usr/source/s3/floor.s

.globl  _floor, _ceil
.globl  floor, ceil
one = 40200

_floor:
        mov     r5,-(sp)
        mov     sp,r5
        movf    4(r5),fr0
        jsr     pc,floor
        br      1f

_ceil:
        mov     r5,-(sp)
        mov     sp,r5
        movf    4(r5),fr0
        jsr     pc,ceil
1:
        mov     (sp)+,r5
        rts     pc

floor:
        tstf    fr0
        cfcc
        bge     1f
        modf    $one,fr0
        cfcc
        beq     2f
        subf    $one,fr1
        br      2f
1:
        modf    $one,fr0
2:
        movf    fr1,fr0
        rts     pc

ceil:
        negf    fr0
        jsr     pc,floor
        negf    fr0
        rts     pc