!=0) {
+        mpz_set(*r, one);
+    } else {
+        mpz_set(*r, zero);
+    }
+}
+
 int ZqField::isTrue(PBigInt a) {
     return mpz_sgn(*a);
 }

@@ -17,6 +17,11 @@ void copyn(PBigInt a, PBigInt b, int n);
     void add(PBigInt r,PBigInt a, PBigInt b);
     void mul(PBigInt r,PBigInt a, PBigInt b);
     void lt(PBigInt r, PBigInt a, PBigInt b);
+    void eq(PBigInt r, PBigInt a, PBigInt b);
+    void gt(PBigInt r, PBigInt a, PBigInt b);
+    void leq(PBigInt r, PBigInt a, PBigInt b);
+    void geq(PBigInt r, PBigInt a, PBigInt b);
+    void neq(PBigInt r, PBigInt a, PBigInt b);
     int isTrue(PBigInt a);
 };
 

@@ -190,15 +190,15 @@ return genShr(ctx, ast);
         } else if (ast.op == "<") {
             return genBinaryOp(ctx, ast, "lt");
         } else if (ast.op == ">") {
-            return genGt(ctx, ast);
+            return genBinaryOp(ctx, ast, "gt");
         } else if (ast.op == "<=") {
-            return genLte(ctx, ast);
+            return genBinaryOp(ctx, ast, "leq");
         } else if (ast.op == ">=") {
-            return genGte(ctx, ast);
+            return genBinaryOp(ctx, ast, "geq");
         } else if (ast.op == "==") {
-            return genEq(ctx, ast);
+            return genBinaryOp(ctx, ast, "eq");
         } else if (ast.op == "!=") {
-            return genNeq(ctx, ast);
+            return genBinaryOp(ctx, ast, "neq");
         } else if (ast.op == "?") {
             return genTerCon(ctx, ast);
         } else {
@@ -280,6 +280,11 @@ const init = getSource(ctx, ast.init);
     const condition = getSource(ctx, ast.condition);
     const step = getSource(ctx, ast.step);
     ctx.code += `\n/* for (${init},${condition},${step}) */\n`;
+}
+
+function genIfSrcComment(ctx, ast) {
+    const condition = getSource(ctx, ast.condition);
+    ctx.code += `\n/* if (${condition}) */\n`;
 }
 
 
@@ -835,6 +840,8 @@ let condVar;
 
 
     const condRef = gen(ctx, ast.condition);
+    if (ctx.error) return;
+
     const cond = ctx.refs[condRef];
     if (!utils.sameSizes(cond.sizes, [1,0])) return ctx.throwError(ast.condition, "Operation cannot be done on an array");
 
@@ -867,6 +874,8 @@ gen(ctx, ast.step);
         if (ctx.error) return;
 
         const condRef2 = gen(ctx, ast.condition);
+        if (ctx.error) return;
+
         const cond2 = ctx.refs[condRef2];
 
