ack/mach/xr17032/libem/rck.s

36 lines
775 B
ArmAsm

#
.sect .text; .sect .rom; .sect .data; .sect .bss
/* Bounds check. Traps if the value is out of range.
* Stack: ( value descriptor -- value )
*
* This ".rck" only works with 4-byte integers. The name is ".rck" and
* not ".rck4" because many back ends only do rck with the word size.
*/
.sect .text
.define .rck
.rck:
lw r4, 0(sp) ! r4 = pointer to descriptor
addiu sp, sp, 4 ! leave value on stack
lw r5, 0(sp) ! r5 = value
lw at, 0(r4) ! at = lower bound
slt at, r5, at ! at = r5 < at
bne at, zero, .trap_erange
nop
lw at, 4(r4) ! at = upper bound
slt at, at, r5 ! at = at < r5
bne at, zero, .trap_erange
nop
jr ra
nop
.define .trap_erange
.trap_erange:
li r4, 1
j .trp
nop