X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=device%2Flib%2F_moduint.c;h=221dea74c6da04d1f94f5c3d47d0672c49cb2e6c;hb=2f6182c2e008dfe9d1ce2f4c3037b2638021f4db;hp=fa56e15ccb7be2271265a563d6f337365599b6fb;hpb=c629d2f5c76ed1e47ad9fc28127dcbe9552664ed;p=fw%2Fsdcc

diff --git a/device/lib/_moduint.c b/device/lib/_moduint.c
index fa56e15c..221dea74 100644
--- a/device/lib/_moduint.c
+++ b/device/lib/_moduint.c
@@ -1,5 +1,4 @@
 /*-------------------------------------------------------------------------
-
   _moduint.c :- routine for unsigned int (16 bit) modulus
 
              Written By -  Sandeep Dutta . sandeep.dutta@usa.net (1999)
@@ -10,44 +9,189 @@
    under the terms of the GNU Library General Public License as published by the
    Free Software Foundation; either version 2, or (at your option) any
    later version.
-   
+
    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Library General Public License for more details.
-   
+
    You should have received a copy of the GNU Library General Public License
    along with this program; if not, write to the Free Software
    Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-   
+
    In other words, you are welcome to use, share and improve this program.
    You are forbidden to forbid anyone else to use, share and improve
-   what you give them.   Help stamp out software-hoarding!  
+   what you give them.   Help stamp out software-hoarding!
 -------------------------------------------------------------------------*/
 
+/*   Assembler-functions are provided for:
+     mcs51 small
+     mcs51 small stack-auto
+*/
+
+#if !defined(SDCC_USE_XSTACK) && !defined(_SDCC_NO_ASM_LIB_FUNCS)
+#  if defined(SDCC_mcs51)
+#    if defined(SDCC_MODEL_SMALL)
+#      if defined(SDCC_STACK_AUTO)
+#        define _MODUINT_ASM_SMALL_AUTO
+#      else
+#        define _MODUINT_ASM_SMALL
+#      endif
+#    endif
+#  endif
+#endif
+
+#if defined _MODUINT_ASM_SMALL || defined _MODUINT_ASM_SMALL_AUTO
+
+static void
+_moduint_dummy (void) _naked
+{
+	_asm
+
+		.globl __moduint
+
+	__moduint:
+
+		#define count   r2
+		#define al      dpl
+		#define ah      dph
+
+#if defined(SDCC_STACK_AUTO) && !defined(SDCC_PARMS_IN_BANK1)
+
+		ar0 = 0			; BUG register set is not considered
+		ar1 = 1
+
+		.globl __modint
+
+		mov	a,sp
+		add	a,#-2		; 2 bytes return address
+		mov	r0,a		; r0 points to bh
+		mov	ar1,@r0		; load bh
+		dec	r0
+		mov	ar0,@r0		; load bl
+
+		#define bl      r0
+		#define bh      r1
+
+	__modint:			; entry point for __modsint
+
+
+#else // SDCC_STACK_AUTO
+
+#if !defined(SDCC_PARMS_IN_BANK1)
+#if defined(SDCC_NOOVERLAY)
+		.area DSEG    (DATA)
+#else
+		.area OSEG    (OVR,DATA)
+#endif
+
+		.globl __moduint_PARM_2
+		.globl __modsint_PARM_2
+
+	__moduint_PARM_2:
+	__modsint_PARM_2:
+		.ds	2
+
+		.area CSEG    (CODE)
+
+		#define bl      (__moduint_PARM_2)
+		#define bh      (__moduint_PARM_2 + 1)
+#else
+		#define bl      (b1_0)
+		#define bh      (b1_1)
+#endif
+#endif // SDCC_STACK_AUTO
+
+		mov	a,bl		; avoid endless loop
+		orl	a,bh
+		jz	div_by_0
+
+		mov	count,#1
+
+	loop1:	mov	a,bl		; b <<= 1
+		add	a,acc
+		mov	bl,a
+		mov	a,bh
+		rlc	a
+		jc	msbset
+		mov	bh,a
+
+		mov	a,al		; a - b
+		subb	a,bl		; here carry is always clear
+		mov	a,ah
+		subb	a,bh
+
+		jc	start
+
+		inc	count
+		sjmp	loop1
+
+
+	start:	clr	c
+		mov	a,bh		; b >>= 1;
+	msbset:	rrc	a
+		mov	bh,a
+		mov	a,bl
+		rrc	a
+		mov	bl,a
+
+
+	loop2:	clr	c
+		mov	a,al		; a - b
+		subb	a,bl
+
+		mov	b,a
+		mov	a,ah
+		subb	a,bh
+
+		jc	smaller		; a >= b?
+
+		mov	ah,a		; -> yes;  a = a - b;
+		mov	al,b
+	smaller:			; -> no
+		clr	c
+		mov	a,bh		; b >>= 1;
+		rrc	a
+		mov	bh,a
+		mov	a,bl
+		rrc	a
+		mov	bl,a
+
+		djnz	count,loop2
+	div_by_0:
+		ret
+
+	_endasm ;
+}
+
+#else  // defined _MODUINT_ASM_SMALL || defined _MODUINT_ASM_SMALL_AUTO
+
 #define MSB_SET(x) ((x >> (8*sizeof(x)-1)) & 1) 
 
-unsigned int  _moduint (unsigned int a ,unsigned int b)
+unsigned int
+_moduint (unsigned int a, unsigned int b)
 {
-    unsigned char count = 0;
+  unsigned char count = 0;
     
     
-        while (!MSB_SET(b)) {
-		b <<= 1;
-		if (b > a)
-		{
-		  b >>=1;
-		  break;
-		}
-		count++;
-	}
-
-        do {
-		if (b <= a) {
-		  a -= b;
-		}
-		b >>= 1;
-	} while (count--);
-
-    return a;
+  while (!MSB_SET(b))
+  {
+    b <<= 1;
+    if (b > a)
+    {
+      b >>=1;
+      break;
+    }
+    count++;
+  }
+  do
+  {
+    if (a >= b)
+      a -= b;
+    b >>= 1;
+  }
+  while (count--);
+  return a;
 }
+
+#endif  // defined _MODUINT_ASM_SMALL || defined _MODUINT_ASM_SMALL_AUTO