.sect .text
! Compare sets a, b.
-! Stack: ( b a -- )
-! With r3 = size of each set
-! Yields r3 = 0 if equal, nonzero if not equal
+! Stack: ( b a size -- result )
+! Result is 0 if equal, nonzero if not equal.
.define .cms
.cms:
+ lwz r3, 0(sp) ! r3 = size of each set
srwi r7, r3, 2
mtspr ctr, r7 ! ctr = size / 4
- mr r4, sp ! r4 = ptr to set a
- add r5, sp, r3 ! r5 = ptr to set b
+ addi r4, sp, 4 ! r4 = ptr to set a
+ add r5, r4, r3 ! r5 = ptr to set b
li r6, 0 ! r6 = index
- add r9, r5, r3 ! r9 = future sp
1:
lwzx r7, r4, r6
lwzx r8, r5, r6
addi r6, r6, 4
bne cr0, 2f ! branch if not equal
bdnz 1b ! loop ctr times
- li r3, 0 ! equal: return 0
+ li r9, 0 ! equal: return 0
b 3f
2:
- li r3, 1 ! not equal: return 1
+ li r9, 1 ! not equal: return 1
3:
- mr sp, r9 ! remove sets from stack
+ slwi r7, r3, 1
+ add sp, sp, r7 ! adjust stack pointer
+ stw r9, 0(sp) ! push result
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