mcs51 small stack-auto
*/
+#include <stdbool.h>
+
#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)
+# if defined(SDCC_STACK_AUTO) && !defined(SDCC_PARMS_IN_BANK1)
# define _DIVULONG_ASM_SMALL_AUTO
# else
# define _DIVULONG_ASM_SMALL
#define count r2
- #define a0 dpl
- #define a1 dph
- #define a2 b
- #define a3 r3
+ #define x0 dpl
+ #define x1 dph
+ #define x2 b
+ #define x3 r3
#define reste0 r4
#define reste1 r5
#define reste2 r6
#define reste3 r7
+#if !defined(SDCC_PARMS_IN_BANK1)
#if defined(SDCC_NOOVERLAY)
.area DSEG (DATA)
.area CSEG (CODE)
- #define b0 (__divulong_PARM_2)
- #define b1 (__divulong_PARM_2 + 1)
- #define b2 (__divulong_PARM_2 + 2)
- #define b3 (__divulong_PARM_2 + 3)
-
- ; parameter a comes in a, b, dph, dpl
- mov a3,a ; save parameter a3
+ #define y0 (__divulong_PARM_2)
+ #define y1 (__divulong_PARM_2 + 1)
+ #define y2 (__divulong_PARM_2 + 2)
+ #define y3 (__divulong_PARM_2 + 3)
+#else
+ #define y0 (b1_0)
+ #define y1 (b1_1)
+ #define y2 (b1_2)
+ #define y3 (b1_3)
+#endif // !SDCC_PARMS_IN_BANK1
+ ; parameter x comes in a, b, dph, dpl
+ mov x3,a ; save parameter x3
mov count,#32
clr a
; optimization loop in lp0 until the first bit is shifted into rest
- lp0: mov a,a0 ; a <<= 1
- add a,a0
- mov a0,a
- mov a,a1
+ lp0: mov a,x0 ; x <<= 1
+ add a,x0
+ mov x0,a
+ mov a,x1
rlc a
- mov a1,a
- mov a,a2
+ mov x1,a
+ mov a,x2
rlc a
- mov a2,a
- mov a,a3
+ mov x2,a
+ mov a,x3
rlc a
- mov a3,a
+ mov x3,a
jc in_lp
djnz count,lp0
sjmp exit
- loop: mov a,a0 ; a <<= 1
- add a,a0
- mov a0,a
- mov a,a1
+ loop: mov a,x0 ; x <<= 1
+ add a,x0
+ mov x0,a
+ mov a,x1
rlc a
- mov a1,a
- mov a,a2
+ mov x1,a
+ mov a,x2
rlc a
- mov a2,a
- mov a,a3
+ mov x2,a
+ mov a,x3
rlc a
- mov a3,a
+ mov x3,a
in_lp: mov a,reste0 ; reste <<= 1
rlc a ; feed in carry
rlc a
mov reste3,a
- mov a,reste0 ; reste - b
- subb a,b0 ; carry is always clear here, because
+ mov a,reste0 ; reste - y
+ subb a,y0 ; carry is always clear here, because
; reste <<= 1 never overflows
mov a,reste1
- subb a,b1
+ subb a,y1
mov a,reste2
- subb a,b2
+ subb a,y2
mov a,reste3
- subb a,b3
+ subb a,y3
- jc minus ; reste >= b?
+ jc minus ; reste >= y?