         if (!inLoop) {
@@ -917,16 +926,45 @@ return `{\n${body}\n}\n`;
 }
 
 function genIf(ctx, ast) {
-    const condition = gen(ctx, ast.condition);
-    if (ctx.error) return;
-    const thenBody = gen(ctx, ast.then);
+    genIfSrcComment(ctx, ast);
+    const condRef = gen(ctx, ast.condition);
     if (ctx.error) return;
-    if (ast.else) {
-        const elseBody = gen(ctx, ast.else);
+    const cond = ctx.refs[condRef];
+    if (!utils.sameSizes(cond.sizes, [1,0])) return ctx.throwError(ast.condition, "Operation cannot be done on an array");
+
+    if (cond.used) {
+        enterConditionalCode(ctx, ast);
+
+        ctx.code += `if (ctx->field->isTrue(${cond.label})) {\n`;
+
+        const oldCode = ctx.code;
+        ctx.code = "";
+
+        gen(ctx, ast.then);
         if (ctx.error) return;
-        return `if (bigInt(${condition}).neq(bigInt(0))) {\n${thenBody}\n} else {\n${elseBody}\n}\n`;
+
+        ctx.code = oldCode + utils.ident(ctx.code);
+
+        if (ast.else) {
+            ctx.code += "} else {\n";
+            const oldCode = ctx.code;
+            ctx.code = "";
+            gen(ctx, ast.else);
+            if (ctx.error) return;
+            ctx.code = oldCode + utils.ident(ctx.code);
+        }
+
+        ctx.code += "}\n";
+
     } else {
-        return `if (bigInt(${condition}).neq(bigInt(0))) {\n${thenBody}\n}\n`;
+        if (!utils.isDefined(cond.value)) return ctx.throwError(ast, "condition value not assigned");
+        if (!cond.value[0].isZero()) {
+            gen(ctx, ast.then);
+        } else {
+            if (ast.else) {
+                gen(ctx, ast.else);
+            }
+        }
     }
 }
 

@@ -17,5 +17,25 @@ lt(a, b) {
         return a.lt(b) ? bigInt(1) : bigInt(0);
     }
 
+    eq(a, b) {
+        return a.eq(b) ? bigInt(1) : bigInt(0);
+    }
+
+    gt(a, b) {
+        return a.gt(b) ? bigInt(1) : bigInt(0);
+    }
+
+    leq(a, b) {
+        return a.leq(b) ? bigInt(1) : bigInt(0);
+    }
+
+    geq(a, b) {
+        return a.geq(b) ? bigInt(1) : bigInt(0);
+    }
+
+    neq(a, b) {
+        return a.neq(b) ? bigInt(1) : bigInt(0);
+    }
+
 };
 

@@ -107,4 +107,26 @@ [{in: __P__.minus(2)}, {out: [__P__.minus(1), 4,  39]}],
             ]
         );
     });
+    it("if unrolled", async () => {
+        await doTest(
+            "ifunrolled.circom",
+            [
+                [{in: 0}, {out: [1, 3, 6]}],
+                [{in: 10}, {out: [11, 13, 16]}],
+                [{in: __P__.minus(2)}, {out: [__P__.minus(1), 1,  4]}],
+            ]
+        );
+    });
+    it("if rolled", async () => {
+        await doTest(
+            "ifrolled.circom",
+            [
+                [{in: 0}, {out: [1, 0, 0]}],
+                [{in: 1}, {out: [0, 1, 0]}],
+                [{in: 2}, {out: [0, 0, 1]}],
+                [{in: 3}, {out: [0, 0, 0]}],
+                [{in: __P__.minus(2)}, {out: [0,0,0]}],
+            ]
+        );
+    });
 });

@@ -0,0 +1,26 @@
+template Main() {
+    signal input in;
+    signal output out[3];
+
+    if (in == 0) {
+        out[0] <-- 1;         // TRUE
+    }
+    if (in != 0) {
+        out[0] <-- 0;
+    }
+
+    if (in ==  1) {
+        out[1] <-- 1;        // TRUE
+    } else {
+        out[1] <-- 0;
+    }
+
+    if (in == 2) {
+        out[2] <-- 1;
+    } else {
+        out[2] <-- 0;        // TRUE
+    }
+
+}
+
+component main = Main();

@@ -0,0 +1,31 @@
+
+
+template Main() {
+    signal input in;
+    signal output out[3];
+
+    var c = 1;
+    if (c == 1) {
+        out[0] <== in +1;         // TRUE
+    }
+    if (c == 0) {
+        out[0] <== in +2;
+    }
+
+    c = c +1;
+    if (c == 2) {
+        out[1] <== in + 3;        // TRUE
+    } else {
+        out[1] <== in + 4;
+    }
+
+    c = c +1;
+    if (c == 2) {
+        out[2] <== in + 5;
+    } else {
+        out[2] <== in + 6;        // TRUE
+    }
+
+}
+
+component main = Main();