From 6580bb08ba4e5e14045e5b914a9bd1f5ef9d22db Mon Sep 17 00:00:00 2001
From: Mathieu Maret <mathieu.maret@gmail.com>
Date: Tue, 21 Mar 2023 23:18:47 +0100
Subject: [PATCH] tinyc : add > support

Also can be run several time
---
 userspace/tiny.c | 41 +++++++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 14 deletions(-)

diff --git a/userspace/tiny.c b/userspace/tiny.c
index 2263595..e475780 100644
--- a/userspace/tiny.c
+++ b/userspace/tiny.c
@@ -23,7 +23,7 @@
  *                  ";"
  *  <paren_expr> ::= "(" <expr> ")"
  *  <expr> ::= <test> | <id> "=" <expr>
- *  <test> ::= <sum> | <sum> "<" <sum>
+ *  <test> ::= <sum> | <sum> "<" <sum> | <sum> ">" <sum>
  *  <sum> ::= <term> | <sum> "+" <term> | <sum> "-" <term>
  *  <term> ::= <id> | <int> | <paren_expr>
  *  <id> ::= "a" | "b" | "c" | "d" | ... | "z"
@@ -58,7 +58,7 @@
 /* Lexer. */
 
 enum { DO_SYM, ELSE_SYM, IF_SYM, WHILE_SYM, LBRA, RBRA, LPAR, RPAR,
-       PLUS, MINUS, LESS, SEMI, EQUAL, INT, ID, EOI };
+       PLUS, MINUS, LESS, MORE, SEMI, EQUAL, INT, ID, EOI };
 
 char *words[] = { "do", "else", "if", "while", NULL };
 
@@ -82,6 +82,7 @@ void next_sym()
       case '+': next_ch(); sym = PLUS; break;
       case '-': next_ch(); sym = MINUS; break;
       case '<': next_ch(); sym = LESS; break;
+      case '>': next_ch(); sym = MORE; break;
       case ';': next_ch(); sym = SEMI; break;
       case '=': next_ch(); sym = EQUAL; break;
       default:
@@ -115,7 +116,7 @@ void next_sym()
 
 /* Parser. */
 
-enum { VAR, CST, ADD, SUB, LT, SET,
+enum { VAR, CST, ADD, SUB, LT, MT, SET,
        IF1, IF2, WHILE, DO, EMPTY, SEQ, EXPR, PROG };
 
 struct node { int kind; struct node *o1, *o2, *o3; int val; };
@@ -141,10 +142,12 @@ node *sum()  /* <sum> ::= <term> | <sum> "+" <term> | <sum> "-" <term> */
   return x;
 }
 
-node *test()  /* <test> ::= <sum> | <sum> "<" <sum> */
+node *test()  /* <test> ::= <sum> | <sum> "<" <sum> | <sum> ">" <sum> */
 { node *t, *x = sum();
   if (sym == LESS)
     { t=x; x=new_node(LT); next_sym(); x->o1=t; x->o2=sum(); }
+  else if (sym == MORE)
+    { t=x; x=new_node(MT); next_sym(); x->o1=t; x->o2=sum(); }
   return x;
 }
 
@@ -219,7 +222,7 @@ node *program()  /* <program> ::= <statement> */
 
 /* Code generator. */
 
-enum { IFETCH, ISTORE, IPUSH, IPOP, IADD, ISUB, ILT, JZ, JNZ, JMP, HALT };
+enum { IFETCH, ISTORE, IPUSH, IPOP, IADD, ISUB, ILT, IMT, JZ, JNZ, JMP, HALT };
 
 typedef char code;
 code object[1000], *here = object;
@@ -236,6 +239,7 @@ void c(node *x)
       case ADD  : c(x->o1); c(x->o2); g(IADD); break;
       case SUB  : c(x->o1); c(x->o2); g(ISUB); break;
       case LT   : c(x->o1); c(x->o2); g(ILT); break;
+      case MT   : c(x->o1); c(x->o2); g(IMT); break;
       case SET  : c(x->o2); g(ISTORE); g(x->o1->val); break;
       case IF1  : c(x->o1); g(JZ); p1=hole(); c(x->o2); fix(p1,here); break;
       case IF2  : c(x->o1); g(JZ); p1=hole(); c(x->o2); g(JMP); p2=hole();
@@ -267,6 +271,7 @@ void run()
       case IADD  : sp[-2] = sp[-2] + sp[-1]; --sp;       goto again;
       case ISUB  : sp[-2] = sp[-2] - sp[-1]; --sp;       goto again;
       case ILT   : sp[-2] = sp[-2] < sp[-1]; --sp;       goto again;
+      case IMT   : sp[-2] = sp[-2] > sp[-1]; --sp;       goto again;
       case JMP   : pc += *pc;                            goto again;
       case JZ    : if (*--sp == 0) pc += *pc; else pc++; goto again;
       case JNZ   : if (*--sp != 0) pc += *pc; else pc++; goto again;
@@ -278,17 +283,25 @@ void run()
 /* Main program. */
 
 int func_tiny()
-{ int i;
+{
+    int i;
+    ch      = ' ';
+    sym     = 0;
+    int_val = 0;
+    memset(id_name, 0, sizeof(id_name));
+    memset(globals, 0, sizeof(globals));
+    memset(object, 0, sizeof(object));
+    here = object;
 
-  c(program());
+    c(program());
 
-  for (i=0; i<26; i++)
-    globals[i] = 0;
-  run();
-  for (i=0; i<26; i++)
-    if (globals[i] != 0)
-      printf("%c = %d\n", 'a'+i, globals[i]);
+    for (i = 0; i < 26; i++)
+        globals[i] = 0;
+    run();
+    for (i = 0; i < 26; i++)
+        if (globals[i] != 0)
+            printf("%c = %d\n", 'a' + i, globals[i]);
 
-  return 0;
+    return 0;
 }