Franks version

diff --git a/mach/m68k4/libem/cms.s b/mach/m68k4/libem/cms.s
index b6f4a51..fa6d1b6 100644 (file)
--- a/mach/m68k4/libem/cms.s
+++ b/mach/m68k4/libem/cms.s
@@ -4,23 +4,23 @@
 .sect .data
 .sect .bss
 
+.sect .text
        ! d0 contains set size
-
-       .sect .text
+       ! on exit d0 is zero for equal, non-zero for not equal
 .cms:
-       move.l  (sp)+,a2        ! return address
-       move.l  sp,a0
-       move.l  sp,a1
-       add     d0,a1
-       move.w  d0,d1
-       asr     #1,d0
+       move.l  (sp)+, d2       ! return address
+       move.l  sp, a0          ! address of top block
+       lea     0(sp, d0.l), a1 ! address of lower block
+       move.l  d0, d1
+       asr.l   #2, d0
 1:
-       cmp     (a0)+,(a1)+
+       cmp.l   (a0)+, (a1)+
        bne     2f
-       sub.l   #1,d0
+       sub.l   #1, d0
        bne     1b
 2:
-       asl     #1,d1
-       add     d1,sp
-       move.l  d0,-(sp)
-       jmp     (a2)
+       asl.l   #1, d1
+       add.l   d1, sp          ! two blocks popped
+       move.l  d2, -(sp)
+       rts
+.align 2

diff --git a/mach/m68k4/libem/cmu.s b/mach/m68k4/libem/cmu.s
index 9f20515..5228ed0 100644 (file)
--- a/mach/m68k4/libem/cmu.s
+++ b/mach/m68k4/libem/cmu.s
@@ -1,32 +1,29 @@
-.define .cmu
+.define        .cmu
 .sect .text
 .sect .rom
 .sect .data
 .sect .bss
 
-       ! d0 : # bytes of 1 block
-       .sect .text
+.sect .text
+       ! on entry d0: # bytes of 1 block
+       ! on exit d0: result
 .cmu:
-       move.l  sp,a0           ! top block
-       add.l   #4,a0
-       move.l  a0,a1
-       add.l   d0,a1           ! lower block
-       move.l  d0,d2
-       asr.l   #2,d0
-       sub.l   #1,d0
-       move.l  #1,d1           ! greater
+       move.l  (sp)+, d2       ! return address
+       move.l  sp, a0          ! address of top block
+       lea     0(sp, d0.l), a1 ! address of lower block
+       move.l  d0, d1
+       asr.l   #2, d0
 1:
-       cmp.l   (a0)+,(a1)+
+       cmp.l   (a0)+, (a1)+
        bne     2f
-       dbf     d0,1b
-       clr.l   d1              ! equal
+       sub.l   #1, d0
+       bne     1b              ! note: on equal carry is set
 2:
        bcc     3f
-       neg.l   d1              ! less
+       neg.l   d0              ! less
 3:
-       asl.l   #1,d2
-       move.l  (sp)+,a0
-       add.l   d2,sp           ! new sp
-       jmp     (a0)
-
+       asl.l   #1, d1
+       add.l   d1, sp          ! new sp; two blocks popped
+       move.l  d2, -(sp)
+       rts
 .align 2

diff --git a/mach/m68k4/libem/exg.s b/mach/m68k4/libem/exg.s
index 396893b..18fd7c1 100644 (file)
--- a/mach/m68k4/libem/exg.s
+++ b/mach/m68k4/libem/exg.s
@@ -1,28 +1,20 @@
-.define .exg
+.define        .exg
 .sect .text
 .sect .rom
 .sect .data
 .sect .bss
 
+.sect .text
        ! d0 : exchange size in bytes
-       .sect .text
 .exg:
-       move.l  (sp)+,d2
-       move.l  sp,a1
-       sub.l   d0,sp
-       move.l  sp,a2
-       asr     #1,d0
-       move.l  d0,d1
-1:
-       move.l  (a1)+,(a2)+
-       sub     #1,d0
-       bgt     1b
-       move.l  sp,a1
-       asr     #1,d1
+       lea     4(sp, d0), a0   ! address of bottom block
+       lea     4(sp), a1       ! address of top block
+       asr.l   #2, d0
+       sub.l   #1, d0
 1:
-       move.l  (a1)+,(a2)+
-       sub     #1,d1
-       bgt     1b
-       move.l  a1,sp
-       move.l  d2,-(sp)
+       move.l  (a1), d1
+       move.l  (a0), (a1)+
+       move.l  d1, (a0)+
+       dbf     d0, 1b
        rts
+.align 2