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
#if defined _DIVULONG_ASM_SMALL
static void
-_divlong_dummy (void) _naked
+_divlong_dummy (void) __naked
{
- _asm
+ __asm
- .globl __divulong
+ .globl __divulong
- __divulong:
+__divulong:
- #define count r2
+ #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
+ #define reste0 r4
+ #define reste1 r5
+ #define reste2 r6
+ #define reste3 r7
+#if !defined(SDCC_PARMS_IN_BANK1)
-#if defined(SDCC_NOOVERLAY) // BUG SDCC_NOOVERLAY is not set by -no-overlay
- .area DSEG (DATA)
+#if defined(SDCC_NOOVERLAY)
+ .area DSEG (DATA)
#else
- .area OSEG (OVR,DATA)
+ .area OSEG (OVR,DATA)
#endif
- .globl __divulong_PARM_2
- .globl __divslong_PARM_2
-
- __divulong_PARM_2:
- __divslong_PARM_2:
- .ds 4
-
- .area CSEG (CODE)
+ .globl __divulong_PARM_2
+ .globl __divslong_PARM_2
- #define b0 (__divulong_PARM_2)
- #define b1 (__divulong_PARM_2 + 1)
- #define b2 (__divulong_PARM_2 + 2)
- #define b3 (__divulong_PARM_2 + 3)
+__divulong_PARM_2:
+__divslong_PARM_2:
+ .ds 4
- ; parameter a comes in a, b, dph, dpl
- mov a3,a ; save parameter a3
+ .area CSEG (CODE)
- mov count,#32
- clr a
- mov reste0,a
- mov reste1,a
- mov reste2,a
- mov reste3,a
+ #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
+ mov reste0,a
+ mov reste1,a
+ mov reste2,a
+ mov reste3,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
- rlc a
- mov a1,a
- mov a,a2
- rlc a
- mov a2,a
- mov a,a3
- rlc a
- mov a3,a
-
- jc in_lp
- djnz count,lp0
-
- sjmp exit
-
- loop: mov a,a0 ; a <<= 1
- add a,a0
- mov a0,a
- mov a,a1
- rlc a
- mov a1,a
- mov a,a2
- rlc a
- mov a2,a
- mov a,a3
- rlc a
- mov a3,a
-
- in_lp: mov a,reste0 ; reste <<= 1
- rlc a ; feed in carry
- mov reste0,a
- mov a,reste1
- rlc a
- mov reste1,a
- mov a,reste2
- rlc a
- mov reste2,a
- mov a,reste3
- rlc a
- mov reste3,a
-
- mov a,reste0 ; reste - b
- subb a,b0 ; carry is always clear here, because
+lp0: mov a,x0 ; x <<= 1
+ add a,x0
+ mov x0,a
+ mov a,x1
+ rlc a
+ mov x1,a
+ mov a,x2
+ rlc a
+ mov x2,a
+ mov a,x3
+ rlc a
+ mov x3,a
+
+ jc in_lp
+ djnz count,lp0
+
+ sjmp exit
+
+loop: mov a,x0 ; x <<= 1
+ add a,x0
+ mov x0,a
+ mov a,x1
+ rlc a
+ mov x1,a
+ mov a,x2
+ rlc a
+ mov x2,a
+ mov a,x3
+ rlc a
+ mov x3,a
+
+in_lp: mov a,reste0 ; reste <<= 1
+ rlc a ; feed in carry
+ mov reste0,a
+ mov a,reste1
+ rlc a
+ mov reste1,a
+ mov a,reste2
+ rlc a
+ mov reste2,a
+ mov a,reste3
+ rlc a
+ mov reste3,a
+
+ mov a,reste0 ; reste - y
+ subb a,y0 ; carry is always clear here, because
; reste <<= 1 never overflows
- mov a,reste1
- subb a,b1
- mov a,reste2
- subb a,b2
- mov a,reste3
- subb a,b3
-
- jc minus ; reste >= b?
-
- ; -> yes; reste -= b;
- mov a,reste0
- subb a,b0 ; carry is always clear here (jc)
- mov reste0,a
- mov a,reste1
- subb a,b1
- mov reste1,a
- mov a,reste2
- subb a,b2
- mov reste2,a
- mov a,reste3
- subb a,b3
- mov reste3,a
-
- orl a0,#1
-
- minus: djnz count,loop ; -> no
-
- exit: mov a,a3 ; prepare the return value
- ret
-
- _endasm ;
+ mov a,reste1
+ subb a,y1
+ mov a,reste2
+ subb a,y2
+ mov a,reste3
+ subb a,y3
+
+ jc minus ; reste >= y?
