* minor size optimizations in chario.c, dosfns.c;

asmsupt.asm: correct fmemchr (all n's) and *memset/*memcpy (n==0)


git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@590 6ac86273-5f31-0410-b378-82cca8765d1b

kernel/asmsupt.asm

@@ -119,6 +119,7 @@ domemcpy:
                 ; And do the built-in byte copy, but do a 16-bit transfer
                 ; whenever possible.
                 shr     cx,1
+		jcxz	memcpy_return
                 rep     movsw
                 jnc     memcpy_return
                 movsb
@@ -183,6 +184,7 @@ domemset:
                 mov	ah, al
 
                 shr	cx,1
+                jcxz	pascal_return
                 rep     stosw
                 jnc     pascal_return
                 stosb
@@ -391,11 +393,11 @@ FMEMCHR:
 
 		mov bl, 8
 
+		jcxz strchr_retzero
                 repne scasb
                 jne strchr_retzero
                 mov dx, es
                 mov ax, di
-                dec ax
                 jmp short strchr_found1
 
 ;**********************************************************************

kernel/chario.c

@@ -218,6 +218,7 @@ STATIC int raw_put_char(int sft_idx, int c)
 STATIC int cooked_put_char(int sft_idx, int c)
 {
   int err = 0;
+  unsigned char scrpos = scr_pos;
   
   /* Test for hold char */
   con_hold(sft_idx);
@@ -225,23 +226,24 @@ STATIC int cooked_put_char(int sft_idx, int c)
   switch (c)
   {
     case CR:
-      scr_pos = 0;
+      scrpos = 0;
       break;
     case LF:
     case BELL:
       break;
     case BS:
-      if (scr_pos > 0)
-        scr_pos--;
+      if (scrpos > 0)
+        scrpos--;
       break;
     case HT:
       do
         err = raw_put_char(sft_idx, ' ');
-      while (err >= 0 && ((++scr_pos) & 7));
+      while (err >= 0 && ((++scrpos) & 7));
       break;
     default:
-      scr_pos++;
+      scrpos++;
   }
+  scr_pos = scrpos;
   if (c != HT)
     err = raw_put_char(sft_idx, c);
   return err;

kernel/dosfns.c

@@ -239,23 +239,25 @@ long DosRWSft(int sft_idx, size_t n, void FAR * bp, int mode)
       {
         size_t cnt = (size_t)rc;
         const char FAR *p = bp;
+        unsigned char scrpos = scr_pos;
         while (cnt--)
         {
           switch (*p++)
           {
           case CR:
-            scr_pos = 0;
+            scrpos = 0;
             break;
           case LF:
           case BELL:
             break;
           case BS:
-            --scr_pos;
+            --scrpos;
             break;
           default:
-            ++scr_pos;
+            ++scrpos;
           }
         }
+        scr_pos = scrpos;
       }
       return rc;
     }
@@ -398,14 +400,9 @@ ULONG DosSeek(unsigned hndl, LONG new_pos, COUNT mode)
 STATIC long get_free_hndl(void)
 {
   psp FAR *p = MK_FP(cu_psp, 0);
-  unsigned hndl;
-
-  for (hndl = 0; hndl < p->ps_maxfiles; hndl++)
-  {
-    if (p->ps_filetab[hndl] == 0xff)
-      return hndl;
-  }
-  return DE_TOOMANY;
+  UBYTE FAR *q = p->ps_filetab;
+  UBYTE FAR *r = fmemchr(q, 0xff, p->ps_maxfiles);
+  return FP_OFF(r) == 0 ? DE_TOOMANY : r - q;
 }
 
 STATIC sft FAR *get_free_sft(COUNT * sft_idx)
@@ -442,18 +439,19 @@ STATIC sft FAR *get_free_sft(COUNT * sft_idx)
 const char FAR *get_root(const char FAR * fname)
 {
   /* find the end                                 */
-  register unsigned length = fstrlen(fname) - 1;
+  register unsigned length = fstrlen(fname);
   char c;
 
   /* now back up to first path seperator or start */
-  while (length != (unsigned)-1)
+  fname += length;
+  while (length)
   {
-    c = fname[length];
+    length--;
+    c = *--fname;
     if (c == '/' || c == '\\' || c == ':')
       break;
-    --length;
   }
-  return fname + length + 1;
+  return fname;
 }
 
 /* initialize SFT fields (for open/creat) for character devices */