ack/mach/vc4/libem/csa.s

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#
/*
* VideoCore IV support library for the ACK
* © 2013 David Given
* This file is redistributable under the terms of the 3-clause BSD license.
* See the file 'Copying' in the root of the distribution for the full text.
*/
#include "videocore.h"
.define .csa
.sect .data
.csa:
! on entry:
! r0 = un-fixed-up descriptor
! r1 = value
add r0, gp
ld r2, 4 (r0) ! check lower bound
b.lo r1, r2, default ! jump to default if r1 < r2
sub r1, r2 ! adjust value to be 0-based
ld r2, 8 (r0) ! check upper bound
b.hi r1, r2, default ! jump to default if r1 > r2
add r1, #3
go:
ld r1, (r0, r1) ! load destination address
add r1, gp
b r1 ! ...and go
default:
mov r1, #0 ! index of default value
b go