Some small changes to reduce local variable count

diff --git a/mach/i86/ncg/mach.c b/mach/i86/ncg/mach.c
index 82e10ab..bc2995d 100644 (file)
--- a/mach/i86/ncg/mach.c
+++ b/mach/i86/ncg/mach.c
@@ -57,9 +57,16 @@ string holstr(n) word n; {
 }
 */
 
+#ifdef REGVARS
+full lbytes;
+#endif
+
 prolog(nlocals) full nlocals; {
 
        fputs("\tpush\tbp\n\tmov\tbp,sp\n", codefile);
+#ifdef REGVARS
+       lbytes = nlocals;
+#else
        switch (nlocals) {
        case 4: fputs("\tpush\tax\n", codefile);
        case 2: fputs("\tpush\tax\n", codefile);
@@ -67,6 +74,7 @@ prolog(nlocals) full nlocals; {
        default:
                fprintf(codefile, "\tsub\tsp,%d\n",nlocals); break;
        }
+#endif
 }
 
 #ifdef REGVARS
@@ -95,6 +103,28 @@ i_regsave()
 
 f_regsave()
 {
+       if (di_off == -lbytes) lbytes -= 2;
+       if (si_off == -lbytes) lbytes -= 2;
+       if (di_off == -lbytes) lbytes -= 2;
+       switch (lbytes) {
+       case 4: fputs("\tpush\tax\n", codefile);
+       case 2: fputs("\tpush\tax\n", codefile);
+       case 0: break;
+       default:
+               fprintf(codefile, "\tsub\tsp,%d\n",lbytes); break;
+       }
+       if (firstreg == 1) {
+               fputs("push di\n", codefile);
+               if (si_off != -1) fputs("push si\n", codefile);
+       }
+       else if (firstreg == -1) {
+               fputs("push si\n", codefile);
+               if (di_off != -1) fputs("push di\n", codefile);
+       }
+       if (di_off >= 0)
+               fprintf(codefile, "mov di,%ld(bp)\n", di_off);
+       if (si_off >= 0)
+               fprintf(codefile, "mov si,%ld(bp)\n", si_off);
 }
 
 regsave(regstr, off, size)
@@ -104,16 +134,10 @@ regsave(regstr, off, size)
        if (strcmp(regstr, "si") == 0) {
                if (! firstreg) firstreg = -1;
                si_off = off;
-               fputs("push si\n", codefile);
-               if (off >= 0)
-                       fprintf(codefile, "mov si,%ld(bp)\n", off);
        }
        else {
                if (! firstreg) firstreg = 1;
                di_off = off;
-               fputs("push di\n", codefile);
-               if (off >= 0)
-                       fprintf(codefile, "mov di,%ld(bp)\n", off);
        }
 }
 

diff --git a/mach/i86/ncg/table b/mach/i86/ncg/table
index aa7f365..e87c79e 100644 (file)
--- a/mach/i86/ncg/table
+++ b/mach/i86/ncg/table
@@ -402,6 +402,10 @@ from rmorconst
 from Xreg_off
   gen add %1.reg,{CONSTR,%1.off}       yields %1.reg
 
+from halfindir
+  uses reusing %1,ADDREG
+  gen move %1,%a                       yields %a
+
 from halfindir
   uses reusing %1,REG
   gen move %1,%a                       yields %a