Donn Seeley, from scratch; Berkeley copyright

SCCS-vsn: lib/libc/vax/gen/udiv.s 5.3
SCCS-vsn: lib/libc/vax/gen/urem.s 5.3

diff --git a/usr/src/lib/libc/vax/gen/udiv.s b/usr/src/lib/libc/vax/gen/udiv.s
index f2668d8..b5b2587 100644 (file)
--- a/usr/src/lib/libc/vax/gen/udiv.s
+++ b/usr/src/lib/libc/vax/gen/udiv.s
@@ -1,77 +1,62 @@
-#ifdef LIBC_SCCS
-       .asciz  "@(#)udiv.s     5.2 (Berkeley) %G%"
-#endif LIBC_SCCS
+/*-
+ * Copyright (c) 1991 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * %sccs.include.redist.c%
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+       .asciz "@(#)udiv.s      5.3 (Berkeley) %G%"
+#endif /* LIBC_SCCS and not lint */

 
 /*
 
 /*

- * udiv - unsigned division for vax-11
- *
- * arguments: dividend, divisor.
- * result: quotient.
- * uses r0-r2
- *
- * If 1 < divisor <= 2147483647, zero-extend the dividend
- * to 64 bits and let ediv do the work.  If the divisor is 1,
- * ediv will overflow if bit 31 of the dividend is on, so
- * just return the dividend unchanged.  If the divisor is 0,
- * do the ediv also, so it will generate the proper exception.
- * All other values of the divisor have bit 31 on: in this case
- * the quotient must be 0 if divisor > dividend, and 1 otherwise,
- * provided that the comparison is made as unsigned.
+ * Unsigned division, PCC flavor.
+ * udiv() takes an ordinary dividend/divisor pair;
+ * audiv() takes a pointer to a dividend and an ordinary divisor.

  */
 
 #include "DEFS.h"
 
  */
 
 #include "DEFS.h"
 

-ASENTRY(udiv, 0)
-       movl    4(ap),r0        /* dividend */
-       movl    8(ap),r2        /* divisor */
-       jeql    1f              /* if divisor=0, force exception */
-       cmpl    r2,$1           /* if divisor <= 1 (signed), */
-       jleq    2f              /*  no division is necessary */
-1:
-       clrl    r1              /* zero-extend the dividend */
-       ediv    r2,r0,r0,r2     /* divide.  q->r0, r->r2 (discarded) */
+#define        DIVIDEND        4(ap)
+#define        DIVISOR         8(ap)
+
+ASENTRY(udiv,0)
+       movl    DIVISOR,r2
+       jlss    Leasy           # big divisor: settle by comparison
+       movl    DIVIDEND,r0
+       jlss    Lhard           # big dividend: extended division
+       divl2   r2,r0           # small divisor and dividend: signed division

        ret
        ret

-2:     
-       jeql    1f              /* if divisor=1, return dividend */
-       cmpl    r0,r2           /* unsigned comparison between */
-       jgequ   2f              /*  dividend and divisor */
-       clrl    r0              /* dividend < divisor, return 0 */
+Lhard:
+       clrl    r1
+       ediv    r2,r0,r0,r1

        ret
        ret

-2:     
-       movl    $1,r0           /* dividend >= divisor, return 1 */
-1:     
+Leasy:
+       cmpl    DIVIDEND,r2
+       jgequ   Lone            # if dividend is as big or bigger, return 1
+       clrl    r0              # else return 0
+       ret
+Lone:
+       movl    $1,r0

        ret
 
        ret
 

-/*
- * audiv - unsigned division for vax-11
- *
- * arguments: *dividend, divisor.
- * result: quotient in r0 and *dividend.
- * uses r0-r2
- */
-
-#include "DEFS.h"
-
-ASENTRY(audiv, 0)
-       movl    *4(ap),r0       /* dividend */
-       movl    8(ap),r2        /* divisor */
-       jeql    1f              /* if divisor=0, force exception */
-       cmpl    r2,$1           /* if divisor <= 1 (signed), */
-       jleq    2f              /*  no division is necessary */
-1:
-       clrl    r1              /* zero-extend the dividend */
-       ediv    r2,r0,r0,r2     /* divide.  q->r0, r->r2 (discarded) */
-       movl    r0,*4(ap)       /* save result */
+ASENTRY(audiv,0)
+       movl    DIVISOR,r2
+       jlss    Laeasy          # big divisor: settle by comparison
+       movl    DIVIDEND,r3
+       movl    (r3),r0
+       jlss    Lahard          # big dividend: extended division
+       divl3   r2,r0,(r3)      # small divisor and dividend: signed division
+       ret
+Lahard:
+       clrl    r1
+       ediv    r2,r0,(r3),r1

        ret
        ret

-2:
-       jeql    1f              /* if divisor=1, return dividend */
-       cmpl    r0,r2           /* unsigned comparison between */
-       jgequ   2f              /*  dividend and divisor */
-       clrl    r0              /* dividend < divisor, return 0 */
-       clrl    *4(ap)          /* save result */
+Laeasy:
+       cmpl    (r3),r2
+       jgequ   Laone           # if dividend is as big or bigger, store 1
+       clrl    (r3)            # else store 0

        ret
        ret

-2:
-       movl    $1,r0           /* dividend >= divisor, return 1 */
-1:
-       movl    r0,*4(ap)       /* save result */
+Laone:
+       movl    $1,(r3)

        ret
        ret

diff --git a/usr/src/lib/libc/vax/gen/urem.s b/usr/src/lib/libc/vax/gen/urem.s
index 0c3fdbe..609bd89 100644 (file)
--- a/usr/src/lib/libc/vax/gen/urem.s
+++ b/usr/src/lib/libc/vax/gen/urem.s
@@ -1,75 +1,62 @@
-#ifdef LIBC_SCCS
-       .asciz  "@(#)urem.s     5.2 (Berkeley) %G%"
-#endif LIBC_SCCS
-
-/*
- * urem - unsigned remainder for vax-11
+/*-
+ * Copyright (c) 1991 The Regents of the University of California.
+ * All rights reserved.

