--- a/mc-codegen.c	Thu Jan 26 15:19:55 2006 +0900
+++ b/mc-codegen.c	Thu Jan 26 21:12:47 2006 +0900
@@ -3378,11 +3378,11 @@
 NMTBL str_ret;
 
 /*
-    If function has structure return value, it has an extra
-    argument for where to write the structure. It have to be
-    a first argument. We add it here and we have to fix all arguments'
-    offset. If it is the last value, we don't have to fix, but
-    gcc has a first argument convention.
+    If function has a structure return value, it has an extra
+    argument for where to write the structure. It has to be
+    the first argument. We add the argument here and we have 
+    to fix all arguments' offset. If this is the last value, 
+    we don't have to fix, but gcc has a first argument convention.
  */
 
 extern void
@@ -3398,7 +3398,7 @@
 	mode=ADECL;
 	type_save = type;
 	/* extra argument for struct return */
-	/* this extra dummy arguments are set at calling sequence */
+	/* This dummy variable is set in the calling sequence */
 	str_ret.nm = "str_ret"; str_ret.sc = EMPTY;
 	str_ret.dsp = 0; str_ret.ty = 0;
 	type=list2(POINTER,t);
@@ -3480,12 +3480,18 @@
         t==UCHAR||t==SHORT||t==USHORT||t==ENUM);
 }
 
+/*
+    Delayed jmp code generation. A jump code will be delayed until
+    new code generation or new label. If label is equal the jumped
+    label, no jump code is necesarry.
+ */
+
 extern void
 checkjmp(int l)
 {
     int p = pending_jmp;
-    pending_jmp = 0;
     if (p) {
+	pending_jmp = 0;
 	if (p!=l) {
 	    control=0;
 	    if (!chk)
@@ -3494,6 +3500,12 @@
     }
 }
 
+/*
+    Delayed jmp code to function leaveing part. The lastexp in
+    a statement expression is also checked. It also handle the
+    first case statement jump in switch statement.
+ */
+
 extern void
 checkret(void)
 {
@@ -3521,6 +3533,10 @@
     }
 }
 
+/*
+    In casading call of struct valued function, an argument for
+    return position will be replaced by calling function.
+ */
 
 extern void
 replace_return_struct(int func,int left) {
@@ -3531,7 +3547,7 @@
 }
 
 
-/* right value , get the value of the variable */
+/* indirect right value , get the value of the variable */
 
 static int
 indirect(int t,int e1,int type)
@@ -3550,6 +3566,10 @@
     return list4(t,e1,offset,type);
 }
 
+/*
+    make right value from original left value.
+    type will be changed.
+ */
 extern int
 rvalue(int e)
 {
@@ -3623,6 +3643,9 @@
     }
 }
 
+/*
+    right value with preserving type global variable
+ */
 extern int
 rvalue_t(int e,int t)
 {
@@ -3633,6 +3656,9 @@
     return e;
 }
 
+/*
+    left value check. Can we assign a value to it?
+ */
 extern void
 lcheck(int e)
 {
@@ -3653,6 +3679,9 @@
 	error(LVERR);
 }
 
+/*
+    Indirect operator.
+ */
 extern int
 indop(int e)
 {
@@ -3670,7 +3699,7 @@
     return(list2(INDIRECT,e));
 }
 
-/* filed name search */
+/* struct field name search */
 
     /* type = list4(s,disp,fields,tag_nptr); */
 
@@ -3693,6 +3722,11 @@
     return 0;
 }
 
+/*
+    Structure operation 
+    a.b, a->b
+ */
+
 extern int
 strop(int e,int ind)
 {
@@ -3743,6 +3777,9 @@
 }
 
 /*
+
+    Binary operator parse tree generation (and optimization)
+
    I don't know how to handle type attribute (const/volatie) in binop
  */
 
@@ -4312,6 +4349,9 @@
     return e;
 }
 
+/*
+    Integer Constant expression is required
+ */
 
 extern int
 cexpr(int e)
@@ -4459,18 +4499,23 @@
 {
     disp-=sz;
 #if 1
-    if (sz>=4 && (disp & (4-1))) {
+    if (sz>=4 && (disp & (4-1))) { // alignment
 	disp &= ~(4-1);
     }
 #endif
     return disp;
 }
 
+/*
+    Allocate new local variable in flat scope
+ */
+
 extern int
 new_lvar(int size)
 {
     int lvar,plvar;
 
+    /* Can we reuse previously freed local variable? */ 
     for (plvar = 0,lvar = lvar_free_list;lvar;lvar = cadr(lvar)) {
         if (caddr(lvar)==size) {
             if (plvar) cadr(plvar) = cadr(lvar);
@@ -4488,6 +4533,10 @@
     return lvar;
 }
 
+/*
+    Free the allocated local variable. 	It may be reused again.
+ */
+
 extern void
 free_lvar(int disp)
 {
@@ -4604,6 +4653,8 @@
 
 /* 
     global name pointer cache
+	global pointer needs dynamic loading or table.
+	it may used again, put it to a register as a cache.
  */
 
 extern void