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Waste less space in unions.

--- a/6/asm.h

+++ b/6/asm.h

@@ -1,4 +1,5 @@

 #define Maxarg 4        /* maximum number of args an insn can have */

+#define Wordsz 4        /* the size of a "natural int" */

 #define Ptrsz 8         /* the size of a machine word (ie, pointer size) */

 #define K 14            /* the number of allocatable registers */

--- a/6/simp.c

+++ b/6/simp.c

@@ -54,6 +54,7 @@

 /* useful constants */

 static Type *tyintptr;

+static Type *tyword;

 static Type *tyvoid;

 static Type *base(Type *t)

@@ -151,6 +152,15 @@

     return n;

 }

+static Node *word(int line, uint v)

+{

+    Node *n;

+

+    n = mkintlit(line, v);

+    n->expr.type = tyword;

+    return n;

+}

+

 static size_t did(Node *n)

 {

     if (n->type == Ndecl) {

@@ -435,10 +445,10 @@

     Ucon *uc;

     if (exprop(n) != Ocons)

-        return load(add(addr(n, tyintptr), disp(n->line, off)));

+        return load(addk(addr(n, mkty(n->line, Tyuint)), off));

     uc = finducon(n);

-    return disp(uc->line, uc->id);

+    return word(uc->line, uc->id);

 }

 static Node *uval(Node *n, size_t off, Type *t)

@@ -486,7 +496,7 @@

             r = mkexpr(a->line, Oeq, x, y, NULL);

             r->expr.type = tyintptr;

             if (uc->etype) {

-                off += Ptrsz;

+                off += Wordsz;

                 v = ucompare(s, a, b, uc->etype, off);

                 r = mkexpr(a->line, Oland, r, v, NULL);

                 r->expr.type = tyintptr;

@@ -910,14 +920,19 @@

         tmp = dst;

     else

         tmp = temp(s, n);

-    u = addr(tmp, exprtype(n));

-    tag = disp(n->line, uc->id);

+

+    /* Set the tag on the ucon */

+    u = addr(tmp, mkty(n->line, Tyuint));

+    tag = mkintlit(n->line, uc->id);

+    tag->expr.type = mkty(n->line, Tyuint);

     append(s, store(u, tag));

+

+

+    /* fill the value, if needed */

     if (!uc->etype)

         return tmp;

-

     elt = rval(s, n->expr.args[1], NULL);

-    u = addk(u, Ptrsz);

+    u = addk(u, Wordsz);

     if (stacktype(uc->etype)) {

         elt = addr(elt, uc->etype);

         sz = disp(n->line, tysize(uc->utype));

@@ -1300,6 +1315,7 @@

     /* declare useful constants */

     tyintptr = mkty(-1, Tyuint64);

+    tyword = mkty(-1, Tyuint);

     tyvoid = mkty(-1, Tyvoid);

     fn = NULL;