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 _DIVUINT_ASM_SMALL || defined _DIVUINT_ASM_SMALL_AUTO
static void
-_divuint_dummy (void) _naked
+_divuint_dummy (void) __naked
{
- _asm
-
- .globl __divuint
+ __asm
- __divuint:
+ .globl __divuint
- #define count r2
- #define reste_l r3
- #define reste_h r4
- #define al dpl
- #define ah dph
+__divuint:
-#ifdef SDCC_STACK_AUTO
+ #define count r2
+ #define reste_l r3
+ #define reste_h r4
+ #define xl dpl
+ #define xh dph
- ar0 = 0 ; BUG register set is not considered
- ar1 = 1
+#if defined(SDCC_PARMS_IN_BANK1)
+ #define yl (b1_0)
+ #define yh (b1_1)
+#else // SDCC_PARMS_IN_BANK1
+ #if defined(SDCC_STACK_AUTO)
- .globl __divint
+ .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
+ mov a,sp
+ add a,#-2 ; 2 bytes return address
+ mov r0,a ; r0 points to yh
+ mov a,@r0 ; load yh
+ mov r1,a
+ dec r0
+ mov a,@r0 ; load yl
+ mov r0,a
- #define bl r0
- #define bh r1
+ #define yl r0
+ #define yh r1
- __divint: ; entry point for __divsint
+__divint: ; entry point for __divsint
-#else // SDCC_STACK_AUTO
+ #else // SDCC_STACK_AUTO
-#if defined(SDCC_NOOVERLAY) // BUG SDCC_NOOVERLAY is not set by -no-overlay
- .area DSEG (DATA)
-#else
- .area OSEG (OVR,DATA)
-#endif
+ #if defined(SDCC_NOOVERLAY)
+ .area DSEG (DATA)
+ #else
+ .area OSEG (OVR,DATA)
+ #endif
- .globl __divuint_PARM_2
- .globl __divsint_PARM_2
+ .globl __divuint_PARM_2
+ .globl __divsint_PARM_2
- __divuint_PARM_2:
- __divsint_PARM_2:
- .ds 2
+__divuint_PARM_2:
+__divsint_PARM_2:
+ .ds 2
- .area CSEG (CODE)
+ .area CSEG (CODE)
- #define bl (__divuint_PARM_2)
- #define bh (__divuint_PARM_2 + 1)
+ #define yl (__divuint_PARM_2)
+ #define yh (__divuint_PARM_2 + 1)
-#endif // SDCC_STACK_AUTO
+ #endif // SDCC_STACK_AUTO
+#endif // SDCC_PARMS_IN_BANK1
- mov count,#16
- clr a
- mov reste_l,a
- mov reste_h,a
+ 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
+loop:
+ mov a,xl ; x <<= 1
+ add a,acc
+ mov xl,a
+ mov a,xh
+ rlc a
+ mov xh,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 <<= 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
+ mov a,reste_l ; reste - y
+ subb a,yl ; here carry is always clear, because
; reste <<= 1 never overflows
- mov b,a
- mov a,reste_h
- subb a,bh
+ mov b,a
+ mov a,reste_h
+ subb a,yh
- jc smaller ; reste >= b?
+ jc smaller ; reste >= y?
- mov reste_h,a ; -> yes; reste = reste - b;
- mov reste_l,b
- orl al,#1
- smaller: ; -> no
- djnz count,loop
- ret
+ mov reste_h,a ; -> yes; reste = reste - y;
+ mov reste_l,b
+ orl xl,#1
+smaller: ; -> no
+ djnz count,loop
+ ret
- _endasm ;
+ __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)
+_divuint (unsigned int x, unsigned int y)
{
unsigned int reste = 0;
unsigned char count = 16;
- #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 |= 1;
- if (reste >= b)
+ if (reste >= y)
{
- reste -= b;
- // a <- (result = 1)
- a |= 1;
+ reste -= y;
+ // x <- (result = 1)
+ x |= 1;
}
}
while (--count);
- return a;
+ return x;
}
#endif // defined _DIVUINT_ASM_SMALL || defined _DIVUINT_ASM_SMALL_AUTO
projects / fw / sdcc / blobdiff