/*-------------------------------------------------------------------------
-
_divuint.c :- routine for unsigned int (16 bit) division
Ecrit par - Jean-Louis Vern . jlvern@writeme.com (1999)
- This program is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by the
+ This library is free software; you can redistribute it and/or modify it
+ 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 program is distributed in the hope that it will be useful,
+
+ 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 General Public License for more details.
-
- You should have received a copy of the GNU General Public License
+ 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 _DIVUINT_ASM_SMALL_AUTO
+# else
+# define _DIVUINT_ASM_SMALL
+# endif
+# endif
+# endif
+#endif
+
+#if defined _DIVUINT_ASM_SMALL || defined _DIVUINT_ASM_SMALL_AUTO
+
+static void
+_divuint_dummy (void) _naked
+{
+ _asm
+
+ .globl __divuint
+
+ __divuint:
+
+ #define count r2
+ #define reste_l r3
+ #define reste_h r4
+ #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 __divint
+
+ 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
+
+ __divint: ; entry point for __divsint
+
+
+#else // SDCC_STACK_AUTO
+
+#if !defined(SDCC_PARMS_IN_BANK1)
+#if defined(SDCC_NOOVERLAY)
+ .area DSEG (DATA)
+#else
+ .area OSEG (OVR,DATA)
+#endif
+
+ .globl __divuint_PARM_2
+ .globl __divsint_PARM_2
+
+ __divuint_PARM_2:
+ __divsint_PARM_2:
+ .ds 2
+
+ .area CSEG (CODE)
+#endif // !SDCC_PARMS_IN_BANK1
+#if defined(SDCC_PARMS_IN_BANK1)
+ #define bl (b1_0)
+ #define bh (b1_1)
+#else
+ #define bl (__divuint_PARM_2)
+ #define bh (__divuint_PARM_2 + 1)
+#endif // SDCC_PARMS_IN_BANK1
+#endif // SDCC_STACK_AUTO
+
+ mov count,#16
+ clr a
+ mov reste_l,a
+ mov reste_h,a
+
+ loop: mov a,al ; a <<= 1
+ add a,acc
+ mov al,a
+ mov a,ah
+ rlc a
+ mov ah,a
+
+ mov a,reste_l ; reste <<= 1
+ rlc a ; feed in carry
+ mov reste_l,a
+ mov a,reste_h
+ rlc a
+ mov reste_h,a
+
+ mov a,reste_l ; reste - b
+ subb a,bl ; here carry is always clear, because
+ ; reste <<= 1 never overflows
+ mov b,a
+ mov a,reste_h
+ subb a,bh
+
+ jc smaller ; reste >= b?
+
+ mov reste_h,a ; -> yes; reste = reste - b;
+ mov reste_l,b
+ orl al,#1
+ smaller: ; -> no
+ djnz count,loop
+ ret
+
+ _endasm ;
+}
+
+#else // defined _DIVUINT_ASM_SMALL || defined _DIVUINT_ASM_SMALL_AUTO
+
#define MSB_SET(x) ((x >> (8*sizeof(x)-1)) & 1)
-unsigned int _divuint (unsigned int a, unsigned int b)
+unsigned int
+_divuint (unsigned int a, unsigned int b)
{
- unsigned int reste = 0 ;
- unsigned char count = 16;
- bit c;
-
- do{
- // reste:a <- 0;
- c = MSB_SET(a);
- a <<= 1;
- reste <<= 1;
- if(c)
- reste |= 1;
-
- if(reste >= b){
- reste -= b;
- // a <- (result = 1)
- a |= 1;
- }
- } while(--count);
-
- return a;
+ unsigned int reste = 0;
+ unsigned char count = 16;
+ #if defined(SDCC_STACK_AUTO) || defined(SDCC_z80)
+ char c;
+ #else
+ bit c;
+ #endif
+
+ do
+ {
+ // reste: a <- 0;
+ c = MSB_SET(a);
+ a <<= 1;
+ reste <<= 1;
+ if (c)
+ reste |= 1;
+
+ if (reste >= b)
+ {
+ reste -= b;
+ // a <- (result = 1)
+ a |= 1;
+ }
+ }
+ while (--count);
+ return a;
}
+
+#endif // defined _DIVUINT_ASM_SMALL || defined _DIVUINT_ASM_SMALL_AUTO