shithub: mc

Info  •  Files  •  Log  •  Branches

Load the return value into the return register.

    We never did this in the epilogue. That's a bad thing.

--- a/8/Makefile

+++ b/8/Makefile

@@ -8,8 +8,5 @@

 LDFLAGS+=-L../parse -lparse

 EXTRADEP=../parse/libparse.a

-../libparse.a:

-	make -C ../parse

-

 include ../mk/lexyacc.mk

 include ../mk/c.mk

--- a/8/gen.h

+++ b/8/gen.h

@@ -20,10 +20,11 @@

 struct Fn {

     char *name; /* assembly name; mangled */

     int isglobl;

-    

+

     /* filled in by the lowering process */

     size_t stksz;

     Htab *locs;

+    Node *ret;

     Htab *bbnames; /* char* => Bb* map */

     Bb *start;

--- a/8/isel.c

+++ b/8/isel.c

@@ -19,6 +19,7 @@

 struct Isel {

     Insn **il;

     size_t ni;

+    Node *ret;

     Htab *locs; /* Node => int stkoff */

 };

@@ -502,13 +503,15 @@

 void epilogue(Isel *s)

 {

-    Loc esp;

-    Loc ebp;

-    Loc stksz;

+    Loc esp, ebp, eax;

+    Loc ret;

     locreg(&esp, Resp);

     locreg(&ebp, Rebp);

-    loclit(&stksz, 16);

+    locreg(&eax, Reax);

+    ret = loc(s, s->ret);

+    if (s->ret)

+      g(s, Imov, &ret, &eax, NULL);

     g(s, Imov, &ebp, &esp, NULL);

     g(s, Ipop, &ebp, NULL);

 }

@@ -522,6 +525,7 @@

     int i;

     is.locs = fn->locs;

+    is.ret = fn->ret;

     prologue(&is, fn->stksz);

     for (i = 0; i < fn->nn; i++)

--- a/8/reduce.c

+++ b/8/reduce.c

@@ -278,7 +278,11 @@

             break;

         case Oret:

             if (n->expr.args[0]) {

-                t = storetmp(s, simp(s, n->expr.args[0]));

+                if (s->fn->ret)

+                    t = s->fn->ret;

+                else

+                    t = s->fn->ret = temp(s, args[0]);

+                t = store(t, simp(s, args[0]));

                 append(s, t);

             }

             jmp(s, s->endlbl);