support of operators

tests/operators2.ispc

@@ -0,0 +1,51 @@
+int off;
+
+export uniform int width() { return programCount; }
+
+struct S {
+    float a;
+};
+
+struct S operator+(struct S rr, struct S rv) {
+    struct S c;
+    c.a = rr.a / rv.a + 3;
+    if (off == 1)
+        c.a = 22;
+    return c;
+}
+
+struct S operator/(struct S rr, struct S rv) {
+    struct S c;
+    c.a = rr.a + rv.a + 10;
+    if (off == 1)
+        c.a = 33;
+    return c;
+}
+
+struct S a;
+struct S b;
+struct S d;
+
+export void f_f(uniform float RET[], uniform float aFOO[]) {
+    int T = programIndex;
+    a.a = aFOO[programIndex];
+    b.a = -aFOO[programIndex];
+    if (programIndex == 3)
+        off = 1;
+    else
+        off = 0;
+    if (T % 2)
+        d = a + b;
+    else
+        d = a / b;
+
+    RET[programIndex] = d.a;
+}
+
+export void result(uniform float RET[4]) {
+    if (programIndex % 2)
+        RET[programIndex] = 2;
+    else
+        RET[programIndex] = 10;
+    RET[3] = 22;
+}