  *
  *

- * arguments: dividend, divisor
- * result: remainder
- * uses r0-r2
- *
- * if 1 < divisor <= 2147483647, zero-extend the dividend
- * to 64 bits and let ediv do the work.  If the divisor is 1,
- * ediv will overflow if bit 31 of the dividend is on, so
- * just return 0.  If the divisor is 0, do the ediv also,
- * so it will generate the proper exception.  All other values
- * of the divisor have bit 31 on: in this case the remainder
- * must be the dividend if divisor > dividend, and the dividend
- * minus the divisor otherwise.  The comparison must be unsigned.
+ * %sccs.include.redist.c%

  */
  */

-#include "DEFS.h"

 
 

-ASENTRY(urem, 0)
-       movl    4(ap),r0        /* dividend */
-       movl    8(ap),r2        /* divisor */
-       jeql    1f              /* if divisor=0, force exception */
-       cmpl    r2,$1           /* if divisor <= 1 (signed), */
-       jleq    2f              /*  no division is necessary */
-1:
-       clrl    r1              /* zero-extend the dividend */
-       ediv    r2,r0,r2,r0     /* divide.  q->r2 (discarded), r->r0 */
-       ret
-2:
-       jneq    1f              /* if divisor=1, return 0 */
-       clrl    r0              /*  (because doing the divide will overflow */
-       ret                     /*  if the dividend has its high bit on) */
-1:
-       cmpl    r0,r2           /* if dividend < divisor (unsigned) */
-       jlssu   1f              /*  remainder is dividend */
-       subl2   r2,r0           /*  else remainder is dividend - divisor */
-1:
-       ret
+#if defined(LIBC_SCCS) && !defined(lint)
+       .asciz "@(#)urem.s      5.3 (Berkeley) %G%"
+#endif /* LIBC_SCCS and not lint */
+
+#include "DEFS.h"

 
 /*
 
 /*

- * aurem - unsigned remainder for vax-11
- *
- * arguments: *dividend, divisor
- * result: remainder in r0 and *dividend
- * uses r0-r2
+ * Unsigned modulus, PCC flavor.
+ * urem() takes an ordinary dividend/divisor pair;
+ * aurem() takes a pointer to a dividend and an ordinary divisor.

  */
  */

-#include "DEFS.h"

 
 

-ASENTRY(aurem, 0)
-       movl    *4(ap),r0       /* dividend */
-       movl    8(ap),r2        /* divisor */
-       jeql    1f              /* if divisor=0, force exception */
-       cmpl    r2,$1           /* if divisor <= 1 (signed), */
-       jleq    2f              /*  no division is necessary */
-1:
-       clrl    r1              /* zero-extend the dividend */
-       ediv    r2,r0,r2,r0     /* divide.  q->r2 (discarded), r->r0 */
-       movl    r0,*4(ap)       /* save result */
+#define        DIVIDEND        4(ap)
+#define        DIVISOR         8(ap)
+
+ASENTRY(urem,0)
+       movl    DIVISOR,r2
+       jlss    Leasy           # big divisor: settle by comparison
+       movl    DIVIDEND,r0
+       jlss    Lhard           # big dividend: need extended division
+       divl3   r2,r0,r1        # small divisor and dividend: signed modulus
+       mull2   r2,r1
+       subl2   r1,r0
+       ret
+Lhard:
+       clrl    r1
+       ediv    r2,r0,r1,r0
+       ret
+Leasy:
+       subl3   r2,DIVIDEND,r0
+       jcc     Ldifference     # if divisor goes in once, return difference
+       movl    DIVIDEND,r0     # if divisor is bigger, return dividend
+Ldifference:
+       ret
+
+ASENTRY(aurem,0)
+       movl    DIVISOR,r2
+       jlss    Laeasy          # big divisor: settle by comparison
+       movl    DIVIDEND,r3
+       movl    (r3),r0
+       jlss    Lahard          # big dividend: need extended division
+       divl3   r2,r0,r1        # small divisor and dividend: signed modulus
+       mull2   r2,r1
+       subl3   r1,r0,(r3)
+       ret
+Lahard:
+       clrl    r1
+       ediv    r2,r0,r1,(r3)

        ret
        ret

-2:
-       jneq    1f              /* if divisor=1, return 0 */
-       clrl    r0              /*  (because doing the divide will overflow */
-       clrl    *4(ap)          /*  if the dividend has its high bit on) */
-       ret     
-1:
-       cmpl    r0,r2           /* if dividend < divisor (unsigned) */
-       jlssu   1f              /*  remainder is dividend */
-       subl2   r2,r0           /*  else remainder is dividend - divisor */
-1:
-       movl    r0,*4(ap)       /* save result */
+Laeasy:
+       subl3   r2,(r3),r0
+       jcs     Ldividend       # if divisor is bigger, leave dividend alone
+       movl    r0,(r3)         # if divisor goes in once, store difference
+Ldividend:

        ret
        ret