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--- sd:tinyc_developer_diary [2026/04/20 04:09] – appledog
+++ sd:tinyc_developer_diary [2026/04/22 17:14] (current) – appledog
@@ Line 822: / Line 822: @@
 At this point I am very close to just rewriting the symbol table to be 32 bit. I mean this is already an insane asylum as it is, but, how hard could rewriting the emitters possibly be? :)
+== Rewriting the symbol table
+Unfortunately the symbol table had to be rewritten and all the emitters. This is not as bad as it sounds but it required a complete review. The good thing is I had a register map, where I used certain registers for certain things as a convention, or this would have been impossible. I will be sure to mention register conventions/register maps in an upcoming tutorial.
+. In every place where the symbol table was written or read, make sure a pointer (GLK) is used. Previously, A was used for this. This wasn't too bad because sym is a marker for symbol table functions.
+. In parse function, emit_call, anything to do with backpatching, etc. we need to make sure we are using a three byte value.
+. Anything which touches HERE or offset 18 of the symbol table. This is an easy search for ex. LDA [@HERE].
+It took a couple of hours. As I ran through various tests it struck me that there are a series of tests I went through a couple of times before to verify things work. As I ran through them again I had the insight to write them down.
+=== TinyC Test programs
+These provide the test cases I used to check my compiler. In order.
+==== First
+<code>
+int main(void) { return 0; }
+</code>
+==== Symbol table
+<code>
+int main(void) { int a = 5; return a; }
+</code>
+bit:
+<code>
+.clear
+int main(void) {
+    int a = 0x123456;
+    return a;
+}
+.compile
+.run
+</code>
+==== Globals
+We can't define them when we make them. It seems like I did something wrong here but I don't know how to fix it. Just define them in main. Whoop de doo.
+<code>
+int g;
+int main(void) {
+    g = 42;
+    return g;
+}
+</code>
+==== function call
+<code>
+int a(int x) { return x + 1; }
+int main(void) { return a(41); }
+</code>
+two arguments:
+<code>
+.clear
+int add(int a, int b) { return a + b; }
+int main(void) { return add(20, 22); }
+.compile
+.run
+</code>
+==== Forward Declarations
+Single
+<code>
+int a(int x);
+int main(void) { return a(41); }
+int helper(int x) { return x + 1; }
+</code>
+multiple
+<code>
+int a();
+int main(void) {
+    return a() + a();
+}
+int a() { return 5; }
+</code>
+==== Recursion
+<code>
+int even(int n);
+int odd(int n);
+int even(int n) { if (n == 0) { return 1; } return odd(n - 1); }
+int odd(int n) { if (n == 0) { return 0; } return even(n - 1); }
+int main(void) { return even(10); }
+</code>
+==== Built-in functions
+<code>
+int main(void) {
+    putchar('h');
+    putchar('i');
+    return 0;
+}
+</code>
+=== Re-wiring pointers
+Unfortunately the changes were far more in depth than I expected, and I had to spend an additional ten hours going over the code to fix pointers, the lexer, and everything in between. Oh, and yet more emitters I forgot needed to be changed. Even the REPL itself didn't print out the full return value. This makes me reconsider my choice to go with a 16 bit system. Should the SD-8516 have been 32 bit? Maybe, maybe not. In the end, it works. A 16 bit system can run a 32 bit c, no problem. I mean, look at Commodore BASIC 2.0. It used floats for ints. Steve Wozniak even made a Sweet-16 so that it could use 16 bit registers. We can do 32 bit in the languages. No problem. We are not going to get any practical advantage from going 32 bit internal since we're running on WASM which is 64 bit native anyways. See? We can have our cake and eat it too here.