+
+ ; -> yes; reste -= y;
+ mov a,reste0
+ subb a,y0 ; carry is always clear here (jc)
+ mov reste0,a
+ mov a,reste1
+ subb a,y1
+ mov reste1,a
+ mov a,reste2
+ subb a,y2
+ mov reste2,a
+ mov a,reste3
+ subb a,y3
+ mov reste3,a
+
+ orl x0,#1
+
+minus: djnz count,loop ; -> no
+
+exit: mov a,x3 ; prepare the return value
+ ret
+
+ __endasm;
}
#elif defined _DIVULONG_ASM_SMALL_AUTO
static void
-_divlong_dummy (void) _naked
+_divlong_dummy (void) __naked
{
- _asm
-
- .globl __divulong
+ __asm
- __divulong:
+ .globl __divulong
- #define count r2
+__divulong:
- #define a0 dpl
- #define a1 dph
- #define a2 b
- #define a3 r3
+ #define count r2
- #define reste0 r4
- #define reste1 r5
- #define reste2 r6
- #define reste3 r7
+ #define x0 dpl
+ #define x1 dph
+ #define x2 b
+ #define x3 r3
- .globl __divlong ; entry point for __divslong
+ #define reste0 r4
+ #define reste1 r5
+ #define reste2 r6
+ #define reste3 r7
- #define b0 r1
+ .globl __divlong ; entry point for __divslong
- 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
+ mov a,sp
+ add a,#-2-3 ; 2 bytes return address, 3 bytes param y
+ mov r0,a ; r0 points to y0
- __divlong: ; entry point for __divslong
+__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
- mov reste0,a
- mov reste1,a
- mov reste2,a
- mov reste3,a
+ mov count,#32
+ clr a
+ mov reste0,a
+ mov reste1,a
+ mov reste2,a
+ mov reste3,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
- rlc a
- mov a1,a
- mov a,a2
- rlc a
- mov a2,a
- mov a,a3
- rlc a
- mov a3,a
-
- jc in_lp
- djnz count,lp0
-
- sjmp exit
-
- loop: mov a,a0 ; a <<= 1
- add a,a0
- mov a0,a
- mov a,a1
- rlc a
- mov a1,a
- mov a,a2
- rlc a
- mov a2,a
- mov a,a3
- rlc a
- mov a3,a
-
- in_lp: mov a,reste0 ; reste <<= 1
- rlc a ; feed in carry
- mov reste0,a
- mov a,reste1
- rlc a
- mov reste1,a
- mov a,reste2
- rlc a
- mov reste2,a
- mov a,reste3
- rlc a
- mov reste3,a
-
- mov a,reste0 ; reste - b
- subb a,b0 ; carry is always clear here, because
- ; reste <<= 1 never overflows
- mov a,reste1
- subb a,@r0 ; b1
- mov a,reste2
- inc r0
- subb a,@r0 ; b2
- mov a,reste3
- inc r0
- subb a,@r0 ; b3
- dec r0
- dec r0
-
- jc minus ; reste >= b?
-
- ; -> yes; reste -= b;
- mov a,reste0
- subb a,b0 ; carry is always clear here (jc)
- mov reste0,a
- mov a,reste1
- subb a,@r0 ; b1
- mov reste1,a
- mov a,reste2
- inc r0
- subb a,@r0 ; b2
- mov reste2,a
- mov a,reste3
- inc r0
- subb a,@r0 ; b3
- mov reste3,a
- dec r0
- dec r0
-
- orl a0,#1
-
- minus: djnz count,loop ; -> no
-
- exit: mov a,a3 ; prepare the return value
- ret
-
- _endasm ;
+lp0: mov a,x0 ; x <<= 1
+ add a,x0
+ mov x0,a
+ mov a,x1
+ rlc a
+ mov x1,a
+ mov a,x2
+ rlc a
+ mov x2,a
+ mov a,x3
+ rlc a
+ mov x3,a
+
+ jc in_lp
+ djnz count,lp0
+
+ sjmp exit
+
+loop: mov a,x0 ; x <<= 1
+ add a,x0
+ mov x0,a
+ mov a,x1
+ rlc a
+ mov x1,a
+ mov a,x2
+ rlc a
+ mov x2,a
+ mov a,x3
+ rlc a
+ mov x3,a
+
+in_lp: mov a,reste0 ; reste <<= 1
+ rlc a ; feed in carry
+ mov reste0,a
+ mov a,reste1
+ rlc a
+ mov reste1,a
+ mov a,reste2
+ rlc a
+ mov reste2,a
+ mov a,reste3
+ rlc a
+ mov reste3,a
+
+ mov a,reste0 ; reste - y
+ subb a,y0 ; carry is always clear here, because
+ ; reste <<= 1 never overflows
+ mov a,reste1
+ subb a,@r0 ; y1
+ mov a,reste2
+ inc r0
+ subb a,@r0 ; y2
+ mov a,reste3
+ inc r0
+ subb a,@r0 ; y3
+ dec r0
+ dec r0
+
+ jc minus ; reste >= y?
+
+ ; -> yes; reste -= y;
+ mov a,reste0
+ subb a,y0 ; carry is always clear here (jc)
+ mov reste0,a
+ mov a,reste1
+ subb a,@r0 ; y1
+ mov reste1,a
+ mov a,reste2
+ inc r0
+ subb a,@r0 ; y2
+ mov reste2,a
+ mov a,reste3
+ inc r0
+ subb a,@r0 ; y3
+ mov reste3,a
+ dec r0
+ dec r0
+
+ orl x0,#1
+
+minus: djnz count,loop ; -> no
+
+exit: mov a,x3 ; prepare the return value
+ ret
+
+ __endasm;
}
#else // _DIVULONG_ASM
#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