ack/mach/powerpc/libem/csa.s
David Given d31bc6a3f9 Made csa and csb work with mcg; adjust the libem functions and the
corresponding invocation in the ncg table so the same helpers can be used for
both mcg and ncg. Add a new IR opcode, FARJUMP, which jumps to a helper
function but saves volatile registers.
2016-11-19 10:55:41 +01:00

48 lines
952 B
ArmAsm

#
! $Source$
! $State$
! $Revision$
#include "powerpc.h"
.sect .text
! this is not a subroutine, but just a
! piece of code that computes the jump-
! address and jumps to it.
! traps if resulting address is zero
!
! Stack: ( value tableaddr -- )
.define .csa
.csa:
lwz r3, 0(sp)
lwz r4, 4(sp)
addi sp, sp, 8
lwz r5, 0(r3) ! load default
mtspr ctr, r5
lwz r5, 4(r3) ! fetch lower bound
subf. r4, r5, r4 ! adjust value
bcctr IFTRUE, LT, 0 ! jump to default if out of range
lwz r5, 8(r3) ! fetch range
cmp cr0, 0, r4, r5
bcctr IFTRUE, GT, 0 ! jump to default if out of range
addi r3, r3, 12 ! skip header
rlwinm r4, r4, 2, 0, 31-2 ! scale value (<<2)
b 1f
1:
lwzx r5, r3, r4 ! load target
b 1f
1:
mtspr ctr, r5
or. r5, r5, r5 ! test it
b 1f
1:
bcctr IFFALSE, EQ, 0 ! jump to target if non-zero
b .trap_ecase ! otherwise trap