- ; -> yes; reste -= b;
+ ; -> yes; reste -= y;
mov a,reste0
- subb a,b0 ; carry is always clear here (jc)
+ subb a,y0 ; carry is always clear here (jc)
mov reste0,a
mov a,reste1
- subb a,b1
+ subb a,y1
mov reste1,a
mov a,reste2
- subb a,b2
+ subb a,y2
mov reste2,a
mov a,reste3
- subb a,b3
+ subb a,y3
mov reste3,a
- orl a0,#1
+ orl x0,#1
minus: djnz count,loop ; -> no
- exit: mov a,a3 ; prepare the return value
+ exit: mov a,x3 ; prepare the return value
ret
_endasm ;
#define count r2
- #define a0 dpl
- #define a1 dph
- #define a2 b
- #define a3 r3
+ #define x0 dpl
+ #define x1 dph
+ #define x2 b
+ #define x3 r3
#define reste0 r4
#define reste1 r5
.globl __divlong ; entry point for __divslong
- #define b0 r1
-
- ar0 = 0 ; BUG register set is not considered
- ar1 = 1
+ #define y0 r1
- ; parameter a comes in a, b, dph, dpl
- mov a3,a ; save parameter a3
+ ; parameter x comes in a, b, dph, dpl
+ mov x3,a ; save parameter x3
mov a,sp
- add a,#-2-3 ; 2 bytes return address, 3 bytes param b
- mov r0,a ; r0 points to b0
+ add a,#-2-3 ; 2 bytes return address, 3 bytes param y
+ mov r0,a ; r0 points to y0
__divlong: ; entry point for __divslong
- mov ar1,@r0 ; load b0
- inc r0 ; r0 points to b1
+ mov a,@r0 ; load y0
+ mov r1,a
+ inc r0 ; r0 points to y1
mov count,#32
clr a
; optimization loop in lp0 until the first bit is shifted into rest
- lp0: mov a,a0 ; a <<= 1
- add a,a0
- mov a0,a
- mov a,a1
+ lp0: mov a,x0 ; x <<= 1
+ add a,x0
+ mov x0,a
+ mov a,x1
rlc a
- mov a1,a
- mov a,a2
+ mov x1,a
+ mov a,x2
rlc a
- mov a2,a
- mov a,a3
+ mov x2,a
+ mov a,x3
rlc a
- mov a3,a
+ mov x3,a
jc in_lp
djnz count,lp0
sjmp exit
- loop: mov a,a0 ; a <<= 1
- add a,a0
- mov a0,a
- mov a,a1
+ loop: mov a,x0 ; x <<= 1
+ add a,x0
+ mov x0,a
+ mov a,x1
rlc a
- mov a1,a
- mov a,a2
+ mov x1,a
+ mov a,x2
rlc a
- mov a2,a
- mov a,a3
+ mov x2,a
+ mov a,x3
rlc a
- mov a3,a
+ mov x3,a
in_lp: mov a,reste0 ; reste <<= 1
rlc a ; feed in carry
rlc a
mov reste3,a
- mov a,reste0 ; reste - b
- subb a,b0 ; carry is always clear here, because
+ mov a,reste0 ; reste - y
+ subb a,y0 ; carry is always clear here, because
; reste <<= 1 never overflows
mov a,reste1
- subb a,@r0 ; b1
+ subb a,@r0 ; y1
mov a,reste2
inc r0
- subb a,@r0 ; b2
+ subb a,@r0 ; y2
mov a,reste3
inc r0
- subb a,@r0 ; b3
+ subb a,@r0 ; y3
dec r0
dec r0
- jc minus ; reste >= b?
+ jc minus ; reste >= y?
- ; -> yes; reste -= b;
+ ; -> yes; reste -= y;
mov a,reste0
- subb a,b0 ; carry is always clear here (jc)
+ subb a,y0 ; carry is always clear here (jc)
mov reste0,a
mov a,reste1
- subb a,@r0 ; b1
+ subb a,@r0 ; y1
mov reste1,a
mov a,reste2
inc r0
- subb a,@r0 ; b2
+ subb a,@r0 ; y2
mov reste2,a
mov a,reste3
inc r0
- subb a,@r0 ; b3
+ subb a,@r0 ; y3
mov reste3,a
dec r0
dec r0
- orl a0,#1
+ orl x0,#1
minus: djnz count,loop ; -> no
- exit: mov a,a3 ; prepare the return value
+ exit: mov a,x3 ; prepare the return value
ret
_endasm ;
#define MSB_SET(x) ((x >> (8*sizeof(x)-1)) & 1)
unsigned long
-_divulong (unsigned long a, unsigned long b)
+_divulong (unsigned long x, unsigned long y)
{
unsigned long reste = 0L;
unsigned char count = 32;
- #if defined(SDCC_STACK_AUTO) || defined(SDCC_z80)
- char c;
- #else
- bit c;
- #endif
+ BOOL c;
do
{
- // reste: a <- 0;
- c = MSB_SET(a);
- a <<= 1;
+ // reste: x <- 0;
+ c = MSB_SET(x);
+ x <<= 1;
reste <<= 1;
if (c)
reste |= 1L;
- if (reste >= b)
+ if (reste >= y)
{
- reste -= b;
- // a <- (result = 1)
- a |= 1L;
+ reste -= y;
+ // x <- (result = 1)
+ x |= 1L;
}
}
while (--count);
- return a;
+ return x;
}
#endif // _DIVULONG_ASM
projects / fw / sdcc / blobdiff